Commit graph

14188 commits

Author SHA1 Message Date
David Sterba
a4bb776cbe btrfs: use struct btrfs_inode inside btrfs_get_name()
Use a struct btrfs_inode in btrfs_get_name() as it's an internal
helper, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:44 +01:00
David Sterba
8dddeb53ab btrfs: use struct btrfs_inode inside btrfs_get_parent()
Use a struct btrfs_inode to btrfs_get_parent() as it's an internal
helper, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:44 +01:00
David Sterba
2d4323ced5 btrfs: use struct btrfs_inode inside btrfs_remap_file_range_prep()
Use a struct btrfs_inode in btrfs_remap_file_range_prep() as it's an
internal helper, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:44 +01:00
David Sterba
8b044e17e5 btrfs: use struct btrfs_inode inside btrfs_remap_file_range()
Use a struct btrfs_inode to btrfs_remap_file_range() as it's an internal
helper, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:44 +01:00
David Sterba
61dbdeb870 btrfs: pass struct btrfs_inode to btrfs_extent_same_range()
Pass a struct btrfs_inode to btrfs_extent_same_range() as it's an
internal interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:44 +01:00
David Sterba
651cef4611 btrfs: pass struct btrfs_inode to btrfs_double_mmap_unlock()
Pass a struct btrfs_inode to btrfs_double_mmap_unlock() as it's an
internal interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:44 +01:00
David Sterba
0061ba125b btrfs: pass struct btrfs_inode to btrfs_double_mmap_lock()
Pass a struct btrfs_inode to btrfs_double_mmap_lock() as it's an
internal interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:44 +01:00
David Sterba
65a66afd1e btrfs: pass struct btrfs_inode to clone_copy_inline_extent()
Pass a struct btrfs_inode to clone_copy_inline_extent() as it's an
internal interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:44 +01:00
David Sterba
41c5a5dc73 btrfs: props: switch prop_handler::extract to struct btrfs_inode
Pass a struct btrfs_inode to the extract() callback as it's an internal
interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:44 +01:00
David Sterba
7e027b767d btrfs: props: switch prop_handler::apply to struct btrfs_inode
Pass a struct btrfs_inode to the apply() callback as it's an internal
interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:44 +01:00
David Sterba
101ab6d1ff btrfs: pass struct btrfs_inode to btrfs_inode_inherit_props()
Pass a struct btrfs_inode to btrfs_inherit_props() as it's an internal
interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:44 +01:00
David Sterba
308a02a447 btrfs: pass struct btrfs_inode to btrfs_load_inode_props()
Pass a struct btrfs_inode to btrfs_load_inode_props() as it's an
internal interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:44 +01:00
David Sterba
a0680a946f btrfs: pass struct btrfs_inode to btrfs_fill_inode()
Pass a struct btrfs_inode to btrfs_fill_inode() as it's an internal
interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:43 +01:00
David Sterba
9882e1d100 btrfs: pass struct btrfs_inode to fill_stack_inode_item()
Pass a struct btrfs_inode to fill_stack_inode_item() as it's an internal
interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:43 +01:00
David Sterba
cb9a1f5ffa btrfs: use struct btrfs_inode inside create_pending_snapshot()
Use a struct btrfs_inode in create_pending_snapshot() as it's an
internal helper, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:43 +01:00
David Sterba
fc11fd0cb8 btrfs: pass struct btrfs_inode to btrfs_defrag_file()
Pass a struct btrfs_inode to btrfs_defrag_file() as it's an internal
interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:43 +01:00
David Sterba
01b2e7de3a btrfs: pass struct btrfs_inode to btrfs_inode_type()
Pass a struct btrfs_inode to btrfs_inode() as it's an internal
interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:43 +01:00
David Sterba
11af82b02b btrfs: pass struct btrfs_inode to new_simple_dir()
Pass a struct btrfs_inode to new_simple_dir() as it's an internal
interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:43 +01:00
David Sterba
4ea2fb9c62 btrfs: pass struct btrfs_inode to btrfs_iget_locked()
Pass a struct btrfs_inode to btrfs_inode() as it's an internal
interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:43 +01:00
David Sterba
d36f84a849 btrfs: pass struct btrfs_inode to btrfs_read_locked_inode()
Pass a struct btrfs_inode to btrfs_read_locked_inode() as it's an
internal interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:43 +01:00
David Sterba
0d12afad24 btrfs: pass struct btrfs_inode to extent_range_clear_dirty_for_io()
Pass a struct btrfs_inode to extent_range_clear_dirty_for_io() as it's
an internal interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:43 +01:00
David Sterba
44dddd493e btrfs: pass struct btrfs_inode to can_nocow_extent()
Pass a struct btrfs_inode to can_nocow_extent() as it's an internal
interface, allowing to remove some use of BTRFS_I.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:43 +01:00
David Sterba
6149c82bda btrfs: update include and forward declarations in headers
Pass over all header files and add missing forward declarations,
includes or fix include types.

Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:43 +01:00
David Sterba
f867ccabb8 btrfs: simplify returns and labels in btrfs_init_fs_root()
There's a label that does nothing else than return, so remove it and
also change other gotos to immediate returns as the function is short
enough for this pattern.

Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:43 +01:00
David Sterba
dba6ae0b43 btrfs: unify ordering of btrfs_key initializations
The btrfs_key is defined as objectid/type/offset and the keys are also
printed like that. For better readability, update all key
initializations to match this order.

Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:42 +01:00
David Sterba
17b9824922 btrfs: zstd: remove local variable for storing page offsets
When using offset_in_page() it's clear what it means, we don't need to
store it in the local variable just to use it right away. There's no
change in the generated code, but keeps the declarations smaller.

Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:42 +01:00
David Sterba
cfb999b81a btrfs: zstd: move zstd_parameters to the workspace
Reduce stack consumption of zstd_compress_folios() by 40 bytes
(10*sizeof(int)) as we can store struct zstd_parameters in the workspace
that is reused for each call.

typedef struct {
	ZSTD_compressionParameters cParams;
	ZSTD_frameParameters fParams;
} ZSTD_parameters;

typedef struct {
    unsigned windowLog;
    unsigned chainLog;
    unsigned hashLog;
    unsigned searchLog;
    unsigned minMatch;
    unsigned targetLength;
    ZSTD_strategy strategy;
} ZSTD_compressionParameters;

typedef struct {
    int contentSizeFlag;
    int checksumFlag;
    int noDictIDFlag;
} ZSTD_frameParameters;

Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:42 +01:00
David Sterba
a8511baf32 btrfs: async-thread: switch local variables need_order bool
Use bool for 0/1 indicators in thresh_exec_hook() and
btrfs_work_helper().

Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:42 +01:00
David Sterba
0128c9a7cd btrfs: add __cold attribute to extent_io_tree_panic()
This is a wrapper that leads to a panic, so add the annotation like the
other similar functions have.

Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:42 +01:00
Johannes Thumshirn
26b38e2816 btrfs: zoned: exit btrfs_can_activate_zone if BTRFS_FS_NEED_ZONE_FINISH is set
If BTRFS_FS_NEED_ZONE_FINISH is already set for the whole filesystem, exit
early in btrfs_can_activate_zone(). There's no need to check if
BTRFS_FS_NEED_ZONE_FINISH needs to be set if it is already set.

Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:42 +01:00
Qu Wenruo
fcc384be06 btrfs: require strict data/metadata split for subpage checks
Since we have btrfs_meta_is_subpage(), we should make btrfs_is_subpage()
to be data inode specific.

This change involves:

- Simplify btrfs_is_subpage()
  Now we only need to do a very simple sectorsize check against
  PAGE_SIZE.
  And since the function is pretty simple now, just make it an inline
  function.

- Add an extra ASSERT() to make sure btrfs_is_subpage() is only called
  on data inode mapping

- Migrate btree_csum_one_bio() to use btrfs_meta_folio_*() helpers
- Migrate alloc_extent_buffer() to use btrfs_meta_folio_*() helpers
- Migrate end_bbio_meta_write() to use btrfs_meta_folio_*() helpers
  Or we will trigger the ASSERT() due to calling btrfs_folio_*() on
  metadata folios.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:42 +01:00
Qu Wenruo
67ebd7a1f1 btrfs: simplify subpage handling of read_extent_buffer_pages_nowait()
By using a shared bio_add_folio_nofail() with calculated
range_start/range_len, so no more explicit subpage routine needed.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:42 +01:00
Qu Wenruo
6c6201278e btrfs: simplify subpage handling of write_one_eb()
Currently inside write_one_eb() we have two different ways of handling
subpage and regular metadata.

The differences are:

- Extra offset/length calculation when adding the folio range to bio for
  subpage cases
- Only decrease wbc->nr_to_write if the whole page is no longer dirty
  for subpage cases
- Use subpage helper for subpage cases

Merge the tow ways into a shared one:

- Always calculate the to-be-queued range
  So that bio_add_folio() can use the same calculated resulted length
  and offset for both cases.

- Use btrfs_meta_folio_clear_dirty() and
  btrfs_meta_folio_set_writeback() helpers
  This will cover both cases.

- Only decrease wbc->nr_to_write if the folio is no longer dirty
  Since we have the folio locked, no one else can modify the folio dirty
  flags (set_extent_buffer_dirty() will also lock the folio for subpage
  cases).

  Thus after our btrfs_meta_folio_clear_dirty() call, if the whole folio
  is no longer dirty, we're submitting the last dirty eb of the folio,
  and can decrease wbc->nr_to_write properly.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:42 +01:00
Qu Wenruo
7895817b31 btrfs: simplify subpage handling of btrfs_clear_buffer_dirty()
The function btrfs_clear_buffer_dirty() is called on dirty extent buffer
that will not be written back.

The function will call btree_clear_folio_dirty() to clear the folio
dirty flag and also clear PAGECACHE_TAG_DIRTY flag.

And we split the subpage and regular handling, as for subpage cases we
should only clear PAGECACHE_TAG_DIRTY if the last dirty extent buffer in
the page is cleared.

So here we can simplify the function by:

- Use the newly introduced btrfs_meta_folio_clear_and_test_dirty() helper
  The helper will return true if we cleared the folio dirty flag.
  With that we can use the same helper for both subpage and regular
  cases.

- Rename btree_clear_folio_dirty() to btree_clear_folio_dirty_tag()
  As we move the folio dirty clearing in the btrfs_clear_buffer_dirty().

- Call btrfs_meta_folio_clear_and_test_dirty() to clear the dirty flags
  for both regular and subpage metadata cases

- Only call btree_clear_folio_dirty_tag() when the folio is no longer
  dirty

- Update the comment inside set_extent_buffer_dirty()
  As there is no separate clear_subpage_extent_buffer_dirty() anymore.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:42 +01:00
Qu Wenruo
ee76e5a742 btrfs: use metadata specific helpers to simplify extent buffer helpers
The following functions are doing metadata specific checks:

- set_extent_buffer_uptodate()
- clear_extent_buffer_uptodate()

The reason why we do not use btrfs_folio_*() helpers for those helpers
is, btrfs_is_subpage() cannot handle dummy extent buffer if nodesize >=
PAGE_SIZE but block size < PAGE_SIZE.

In that case, we do not need to attach extra bitmaps to the extent
buffer folio. But since dummy extent buffer folios are not attached to
btree inode, btrfs_is_subpage() will return true, causing problems.

And the following are using btrfs_folio_*() helpers for metadata, but
in theory we should use metadata specific checks:

- set_extent_buffer_dirty()

This is not causing problems because a dummy extent buffer should never
be marked dirty.

To make code simpler, introduce btrfs_meta_folio_*() helpers, to do
the metadata specific handling, so that we do not to open-code such
checks in above involved functions.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:41 +01:00
Qu Wenruo
57a3212674 btrfs: make subpage attach and detach handle metadata properly
Currently subpage attach/detach is not doing proper dummy extent buffer
subpage check, as btrfs_is_subpage() is not reliable for dummy extent
buffer folios.

Since we have a metadata specific check now, use that for
btrfs_attach_subpage() first.

Then enhance btrfs_detach_subpage() to accept a type parameter, so that
we can do extra checks for dummy extent buffers properly.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:41 +01:00
Qu Wenruo
f64e818153 btrfs: factor out metadata subpage detection into a dedicated helper
Currently we have only one btrfs_is_subpage() to cover both data and
metadata.

But there is a special case for metadata:

- dummy extent buffer, sector size < PAGE_SIZE and node size >= PAGE_SIZE

In such case, btrfs_is_subpage() will return true for extent buffer
folio.

But that is not correct, and that's exactly why we have some open-coded
checks for functions like set_extent_buffer_uptodate() and
clear_extent_buffer_uptodate().

Just extract the metadata specific checks into a helper, and replace
those call sites.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:41 +01:00
Qu Wenruo
619611e87f btrfs: remove btrfs_fs_info::sectors_per_page
For the future large folio support, our filemap can have folios with
different sizes, thus we can no longer rely on a fixed blocks_per_page
value.

To prepare for that future, here we do:

- Remove btrfs_fs_info::sectors_per_page

- Introduce a helper, btrfs_blocks_per_folio()
  Which uses the folio size to calculate the number of blocks for each
  folio.

- Migrate the existing btrfs_fs_info::sectors_per_page to use that
  helper
  There are some exceptions:

  * Metadata nodesize < page size support
    In the future, even if we support large folios, we will only
    allocate a folio that matches our nodesize.
    Thus we won't have a folio covering multiple metadata unless
    nodesize < page size.

  * Existing subpage bitmap dump
    We use a single unsigned long to store the bitmap.
    That means until we change the bitmap dumping code, our upper limit
    for folio size will only be 256K (4K block size, 64 bit unsigned
    long).

  * btrfs_is_subpage() check
    This will be migrated into a future patch.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:41 +01:00
Daniel Vacek
da798fa519 btrfs: zstd: enable negative compression levels mount option
Allow using the fast modes (negative compression levels) of zstd as a
mount option.

As per the results, the compression ratio is (expectedly) lower:

for level in {-15..-1} 1 2 3; \
do printf "level %3d\n" $level; \
  mount -o compress=zstd:$level /dev/sdb /mnt/test/; \
  grep sdb /proc/mounts; \
  cp -r /usr/bin       /mnt/test/; sync; compsize /mnt/test/bin; \
  cp -r /usr/share/doc /mnt/test/; sync; compsize /mnt/test/doc; \
  cp    enwik9         /mnt/test/; sync; compsize /mnt/test/enwik9; \
  cp    linux-6.13.tar /mnt/test/; sync; compsize /mnt/test/linux-6.13.tar; \
  rm -r /mnt/test/{bin,doc,enwik9,linux-6.13.tar}; \
  umount /mnt/test/; \
done |& tee results | \
awk '/^level/{print}/^TOTAL/{print$3"\t"$2"  |"}' | paste - - - - -

		266M	bin  |	45M	doc  |	953M	wiki |	1.4G	source
=============================+===============+===============+===============+
level -15	180M	67%  |	30M	68%  |	694M	72%  |	598M	40%  |
level -14	180M	67%  |	30M	67%  |	683M	71%  |	581M	39%  |
level -13	177M	66%  |	29M	66%  |	671M	70%  |	566M	38%  |
level -12	174M	65%  |	29M	65%  |	658M	69%  |	548M	37%  |
level -11	174M	65%  |	28M	64%  |	645M	67%  |	530M	35%  |
level -10	171M	64%  |	28M	62%  |	631M	66%  |	512M	34%  |
level  -9	165M	62%  |	27M	61%  |	615M	64%  |	493M	33%  |
level  -8	161M	60%  |	27M	59%  |	598M	62%  |	475M	32%  |
level  -7	155M	58%  |	26M	58%  |	582M	61%  |	457M	30%  |
level  -6	151M	56%  |	25M	56%  |	565M	59%  |	437M	29%  |
level  -5	145M	54%  |	24M	55%  |	545M	57%  |	417M	28%  |
level  -4	139M	52%  |	23M	52%  |	520M	54%  |	391M	26%  |
level  -3	135M	50%  |	22M	50%  |	495M	51%  |	369M	24%  |
level  -2	127M	47%  |	22M	48%  |	470M	49%  |	349M	23%  |
level  -1	120M	45%  |	21M	47%  |	452M	47%  |	332M	22%  |
level   1	110M	41%  |	17M	39%  |	362M	38%  |	290M	19%  |
level   2	106M	40%  |	17M	38%  |	349M	36%  |	288M	19%  |
level   3	104M	39%  |	16M	37%  |	340M	35%  |	276M	18%  |

The samples represent some data sets that can be commonly found and show
approximate compressibility. The fast levels trade off speed for ratio
and are best suitable for highly compressible data.

As can be seen above, comparing the results to the current default zstd
level 3, the negative levels are roughly 2x worse at -15 and the
ratio increases almost linearly with each level.

Signed-off-by: Daniel Vacek <neelx@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:41 +01:00
Qu Wenruo
94f6c5c17e btrfs: move ordered extent cleanup to where they are allocated
The ordered extent cleanup is hard to grasp because it doesn't follow
the common cleanup-asap pattern.

E.g. run_delalloc_nocow() and cow_file_range() allocate one or more
ordered extent, but if any error is hit, the cleanup is done later inside
btrfs_run_delalloc_range().

To change the existing delayed cleanup:

- Update the comment on error handling of run_delalloc_nocow()
  There are in fact 3 different cases other than 2 if we are doing
  ordered extents cleanup inside run_delalloc_nocow():

  1) @cow_start and @cow_end not set
     No fallback to COW at all.
     Before @cur_offset we need to cleanup the OE and page dirty.
     After @cur_offset just clear all involved page and extent flags.

  2) @cow_start set but @cow_end not set.
     This means we failed before even calling fallback_to_cow().
     It's just a variant of case 1), where it's @cow_start splitting
     the two parts (and we should just ignore @cur_offset since it's
     advanced without any new ordered extent).

  3) @cow_start and @cow_end both set
     This means fallback_to_cow() failed, meaning [start, cow_start)
     needs the regular OE and dirty folio cleanup, and skip range
     [cow_start, cow_end) as cow_file_range() has done the cleanup,
     and eventually cleanup [cow_end, end) range.

- Only reset @cow_start after fallback_to_cow() succeeded
  As above case 2) and 3) are both relying on @cow_start to determine
  the cleanup range.

- Move btrfs_cleanup_ordered_extents() into run_delalloc_nocow(),
  cow_file_range() and nocow_one_range()

  For cow_file_range() it's pretty straightforward and easy.

  For run_delalloc_nocow() refer to the above 3 different error cases.

  For nocow_one_range() if we hit an error, we need to cleanup the
  ordered extents by ourselves.
  And then it will fallback to case 1), since @cur_offset is not yet
  advanced, the existing cleanup will co-operate with nocow_one_range()
  well.

- Remove the btrfs_cleanup_ordered_extents() inside submit_uncompressed_range()
  As failed cow_file_range() will do all the proper cleanup now.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:41 +01:00
Qu Wenruo
10326fdcb3 btrfs: factor out nocow ordered extent and extent map generation into a helper
Currently we're doing all the ordered extent and extent map generation
inside a while() loop of run_delalloc_nocow().  This makes it pretty
hard to read, nor doing proper error handling.

So move that part of code into a helper, nocow_one_range().

This should not change anything, but there is a tiny timing change where
btrfs_dec_nocow_writers() is only called after nocow_one_range() helper
exits.

This timing change is small, and makes error handling easier, thus
should be fine.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:41 +01:00
Qu Wenruo
ecde48a1a6 btrfs: expose per-inode stable writes flag
The address space flag AS_STABLE_WRITES determine if FGP_STABLE for will
wait for the folio to finish its writeback.

For btrfs, due to the default data checksum behavior, if we modify the
folio while it's still under writeback, it will cause data checksum
mismatch.  Thus for quite some call sites we manually call
folio_wait_writeback() to prevent such problem from happening.

Currently there is only one call site inside btrfs really utilizing
FGP_STABLE, and in that case we also manually call folio_wait_writeback()
to do the waiting.

But it's better to properly expose the stable writes flag to a per-inode
basis, to allow call sites to fully benefit from FGP_STABLE flag.
E.g. for inodes with NODATASUM allowing beginning dirtying the page
without waiting for writeback.

This involves:

- Update the mapping's stable write flag when setting/clearing NODATASUM
  inode flag using ioctl
  This only works for empty files, so it should be fine.

- Update the mapping's stable write flag when reading an inode from disk

- Remove the explicit folio_wait_writeback() for FGP_BEGINWRITE call
  site

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:41 +01:00
Qu Wenruo
aa60fe12b4 btrfs: zlib: refactor S390x HW acceleration buffer preparation
Currently for s390x HW zlib compression, to get the best performance we
need a buffer size which is larger than a page.

This means we need to copy multiple pages into workspace->buf, then use
that buffer as zlib compression input.

Currently it's hardcoded using page sized folio, and all the handling
are deep inside a loop.

Refactor the code by:

- Introduce a dedicated helper to do the buffer copy
  The new helper will be called copy_data_into_buffer().

- Add extra ASSERT()s
  * Make sure we only go into the function for hardware acceleration
  * Make sure we still get page sized folio

- Prepare for future large folios
  This means we will rely on the folio size, other than PAGE_SIZE to do
  the copy.

- Handle the folio mapping and unmapping inside the helper function
  For S390x hardware acceleration case, it never utilize the @data_in
  pointer, thus we can do folio mapping/unmapping all inside the function.

Acked-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Tested-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:41 +01:00
Filipe Manana
87d6aaf79b btrfs: avoid assigning twice to block_start at btrfs_do_readpage()
At btrfs_do_readpage() if we get an extent map for a prealloc extent we
end up assigning twice to the 'block_start' variable, first the value
returned by extent_map_block_start() and then EXTENT_MAP_HOLE. This is
pointless so make it more clear by using an if-else statement and doing
only one assignment. Also, while at it, move the declaration of
'block_start' into the while loop's scope, since it's not used outside of
it and the related 'disk_bytenr' is also declared in this scope.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:41 +01:00
Qu Wenruo
968f19c5b1 btrfs: always fallback to buffered write if the inode requires checksum
[BUG]
It is a long known bug that VM image on btrfs can lead to data csum
mismatch, if the qemu is using direct-io for the image (this is commonly
known as cache mode 'none').

[CAUSE]
Inside the VM, if the fs is EXT4 or XFS, or even NTFS from Windows, the
fs is allowed to dirty/modify the folio even if the folio is under
writeback (as long as the address space doesn't have AS_STABLE_WRITES
flag inherited from the block device).

This is a valid optimization to improve the concurrency, and since these
filesystems have no extra checksum on data, the content change is not a
problem at all.

But the final write into the image file is handled by btrfs, which needs
the content not to be modified during writeback, or the checksum will
not match the data (checksum is calculated before submitting the bio).

So EXT4/XFS/NTRFS assume they can modify the folio under writeback, but
btrfs requires no modification, this leads to the false csum mismatch.

This is only a controlled example, there are even cases where
multi-thread programs can submit a direct IO write, then another thread
modifies the direct IO buffer for whatever reason.

For such cases, btrfs has no sane way to detect such cases and leads to
false data csum mismatch.

[FIX]
I have considered the following ideas to solve the problem:

- Make direct IO to always skip data checksum
  This not only requires a new incompatible flag, as it breaks the
  current per-inode NODATASUM flag.
  But also requires extra handling for no csum found cases.

  And this also reduces our checksum protection.

- Let hardware handle all the checksum
  AKA, just nodatasum mount option.
  That requires trust for hardware (which is not that trustful in a lot
  of cases), and it's not generic at all.

- Always fallback to buffered write if the inode requires checksum
  This was suggested by Christoph, and is the solution utilized by this
  patch.

  The cost is obvious, the extra buffer copying into page cache, thus it
  reduces the performance.
  But at least it's still user configurable, if the end user still wants
  the zero-copy performance, just set NODATASUM flag for the inode
  (which is a common practice for VM images on btrfs).

  Since we cannot trust user space programs to keep the buffer
  consistent during direct IO, we have no choice but always falling back
  to buffered IO.  At least by this, we avoid the more deadly false data
  checksum mismatch error.

Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-18 20:35:32 +01:00
Qu Wenruo
c5e8f2924a btrfs: remove duplicated metadata folio flag update in end_bbio_meta_read()
In that function we call set_extent_buffer_uptodate() or
clear_extent_buffer_uptodate(), which will already update the uptodate
flag for all the involved extent buffer folios.

Thus there is no need to update the folio uptodate flags again.

Just remove the open-coded part.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-17 14:44:43 +01:00
Matthew Wilcox (Oracle)
8be4cb04cb btrfs: convert io_ctl_prepare_pages() to work on folios
Retrieve folios instead of pages and work on them throughout.  Removes
a few calls to compound_head() and a reference to page->mapping.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-17 14:44:43 +01:00
Matthew Wilcox (Oracle)
b9967834ab btrfs: update some folio related comments
Remove references to the page lock and page->mapping.  Also btrfs folios
can never be swizzled into swap (mentioned in extent_write_cache_pages()).

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-17 14:44:42 +01:00
Daniel Vacek
96b2854de8 btrfs: keep private struct on stack for sync reads in btrfs_encoded_read_regular_fill_pages()
Only allocate the btrfs_encoded_read_private structure for asynchronous
(io_uring) mode.

There's no need to allocate an object from slab in the synchronous mode. In
such a case stack can be happily used as it used to be before 68d3b27e05
("btrfs: move priv off stack in btrfs_encoded_read_regular_fill_pages()")
which was a preparation for the async mode.

While at it, fix the comment to reflect the atomic => refcount change in
d29662695e ("btrfs: fix use-after-free waiting for encoded read endios").

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Daniel Vacek <neelx@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-17 14:44:42 +01:00
Easwar Hariharan
8ef9019ed2 btrfs: convert timeouts to secs_to_jiffies()
Commit b35108a51c ("jiffies: Define secs_to_jiffies()") introduced
secs_to_jiffies().  As the value here is a multiple of 1000, use
secs_to_jiffies() instead of msecs_to_jiffies() to avoid the
multiplication

This is converted using scripts/coccinelle/misc/secs_to_jiffies.cocci with
the following Coccinelle rules:

@depends on patch@
expression E;
@@

-msecs_to_jiffies
+secs_to_jiffies
(E
- * \( 1000 \| MSEC_PER_SEC \)
)

Link: https://lkml.kernel.org/r/20250225-converge-secs-to-jiffies-part-two-v3-5-a43967e36c88@linux.microsoft.com
Signed-off-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Acked-by: David Sterba <dsterba@suse.com>
Cc: Carlos Maiolino <cem@kernel.org>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Chris Mason <clm@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Damien Le Maol <dlemoal@kernel.org>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dick Kennedy <dick.kennedy@broadcom.com>
Cc: Dongsheng Yang <dongsheng.yang@easystack.cn>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Frank Li <frank.li@nxp.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Ilpo Jarvinen <ilpo.jarvinen@linux.intel.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: James Bottomley <james.bottomley@HansenPartnership.com>
Cc: James Smart <james.smart@broadcom.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Julia Lawall <julia.lawall@inria.fr>
Cc: Kalesh Anakkur Purayil <kalesh-anakkur.purayil@broadcom.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Mark Brown <broonie@kernel.org>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Nicolas Palix <nicolas.palix@imag.fr>
Cc: Niklas Cassel <cassel@kernel.org>
Cc: Oded Gabbay <ogabbay@kernel.org>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Selvin Thyparampil Xavier <selvin.xavier@broadcom.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Shyam-sundar S-k <Shyam-sundar.S-k@amd.com>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16 23:24:16 -07:00
Linus Torvalds
6ceb6346b0 for-6.14-rc5-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmfLM5wACgkQxWXV+ddt
 WDsK3A/7BEIUzin4CpmhBkFQamPCLjLL+Zz2etmoYWCrKnNPRMutVbsgeRM43cBt
 NXMD4RSoeXO/aYzrPhe4KMP4a5PkI02v2CEpPJqMRPmbADGyExx5Vnh68ioZWQbi
 N54Sd5LqhMT9FcViG46VJXr+MOBKIzO8++TxswIrCDO+6X/Y39+xZGxj4DXrnF38
 zgvxbILbiH+7vC1m9NV8K7Vl0jp36hQKcCjJYCfohbVoFQiyvmuh2x0LDL2HnIfH
 VpREP+eo/a3ZO8vPo7+4HZ5DVf5AolulbEC6myxsvFScLhWlh218plVyuv4QyACW
 RYDm9MqLqfqOkEDgj+Tb0C4s6uyVon5xbRL3aNbSE73KnUVeb/bB77qAejjzAkIr
 MvEEeEJp0H34OZm2fnUyFIu3ShDcSif1qH0rCOm1rBeqYZZsX7ny7TvKIqkgrsKk
 JbzgpYLyzzqTHs9QERw3OUhIBuefFCs4HlUeukLbUCdqI+ruPp5s76jfHQnT3dzG
 ad5CUW8eHf6mkU93dUlQIeDJSVPdaanf0Whomk3eOKgBeu8+gNp9R41kKJ7UtoA9
 GG504bqNjSe8t0sVmSyuE30BWAQWYnyCSY/9u46JrB6MtfWv+wikU/Nox4qZjM4d
 UhhWkDTELaTngcYkbm5+MD0DkkglTeqEbR9gCM21c9xiJrojhcw=
 =v6KI
 -----END PGP SIGNATURE-----

Merge tag 'for-6.14-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - fix leaked extent map after error when reading chunks

 - replace use of deprecated strncpy

 - in zoned mode, fixed range when ulocking extent range, causing a hang

* tag 'for-6.14-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix a leaked chunk map issue in read_one_chunk()
  btrfs: replace deprecated strncpy() with strscpy()
  btrfs: zoned: fix extent range end unlock in cow_file_range()
2025-03-07 11:17:30 -10:00
Haoxiang Li
35d99c68af btrfs: fix a leaked chunk map issue in read_one_chunk()
Add btrfs_free_chunk_map() to free the memory allocated
by btrfs_alloc_chunk_map() if btrfs_add_chunk_map() fails.

Fixes: 7dc66abb5a ("btrfs: use a dedicated data structure for chunk maps")
CC: stable@vger.kernel.org
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Haoxiang Li <haoxiang_li2024@163.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-03-06 14:40:09 +01:00
NeilBrown
88d5baf690
Change inode_operations.mkdir to return struct dentry *
Some filesystems, such as NFS, cifs, ceph, and fuse, do not have
complete control of sequencing on the actual filesystem (e.g.  on a
different server) and may find that the inode created for a mkdir
request already exists in the icache and dcache by the time the mkdir
request returns.  For example, if the filesystem is mounted twice the
directory could be visible on the other mount before it is on the
original mount, and a pair of name_to_handle_at(), open_by_handle_at()
calls could instantiate the directory inode with an IS_ROOT() dentry
before the first mkdir returns.

This means that the dentry passed to ->mkdir() may not be the one that
is associated with the inode after the ->mkdir() completes.  Some
callers need to interact with the inode after the ->mkdir completes and
they currently need to perform a lookup in the (rare) case that the
dentry is no longer hashed.

This lookup-after-mkdir requires that the directory remains locked to
avoid races.  Planned future patches to lock the dentry rather than the
directory will mean that this lookup cannot be performed atomically with
the mkdir.

To remove this barrier, this patch changes ->mkdir to return the
resulting dentry if it is different from the one passed in.
Possible returns are:
  NULL - the directory was created and no other dentry was used
  ERR_PTR() - an error occurred
  non-NULL - this other dentry was spliced in

This patch only changes file-systems to return "ERR_PTR(err)" instead of
"err" or equivalent transformations.  Subsequent patches will make
further changes to some file-systems to return a correct dentry.

Not all filesystems reliably result in a positive hashed dentry:

- NFS, cifs, hostfs will sometimes need to perform a lookup of
  the name to get inode information.  Races could result in this
  returning something different. Note that this lookup is
  non-atomic which is what we are trying to avoid.  Placing the
  lookup in filesystem code means it only happens when the filesystem
  has no other option.
- kernfs and tracefs leave the dentry negative and the ->revalidate
  operation ensures that lookup will be called to correctly populate
  the dentry.  This could be fixed but I don't think it is important
  to any of the users of vfs_mkdir() which look at the dentry.

The recommendation to use
    d_drop();d_splice_alias()
is ugly but fits with current practice.  A planned future patch will
change this.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/20250227013949.536172-2-neilb@suse.de
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-27 20:00:17 +01:00
Thorsten Blum
2df2c6ed89 btrfs: replace deprecated strncpy() with strscpy()
strncpy() is deprecated for NUL-terminated destination buffers. Use
strscpy() instead and don't zero-initialize the param array.

Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-02-26 09:24:01 +01:00
Naohiro Aota
5a4041f2c4 btrfs: zoned: fix extent range end unlock in cow_file_range()
Running generic/751 on the for-next branch often results in a hang like
below. They are both stack by locking an extent. This suggests someone
forget to unlock an extent.

  INFO: task kworker/u128:1:12 blocked for more than 323 seconds.
        Not tainted 6.13.0-BTRFS-ZNS+ #503
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  task:kworker/u128:1  state:D stack:0     pid:12    tgid:12    ppid:2      flags:0x00004000
  Workqueue: btrfs-fixup btrfs_work_helper [btrfs]
  Call Trace:
   <TASK>
   __schedule+0x534/0xdd0
   schedule+0x39/0x140
   __lock_extent+0x31b/0x380 [btrfs]
   ? __pfx_autoremove_wake_function+0x10/0x10
   btrfs_writepage_fixup_worker+0xf1/0x3a0 [btrfs]
   btrfs_work_helper+0xff/0x480 [btrfs]
   ? lock_release+0x178/0x2c0
   process_one_work+0x1ee/0x570
   ? srso_return_thunk+0x5/0x5f
   worker_thread+0x1d1/0x3b0
   ? __pfx_worker_thread+0x10/0x10
   kthread+0x10b/0x230
   ? __pfx_kthread+0x10/0x10
   ret_from_fork+0x30/0x50
   ? __pfx_kthread+0x10/0x10
   ret_from_fork_asm+0x1a/0x30
   </TASK>
  INFO: task kworker/u134:0:184 blocked for more than 323 seconds.
        Not tainted 6.13.0-BTRFS-ZNS+ #503
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  task:kworker/u134:0  state:D stack:0     pid:184   tgid:184   ppid:2      flags:0x00004000
  Workqueue: writeback wb_workfn (flush-btrfs-4)
  Call Trace:
   <TASK>
   __schedule+0x534/0xdd0
   schedule+0x39/0x140
   __lock_extent+0x31b/0x380 [btrfs]
   ? __pfx_autoremove_wake_function+0x10/0x10
   find_lock_delalloc_range+0xdb/0x260 [btrfs]
   writepage_delalloc+0x12f/0x500 [btrfs]
   ? srso_return_thunk+0x5/0x5f
   extent_write_cache_pages+0x232/0x840 [btrfs]
   btrfs_writepages+0x72/0x130 [btrfs]
   do_writepages+0xe7/0x260
   ? srso_return_thunk+0x5/0x5f
   ? lock_acquire+0xd2/0x300
   ? srso_return_thunk+0x5/0x5f
   ? find_held_lock+0x2b/0x80
   ? wbc_attach_and_unlock_inode.part.0+0x102/0x250
   ? wbc_attach_and_unlock_inode.part.0+0x102/0x250
   __writeback_single_inode+0x5c/0x4b0
   writeback_sb_inodes+0x22d/0x550
   __writeback_inodes_wb+0x4c/0xe0
   wb_writeback+0x2f6/0x3f0
   wb_workfn+0x32a/0x510
   process_one_work+0x1ee/0x570
   ? srso_return_thunk+0x5/0x5f
   worker_thread+0x1d1/0x3b0
   ? __pfx_worker_thread+0x10/0x10
   kthread+0x10b/0x230
   ? __pfx_kthread+0x10/0x10
   ret_from_fork+0x30/0x50
   ? __pfx_kthread+0x10/0x10
   ret_from_fork_asm+0x1a/0x30
   </TASK>

This happens because we have another success path for the zoned mode. When
there is no active zone available, btrfs_reserve_extent() returns
-EAGAIN. In this case, we have two reactions.

(1) If the given range is never allocated, we can only wait for someone
    to finish a zone, so wait on BTRFS_FS_NEED_ZONE_FINISH bit and retry
    afterward.

(2) Or, if some allocations are already done, we must bail out and let
    the caller to send IOs for the allocation. This is because these IOs
    may be necessary to finish a zone.

The commit 06f3642847 ("btrfs: do proper folio cleanup when
cow_file_range() failed") moved the unlock code from the inside of the
loop to the outside. So, previously, the allocated extents are unlocked
just after the allocation and so before returning from the function.
However, they are no longer unlocked on the case (2) above. That caused
the hang issue.

Fix the issue by modifying the 'end' to the end of the allocated
range. Then, we can exit the loop and the same unlock code can properly
handle the case.

Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Tested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Fixes: 06f3642847 ("btrfs: do proper folio cleanup when cow_file_range() failed")
CC: stable@vger.kernel.org
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-02-26 09:23:57 +01:00
Linus Torvalds
cc8a0934d0 for-6.14-rc4-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAme95g8ACgkQxWXV+ddt
 WDvi3g//V55iBXnPv0Jrs7b95GRskYv8A4vJsZhGtub4PlcEh8S6Q1IoU3qwiKHv
 E2THDA/A14qetxh3tSo73+RdS3JHpIH4QKjO54k74gOh45OEUs4Lq8NBAujmpz4b
 BMZZnM5iyZipNfbebUa/XxlPLvHg8D2rUqwycS/A0c5BE56HTvVzmKL3RdUfkAvA
 uZaJa6FOKfr6ge3ikl/dm+Rl7f+ZymIK4T9XsW3Lt223siYvcLJvWEIL0tk9B1y/
 ZUQNqPOCHY0mX/zPC0425LoeH3LWDPyZPCakaY8tiwI20p/sP+hPLBC8WDrJvoam
 losu6v8EqkYK9zND/ETVq3d1Y9mzub/soKuM+aDQ/UM0JXz1vI3RYQcpskECR0Gf
 ZPq5tv+dSBbMmscvkxnkuNBaTr3IbOhkxaKwOvdoRN9F4HbmhgxTscshaQHklmiG
 4qRx2HtW9Zw8ufyLUFUYaRAj45eFDZMQStQMCNSECD8X+fS6CPGUqGFcuXrm+kLL
 v6k0cbvh1NOLSchqtfR4rochJFUp5veUNHoYQ7YRy3CqV1yrF7iM1e0G1rvyOQYQ
 9tpN93IYwLItRdUjtqyS/q8WOddRTo0LTqh5HDXPnLd3jc/kO7KjHv9dJna7wyhO
 MUJmLlpy1dRDHCvTl70oF0Nxe4Ve20n7U2QayF5bMGtCmQnzGL0=
 =4+6s
 -----END PGP SIGNATURE-----

Merge tag 'for-6.14-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - extent map shrinker fixes:
     - fix potential use after free accessing an inode to reach fs_info,
       the shrinker could do iput() in the meantime
     - skip unnecessary scanning of inodes without extent maps
     - do direct iput(), no need for indirection via workqueue

 - in block < page mode, fix race when extending i_size in buffered mode

 - fix minor memory leak in selftests

 - print descriptive error message when seeding device is not found

* tag 'for-6.14-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix data overwriting bug during buffered write when block size < page size
  btrfs: output an error message if btrfs failed to find the seed fsid
  btrfs: do regular iput instead of delayed iput during extent map shrinking
  btrfs: skip inodes without loaded extent maps when shrinking extent maps
  btrfs: fix use-after-free on inode when scanning root during em shrinking
  btrfs: selftests: fix btrfs_test_delayed_refs() leak of transaction
2025-02-25 09:42:15 -08:00
Qu Wenruo
efa11fd269 btrfs: fix data overwriting bug during buffered write when block size < page size
[BUG]
When running generic/418 with a btrfs whose block size < page size
(subpage cases), it always fails.

And the following minimal reproducer is more than enough to trigger it
reliably:

workload()
{
        mkfs.btrfs -s 4k -f $dev > /dev/null
        dmesg -C
        mount $dev $mnt
        $fsstree_dir/src/dio-invalidate-cache -r -b 4096 -n 3 -i 1 -f $mnt/diotest
        ret=$?
        umount $mnt
        stop_trace
        if [ $ret -ne 0 ]; then
                fail
        fi
}

for (( i = 0; i < 1024; i++)); do
        echo "=== $i/$runtime ==="
        workload
done

[CAUSE]
With extra trace printk added to the following functions:
- btrfs_buffered_write()
  * Which folio is touched
  * The file offset (start) where the buffered write is at
  * How many bytes are copied
  * The content of the write (the first 2 bytes)

- submit_one_sector()
  * Which folio is touched
  * The position inside the folio
  * The content of the page cache (the first 2 bytes)

- pagecache_isize_extended()
  * The parameters of the function itself
  * The parameters of the folio_zero_range()

Which are enough to show the problem:

  22.158114: btrfs_buffered_write: folio pos=0 start=0 copied=4096 content=0x0101
  22.158161: submit_one_sector: r/i=5/257 folio=0 pos=0 content=0x0101
  22.158609: btrfs_buffered_write: folio pos=0 start=4096 copied=4096 content=0x0101
  22.158634: btrfs_buffered_write: folio pos=0 start=8192 copied=4096 content=0x0101
  22.158650: pagecache_isize_extended: folio=0 from=4096 to=8192 bsize=4096 zero off=4096 len=8192
  22.158682: submit_one_sector: r/i=5/257 folio=0 pos=4096 content=0x0000
  22.158686: submit_one_sector: r/i=5/257 folio=0 pos=8192 content=0x0101

The tool dio-invalidate-cache will start 3 threads, each doing a buffered
write with 0x01 at offset 0, 4096 and 8192, do a fsync, then do a direct read,
and compare the read buffer with the write buffer.

Note that all 3 btrfs_buffered_write() are writing the correct 0x01 into
the page cache.

But at submit_one_sector(), at file offset 4096, the content is zeroed
out, by pagecache_isize_extended().

The race happens like this:
 Thread A is writing into range [4K, 8K).
 Thread B is writing into range [8K, 12k).

               Thread A              |         Thread B
-------------------------------------+------------------------------------
btrfs_buffered_write()               | btrfs_buffered_write()
|- old_isize = 4K;                   | |- old_isize = 4096;
|- btrfs_inode_lock()                | |
|- write into folio range [4K, 8K)   | |
|- pagecache_isize_extended()        | |
|  extend isize from 4096 to 8192    | |
|  no folio_zero_range() called      | |
|- btrfs_inode_lock()                | |
                                     | |- btrfs_inode_lock()
				     | |- write into folio range [8K, 12K)
				     | |- pagecache_isize_extended()
				     | |  calling folio_zero_range(4K, 8K)
				     | |  This is caused by the old_isize is
				     | |  grabbed too early, without any
				     | |  inode lock.
				     | |- btrfs_inode_unlock()

The @old_isize is grabbed without inode lock, causing race between two
buffered write threads and making pagecache_isize_extended() to zero
range which is still containing cached data.

And this is only affecting subpage btrfs, because for regular blocksize
== page size case, the function pagecache_isize_extended() will do
nothing if the block size >= page size.

[FIX]
Grab the old i_size while holding the inode lock.
This means each buffered write thread will have a stable view of the
old inode size, thus avoid the above race.

CC: stable@vger.kernel.org # 5.15+
Fixes: 5e8b9ef303 ("btrfs: move pos increment and pagecache extension to btrfs_buffered_write")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-02-21 09:32:24 +01:00
Qu Wenruo
b1bf18223a btrfs: output an error message if btrfs failed to find the seed fsid
[BUG]
If btrfs failed to locate the seed device for whatever reason, mounting
the sprouted device will fail without any meaning error message:

  # mkfs.btrfs -f /dev/test/scratch1
  # btrfstune -S1 /dev/test/scratch1
  # mount /dev/test/scratch1 /mnt/btrfs
  # btrfs dev add -f /dev/test/scratch2 /mnt/btrfs
  # umount /mnt/btrfs
  # btrfs dev scan -u
  # btrfs mount /dev/test/scratch2 /mnt/btrfs
  mount: /mnt/btrfs: fsconfig system call failed: No such file or directory.
        dmesg(1) may have more information after failed mount system call.
  # dmesg -t | tail -n6
  BTRFS info (device dm-5): first mount of filesystem 64252ded-5953-4868-b962-cea48f7ac4ea
  BTRFS info (device dm-5): using crc32c (crc32c-generic) checksum algorithm
  BTRFS info (device dm-5): using free-space-tree
  BTRFS error (device dm-5): failed to read chunk tree: -2
  BTRFS error (device dm-5): open_ctree failed: -2

[CAUSE]
The failure to mount is pretty straight forward, just unable to find the
seed device and its fsid, caused by `btrfs dev scan -u`.

But the lack of any useful info is a problem.

[FIX]
Just add an extra error message in open_seed_devices() to indicate the
error.

Now the error message would look like this:

 BTRFS info (device dm-4): first mount of filesystem 7769223d-4db1-4e4c-ac29-0a96f53576ab
 BTRFS info (device dm-4): using crc32c (crc32c-generic) checksum algorithm
 BTRFS info (device dm-4): using free-space-tree
 BTRFS error (device dm-4): failed to find fsid e87c12e6-584b-4e98-8b88-962c33a619ff when attempting to open seed devices
 BTRFS error (device dm-4): failed to read chunk tree: -2
 BTRFS error (device dm-4): open_ctree failed: -2

Link: https://github.com/kdave/btrfs-progs/issues/959
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-02-21 09:32:16 +01:00
Filipe Manana
15b3b3254d btrfs: do regular iput instead of delayed iput during extent map shrinking
The extent map shrinker now runs in the system unbound workqueue and no
longer in kswapd context so it can directly do an iput() on inodes even
if that blocks or needs to acquire any lock (we aren't holding any locks
when requesting the delayed iput from the shrinker). So we don't need to
add a delayed iput, wake up the cleaner and delegate the iput() to the
cleaner, which also adds extra contention on the spinlock that protects
the delayed iputs list.

Reported-by: Ivan Shapovalov <intelfx@intelfx.name>
Tested-by: Ivan Shapovalov <intelfx@intelfx.name>
Link: https://lore.kernel.org/linux-btrfs/0414d690ac5680d0d77dfc930606cdc36e42e12f.camel@intelfx.name/
CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-02-21 09:32:11 +01:00
Filipe Manana
c6c9c4d564 btrfs: skip inodes without loaded extent maps when shrinking extent maps
If there are inodes that don't have any loaded extent maps, we end up
grabbing a reference on them and later adding a delayed iput, which wakes
up the cleaner and makes it do unnecessary work. This is common when for
example the inodes were open only to run stat(2) or all their extent maps
were already released through the folio release callback
(btrfs_release_folio()) or released by a previous run of the shrinker, or
directories which never have extent maps.

Reported-by: Ivan Shapovalov <intelfx@intelfx.name>
Tested-by: Ivan Shapovalov <intelfx@intelfx.name>
Link: https://lore.kernel.org/linux-btrfs/0414d690ac5680d0d77dfc930606cdc36e42e12f.camel@intelfx.name/
CC: stable@vger.kernel.org # 6.13+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-02-21 09:32:07 +01:00
Filipe Manana
59f37036bb btrfs: fix use-after-free on inode when scanning root during em shrinking
At btrfs_scan_root() we are accessing the inode's root (and fs_info) in a
call to btrfs_fs_closing() after we have scheduled the inode for a delayed
iput, and that can result in a use-after-free on the inode in case the
cleaner kthread does the iput before we dereference the inode in the call
to btrfs_fs_closing().

Fix this by using the fs_info stored already in a local variable instead
of doing inode->root->fs_info.

Fixes: 1020443840 ("btrfs: make the extent map shrinker run asynchronously as a work queue job")
CC: stable@vger.kernel.org # 6.13+
Tested-by: Ivan Shapovalov <intelfx@intelfx.name>
Link: https://lore.kernel.org/linux-btrfs/0414d690ac5680d0d77dfc930606cdc36e42e12f.camel@intelfx.name/
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-02-21 09:31:48 +01:00
David Disseldorp
290237fde9 btrfs: selftests: fix btrfs_test_delayed_refs() leak of transaction
The btrfs_transaction struct leaks, which can cause sporadic fstests
failures when kmemleak checking is enabled:

kmemleak: 5 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
> cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff88810fdc6c00 (size 512):
  comm "modprobe", pid 203, jiffies 4294892552
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace (crc 6736050f):
    __kmalloc_cache_noprof+0x133/0x2c0
    btrfs_test_delayed_refs+0x6f/0xbb0 [btrfs]
    btrfs_run_sanity_tests.cold+0x91/0xf9 [btrfs]
    0xffffffffa02fd055
    do_one_initcall+0x49/0x1c0
    do_init_module+0x5b/0x1f0
    init_module_from_file+0x70/0x90
    idempotent_init_module+0xe8/0x2c0
    __x64_sys_finit_module+0x6b/0xd0
    do_syscall_64+0x54/0x110
    entry_SYSCALL_64_after_hwframe+0x76/0x7e

The transaction struct was initially stack-allocated but switched to
heap following frame size compiler warnings.

Fixes: 2b34879d97 ("btrfs: selftests: add delayed ref self test cases")
Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-02-17 17:24:14 +01:00
Linus Torvalds
945ce413ac for-6.14-rc2-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmeuSwwACgkQxWXV+ddt
 WDtQ8Q//fsTAu1DLjeVrzMhVNswGwr3PgWzLk3PqWTDEG9UeR/jJYntIPglVyhhP
 Mp2E3CYe2rlWwK0K3PITDu179tLrnCvbfKEPwWvyVZw5D0EDjPQYs9/H5ztSE8O4
 4i3kv2LjlXHE3h62tjNoeHL4NK1SRJcFeH69XhhIe0ELvTQVarvfJupZwdQQivWg
 sDlQXklXxl1kEtHVGnmz6jd09a0vti7xw8MAG6QiIP83Hvt6Ie+NLfTfTCkRIWSK
 95mPM+1YhmLQe15sD8xjHyYmH5E0cEXQh1Pvlz6xqQWRvZERG8Pmj+iwFTLaw4iA
 JR6sN2/KFgXE9OIGbFqQ+dvm++2hWcnPwW+h6EdOSj0DQkupbJm4VeBK0WQ4YZ+x
 Q0OQXPTfGpcjp7KyJrT6EZFq5VxeEfOz4hozhiCSTs+Xpx7Oh/2THL01N/dUMn0C
 SNR9E4/Rlq7rWV7euGwicwo/tZZIdCr4ihUGk4jpamlUbIXj+2SrOc4cpQdypmsO
 DeYvwzIXnPe8/Eo3rZ5ej0DK7GxfEFyd6v6l0oS6HepvMJ6y6/eiOYteVbGpvhXv
 J2M6PLstiZc152VHPApN9+ZlXBeGjyMfxLcsweblpSBBt/57otY6cMhqNuIp0j9B
 0zP3KKOwrIJ8tzcwjMSH+2OZsDQ7oc7eiJI08r0IcpCbCBTIeyE=
 =0hI+
 -----END PGP SIGNATURE-----

Merge tag 'for-6.14-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - fix stale page cache after race between readahead and direct IO write

 - fix hole expansion when writing at an offset beyond EOF, the range
   will not be zeroed

 - use proper way to calculate offsets in folio ranges

* tag 'for-6.14-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix hole expansion when writing at an offset beyond EOF
  btrfs: fix stale page cache after race between readahead and direct IO write
  btrfs: fix two misuses of folio_shift()
2025-02-13 12:06:29 -08:00
Filipe Manana
da2dccd745 btrfs: fix hole expansion when writing at an offset beyond EOF
At btrfs_write_check() if our file's i_size is not sector size aligned and
we have a write that starts at an offset larger than the i_size that falls
within the same page of the i_size, then we end up not zeroing the file
range [i_size, write_offset).

The code is this:

    start_pos = round_down(pos, fs_info->sectorsize);
    oldsize = i_size_read(inode);
    if (start_pos > oldsize) {
        /* Expand hole size to cover write data, preventing empty gap */
        loff_t end_pos = round_up(pos + count, fs_info->sectorsize);

        ret = btrfs_cont_expand(BTRFS_I(inode), oldsize, end_pos);
        if (ret)
            return ret;
    }

So if our file's i_size is 90269 bytes and a write at offset 90365 bytes
comes in, we get 'start_pos' set to 90112 bytes, which is less than the
i_size and therefore we don't zero out the range [90269, 90365) by
calling btrfs_cont_expand().

This is an old bug introduced in commit 9036c10208 ("Btrfs: update hole
handling v2"), from 2008, and the buggy code got moved around over the
years.

Fix this by discarding 'start_pos' and comparing against the write offset
('pos') without any alignment.

This bug was recently exposed by test case generic/363 which tests this
scenario by polluting ranges beyond EOF with an mmap write and than verify
that after a file increases we get zeroes for the range which is supposed
to be a hole and not what we wrote with the previous mmaped write.

We're only seeing this exposed now because generic/363 used to run only
on xfs until last Sunday's fstests update.

The test was failing like this:

   $ ./check generic/363
   FSTYP         -- btrfs
   PLATFORM      -- Linux/x86_64 debian0 6.13.0-rc7-btrfs-next-185+ #17 SMP PREEMPT_DYNAMIC Mon Feb  3 12:28:46 WET 2025
   MKFS_OPTIONS  -- /dev/sdc
   MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1

   generic/363 0s ... [failed, exit status 1]- output mismatch (see /home/fdmanana/git/hub/xfstests/results//generic/363.out.bad)
       --- tests/generic/363.out	2025-02-05 15:31:14.013646509 +0000
       +++ /home/fdmanana/git/hub/xfstests/results//generic/363.out.bad	2025-02-05 17:25:33.112630781 +0000
       @@ -1 +1,46 @@
        QA output created by 363
       +READ BAD DATA: offset = 0xdcad, size = 0xd921, fname = /home/fdmanana/btrfs-tests/dev/junk
       +OFFSET      GOOD    BAD     RANGE
       +0x1609d     0x0000  0x3104  0x0
       +operation# (mod 256) for the bad data may be 4
       +0x1609e     0x0000  0x0472  0x1
       +operation# (mod 256) for the bad data may be 4
       ...
       (Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/generic/363.out /home/fdmanana/git/hub/xfstests/results//generic/363.out.bad'  to see the entire diff)
   Ran: generic/363
   Failures: generic/363
   Failed 1 of 1 tests

Fixes: 9036c10208 ("Btrfs: update hole handling v2")
CC: stable@vger.kernel.org
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-02-11 23:09:03 +01:00
Filipe Manana
acc18e1c1d btrfs: fix stale page cache after race between readahead and direct IO write
After commit ac325fc2aa ("btrfs: do not hold the extent lock for entire
read") we can now trigger a race between a task doing a direct IO write
and readahead. When this race is triggered it results in tasks getting
stale data when they attempt do a buffered read (including the task that
did the direct IO write).

This race can be sporadically triggered with test case generic/418, failing
like this:

   $ ./check generic/418
   FSTYP         -- btrfs
   PLATFORM      -- Linux/x86_64 debian0 6.13.0-rc7-btrfs-next-185+ #17 SMP PREEMPT_DYNAMIC Mon Feb  3 12:28:46 WET 2025
   MKFS_OPTIONS  -- /dev/sdc
   MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1

   generic/418 14s ... - output mismatch (see /home/fdmanana/git/hub/xfstests/results//generic/418.out.bad)
       --- tests/generic/418.out	2020-06-10 19:29:03.850519863 +0100
       +++ /home/fdmanana/git/hub/xfstests/results//generic/418.out.bad	2025-02-03 15:42:36.974609476 +0000
       @@ -1,2 +1,5 @@
        QA output created by 418
       +cmpbuf: offset 0: Expected: 0x1, got 0x0
       +[6:0] FAIL - comparison failed, offset 24576
       +diotest -wp -b 4096 -n 8 -i 4 failed at loop 3
        Silence is golden
       ...
       (Run 'diff -u /home/fdmanana/git/hub/xfstests/tests/generic/418.out /home/fdmanana/git/hub/xfstests/results//generic/418.out.bad'  to see the entire diff)
   Ran: generic/418
   Failures: generic/418
   Failed 1 of 1 tests

The race happens like this:

1) A file has a prealloc extent for the range [16K, 28K);

2) Task A starts a direct IO write against file range [24K, 28K).
   At the start of the direct IO write it invalidates the page cache at
   __iomap_dio_rw() with kiocb_invalidate_pages() for the 4K page at file
   offset 24K;

3) Task A enters btrfs_dio_iomap_begin() and locks the extent range
   [24K, 28K);

4) Task B starts a readahead for file range [16K, 28K), entering
   btrfs_readahead().

   First it attempts to read the page at offset 16K by entering
   btrfs_do_readpage(), where it calls get_extent_map(), locks the range
   [16K, 20K) and gets the extent map for the range [16K, 28K), caching
   it into the 'em_cached' variable declared in the local stack of
   btrfs_readahead(), and then unlocks the range [16K, 20K).

   Since the extent map has the prealloc flag, at btrfs_do_readpage() we
   zero out the page's content and don't submit any bio to read the page
   from the extent.

   Then it attempts to read the page at offset 20K entering
   btrfs_do_readpage() where we reuse the previously cached extent map
   (decided by get_extent_map()) since it spans the page's range and
   it's still in the inode's extent map tree.

   Just like for the previous page, we zero out the page's content since
   the extent map has the prealloc flag set.

   Then it attempts to read the page at offset 24K entering
   btrfs_do_readpage() where we reuse the previously cached extent map
   (decided by get_extent_map()) since it spans the page's range and
   it's still in the inode's extent map tree.

   Just like for the previous pages, we zero out the page's content since
   the extent map has the prealloc flag set. Note that we didn't lock the
   extent range [24K, 28K), so we didn't synchronize with the ongoing
   direct IO write being performed by task A;

5) Task A enters btrfs_create_dio_extent() and creates an ordered extent
   for the range [24K, 28K), with the flags BTRFS_ORDERED_DIRECT and
   BTRFS_ORDERED_PREALLOC set;

6) Task A unlocks the range [24K, 28K) at btrfs_dio_iomap_begin();

7) The ordered extent enters btrfs_finish_one_ordered() and locks the
   range [24K, 28K);

8) Task A enters fs/iomap/direct-io.c:iomap_dio_complete() and it tries
   to invalidate the page at offset 24K by calling
   kiocb_invalidate_post_direct_write(), resulting in a call chain that
   ends up at btrfs_release_folio().

   The btrfs_release_folio() call ends up returning false because the range
   for the page at file offset 24K is currently locked by the task doing
   the ordered extent completion in the previous step (7), so we have:

   btrfs_release_folio() ->
      __btrfs_release_folio() ->
         try_release_extent_mapping() ->
	     try_release_extent_state()

   This last function checking that the range is locked and returning false
   and propagating it up to btrfs_release_folio().

   So this results in a failure to invalidate the page and
   kiocb_invalidate_post_direct_write() triggers this message logged in
   dmesg:

     Page cache invalidation failure on direct I/O.  Possible data corruption due to collision with buffered I/O!

   After this we leave the page cache with stale data for the file range
   [24K, 28K), filled with zeroes instead of the data written by direct IO
   write (all bytes with a 0x01 value), so any task attempting to read with
   buffered IO, including the task that did the direct IO write, will get
   all bytes in the range with a 0x00 value instead of the written data.

Fix this by locking the range, with btrfs_lock_and_flush_ordered_range(),
at the two callers of btrfs_do_readpage() instead of doing it at
get_extent_map(), just like we did before commit ac325fc2aa ("btrfs: do
not hold the extent lock for entire read"), and unlocking the range after
all the calls to btrfs_do_readpage(). This way we never reuse a cached
extent map without flushing any pending ordered extents from a concurrent
direct IO write.

Fixes: ac325fc2aa ("btrfs: do not hold the extent lock for entire read")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-02-11 23:09:03 +01:00
Matthew Wilcox (Oracle)
01af106a07 btrfs: fix two misuses of folio_shift()
It is meaningless to shift a byte count by folio_shift().  The folio index
is in units of PAGE_SIZE, not folio_size().  We can use folio_contains()
to make this work for arbitrary-order folios, so remove the assertion
that the folios are of order 0.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-02-07 20:51:18 +01:00
Linus Torvalds
92514ef226 for-6.14-rc1-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmejbmkACgkQxWXV+ddt
 WDuXuQ/8DETuhqww7hwrDgHyDHRgj/783Oy1+V/jJPQZ1hpjAbSJBU7aKxneAMMc
 Gj4ExbDfjd8kRAvsE71/1McJqVBd6CiuBG/k65vjqVS4lM8mEasVefCa4OsOR3iB
 gGzQeNbrDzIs3IOg8hM1l1iPDkI/AyOyeysD/qNMdWO4mcKEMwrBYkQJhL6+DzfE
 BKVP+NAdK4iv/W/EngAqvcd7mq2RdxeR9nBesHnKTzPCVFf6bBT3b3Qem/ovY6Td
 ZNQLjx9GXumDj0jSiyRI5rxjSYOrqSU4JV+1C7ghOwBj2uD2SZxAvghuRSuUTKnN
 9/9x1RNO7i+FE3GHzYWShhHkNuuLZspmi2J1neSttQ5Jy/PFJR/tUAED5zY6Nl0X
 73GWSzLlmaJ+E77DkTJksBYmRrnwtA6plMKD4umDCHw0lNu/0GCvxtZY1T1ZiKy2
 yK37Ja559+k7RPIdKoyHo81A7num4gLeBZTqd9F/XPjU26b57Qnqk1LetgGeT8xk
 IZFQtz9HdmvLwwbxWwNvp1ttRf+1dj1lpVnb5n6r0d8Uyta9tgQpDvwhNjluBsEx
 AQxK9yUZ5kAXEEbEyDwoOsZ5yjwkaMzqRpQWWappb0jCLm5dADI87odFRaOSlgWS
 WoXL6Vbod8G5vaEVwPDl6yuSS+609c7M8ftBlgvcx3XZ5/N6y2M=
 =YjCE
 -----END PGP SIGNATURE-----

Merge tag 'for-6.14-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - add lockdep annotation for relocation root to fix a splat warning
   while merging roots

 - fix assertion failure when splitting ordered extent after transaction
   abort

 - don't print 'qgroup inconsistent' message when rescan process updates
   qgroup data sooner than the subvolume deletion process

 - fix use-after-free (accessing the error number) when attempting to
   join an aborted transaction

 - avoid starting new transaction if not necessary when cleaning qgroup
   during subvolume drop

* tag 'for-6.14-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: avoid starting new transaction when cleaning qgroup during subvolume drop
  btrfs: fix use-after-free when attempting to join an aborted transaction
  btrfs: do not output error message if a qgroup has been already cleaned up
  btrfs: fix assertion failure when splitting ordered extent after transaction abort
  btrfs: fix lockdep splat while merging a relocation root
2025-02-05 08:13:07 -08:00
Linus Torvalds
9c5968db9e The various patchsets are summarized below. Plus of course many
indivudual patches which are described in their changelogs.
 
 - "Allocate and free frozen pages" from Matthew Wilcox reorganizes the
   page allocator so we end up with the ability to allocate and free
   zero-refcount pages.  So that callers (ie, slab) can avoid a refcount
   inc & dec.
 
 - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to use
   large folios other than PMD-sized ones.
 
 - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance and
   fixes for this small built-in kernel selftest.
 
 - "mas_anode_descend() related cleanup" from Wei Yang tidies up part of
   the mapletree code.
 
 - "mm: fix format issues and param types" from Keren Sun implements a
   few minor code cleanups.
 
 - "simplify split calculation" from Wei Yang provides a few fixes and a
   test for the mapletree code.
 
 - "mm/vma: make more mmap logic userland testable" from Lorenzo Stoakes
   continues the work of moving vma-related code into the (relatively) new
   mm/vma.c.
 
 - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
   Hildenbrand cleans up and rationalizes handling of gfp flags in the page
   allocator.
 
 - "readahead: Reintroduce fix for improper RA window sizing" from Jan
   Kara is a second attempt at fixing a readahead window sizing issue.  It
   should reduce the amount of unnecessary reading.
 
 - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
   addresses an issue where "huge" amounts of pte pagetables are
   accumulated
   (https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/).
   Qi's series addresses this windup by synchronously freeing PTE memory
   within the context of madvise(MADV_DONTNEED).
 
 - "selftest/mm: Remove warnings found by adding compiler flags" from
   Muhammad Usama Anjum fixes some build warnings in the selftests code
   when optional compiler warnings are enabled.
 
 - "mm: don't use __GFP_HARDWALL when migrating remote pages" from David
   Hildenbrand tightens the allocator's observance of __GFP_HARDWALL.
 
 - "pkeys kselftests improvements" from Kevin Brodsky implements various
   fixes and cleanups in the MM selftests code, mainly pertaining to the
   pkeys tests.
 
 - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
   estimate application working set size.
 
 - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
   provides some cleanups to memcg's hugetlb charging logic.
 
 - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
   removes the global swap cgroup lock.  A speedup of 10% for a tmpfs-based
   kernel build was demonstrated.
 
 - "zram: split page type read/write handling" from Sergey Senozhatsky
   has several fixes and cleaups for zram in the area of zram_write_page().
   A watchdog softlockup warning was eliminated.
 
 - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin Brodsky
   cleans up the pagetable destructor implementations.  A rare
   use-after-free race is fixed.
 
 - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
   simplifies and cleans up the debugging code in the VMA merging logic.
 
 - "Account page tables at all levels" from Kevin Brodsky cleans up and
   regularizes the pagetable ctor/dtor handling.  This results in
   improvements in accounting accuracy.
 
 - "mm/damon: replace most damon_callback usages in sysfs with new core
   functions" from SeongJae Park cleans up and generalizes DAMON's sysfs
   file interface logic.
 
 - "mm/damon: enable page level properties based monitoring" from
   SeongJae Park increases the amount of information which is presented in
   response to DAMOS actions.
 
 - "mm/damon: remove DAMON debugfs interface" from SeongJae Park removes
   DAMON's long-deprecated debugfs interfaces.  Thus the migration to sysfs
   is completed.
 
 - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from Peter
   Xu cleans up and generalizes the hugetlb reservation accounting.
 
 - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
   removes a never-used feature of the alloc_pages_bulk() interface.
 
 - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
   extends DAMOS filters to support not only exclusion (rejecting), but
   also inclusion (allowing) behavior.
 
 - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
   "introduces a new memory descriptor for zswap.zpool that currently
   overlaps with struct page for now.  This is part of the effort to reduce
   the size of struct page and to enable dynamic allocation of memory
   descriptors."
 
 - "mm, swap: rework of swap allocator locks" from Kairui Song redoes and
   simplifies the swap allocator locking.  A speedup of 400% was
   demonstrated for one workload.  As was a 35% reduction for kernel build
   time with swap-on-zram.
 
 - "mm: update mips to use do_mmap(), make mmap_region() internal" from
   Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
   mmap_region() can be made MM-internal.
 
 - "mm/mglru: performance optimizations" from Yu Zhao fixes a few MGLRU
   regressions and otherwise improves MGLRU performance.
 
 - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae Park
   updates DAMON documentation.
 
 - "Cleanup for memfd_create()" from Isaac Manjarres does that thing.
 
 - "mm: hugetlb+THP folio and migration cleanups" from David Hildenbrand
   provides various cleanups in the areas of hugetlb folios, THP folios and
   migration.
 
 - "Uncached buffered IO" from Jens Axboe implements the new
   RWF_DONTCACHE flag which provides synchronous dropbehind for pagecache
   reading and writing.  To permite userspace to address issues with
   massive buildup of useless pagecache when reading/writing fast devices.
 
 - "selftests/mm: virtual_address_range: Reduce memory" from Thomas
   Weißschuh fixes and optimizes some of the MM selftests.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZ5a+cwAKCRDdBJ7gKXxA
 jtoyAP9R58oaOKPJuTizEKKXvh/RpMyD6sYcz/uPpnf+cKTZxQEAqfVznfWlw/Lz
 uC3KRZYhmd5YrxU4o+qjbzp9XWX/xAE=
 =Ib2s
 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "The various patchsets are summarized below. Plus of course many
  indivudual patches which are described in their changelogs.

   - "Allocate and free frozen pages" from Matthew Wilcox reorganizes
     the page allocator so we end up with the ability to allocate and
     free zero-refcount pages. So that callers (ie, slab) can avoid a
     refcount inc & dec

   - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to
     use large folios other than PMD-sized ones

   - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance
     and fixes for this small built-in kernel selftest

   - "mas_anode_descend() related cleanup" from Wei Yang tidies up part
     of the mapletree code

   - "mm: fix format issues and param types" from Keren Sun implements a
     few minor code cleanups

   - "simplify split calculation" from Wei Yang provides a few fixes and
     a test for the mapletree code

   - "mm/vma: make more mmap logic userland testable" from Lorenzo
     Stoakes continues the work of moving vma-related code into the
     (relatively) new mm/vma.c

   - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
     Hildenbrand cleans up and rationalizes handling of gfp flags in the
     page allocator

   - "readahead: Reintroduce fix for improper RA window sizing" from Jan
     Kara is a second attempt at fixing a readahead window sizing issue.
     It should reduce the amount of unnecessary reading

   - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
     addresses an issue where "huge" amounts of pte pagetables are
     accumulated:

       https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/

     Qi's series addresses this windup by synchronously freeing PTE
     memory within the context of madvise(MADV_DONTNEED)

   - "selftest/mm: Remove warnings found by adding compiler flags" from
     Muhammad Usama Anjum fixes some build warnings in the selftests
     code when optional compiler warnings are enabled

   - "mm: don't use __GFP_HARDWALL when migrating remote pages" from
     David Hildenbrand tightens the allocator's observance of
     __GFP_HARDWALL

   - "pkeys kselftests improvements" from Kevin Brodsky implements
     various fixes and cleanups in the MM selftests code, mainly
     pertaining to the pkeys tests

   - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
     estimate application working set size

   - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
     provides some cleanups to memcg's hugetlb charging logic

   - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
     removes the global swap cgroup lock. A speedup of 10% for a
     tmpfs-based kernel build was demonstrated

   - "zram: split page type read/write handling" from Sergey Senozhatsky
     has several fixes and cleaups for zram in the area of
     zram_write_page(). A watchdog softlockup warning was eliminated

   - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin
     Brodsky cleans up the pagetable destructor implementations. A rare
     use-after-free race is fixed

   - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
     simplifies and cleans up the debugging code in the VMA merging
     logic

   - "Account page tables at all levels" from Kevin Brodsky cleans up
     and regularizes the pagetable ctor/dtor handling. This results in
     improvements in accounting accuracy

   - "mm/damon: replace most damon_callback usages in sysfs with new
     core functions" from SeongJae Park cleans up and generalizes
     DAMON's sysfs file interface logic

   - "mm/damon: enable page level properties based monitoring" from
     SeongJae Park increases the amount of information which is
     presented in response to DAMOS actions

   - "mm/damon: remove DAMON debugfs interface" from SeongJae Park
     removes DAMON's long-deprecated debugfs interfaces. Thus the
     migration to sysfs is completed

   - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from
     Peter Xu cleans up and generalizes the hugetlb reservation
     accounting

   - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
     removes a never-used feature of the alloc_pages_bulk() interface

   - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
     extends DAMOS filters to support not only exclusion (rejecting),
     but also inclusion (allowing) behavior

   - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
     introduces a new memory descriptor for zswap.zpool that currently
     overlaps with struct page for now. This is part of the effort to
     reduce the size of struct page and to enable dynamic allocation of
     memory descriptors

   - "mm, swap: rework of swap allocator locks" from Kairui Song redoes
     and simplifies the swap allocator locking. A speedup of 400% was
     demonstrated for one workload. As was a 35% reduction for kernel
     build time with swap-on-zram

   - "mm: update mips to use do_mmap(), make mmap_region() internal"
     from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
     mmap_region() can be made MM-internal

   - "mm/mglru: performance optimizations" from Yu Zhao fixes a few
     MGLRU regressions and otherwise improves MGLRU performance

   - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae
     Park updates DAMON documentation

   - "Cleanup for memfd_create()" from Isaac Manjarres does that thing

   - "mm: hugetlb+THP folio and migration cleanups" from David
     Hildenbrand provides various cleanups in the areas of hugetlb
     folios, THP folios and migration

   - "Uncached buffered IO" from Jens Axboe implements the new
     RWF_DONTCACHE flag which provides synchronous dropbehind for
     pagecache reading and writing. To permite userspace to address
     issues with massive buildup of useless pagecache when
     reading/writing fast devices

   - "selftests/mm: virtual_address_range: Reduce memory" from Thomas
     Weißschuh fixes and optimizes some of the MM selftests"

* tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits)
  mm/compaction: fix UBSAN shift-out-of-bounds warning
  s390/mm: add missing ctor/dtor on page table upgrade
  kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags()
  tools: add VM_WARN_ON_VMG definition
  mm/damon/core: use str_high_low() helper in damos_wmark_wait_us()
  seqlock: add missing parameter documentation for raw_seqcount_try_begin()
  mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh
  mm/page_alloc: remove the incorrect and misleading comment
  zram: remove zcomp_stream_put() from write_incompressible_page()
  mm: separate move/undo parts from migrate_pages_batch()
  mm/kfence: use str_write_read() helper in get_access_type()
  selftests/mm/mkdirty: fix memory leak in test_uffdio_copy()
  kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags()
  selftests/mm: virtual_address_range: avoid reading from VM_IO mappings
  selftests/mm: vm_util: split up /proc/self/smaps parsing
  selftests/mm: virtual_address_range: unmap chunks after validation
  selftests/mm: virtual_address_range: mmap() without PROT_WRITE
  selftests/memfd/memfd_test: fix possible NULL pointer dereference
  mm: add FGP_DONTCACHE folio creation flag
  mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue
  ...
2025-01-26 18:36:23 -08:00
Kairui Song
27701521be mm, swap: clean up device availability check
Remove highest_bit and lowest_bit.  After the HDD allocation path has been
removed, the only purpose of these two fields is to determine whether the
device is full or not, which can instead be determined by checking the
inuse_pages.

Link: https://lkml.kernel.org/r/20250113175732.48099-6-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Barry Song <v-songbaohua@oppo.com>
Cc: Chis Li <chrisl@kernel.org>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Hugh Dickens <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:36 -08:00
Luiz Capitulino
6bf9b5b40a mm: alloc_pages_bulk: rename API
The previous commit removed the page_list argument from
alloc_pages_bulk_noprof() along with the alloc_pages_bulk_list() function.

Now that only the *_array() flavour of the API remains, we can do the
following renaming (along with the _noprof() ones):

  alloc_pages_bulk_array -> alloc_pages_bulk
  alloc_pages_bulk_array_mempolicy -> alloc_pages_bulk_mempolicy
  alloc_pages_bulk_array_node -> alloc_pages_bulk_node

Link: https://lkml.kernel.org/r/275a3bbc0be20fbe9002297d60045e67ab3d4ada.1734991165.git.luizcap@redhat.com
Signed-off-by: Luiz Capitulino <luizcap@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:31 -08:00
Linus Torvalds
8883957b3c \n
-----BEGIN PGP SIGNATURE-----
 
 iQEzBAABCAAdFiEEq1nRK9aeMoq1VSgcnJ2qBz9kQNkFAmePs7oACgkQnJ2qBz9k
 QNmHuAf9GkLnY5u1/81xP5V9ukZ4N2yeMW0dydLS5cjWj/St5ELeMAza3jeqtJtD
 j36vbnmy2c5pPaGLAK8BJpMXT/R2TkmmKD004zcfqF2S3SgbGzdgO1zMZzq9KJpM
 woRKZtLuglDajedsDEBBcKotBhlN2+C/sQlFuL1mX4zitk9ajr0qYUB1+JqOeg5f
 qwPsDLT077ADpxd7lVIMcm+OqbduP5KWkBKYHpn7lJcLe1eqVMMzceJroW42zhVG
 Dq8Iln26bbU9Wx6FSPFCUcHEzHRHUfXmu07HN9U0X++0QgWjrmBQQLooGFB/bR4a
 edBrPpVas6xE4/brjgFX3gOKtv8xYg==
 =ewDV
 -----END PGP SIGNATURE-----

Merge tag 'fsnotify_hsm_for_v6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull fsnotify pre-content notification support from Jan Kara:
 "This introduces a new fsnotify event (FS_PRE_ACCESS) that gets
  generated before a file contents is accessed.

  The event is synchronous so if there is listener for this event, the
  kernel waits for reply. On success the execution continues as usual,
  on failure we propagate the error to userspace. This allows userspace
  to fill in file content on demand from slow storage. The context in
  which the events are generated has been picked so that we don't hold
  any locks and thus there's no risk of a deadlock for the userspace
  handler.

  The new pre-content event is available only for users with global
  CAP_SYS_ADMIN capability (similarly to other parts of fanotify
  functionality) and it is an administrator responsibility to make sure
  the userspace event handler doesn't do stupid stuff that can DoS the
  system.

  Based on your feedback from the last submission, fsnotify code has
  been improved and now file->f_mode encodes whether pre-content event
  needs to be generated for the file so the fast path when nobody wants
  pre-content event for the file just grows the additional file->f_mode
  check. As a bonus this also removes the checks whether the old
  FS_ACCESS event needs to be generated from the fast path. Also the
  place where the event is generated during page fault has been moved so
  now filemap_fault() generates the event if and only if there is no
  uptodate folio in the page cache.

  Also we have dropped FS_PRE_MODIFY event as current real-world users
  of the pre-content functionality don't really use it so let's start
  with the minimal useful feature set"

* tag 'fsnotify_hsm_for_v6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: (21 commits)
  fanotify: Fix crash in fanotify_init(2)
  fs: don't block write during exec on pre-content watched files
  fs: enable pre-content events on supported file systems
  ext4: add pre-content fsnotify hook for DAX faults
  btrfs: disable defrag on pre-content watched files
  xfs: add pre-content fsnotify hook for DAX faults
  fsnotify: generate pre-content permission event on page fault
  mm: don't allow huge faults for files with pre content watches
  fanotify: disable readahead if we have pre-content watches
  fanotify: allow to set errno in FAN_DENY permission response
  fanotify: report file range info with pre-content events
  fanotify: introduce FAN_PRE_ACCESS permission event
  fsnotify: generate pre-content permission event on truncate
  fsnotify: pass optional file access range in pre-content event
  fsnotify: introduce pre-content permission events
  fanotify: reserve event bit of deprecated FAN_DIR_MODIFY
  fanotify: rename a misnamed constant
  fanotify: don't skip extra event info if no info_mode is set
  fsnotify: check if file is actually being watched for pre-content events on open
  fsnotify: opt-in for permission events at file open time
  ...
2025-01-23 13:36:06 -08:00
Filipe Manana
fdef89ce6f btrfs: avoid starting new transaction when cleaning qgroup during subvolume drop
At btrfs_qgroup_cleanup_dropped_subvolume() all we want to commit the
current transaction in order to have all the qgroup rfer/excl numbers up
to date. However we are using btrfs_start_transaction(), which joins the
current transaction if there is one that is not yet committing, but also
starts a new one if there is none or if the current one is already
committing (its state is >= TRANS_STATE_COMMIT_START). This later case
results in unnecessary IO, wasting time and a pointless rotation of the
backup roots in the super block.

So instead of using btrfs_start_transaction() followed by a
btrfs_commit_transaction(), use btrfs_commit_current_transaction() which
achieves our purpose and avoids starting and committing new transactions.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-23 22:34:17 +01:00
Filipe Manana
e2f0943cf3 btrfs: fix use-after-free when attempting to join an aborted transaction
When we are trying to join the current transaction and if it's aborted,
we read its 'aborted' field after unlocking fs_info->trans_lock and
without holding any extra reference count on it. This means that a
concurrent task that is aborting the transaction may free the transaction
before we read its 'aborted' field, leading to a use-after-free.

Fix this by reading the 'aborted' field while holding fs_info->trans_lock
since any freeing task must first acquire that lock and set
fs_info->running_transaction to NULL before freeing the transaction.

This was reported by syzbot and Dmitry with the following stack traces
from KASAN:

   ==================================================================
   BUG: KASAN: slab-use-after-free in join_transaction+0xd9b/0xda0 fs/btrfs/transaction.c:278
   Read of size 4 at addr ffff888011839024 by task kworker/u4:9/1128

   CPU: 0 UID: 0 PID: 1128 Comm: kworker/u4:9 Not tainted 6.13.0-rc7-syzkaller-00019-gc45323b7560e #0
   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
   Workqueue: events_unbound btrfs_async_reclaim_data_space
   Call Trace:
    <TASK>
    __dump_stack lib/dump_stack.c:94 [inline]
    dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
    print_address_description mm/kasan/report.c:378 [inline]
    print_report+0x169/0x550 mm/kasan/report.c:489
    kasan_report+0x143/0x180 mm/kasan/report.c:602
    join_transaction+0xd9b/0xda0 fs/btrfs/transaction.c:278
    start_transaction+0xaf8/0x1670 fs/btrfs/transaction.c:697
    flush_space+0x448/0xcf0 fs/btrfs/space-info.c:803
    btrfs_async_reclaim_data_space+0x159/0x510 fs/btrfs/space-info.c:1321
    process_one_work kernel/workqueue.c:3236 [inline]
    process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317
    worker_thread+0x870/0xd30 kernel/workqueue.c:3398
    kthread+0x2f0/0x390 kernel/kthread.c:389
    ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
    ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
    </TASK>

   Allocated by task 5315:
    kasan_save_stack mm/kasan/common.c:47 [inline]
    kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
    poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
    __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
    kasan_kmalloc include/linux/kasan.h:260 [inline]
    __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4329
    kmalloc_noprof include/linux/slab.h:901 [inline]
    join_transaction+0x144/0xda0 fs/btrfs/transaction.c:308
    start_transaction+0xaf8/0x1670 fs/btrfs/transaction.c:697
    btrfs_create_common+0x1b2/0x2e0 fs/btrfs/inode.c:6572
    lookup_open fs/namei.c:3649 [inline]
    open_last_lookups fs/namei.c:3748 [inline]
    path_openat+0x1c03/0x3590 fs/namei.c:3984
    do_filp_open+0x27f/0x4e0 fs/namei.c:4014
    do_sys_openat2+0x13e/0x1d0 fs/open.c:1402
    do_sys_open fs/open.c:1417 [inline]
    __do_sys_creat fs/open.c:1495 [inline]
    __se_sys_creat fs/open.c:1489 [inline]
    __x64_sys_creat+0x123/0x170 fs/open.c:1489
    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

   Freed by task 5336:
    kasan_save_stack mm/kasan/common.c:47 [inline]
    kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
    kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582
    poison_slab_object mm/kasan/common.c:247 [inline]
    __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
    kasan_slab_free include/linux/kasan.h:233 [inline]
    slab_free_hook mm/slub.c:2353 [inline]
    slab_free mm/slub.c:4613 [inline]
    kfree+0x196/0x430 mm/slub.c:4761
    cleanup_transaction fs/btrfs/transaction.c:2063 [inline]
    btrfs_commit_transaction+0x2c97/0x3720 fs/btrfs/transaction.c:2598
    insert_balance_item+0x1284/0x20b0 fs/btrfs/volumes.c:3757
    btrfs_balance+0x992/0x10c0 fs/btrfs/volumes.c:4633
    btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
    vfs_ioctl fs/ioctl.c:51 [inline]
    __do_sys_ioctl fs/ioctl.c:906 [inline]
    __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

   The buggy address belongs to the object at ffff888011839000
    which belongs to the cache kmalloc-2k of size 2048
   The buggy address is located 36 bytes inside of
    freed 2048-byte region [ffff888011839000, ffff888011839800)

   The buggy address belongs to the physical page:
   page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11838
   head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
   flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
   page_type: f5(slab)
   raw: 00fff00000000040 ffff88801ac42000 ffffea0000493400 dead000000000002
   raw: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000
   head: 00fff00000000040 ffff88801ac42000 ffffea0000493400 dead000000000002
   head: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000
   head: 00fff00000000003 ffffea0000460e01 ffffffffffffffff 0000000000000000
   head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
   page dumped because: kasan: bad access detected
   page_owner tracks the page as allocated
   page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 57, tgid 57 (kworker/0:2), ts 67248182943, free_ts 67229742023
    set_page_owner include/linux/page_owner.h:32 [inline]
    post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1558
    prep_new_page mm/page_alloc.c:1566 [inline]
    get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3476
    __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4753
    alloc_pages_mpol_noprof+0x3e1/0x780 mm/mempolicy.c:2269
    alloc_slab_page+0x6a/0x110 mm/slub.c:2423
    allocate_slab+0x5a/0x2b0 mm/slub.c:2589
    new_slab mm/slub.c:2642 [inline]
    ___slab_alloc+0xc27/0x14a0 mm/slub.c:3830
    __slab_alloc+0x58/0xa0 mm/slub.c:3920
    __slab_alloc_node mm/slub.c:3995 [inline]
    slab_alloc_node mm/slub.c:4156 [inline]
    __do_kmalloc_node mm/slub.c:4297 [inline]
    __kmalloc_node_track_caller_noprof+0x2e9/0x4c0 mm/slub.c:4317
    kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:609
    __alloc_skb+0x1f3/0x440 net/core/skbuff.c:678
    alloc_skb include/linux/skbuff.h:1323 [inline]
    alloc_skb_with_frags+0xc3/0x820 net/core/skbuff.c:6612
    sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2884
    sock_alloc_send_skb include/net/sock.h:1803 [inline]
    mld_newpack+0x1c3/0xaf0 net/ipv6/mcast.c:1747
    add_grhead net/ipv6/mcast.c:1850 [inline]
    add_grec+0x1492/0x19a0 net/ipv6/mcast.c:1988
    mld_send_cr net/ipv6/mcast.c:2114 [inline]
    mld_ifc_work+0x691/0xd90 net/ipv6/mcast.c:2651
   page last free pid 5300 tgid 5300 stack trace:
    reset_page_owner include/linux/page_owner.h:25 [inline]
    free_pages_prepare mm/page_alloc.c:1127 [inline]
    free_unref_page+0xd3f/0x1010 mm/page_alloc.c:2659
    __slab_free+0x2c2/0x380 mm/slub.c:4524
    qlink_free mm/kasan/quarantine.c:163 [inline]
    qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
    kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
    __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
    kasan_slab_alloc include/linux/kasan.h:250 [inline]
    slab_post_alloc_hook mm/slub.c:4119 [inline]
    slab_alloc_node mm/slub.c:4168 [inline]
    __do_kmalloc_node mm/slub.c:4297 [inline]
    __kmalloc_noprof+0x236/0x4c0 mm/slub.c:4310
    kmalloc_noprof include/linux/slab.h:905 [inline]
    kzalloc_noprof include/linux/slab.h:1037 [inline]
    fib_create_info+0xc14/0x25b0 net/ipv4/fib_semantics.c:1435
    fib_table_insert+0x1f6/0x1f20 net/ipv4/fib_trie.c:1231
    fib_magic+0x3d8/0x620 net/ipv4/fib_frontend.c:1112
    fib_add_ifaddr+0x40c/0x5e0 net/ipv4/fib_frontend.c:1156
    fib_netdev_event+0x375/0x490 net/ipv4/fib_frontend.c:1494
    notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85
    __dev_notify_flags+0x207/0x400
    dev_change_flags+0xf0/0x1a0 net/core/dev.c:9045
    do_setlink+0xc90/0x4210 net/core/rtnetlink.c:3109
    rtnl_changelink net/core/rtnetlink.c:3723 [inline]
    __rtnl_newlink net/core/rtnetlink.c:3875 [inline]
    rtnl_newlink+0x1bb6/0x2210 net/core/rtnetlink.c:4012

   Memory state around the buggy address:
    ffff888011838f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
    ffff888011838f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
   >ffff888011839000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
    ffff888011839080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
    ffff888011839100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
   ==================================================================

Reported-by: syzbot+45212e9d87a98c3f5b42@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/678e7da5.050a0220.303755.007c.GAE@google.com/
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Link: https://lore.kernel.org/linux-btrfs/CACT4Y+ZFBdo7pT8L2AzM=vegZwjp-wNkVJZQf0Ta3vZqtExaSw@mail.gmail.com/
Fixes: 871383be59 ("btrfs: add missing unlocks to transaction abort paths")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-23 22:34:14 +01:00
Qu Wenruo
c9c8637933 btrfs: do not output error message if a qgroup has been already cleaned up
[BUG]
There is a bug report that btrfs outputs the following error message:

  BTRFS info (device nvme0n1p2): qgroup scan completed (inconsistency flag cleared)
  BTRFS warning (device nvme0n1p2): failed to cleanup qgroup 0/1179: -2

[CAUSE]
The error itself is pretty harmless, and the end user should ignore it.

When a subvolume is fully dropped, btrfs will call
btrfs_qgroup_cleanup_dropped_subvolume() to delete the qgroup.

However if a qgroup rescan happened before a subvolume fully dropped,
qgroup for that subvolume will not be re-created, as rescan will only
create new qgroup if there is a BTRFS_ROOT_REF_KEY found.

But before we drop a subvolume, the subvolume is unlinked thus there is no
BTRFS_ROOT_REF_KEY.

In that case, btrfs_remove_qgroup() will fail with -ENOENT and trigger
the above error message.

[FIX]
Just ignore -ENOENT error from btrfs_remove_qgroup() inside
btrfs_qgroup_cleanup_dropped_subvolume().

Reported-by: John Shand <jshand2013@gmail.com>
Link: https://bugzilla.suse.com/show_bug.cgi?id=1236056
Fixes: 839d6ea4f8 ("btrfs: automatically remove the subvolume qgroup")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-23 22:34:11 +01:00
Filipe Manana
0d85f5c2dd btrfs: fix assertion failure when splitting ordered extent after transaction abort
If while we are doing a direct IO write a transaction abort happens, we
mark all existing ordered extents with the BTRFS_ORDERED_IOERR flag (done
at btrfs_destroy_ordered_extents()), and then after that if we enter
btrfs_split_ordered_extent() and the ordered extent has bytes left
(meaning we have a bio that doesn't cover the whole ordered extent, see
details at btrfs_extract_ordered_extent()), we will fail on the following
assertion at btrfs_split_ordered_extent():

   ASSERT(!(flags & ~BTRFS_ORDERED_TYPE_FLAGS));

because the BTRFS_ORDERED_IOERR flag is set and the definition of
BTRFS_ORDERED_TYPE_FLAGS is just the union of all flags that identify the
type of write (regular, nocow, prealloc, compressed, direct IO, encoded).

Fix this by returning an error from btrfs_extract_ordered_extent() if we
find the BTRFS_ORDERED_IOERR flag in the ordered extent. The error will
be the error that resulted in the transaction abort or -EIO if no
transaction abort happened.

This was recently reported by syzbot with the following trace:

   FAULT_INJECTION: forcing a failure.
   name failslab, interval 1, probability 0, space 0, times 1
   CPU: 0 UID: 0 PID: 5321 Comm: syz.0.0 Not tainted 6.13.0-rc5-syzkaller #0
   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
   Call Trace:
    <TASK>
    __dump_stack lib/dump_stack.c:94 [inline]
    dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
    fail_dump lib/fault-inject.c:53 [inline]
    should_fail_ex+0x3b0/0x4e0 lib/fault-inject.c:154
    should_failslab+0xac/0x100 mm/failslab.c:46
    slab_pre_alloc_hook mm/slub.c:4072 [inline]
    slab_alloc_node mm/slub.c:4148 [inline]
    __do_kmalloc_node mm/slub.c:4297 [inline]
    __kmalloc_noprof+0xdd/0x4c0 mm/slub.c:4310
    kmalloc_noprof include/linux/slab.h:905 [inline]
    kzalloc_noprof include/linux/slab.h:1037 [inline]
    btrfs_chunk_alloc_add_chunk_item+0x244/0x1100 fs/btrfs/volumes.c:5742
    reserve_chunk_space+0x1ca/0x2c0 fs/btrfs/block-group.c:4292
    check_system_chunk fs/btrfs/block-group.c:4319 [inline]
    do_chunk_alloc fs/btrfs/block-group.c:3891 [inline]
    btrfs_chunk_alloc+0x77b/0xf80 fs/btrfs/block-group.c:4187
    find_free_extent_update_loop fs/btrfs/extent-tree.c:4166 [inline]
    find_free_extent+0x42d1/0x5810 fs/btrfs/extent-tree.c:4579
    btrfs_reserve_extent+0x422/0x810 fs/btrfs/extent-tree.c:4672
    btrfs_new_extent_direct fs/btrfs/direct-io.c:186 [inline]
    btrfs_get_blocks_direct_write+0x706/0xfa0 fs/btrfs/direct-io.c:321
    btrfs_dio_iomap_begin+0xbb7/0x1180 fs/btrfs/direct-io.c:525
    iomap_iter+0x697/0xf60 fs/iomap/iter.c:90
    __iomap_dio_rw+0xeb9/0x25b0 fs/iomap/direct-io.c:702
    btrfs_dio_write fs/btrfs/direct-io.c:775 [inline]
    btrfs_direct_write+0x610/0xa30 fs/btrfs/direct-io.c:880
    btrfs_do_write_iter+0x2a0/0x760 fs/btrfs/file.c:1397
    do_iter_readv_writev+0x600/0x880
    vfs_writev+0x376/0xba0 fs/read_write.c:1050
    do_pwritev fs/read_write.c:1146 [inline]
    __do_sys_pwritev2 fs/read_write.c:1204 [inline]
    __se_sys_pwritev2+0x196/0x2b0 fs/read_write.c:1195
    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
    entry_SYSCALL_64_after_hwframe+0x77/0x7f
   RIP: 0033:0x7f1281f85d29
   RSP: 002b:00007f12819fe038 EFLAGS: 00000246 ORIG_RAX: 0000000000000148
   RAX: ffffffffffffffda RBX: 00007f1282176080 RCX: 00007f1281f85d29
   RDX: 0000000000000001 RSI: 0000000020000240 RDI: 0000000000000005
   RBP: 00007f12819fe090 R08: 0000000000000000 R09: 0000000000000003
   R10: 0000000000007000 R11: 0000000000000246 R12: 0000000000000002
   R13: 0000000000000000 R14: 00007f1282176080 R15: 00007ffcb9e23328
    </TASK>
   BTRFS error (device loop0 state A): Transaction aborted (error -12)
   BTRFS: error (device loop0 state A) in btrfs_chunk_alloc_add_chunk_item:5745: errno=-12 Out of memory
   BTRFS info (device loop0 state EA): forced readonly
   assertion failed: !(flags & ~BTRFS_ORDERED_TYPE_FLAGS), in fs/btrfs/ordered-data.c:1234
   ------------[ cut here ]------------
   kernel BUG at fs/btrfs/ordered-data.c:1234!
   Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI
   CPU: 0 UID: 0 PID: 5321 Comm: syz.0.0 Not tainted 6.13.0-rc5-syzkaller #0
   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
   RIP: 0010:btrfs_split_ordered_extent+0xd8d/0xe20 fs/btrfs/ordered-data.c:1234
   RSP: 0018:ffffc9000d1df2b8 EFLAGS: 00010246
   RAX: 0000000000000057 RBX: 000000000006a000 RCX: 9ce21886c4195300
   RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
   RBP: 0000000000000091 R08: ffffffff817f0a3c R09: 1ffff92001a3bdf4
   R10: dffffc0000000000 R11: fffff52001a3bdf5 R12: 1ffff1100a45f401
   R13: ffff8880522fa018 R14: dffffc0000000000 R15: 000000000006a000
   FS:  00007f12819fe6c0(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: 0000557750bd7da8 CR3: 00000000400ea000 CR4: 0000000000352ef0
   DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
   DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
   Call Trace:
    <TASK>
    btrfs_extract_ordered_extent fs/btrfs/direct-io.c:702 [inline]
    btrfs_dio_submit_io+0x4be/0x6d0 fs/btrfs/direct-io.c:737
    iomap_dio_submit_bio fs/iomap/direct-io.c:85 [inline]
    iomap_dio_bio_iter+0x1022/0x1740 fs/iomap/direct-io.c:447
    __iomap_dio_rw+0x13b7/0x25b0 fs/iomap/direct-io.c:703
    btrfs_dio_write fs/btrfs/direct-io.c:775 [inline]
    btrfs_direct_write+0x610/0xa30 fs/btrfs/direct-io.c:880
    btrfs_do_write_iter+0x2a0/0x760 fs/btrfs/file.c:1397
    do_iter_readv_writev+0x600/0x880
    vfs_writev+0x376/0xba0 fs/read_write.c:1050
    do_pwritev fs/read_write.c:1146 [inline]
    __do_sys_pwritev2 fs/read_write.c:1204 [inline]
    __se_sys_pwritev2+0x196/0x2b0 fs/read_write.c:1195
    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
    entry_SYSCALL_64_after_hwframe+0x77/0x7f
   RIP: 0033:0x7f1281f85d29
   RSP: 002b:00007f12819fe038 EFLAGS: 00000246 ORIG_RAX: 0000000000000148
   RAX: ffffffffffffffda RBX: 00007f1282176080 RCX: 00007f1281f85d29
   RDX: 0000000000000001 RSI: 0000000020000240 RDI: 0000000000000005
   RBP: 00007f12819fe090 R08: 0000000000000000 R09: 0000000000000003
   R10: 0000000000007000 R11: 0000000000000246 R12: 0000000000000002
   R13: 0000000000000000 R14: 00007f1282176080 R15: 00007ffcb9e23328
    </TASK>
   Modules linked in:
   ---[ end trace 0000000000000000 ]---
   RIP: 0010:btrfs_split_ordered_extent+0xd8d/0xe20 fs/btrfs/ordered-data.c:1234
   RSP: 0018:ffffc9000d1df2b8 EFLAGS: 00010246
   RAX: 0000000000000057 RBX: 000000000006a000 RCX: 9ce21886c4195300
   RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
   RBP: 0000000000000091 R08: ffffffff817f0a3c R09: 1ffff92001a3bdf4
   R10: dffffc0000000000 R11: fffff52001a3bdf5 R12: 1ffff1100a45f401
   R13: ffff8880522fa018 R14: dffffc0000000000 R15: 000000000006a000
   FS:  00007f12819fe6c0(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: 0000557750bd7da8 CR3: 00000000400ea000 CR4: 0000000000352ef0
   DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
   DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

In this case the transaction abort was due to (an injected) memory
allocation failure when attempting to allocate a new chunk.

Reported-by: syzbot+f60d8337a5c8e8d92a77@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/6777f2dd.050a0220.178762.0045.GAE@google.com/
Fixes: 52b1fdca23 ("btrfs: handle completed ordered extents in btrfs_split_ordered_extent")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-23 22:34:09 +01:00
Filipe Manana
a216542027 btrfs: fix lockdep splat while merging a relocation root
When COWing a relocation tree path, at relocation.c:replace_path(), we
can trigger a lockdep splat while we are in the btrfs_search_slot() call
against the relocation root. This happens in that callchain at
ctree.c:read_block_for_search() when we happen to find a child extent
buffer already loaded through the fs tree with a lockdep class set to
the fs tree. So when we attempt to lock that extent buffer through a
relocation tree we have to reset the lockdep class to the class for a
relocation tree, since a relocation tree has extent buffers that used
to belong to a fs tree and may currently be already loaded (we swap
extent buffers between the two trees at the end of replace_path()).

However we are missing calls to btrfs_maybe_reset_lockdep_class() to reset
the lockdep class at ctree.c:read_block_for_search() before we read lock
an extent buffer, just like we did for btrfs_search_slot() in commit
b40130b23c ("btrfs: fix lockdep splat with reloc root extent buffers").

So add the missing btrfs_maybe_reset_lockdep_class() calls before the
attempts to read lock an extent buffer at ctree.c:read_block_for_search().

The lockdep splat was reported by syzbot and it looks like this:

   ======================================================
   WARNING: possible circular locking dependency detected
   6.13.0-rc5-syzkaller-00163-gab75170520d4 #0 Not tainted
   ------------------------------------------------------
   syz.0.0/5335 is trying to acquire lock:
   ffff8880545dbc38 (btrfs-tree-01){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146

   but task is already holding lock:
   ffff8880545dba58 (btrfs-treloc-02/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189

   which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

   -> #2 (btrfs-treloc-02/1){+.+.}-{4:4}:
          reacquire_held_locks+0x3eb/0x690 kernel/locking/lockdep.c:5374
          __lock_release kernel/locking/lockdep.c:5563 [inline]
          lock_release+0x396/0xa30 kernel/locking/lockdep.c:5870
          up_write+0x79/0x590 kernel/locking/rwsem.c:1629
          btrfs_force_cow_block+0x14b3/0x1fd0 fs/btrfs/ctree.c:660
          btrfs_cow_block+0x371/0x830 fs/btrfs/ctree.c:755
          btrfs_search_slot+0xc01/0x3180 fs/btrfs/ctree.c:2153
          replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
          merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
          merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
          relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
          btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
          btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
          __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
          btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
          btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
          vfs_ioctl fs/ioctl.c:51 [inline]
          __do_sys_ioctl fs/ioctl.c:906 [inline]
          __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   -> #1 (btrfs-tree-01/1){+.+.}-{4:4}:
          lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
          down_write_nested+0xa2/0x220 kernel/locking/rwsem.c:1693
          btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189
          btrfs_init_new_buffer fs/btrfs/extent-tree.c:5052 [inline]
          btrfs_alloc_tree_block+0x41c/0x1440 fs/btrfs/extent-tree.c:5132
          btrfs_force_cow_block+0x526/0x1fd0 fs/btrfs/ctree.c:573
          btrfs_cow_block+0x371/0x830 fs/btrfs/ctree.c:755
          btrfs_search_slot+0xc01/0x3180 fs/btrfs/ctree.c:2153
          btrfs_insert_empty_items+0x9c/0x1a0 fs/btrfs/ctree.c:4351
          btrfs_insert_empty_item fs/btrfs/ctree.h:688 [inline]
          btrfs_insert_inode_ref+0x2bb/0xf80 fs/btrfs/inode-item.c:330
          btrfs_rename_exchange fs/btrfs/inode.c:7990 [inline]
          btrfs_rename2+0xcb7/0x2b90 fs/btrfs/inode.c:8374
          vfs_rename+0xbdb/0xf00 fs/namei.c:5067
          do_renameat2+0xd94/0x13f0 fs/namei.c:5224
          __do_sys_renameat2 fs/namei.c:5258 [inline]
          __se_sys_renameat2 fs/namei.c:5255 [inline]
          __x64_sys_renameat2+0xce/0xe0 fs/namei.c:5255
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   -> #0 (btrfs-tree-01){++++}-{4:4}:
          check_prev_add kernel/locking/lockdep.c:3161 [inline]
          check_prevs_add kernel/locking/lockdep.c:3280 [inline]
          validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
          __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
          lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
          down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649
          btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146
          btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline]
          read_block_for_search+0x718/0xbb0 fs/btrfs/ctree.c:1610
          btrfs_search_slot+0x1274/0x3180 fs/btrfs/ctree.c:2237
          replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
          merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
          merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
          relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
          btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
          btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
          __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
          btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
          btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
          vfs_ioctl fs/ioctl.c:51 [inline]
          __do_sys_ioctl fs/ioctl.c:906 [inline]
          __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
          do_syscall_x64 arch/x86/entry/common.c:52 [inline]
          do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
          entry_SYSCALL_64_after_hwframe+0x77/0x7f

   other info that might help us debug this:

   Chain exists of:
     btrfs-tree-01 --> btrfs-tree-01/1 --> btrfs-treloc-02/1

    Possible unsafe locking scenario:

          CPU0                    CPU1
          ----                    ----
     lock(btrfs-treloc-02/1);
                                  lock(btrfs-tree-01/1);
                                  lock(btrfs-treloc-02/1);
     rlock(btrfs-tree-01);

    *** DEADLOCK ***

   8 locks held by syz.0.0/5335:
    #0: ffff88801e3ae420 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5e/0x200 fs/namespace.c:559
    #1: ffff888052c760d0 (&fs_info->reclaim_bgs_lock){+.+.}-{4:4}, at: __btrfs_balance+0x4c2/0x26b0 fs/btrfs/volumes.c:4183
    #2: ffff888052c74850 (&fs_info->cleaner_mutex){+.+.}-{4:4}, at: btrfs_relocate_block_group+0x775/0xd90 fs/btrfs/relocation.c:4086
    #3: ffff88801e3ae610 (sb_internal#2){.+.+}-{0:0}, at: merge_reloc_root+0xf11/0x1ad0 fs/btrfs/relocation.c:1659
    #4: ffff888052c76470 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x405/0xda0 fs/btrfs/transaction.c:288
    #5: ffff888052c76498 (btrfs_trans_num_extwriters){++++}-{0:0}, at: join_transaction+0x405/0xda0 fs/btrfs/transaction.c:288
    #6: ffff8880545db878 (btrfs-tree-01/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189
    #7: ffff8880545dba58 (btrfs-treloc-02/1){+.+.}-{4:4}, at: btrfs_tree_lock_nested+0x2f/0x250 fs/btrfs/locking.c:189

   stack backtrace:
   CPU: 0 UID: 0 PID: 5335 Comm: syz.0.0 Not tainted 6.13.0-rc5-syzkaller-00163-gab75170520d4 #0
   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
   Call Trace:
    <TASK>
    __dump_stack lib/dump_stack.c:94 [inline]
    dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
    print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
    check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
    check_prev_add kernel/locking/lockdep.c:3161 [inline]
    check_prevs_add kernel/locking/lockdep.c:3280 [inline]
    validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
    __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
    lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
    down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649
    btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146
    btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline]
    read_block_for_search+0x718/0xbb0 fs/btrfs/ctree.c:1610
    btrfs_search_slot+0x1274/0x3180 fs/btrfs/ctree.c:2237
    replace_path+0x1243/0x2740 fs/btrfs/relocation.c:1224
    merge_reloc_root+0xc46/0x1ad0 fs/btrfs/relocation.c:1692
    merge_reloc_roots+0x3b3/0x980 fs/btrfs/relocation.c:1942
    relocate_block_group+0xb0a/0xd40 fs/btrfs/relocation.c:3754
    btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4087
    btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3494
    __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4278
    btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4655
    btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3670
    vfs_ioctl fs/ioctl.c:51 [inline]
    __do_sys_ioctl fs/ioctl.c:906 [inline]
    __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
    entry_SYSCALL_64_after_hwframe+0x77/0x7f
   RIP: 0033:0x7f1ac6985d29
   Code: ff ff c3 (...)
   RSP: 002b:00007f1ac63fe038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
   RAX: ffffffffffffffda RBX: 00007f1ac6b76160 RCX: 00007f1ac6985d29
   RDX: 0000000020000180 RSI: 00000000c4009420 RDI: 0000000000000007
   RBP: 00007f1ac6a01b08 R08: 0000000000000000 R09: 0000000000000000
   R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
   R13: 0000000000000001 R14: 00007f1ac6b76160 R15: 00007fffda145a88
    </TASK>

Reported-by: syzbot+63913e558c084f7f8fdc@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/677b3014.050a0220.3b53b0.0064.GAE@google.com/
Fixes: 99785998ed ("btrfs: reduce lock contention when eb cache miss for btree search")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-23 22:34:05 +01:00
Linus Torvalds
0eb4aaa230 for-6.14-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmeHvVQACgkQxWXV+ddt
 WDsJ6w//cPqI8tf3kMxurZcG7clJRIIISotPrC6hm3UDNpJLa7HDaVJ50FAoIhMV
 sB4RQNZky4mfB6ypXxmETzV3ZHvP0+oFgRs72Ommi0ZbdnBgxhaUTrDXLKl52o4r
 UoeqvRKReEYOesN09rPXYPwytUOkxHU/GjNzv7bC/Tzvq/xKaIN5qMYZwkHtJ8PK
 JtCFypfbmDPNDJz37l0BhRya2oMtpcUtxM9uP8RWVuQtaELgjcy56W/+osoyJTy9
 FSKaoWUPsDVDufnILlGR8Kub2Z5mcISVqyARUdr/q3j5CDfyTdQvahmUy7sHgUAe
 HGh5QBdRJu1QTvdZw+nK4YCaYpK6Nj4liDtO1cwVitde5RXsJrt6kYBLlY/kU2Qr
 KODOloM/zVKxULR0ARl11NULZquUsczP6Wxfn+dtyDJ3JGlY9OcuESmorHoUtkMX
 75Tj1AtRMNcfZAE2HquL1Oz3bIMcg4btDJsC+9Yp5K11SP12XpOwC42k/9Bx3iBe
 Iki0BSuppFqX5MMY3OEWzD1pz2vOGYR8ISD6EIsjpjl2vBeRwydaCCZfuszSC7gl
 Y4goSdwFMPVlqllL1h27XUjKVXvttCqqdB6P28MbvZKnFAPlm189BJQZC5cbHAJU
 ceBww5PvI9QxnJnFG5iOLcnko6liUWPP9l2c5LLtUsJIi8B5Hu0=
 =SXLv
 -----END PGP SIGNATURE-----

Merge tag 'for-6.14-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "User visible changes, features:

   - rebuilding of the free space tree at mount time is done in more
     transactions, fix potential hangs when the transaction thread is
     blocked due to large amount of block groups

   - more read IO balancing strategies (experimental config), add two
     new ways how to select a device for read if the profiles allow that
     (all RAID1*), the current default selects the device by pid which
     is good on average but less performant for single reader workloads

       - select preferred device for all reads (namely for testing)
       - round-robin, balance reads across devices relevant for the
         requested IO range

   - add encoded write ioctl support to io_uring (read was added in
     6.12), basis for writing send stream using that instead of
     syscalls, non-blocking mode is not yet implemented

   - support FS_IOC_READ_VERITY_METADATA, applications can use the
     metadata to do their own verification

   - pass inode's i_write_hint to bios, for parity with other
     filesystems, ioctls F_GET_RW_HINT/F_SET_RW_HINT

  Core:

   - in zoned mode: allow to directly reclaim a block group by simply
     resetting it, then it can be reused and another block group does
     not need to be allocated

   - super block validation now also does more comprehensive sys array
     validation, adding it to the points where superblock is validated
     (post-read, pre-write)

   - subpage mode fixes:
      - fix double accounting of blocks due to some races
      - improved or fixed error handling in a few cases (compression,
        delalloc)

   - raid stripe tree:
      - fix various cases with extent range splitting or deleting
      - implement hole punching to extent range
      - reduce number of stripe tree lookups during bio submission
      - more self-tests

   - updated self-tests (delayed refs)

   - error handling improvements

   - cleanups, refactoring
      - remove rest of backref caching infrastructure from relocation,
        not needed anymore
      - error message updates
      - remove unnecessary calls when extent buffer was marked dirty
      - unused parameter removal
      - code moved to new files

  Other code changes: add rb_find_add_cached() to the rb-tree API"

* tag 'for-6.14-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (127 commits)
  btrfs: selftests: add a selftest for deleting two out of three extents
  btrfs: selftests: add test for punching a hole into 3 RAID stripe-extents
  btrfs: selftests: add selftest for punching holes into the RAID stripe extents
  btrfs: selftests: test RAID stripe-tree deletion spanning two items
  btrfs: selftests: don't split RAID extents in half
  btrfs: selftests: check for correct return value of failed lookup
  btrfs: don't use btrfs_set_item_key_safe on RAID stripe-extents
  btrfs: implement hole punching for RAID stripe extents
  btrfs: fix deletion of a range spanning parts two RAID stripe extents
  btrfs: fix tail delete of RAID stripe-extents
  btrfs: fix front delete range calculation for RAID stripe extents
  btrfs: assert RAID stripe-extent length is always greater than 0
  btrfs: don't try to delete RAID stripe-extents if we don't need to
  btrfs: selftests: correct RAID stripe-tree feature flag setting
  btrfs: add io_uring interface for encoded writes
  btrfs: remove the unused locked_folio parameter from btrfs_cleanup_ordered_extents()
  btrfs: add extra error messages for delalloc range related errors
  btrfs: subpage: dump the involved bitmap when ASSERT() failed
  btrfs: subpage: fix the bitmap dump of the locked flags
  btrfs: do proper folio cleanup when run_delalloc_nocow() failed
  ...
2025-01-20 13:09:30 -08:00
Linus Torvalds
ed8fd8d5dd for-6.13-rc7-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmeI5MAACgkQxWXV+ddt
 WDtMIg//WwV2p/gQmFMfFu7txZQQrt6m6nMuq/2y0qAA+d2e9oXFr3jNLlho0RwL
 hvSM5IEsxzL1ujh67tqxUBojvRjq+CRwiI6fxFO13dLIMrlKoiINtuOEiIhgZr/Q
 K+weXC4yHCFSB4q82dcr5i++/GVdY8wBoLHGe4zdJ0TVtM0xHrYVQ/4PXAGMX97V
 Bmv038aAMpRJTxJ6rcObloNxOb+WoyM0DIRbJ2UWVmy+bOLHMEa/jSkkQDWwcuPV
 UJjQgXz21FXiJqhtcndM58mEsKfe1WV9gG3lihedyb/xNeCPggqkDbfSzZU55Lkm
 vRXSgklbkifK6RTqrozg7e38MV+rZMwwNzqysMxNtlvrC5R+0A6of4t2Ny1vaeGG
 flcVncbLi/ip9J4fMLUpVS0fbAZjQgIJca6fbgM7Ajdzvm9rIDGpR078GW1zDlg2
 20f7isQWqSkj3i9kPElGbDT65RvcxR5EpJQfwr78+bsgSsyBGwghhAJ5F7vqZh5L
 wdmJOYxkwq5r1YxeuEQPVv404WPrwZE2Gyk6TGXkzpA+l6isCViY3NTyQPBOMH9y
 2GEelW61QSKtc5BPp1h85Aw74wtSCpGkCY+t/v03oQ6PBssWIsVcXZ7NnjJh9+72
 U+JY0H7UPyyczEzicEGlwWYBWs2/KeBuCrladNCkv3S5TWgB5yQ=
 =sF6v
 -----END PGP SIGNATURE-----

Merge tag 'for-6.13-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fix from David Sterba:

 - handle d_path() errors when canonicalizing device mapper paths during
   device scan

* tag 'for-6.13-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: add the missing error handling inside get_canonical_dev_path
2025-01-16 08:54:33 -08:00
Johannes Thumshirn
9d0c23db26 btrfs: selftests: add a selftest for deleting two out of three extents
Add a selftest creating three extents and then deleting two out of the
three extents.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-14 15:57:55 +01:00
Johannes Thumshirn
cfda28fb70 btrfs: selftests: add test for punching a hole into 3 RAID stripe-extents
Test creating a range of three RAID stripe-extents and then punch a hole
in the middle, deleting all of the middle extents and partially deleting
the "book ends".

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-14 15:56:40 +01:00
Johannes Thumshirn
27ae15b25b btrfs: selftests: add selftest for punching holes into the RAID stripe extents
Add a selftest for punching a hole into a RAID stripe extent. The test
create an 1M extent and punches a 64k bytes long hole at offset of 32k from
the start of the extent.

Afterwards it verifies the start and length of both resulting new extents
"left" and "right" as well as the absence of the hole.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-14 15:54:45 +01:00
Johannes Thumshirn
1d395c3926 btrfs: selftests: test RAID stripe-tree deletion spanning two items
Add a selftest for RAID stripe-tree deletion with a delete range spanning
two items, so that we're punching a hole into two adjacent RAID stripe
extents truncating the first and "moving" the second to the right.

The following diagram illustrates the operation:

 |--- RAID Stripe Extent ---||--- RAID Stripe Extent ---|
 |-----  keep  -----|--- drop ---|-----  keep  ----|

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-14 15:54:44 +01:00
Johannes Thumshirn
a0afdec255 btrfs: selftests: don't split RAID extents in half
The selftests for partially deleting the start or tail of RAID
stripe-extents split these extents in half.

This can hide errors in the calculation, so don't split the RAID
stripe-extents in half but delete the first or last 16K of the 64K
extents.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-14 15:52:30 +01:00
Johannes Thumshirn
d44d3d724b btrfs: selftests: check for correct return value of failed lookup
Commit 5e72aabc1f ("btrfs: return ENODATA in case RST lookup fails")
changed btrfs_get_raid_extent_offset()'s return value to ENODATA in case
the RAID stripe-tree lookup failed.

Adjust the test cases which check for absence of a given range to check
for ENODATA as return value in this case.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-14 15:52:30 +01:00
Johannes Thumshirn
dc14ba1078 btrfs: don't use btrfs_set_item_key_safe on RAID stripe-extents
Don't use btrfs_set_item_key_safe() to modify the keys in the RAID
stripe-tree, as this can lead to corruption of the tree, which is caught
by the checks in btrfs_set_item_key_safe():

 BTRFS info (device nvme1n1): leaf 49168384 gen 15 total ptrs 194 free space 8329 owner 12
 BTRFS info (device nvme1n1): refs 2 lock_owner 1030 current 1030
  [ snip ]
  item 105 key (354549760 230 20480) itemoff 14587 itemsize 16
                  stride 0 devid 5 physical 67502080
  item 106 key (354631680 230 4096) itemoff 14571 itemsize 16
                  stride 0 devid 1 physical 88559616
  item 107 key (354631680 230 32768) itemoff 14555 itemsize 16
                  stride 0 devid 1 physical 88555520
  item 108 key (354717696 230 28672) itemoff 14539 itemsize 16
                  stride 0 devid 2 physical 67604480
  [ snip ]
 BTRFS critical (device nvme1n1): slot 106 key (354631680 230 32768) new key (354635776 230 4096)
 ------------[ cut here ]------------
 kernel BUG at fs/btrfs/ctree.c:2602!
 Oops: invalid opcode: 0000 [#1] PREEMPT SMP PTI
 CPU: 1 UID: 0 PID: 1055 Comm: fsstress Not tainted 6.13.0-rc1+ #1464
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
 RIP: 0010:btrfs_set_item_key_safe+0xf7/0x270
 Code: <snip>
 RSP: 0018:ffffc90001337ab0 EFLAGS: 00010287
 RAX: 0000000000000000 RBX: ffff8881115fd000 RCX: 0000000000000000
 RDX: 0000000000000001 RSI: 0000000000000001 RDI: 00000000ffffffff
 RBP: ffff888110ed6f50 R08: 00000000ffffefff R09: ffffffff8244c500
 R10: 00000000ffffefff R11: 00000000ffffffff R12: ffff888100586000
 R13: 00000000000000c9 R14: ffffc90001337b1f R15: ffff888110f23b58
 FS:  00007f7d75c72740(0000) GS:ffff88813bd00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007fa811652c60 CR3: 0000000111398001 CR4: 0000000000370eb0
 Call Trace:
  <TASK>
  ? __die_body.cold+0x14/0x1a
  ? die+0x2e/0x50
  ? do_trap+0xca/0x110
  ? do_error_trap+0x65/0x80
  ? btrfs_set_item_key_safe+0xf7/0x270
  ? exc_invalid_op+0x50/0x70
  ? btrfs_set_item_key_safe+0xf7/0x270
  ? asm_exc_invalid_op+0x1a/0x20
  ? btrfs_set_item_key_safe+0xf7/0x270
  btrfs_partially_delete_raid_extent+0xc4/0xe0
  btrfs_delete_raid_extent+0x227/0x240
  __btrfs_free_extent.isra.0+0x57f/0x9c0
  ? exc_coproc_segment_overrun+0x40/0x40
  __btrfs_run_delayed_refs+0x2fa/0xe80
  btrfs_run_delayed_refs+0x81/0xe0
  btrfs_commit_transaction+0x2dd/0xbe0
  ? preempt_count_add+0x52/0xb0
  btrfs_sync_file+0x375/0x4c0
  do_fsync+0x39/0x70
  __x64_sys_fsync+0x13/0x20
  do_syscall_64+0x54/0x110
  entry_SYSCALL_64_after_hwframe+0x76/0x7e
 RIP: 0033:0x7f7d7550ef90
 Code: <snip>
 RSP: 002b:00007ffd70237248 EFLAGS: 00000202 ORIG_RAX: 000000000000004a
 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f7d7550ef90
 RDX: 000000000000013a RSI: 000000000040eb28 RDI: 0000000000000004
 RBP: 000000000000001b R08: 0000000000000078 R09: 00007ffd7023725c
 R10: 00007f7d75400390 R11: 0000000000000202 R12: 028f5c28f5c28f5c
 R13: 8f5c28f5c28f5c29 R14: 000000000040b520 R15: 00007f7d75c726c8
  </TASK>

While the root cause of the tree order corruption isn't clear, using
btrfs_duplicate_item() to copy the item and then adjusting both the key
and the per-device physical addresses is a safe way to counter this
problem.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-14 15:52:22 +01:00
Johannes Thumshirn
6aa0e7cc56 btrfs: implement hole punching for RAID stripe extents
If the stripe extent we want to delete starts before the range we want to
delete and ends after the range we want to delete we're punching a
hole in the stripe extent:

  |--- RAID Stripe Extent ---|
  | keep |--- drop ---| keep |

This means we need to a) truncate the existing item and b)
create a second item for the remaining range.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-14 15:52:13 +01:00
Johannes Thumshirn
7664311904 btrfs: fix deletion of a range spanning parts two RAID stripe extents
When a user requests the deletion of a range that spans multiple stripe
extents and btrfs_search_slot() returns us the second RAID stripe extent,
we need to pick the previous item and truncate it, if there's still a
range to delete left, move on to the next item.

The following diagram illustrates the operation:

 |--- RAID Stripe Extent ---||--- RAID Stripe Extent ---|
        |--- keep  ---|--- drop ---|

While at it, comment the trivial case of a whole item delete as well.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-14 15:51:24 +01:00
Johannes Thumshirn
50cae2ca69 btrfs: fix tail delete of RAID stripe-extents
Fix tail delete of RAID stripe-extents, if there is a range to be deleted
as well after the tail delete of the extent.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-14 15:49:10 +01:00
Johannes Thumshirn
a678543e60 btrfs: fix front delete range calculation for RAID stripe extents
When deleting the front of a RAID stripe-extent the delete code
miscalculates the size on how much to pad the remaining extent part in the
front.

Fix the calculation so we're always having the sizes we expect.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-14 15:49:04 +01:00
Johannes Thumshirn
5a0e38eab7 btrfs: assert RAID stripe-extent length is always greater than 0
When modifying a RAID stripe-extent, ASSERT() that the length of the new
RAID stripe-extent is always greater than 0.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-14 15:48:56 +01:00
Johannes Thumshirn
9257d8632a btrfs: don't try to delete RAID stripe-extents if we don't need to
Even if the RAID stripe-tree is not enabled in the filesystem,
do_free_extent_accounting() still calls into btrfs_delete_raid_extent().

Check if the extent in question is on a block-group that has a profile
which is used by RAID stripe-tree before attempting to delete a stripe
extent. Return early if it doesn't, otherwise we're doing a unnecessary
search.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-14 15:48:46 +01:00
Johannes Thumshirn
c221a9a29d btrfs: selftests: correct RAID stripe-tree feature flag setting
RAID stripe-tree is an incompatible feature not a read-only compatible, so
set the incompat flag not a compat_ro one in the selftest code.

Subsequent changes in btrfs_delete_raid_extent() will start checking for
this flag.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-14 15:47:54 +01:00
Qu Wenruo
fe4de594f7 btrfs: add the missing error handling inside get_canonical_dev_path
Inside function get_canonical_dev_path(), we call d_path() to get the
final device path.

But d_path() can return error, and in that case the next strscpy() call
will trigger an invalid memory access.

Add back the missing error handling for d_path().

Reported-by: Boris Burkov <boris@bur.io>
Fixes: 7e06de7c83 ("btrfs: canonicalize the device path before adding it")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 21:39:52 +01:00
Mark Harmstone
e32dcdb0af btrfs: add io_uring interface for encoded writes
Add an io_uring interface for encoded writes, with the same parameters
as the BTRFS_IOC_ENCODED_WRITE ioctl.

As with the encoded reads code, there's a test program for this at
https://github.com/maharmstone/io_uring-encoded, and I'll get this
worked into an fstest.

How io_uring works is that it initially calls btrfs_uring_cmd with the
IO_URING_F_NONBLOCK flag set, and if we return -EAGAIN it tries again in
a kthread with the flag cleared.

Ideally we'd honour this and call try_lock etc., but there's still a lot
of work to be done to create non-blocking versions of all the functions
in our write path. Instead, just validate the input in
btrfs_uring_encoded_write() on the first pass and return -EAGAIN, with a
view to properly optimizing the optimistic path later on.

Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 21:06:31 +01:00
Qu Wenruo
bf50aca633 btrfs: remove the unused locked_folio parameter from btrfs_cleanup_ordered_extents()
The function btrfs_cleanup_ordered_extents() is only called in error
handling path, and the last caller with a @locked_folio parameter was
removed to fix a bug in the btrfs_run_delalloc_range() error handling.

There is no need to pass @locked_folio parameter anymore.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 16:00:50 +01:00
Qu Wenruo
975a6a8855 btrfs: add extra error messages for delalloc range related errors
All the error handling bugs I hit so far are all -ENOSPC from either:

- cow_file_range()
- run_delalloc_nocow()
- submit_uncompressed_range()

Previously when those functions failed, there was no error message at
all, making the debugging much harder.

So here we introduce extra error messages for:

- cow_file_range()
- run_delalloc_nocow()
- submit_uncompressed_range()
- writepage_delalloc() when btrfs_run_delalloc_range() failed
- extent_writepage() when extent_writepage_io() failed

One example of the new debug error messages is the following one:

  run fstests generic/750 at 2024-12-08 12:41:41
  BTRFS: device fsid 461b25f5-e240-4543-8deb-e7c2bd01a6d3 devid 1 transid 8 /dev/mapper/test-scratch1 (253:4) scanned by mount (2436600)
  BTRFS info (device dm-4): first mount of filesystem 461b25f5-e240-4543-8deb-e7c2bd01a6d3
  BTRFS info (device dm-4): using crc32c (crc32c-arm64) checksum algorithm
  BTRFS info (device dm-4): forcing free space tree for sector size 4096 with page size 65536
  BTRFS info (device dm-4): using free-space-tree
  BTRFS warning (device dm-4): read-write for sector size 4096 with page size 65536 is experimental
  BTRFS info (device dm-4): checking UUID tree
  BTRFS error (device dm-4): cow_file_range failed, root=363 inode=412 start=503808 len=98304: -28
  BTRFS error (device dm-4): run_delalloc_nocow failed, root=363 inode=412 start=503808 len=98304: -28
  BTRFS error (device dm-4): failed to run delalloc range, root=363 ino=412 folio=458752 submit_bitmap=11-15 start=503808 len=98304: -28

Which shows an error from cow_file_range() which is called inside a
nocow write attempt, along with the extra bitmap from
writepage_delalloc().

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 15:59:35 +01:00
Qu Wenruo
61d730731b btrfs: subpage: dump the involved bitmap when ASSERT() failed
For btrfs_folio_assert_not_dirty() and btrfs_folio_set_lock(), we call
bitmap_test_range_all_zero() to ensure the involved range has no
dirty/lock bit already set.

However with my recent enhanced delalloc range error handling, I was
hitting the ASSERT() inside btrfs_folio_set_lock(), and it turns out
that some error handling path is not properly updating the folio flags.

So add some extra dumping for the ASSERTs to dump the involved bitmap
to help debug.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 15:57:51 +01:00
Qu Wenruo
396294d1af btrfs: subpage: fix the bitmap dump of the locked flags
We're dumping the locked bitmap into the @checked_bitmap variable,
printing incorrect values during debug.

Thankfully even during my development I haven't hit a case where I need
to dump the locked bitmap.  But for the sake of consistency, fix it by
dupping the locked bitmap into @locked_bitmap variable for output.

Fixes: 75258f20fb ("btrfs: subpage: dump extra subpage bitmaps for debug")
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 15:53:47 +01:00
Qu Wenruo
c2b47df81c btrfs: do proper folio cleanup when run_delalloc_nocow() failed
[BUG]
With CONFIG_DEBUG_VM set, test case generic/476 has some chance to crash
with the following VM_BUG_ON_FOLIO():

  BTRFS error (device dm-3): cow_file_range failed, start 1146880 end 1253375 len 106496 ret -28
  BTRFS error (device dm-3): run_delalloc_nocow failed, start 1146880 end 1253375 len 106496 ret -28
  page: refcount:4 mapcount:0 mapping:00000000592787cc index:0x12 pfn:0x10664
  aops:btrfs_aops [btrfs] ino:101 dentry name(?):"f1774"
  flags: 0x2fffff80004028(uptodate|lru|private|node=0|zone=2|lastcpupid=0xfffff)
  page dumped because: VM_BUG_ON_FOLIO(!folio_test_locked(folio))
  ------------[ cut here ]------------
  kernel BUG at mm/page-writeback.c:2992!
  Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
  CPU: 2 UID: 0 PID: 3943513 Comm: kworker/u24:15 Tainted: G           OE      6.12.0-rc7-custom+ #87
  Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
  Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022
  Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs]
  pc : folio_clear_dirty_for_io+0x128/0x258
  lr : folio_clear_dirty_for_io+0x128/0x258
  Call trace:
   folio_clear_dirty_for_io+0x128/0x258
   btrfs_folio_clamp_clear_dirty+0x80/0xd0 [btrfs]
   __process_folios_contig+0x154/0x268 [btrfs]
   extent_clear_unlock_delalloc+0x5c/0x80 [btrfs]
   run_delalloc_nocow+0x5f8/0x760 [btrfs]
   btrfs_run_delalloc_range+0xa8/0x220 [btrfs]
   writepage_delalloc+0x230/0x4c8 [btrfs]
   extent_writepage+0xb8/0x358 [btrfs]
   extent_write_cache_pages+0x21c/0x4e8 [btrfs]
   btrfs_writepages+0x94/0x150 [btrfs]
   do_writepages+0x74/0x190
   filemap_fdatawrite_wbc+0x88/0xc8
   start_delalloc_inodes+0x178/0x3a8 [btrfs]
   btrfs_start_delalloc_roots+0x174/0x280 [btrfs]
   shrink_delalloc+0x114/0x280 [btrfs]
   flush_space+0x250/0x2f8 [btrfs]
   btrfs_async_reclaim_data_space+0x180/0x228 [btrfs]
   process_one_work+0x164/0x408
   worker_thread+0x25c/0x388
   kthread+0x100/0x118
   ret_from_fork+0x10/0x20
  Code: 910a8021 a90363f7 a9046bf9 94012379 (d4210000)
  ---[ end trace 0000000000000000 ]---

[CAUSE]
The first two lines of extra debug messages show the problem is caused
by the error handling of run_delalloc_nocow().

E.g. we have the following dirtied range (4K blocksize 4K page size):

    0                 16K                  32K
    |//////////////////////////////////////|
    |  Pre-allocated  |

And the range [0, 16K) has a preallocated extent.

- Enter run_delalloc_nocow() for range [0, 16K)
  Which found range [0, 16K) is preallocated, can do the proper NOCOW
  write.

- Enter fallback_to_fow() for range [16K, 32K)
  Since the range [16K, 32K) is not backed by preallocated extent, we
  have to go COW.

- cow_file_range() failed for range [16K, 32K)
  So cow_file_range() will do the clean up by clearing folio dirty,
  unlock the folios.

  Now the folios in range [16K, 32K) is unlocked.

- Enter extent_clear_unlock_delalloc() from run_delalloc_nocow()
  Which is called with PAGE_START_WRITEBACK to start page writeback.
  But folios can only be marked writeback when it's properly locked,
  thus this triggered the VM_BUG_ON_FOLIO().

Furthermore there is another hidden but common bug that
run_delalloc_nocow() is not clearing the folio dirty flags in its error
handling path.
This is the common bug shared between run_delalloc_nocow() and
cow_file_range().

[FIX]
- Clear folio dirty for range [@start, @cur_offset)
  Introduce a helper, cleanup_dirty_folios(), which
  will find and lock the folio in the range, clear the dirty flag and
  start/end the writeback, with the extra handling for the
  @locked_folio.

- Introduce a helper to clear folio dirty, start and end writeback

- Introduce a helper to record the last failed COW range end
  This is to trace which range we should skip, to avoid double
  unlocking.

- Skip the failed COW range for the error handling

CC: stable@vger.kernel.org
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 15:52:17 +01:00
Qu Wenruo
06f3642847 btrfs: do proper folio cleanup when cow_file_range() failed
[BUG]
When testing with COW fixup marked as BUG_ON() (this is involved with the
new pin_user_pages*() change, which should not result new out-of-band
dirty pages), I hit a crash triggered by the BUG_ON() from hitting COW
fixup path.

This BUG_ON() happens just after a failed btrfs_run_delalloc_range():

  BTRFS error (device dm-2): failed to run delalloc range, root 348 ino 405 folio 65536 submit_bitmap 6-15 start 90112 len 106496: -28
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/extent_io.c:1444!
  Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
  CPU: 0 UID: 0 PID: 434621 Comm: kworker/u24:8 Tainted: G           OE      6.12.0-rc7-custom+ #86
  Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022
  Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs]
  pc : extent_writepage_io+0x2d4/0x308 [btrfs]
  lr : extent_writepage_io+0x2d4/0x308 [btrfs]
  Call trace:
   extent_writepage_io+0x2d4/0x308 [btrfs]
   extent_writepage+0x218/0x330 [btrfs]
   extent_write_cache_pages+0x1d4/0x4b0 [btrfs]
   btrfs_writepages+0x94/0x150 [btrfs]
   do_writepages+0x74/0x190
   filemap_fdatawrite_wbc+0x88/0xc8
   start_delalloc_inodes+0x180/0x3b0 [btrfs]
   btrfs_start_delalloc_roots+0x174/0x280 [btrfs]
   shrink_delalloc+0x114/0x280 [btrfs]
   flush_space+0x250/0x2f8 [btrfs]
   btrfs_async_reclaim_data_space+0x180/0x228 [btrfs]
   process_one_work+0x164/0x408
   worker_thread+0x25c/0x388
   kthread+0x100/0x118
   ret_from_fork+0x10/0x20
  Code: aa1403e1 9402f3ef aa1403e0 9402f36f (d4210000)
  ---[ end trace 0000000000000000 ]---

[CAUSE]
That failure is mostly from cow_file_range(), where we can hit -ENOSPC.

Although the -ENOSPC is already a bug related to our space reservation
code, let's just focus on the error handling.

For example, we have the following dirty range [0, 64K) of an inode,
with 4K sector size and 4K page size:

   0        16K        32K       48K       64K
   |///////////////////////////////////////|
   |#######################################|

Where |///| means page are still dirty, and |###| means the extent io
tree has EXTENT_DELALLOC flag.

- Enter extent_writepage() for page 0

- Enter btrfs_run_delalloc_range() for range [0, 64K)

- Enter cow_file_range() for range [0, 64K)

- Function btrfs_reserve_extent() only reserved one 16K extent
  So we created extent map and ordered extent for range [0, 16K)

   0        16K        32K       48K       64K
   |////////|//////////////////////////////|
   |<- OE ->|##############################|

   And range [0, 16K) has its delalloc flag cleared.
   But since we haven't yet submit any bio, involved 4 pages are still
   dirty.

- Function btrfs_reserve_extent() returns with -ENOSPC
  Now we have to run error cleanup, which will clear all
  EXTENT_DELALLOC* flags and clear the dirty flags for the remaining
  ranges:

   0        16K        32K       48K       64K
   |////////|                              |
   |        |                              |

  Note that range [0, 16K) still has its pages dirty.

- Some time later, writeback is triggered again for the range [0, 16K)
  since the page range still has dirty flags.

- btrfs_run_delalloc_range() will do nothing because there is no
  EXTENT_DELALLOC flag.

- extent_writepage_io() finds page 0 has no ordered flag
  Which falls into the COW fixup path, triggering the BUG_ON().

Unfortunately this error handling bug dates back to the introduction of
btrfs.  Thankfully with the abuse of COW fixup, at least it won't crash
the kernel.

[FIX]
Instead of immediately unlocking the extent and folios, we keep the extent
and folios locked until either erroring out or the whole delalloc range
finished.

When the whole delalloc range finished without error, we just unlock the
whole range with PAGE_SET_ORDERED (and PAGE_UNLOCK for !keep_locked
cases), with EXTENT_DELALLOC and EXTENT_LOCKED cleared.
And the involved folios will be properly submitted, with their dirty
flags cleared during submission.

For the error path, it will be a little more complex:

- The range with ordered extent allocated (range (1))
  We only clear the EXTENT_DELALLOC and EXTENT_LOCKED, as the remaining
  flags are cleaned up by
  btrfs_mark_ordered_io_finished()->btrfs_finish_one_ordered().

  For folios we finish the IO (clear dirty, start writeback and
  immediately finish the writeback) and unlock the folios.

- The range with reserved extent but no ordered extent (range(2))
- The range we never touched (range(3))
  For both range (2) and range(3) the behavior is not changed.

Now even if cow_file_range() failed halfway with some successfully
reserved extents/ordered extents, we will keep all folios clean, so
there will be no future writeback triggered on them.

CC: stable@vger.kernel.org
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 15:50:12 +01:00
Qu Wenruo
a7858d5c36 btrfs: fix error handling of submit_uncompressed_range()
[BUG]
If we failed to compress the range, or cannot reserve a large enough
data extent (e.g. too fragmented free space), we will fall back to
submit_uncompressed_range().

But inside submit_uncompressed_range(), run_delalloc_cow() can also fail
due to -ENOSPC or any other error.

In that case there are 3 bugs in the error handling:

1) Double freeing for the same ordered extent
   This can lead to crash due to ordered extent double accounting

2) Start/end writeback without updating the subpage writeback bitmap

3) Unlock the folio without clear the subpage lock bitmap

Both bugs 2) and 3) will crash the kernel if the btrfs block size is
smaller than folio size, as the next time the folio gets writeback/lock
updates, subpage will find the bitmap already have the range set,
triggering an ASSERT().

[CAUSE]
Bug 1) happens in the following call chain:

  submit_uncompressed_range()
  |- run_delalloc_cow()
  |  |- cow_file_range()
  |     |- btrfs_reserve_extent()
  |        Failed with -ENOSPC or whatever error
  |
  |- btrfs_clean_up_ordered_extents()
  |  |- btrfs_mark_ordered_io_finished()
  |     Which cleans all the ordered extents in the async_extent range.
  |
  |- btrfs_mark_ordered_io_finished()
     Which cleans the folio range.

The finished ordered extents may not be immediately removed from the
ordered io tree, as they are removed inside a work queue.

So the second btrfs_mark_ordered_io_finished() may find the finished but
not-yet-removed ordered extents, and double free them.

Furthermore, the second btrfs_mark_ordered_io_finished() is not subpage
compatible, as it uses fixed folio_pos() with PAGE_SIZE, which can cover
other ordered extents.

Bugs 2) and 3) are more straightforward, btrfs just calls folio_unlock(),
folio_start_writeback() and folio_end_writeback(), other than the helpers
which handle subpage cases.

[FIX]
For bug 1) since the first btrfs_cleanup_ordered_extents() call is
handling the whole range, we should not do the second
btrfs_mark_ordered_io_finished() call.

And for the first btrfs_cleanup_ordered_extents(), we no longer need to
pass the @locked_page parameter, as we are already in the async extent
context, thus will never rely on the error handling inside
btrfs_run_delalloc_range().

So just let the btrfs_clean_up_ordered_extents() handle every folio
equally.

For bug 2) we should not even call
folio_start_writeback()/folio_end_writeback() anymore.
As the error handling protocol, cow_file_range() should clear
dirty flag and start/finish the writeback for the whole range passed in.

For bug 3) just change the folio_unlock() to btrfs_folio_end_lock()
helper.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 15:36:06 +01:00
Qu Wenruo
8bf334beb3 btrfs: fix double accounting race when extent_writepage_io() failed
[BUG]
If submit_one_sector() failed inside extent_writepage_io() for sector
size < page size cases (e.g. 4K sector size and 64K page size), then
we can hit double ordered extent accounting error.

This should be very rare, as submit_one_sector() only fails when we
failed to grab the extent map, and such extent map should exist inside
the memory and has been pinned.

[CAUSE]
For example we have the following folio layout:

    0  4K          32K    48K   60K 64K
    |//|           |//////|     |///|

Where |///| is the dirty range we need to writeback. The 3 different
dirty ranges are submitted for regular COW.

Now we hit the following sequence:

- submit_one_sector() returned 0 for [0, 4K)

- submit_one_sector() returned 0 for [32K, 48K)

- submit_one_sector() returned error for [60K, 64K)

- btrfs_mark_ordered_io_finished() called for the whole folio
  This will mark the following ranges as finished:
  * [0, 4K)
  * [32K, 48K)
    Both ranges have their IO already submitted, this cleanup will
    lead to double accounting.

  * [60K, 64K)
    That's the correct cleanup.

The only good news is, this error is only theoretical, as the target
extent map is always pinned, thus we should directly grab it from
memory, other than reading it from the disk.

[FIX]
Instead of calling btrfs_mark_ordered_io_finished() for the whole folio
range, which can touch ranges we should not touch, instead
move the error handling inside extent_writepage_io().

So that we can cleanup exact sectors that ought to be submitted but failed.

This provides much more accurate cleanup, avoiding the double accounting.

CC: stable@vger.kernel.org # 5.15+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 15:33:43 +01:00
Qu Wenruo
72dad8e377 btrfs: fix double accounting race when btrfs_run_delalloc_range() failed
[BUG]
When running btrfs with block size (4K) smaller than page size (64K,
aarch64), there is a very high chance to crash the kernel at
generic/750, with the following messages:
(before the call traces, there are 3 extra debug messages added)

  BTRFS warning (device dm-3): read-write for sector size 4096 with page size 65536 is experimental
  BTRFS info (device dm-3): checking UUID tree
  hrtimer: interrupt took 5451385 ns
  BTRFS error (device dm-3): cow_file_range failed, root=4957 inode=257 start=1605632 len=69632: -28
  BTRFS error (device dm-3): run_delalloc_nocow failed, root=4957 inode=257 start=1605632 len=69632: -28
  BTRFS error (device dm-3): failed to run delalloc range, root=4957 ino=257 folio=1572864 submit_bitmap=8-15 start=1605632 len=69632: -28
  ------------[ cut here ]------------
  WARNING: CPU: 2 PID: 3020984 at ordered-data.c:360 can_finish_ordered_extent+0x370/0x3b8 [btrfs]
  CPU: 2 UID: 0 PID: 3020984 Comm: kworker/u24:1 Tainted: G           OE      6.13.0-rc1-custom+ #89
  Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
  Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022
  Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs]
  pc : can_finish_ordered_extent+0x370/0x3b8 [btrfs]
  lr : can_finish_ordered_extent+0x1ec/0x3b8 [btrfs]
  Call trace:
   can_finish_ordered_extent+0x370/0x3b8 [btrfs] (P)
   can_finish_ordered_extent+0x1ec/0x3b8 [btrfs] (L)
   btrfs_mark_ordered_io_finished+0x130/0x2b8 [btrfs]
   extent_writepage+0x10c/0x3b8 [btrfs]
   extent_write_cache_pages+0x21c/0x4e8 [btrfs]
   btrfs_writepages+0x94/0x160 [btrfs]
   do_writepages+0x74/0x190
   filemap_fdatawrite_wbc+0x74/0xa0
   start_delalloc_inodes+0x17c/0x3b0 [btrfs]
   btrfs_start_delalloc_roots+0x17c/0x288 [btrfs]
   shrink_delalloc+0x11c/0x280 [btrfs]
   flush_space+0x288/0x328 [btrfs]
   btrfs_async_reclaim_data_space+0x180/0x228 [btrfs]
   process_one_work+0x228/0x680
   worker_thread+0x1bc/0x360
   kthread+0x100/0x118
   ret_from_fork+0x10/0x20
  ---[ end trace 0000000000000000 ]---
  BTRFS critical (device dm-3): bad ordered extent accounting, root=4957 ino=257 OE offset=1605632 OE len=16384 to_dec=16384 left=0
  BTRFS critical (device dm-3): bad ordered extent accounting, root=4957 ino=257 OE offset=1622016 OE len=12288 to_dec=12288 left=0
  Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
  BTRFS critical (device dm-3): bad ordered extent accounting, root=4957 ino=257 OE offset=1634304 OE len=8192 to_dec=4096 left=0
  CPU: 1 UID: 0 PID: 3286940 Comm: kworker/u24:3 Tainted: G        W  OE      6.13.0-rc1-custom+ #89
  Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022
  Workqueue:  btrfs_work_helper [btrfs] (btrfs-endio-write)
  pstate: 404000c5 (nZcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  pc : process_one_work+0x110/0x680
  lr : worker_thread+0x1bc/0x360
  Call trace:
   process_one_work+0x110/0x680 (P)
   worker_thread+0x1bc/0x360 (L)
   worker_thread+0x1bc/0x360
   kthread+0x100/0x118
   ret_from_fork+0x10/0x20
  Code: f84086a1 f9000fe1 53041c21 b9003361 (f9400661)
  ---[ end trace 0000000000000000 ]---
  Kernel panic - not syncing: Oops: Fatal exception
  SMP: stopping secondary CPUs
  SMP: failed to stop secondary CPUs 2-3
  Dumping ftrace buffer:
     (ftrace buffer empty)
  Kernel Offset: 0x275bb9540000 from 0xffff800080000000
  PHYS_OFFSET: 0xffff8fbba0000000
  CPU features: 0x100,00000070,00801250,8201720b

[CAUSE]
The above warning is triggered immediately after the delalloc range
failure, this happens in the following sequence:

- Range [1568K, 1636K) is dirty

   1536K  1568K     1600K    1636K  1664K
   |      |/////////|////////|      |

  Where 1536K, 1600K and 1664K are page boundaries (64K page size)

- Enter extent_writepage() for page 1536K

- Enter run_delalloc_nocow() with locked page 1536K and range
  [1568K, 1636K)
  This is due to the inode having preallocated extents.

- Enter cow_file_range() with locked page 1536K and range
  [1568K, 1636K)

- btrfs_reserve_extent() only reserved two extents
  The main loop of cow_file_range() only reserved two data extents,

  Now we have:

   1536K  1568K        1600K    1636K  1664K
   |      |<-->|<--->|/|///////|      |
               1584K  1596K
  Range [1568K, 1596K) has an ordered extent reserved.

- btrfs_reserve_extent() failed inside cow_file_range() for file offset
  1596K
  This is already a bug in our space reservation code, but for now let's
  focus on the error handling path.

  Now cow_file_range() returned -ENOSPC.

- btrfs_run_delalloc_range() do error cleanup <<< ROOT CAUSE
  Call btrfs_cleanup_ordered_extents() with locked folio 1536K and range
  [1568K, 1636K)

  Function btrfs_cleanup_ordered_extents() normally needs to skip the
  ranges inside the folio, as it will normally be cleaned up by
  extent_writepage().

  Such split error handling is already problematic in the first place.

  What's worse is the folio range skipping itself, which is not taking
  subpage cases into consideration at all, it will only skip the range
  if the page start >= the range start.
  In our case, the page start < the range start, since for subpage cases
  we can have delalloc ranges inside the folio but not covering the
  folio.

  So it doesn't skip the page range at all.
  This means all the ordered extents, both [1568K, 1584K) and
  [1584K, 1596K) will be marked as IOERR.

  And these two ordered extents have no more pending ios, they are marked
  finished, and *QUEUED* to be deleted from the io tree.

- extent_writepage() do error cleanup
  Call btrfs_mark_ordered_io_finished() for the range [1536K, 1600K).

  Although ranges [1568K, 1584K) and [1584K, 1596K) are finished, the
  deletion from io tree is async, it may or may not happen at this
  time.

  If the ranges have not yet been removed, we will do double cleaning on
  those ranges, triggering the above ordered extent warnings.

In theory there are other bugs, like the cleanup in extent_writepage()
can cause double accounting on ranges that are submitted asynchronously
(compression for example).

But that's much harder to trigger because normally we do not mix regular
and compression delalloc ranges.

[FIX]
The folio range split is already buggy and not subpage compatible, it
was introduced a long time ago where subpage support was not even considered.

So instead of splitting the ordered extents cleanup into the folio range
and out of folio range, do all the cleanup inside writepage_delalloc().

- Pass @NULL as locked_folio for btrfs_cleanup_ordered_extents() in
  btrfs_run_delalloc_range()

- Skip the btrfs_cleanup_ordered_extents() if writepage_delalloc()
  failed

  So all ordered extents are only cleaned up by
  btrfs_run_delalloc_range().

- Handle the ranges that already have ordered extents allocated
  If part of the folio already has ordered extent allocated, and
  btrfs_run_delalloc_range() failed, we also need to cleanup that range.

Now we have a concentrated error handling for ordered extents during
btrfs_run_delalloc_range().

Fixes: d1051d6ebf ("btrfs: Fix error handling in btrfs_cleanup_ordered_extents")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 15:26:23 +01:00
David Sterba
311473984c btrfs: async-thread: rename DFT_THRESHOLD to DEFAULT_THRESHOLD
Rename the macro so it's obvious what it means.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:23 +01:00
David Sterba
ef8c0047aa btrfs: remove redundant variables from __process_folios_contig() and lock_delalloc_folios()
Same pattern in both functions, we really only use index, start_index is
redundant.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:23 +01:00
David Sterba
248c4ff393 btrfs: split waiting from read_extent_buffer_pages(), drop parameter wait
There are only 2 WAIT_* values left for wait parameter, we can encode
this to the function name if the waiting functionality is split.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:23 +01:00
David Sterba
db9eef2ea8 btrfs: remove unused define WAIT_PAGE_LOCK for extent io
Last use was in the readahead code that got removed by f26c923860
("btrfs: remove reada infrastructure").

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:23 +01:00
David Sterba
f8e0b8f9c2 btrfs: unwrap folio locking helpers
Another conversion to folio API, use the folio locking directly instead
of back and forth page <-> folio conversions.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:23 +01:00
David Sterba
549a88acbe btrfs: change return type to bool type of check_eb_alignment()
The check function pattern is supposed to return true/false, currently
there's only one error code.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:23 +01:00
David Sterba
a43caf82a1 btrfs: switch grab_extent_buffer() to folios
Use the folio API, remove page_folio/folio_page conversions.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:22 +01:00
David Sterba
cc8f51a355 btrfs: rename btrfs_release_extent_buffer_pages() to mention folios
Continue page to folio updates, sync what the function does with it's
name.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:22 +01:00
David Sterba
a722c72bef btrfs: open code __free_extent_buffer()
Using the kmem cache freeing directly is clear enough, we don't need to
wrap it.  All the users are in the same file.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:22 +01:00
David Sterba
b6160baed3 btrfs: drop one time used local variable in end_bbio_meta_write()
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:22 +01:00
David Sterba
075adeeb92 btrfs: make wait_on_extent_buffer_writeback() static inline
The simple helper can be inlined, no need for the separate function.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:22 +01:00
David Sterba
011a9a1f24 btrfs: use btrfs_inode in extent_writepage()
As extent_writepage() is internal helper we should use our inode type,
so change it from struct inode.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:22 +01:00
David Sterba
06de96faf7 btrfs: rename __get_extent_map() and pass btrfs_inode
The double underscore naming scheme does not apply here, there's only
only get_extent_map(). As the definition is changed also pass the struct
btrfs_inode.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:22 +01:00
David Sterba
3a1c46dbc9 btrfs: open code set_page_extent_mapped()
The function set_page_extent_mapped() is now a simple wrapper so use the
folio helper.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:22 +01:00
David Sterba
2b41599bff btrfs: rename __unlock_for_delalloc() and drop underscores
Drop the leading underscores in '__unlock_for_delalloc()' and rename it
to 'unlock_delalloc_folio()'. This also ensures naming parity with
'lock_delalloc_folios()'.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:22 +01:00
David Sterba
2a1e8378dc btrfs: use SECTOR_SIZE defines in btrfs_issue_discard()
Use the existing define for single sector size.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:22 +01:00
David Sterba
6d67ff1c0b btrfs: remove stray comment about SRCU
The subvol_srcu was removed in c75e839414 ("btrfs: kill the
subvol_srcu") years ago.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:21 +01:00
David Sterba
5f14eb12a3 btrfs: drop unused parameter fs_info to btrfs_delete_delayed_insertion_item()
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:21 +01:00
Jing Xia
2fa07d7a0f btrfs: pass write-hint for buffered IO
Commit 449813515d ("block, fs: Restore the per-bio/request data
lifetime fields") restored write-hint support in btrfs. But that is
applicable only for direct IO. This patch supports passing
write-hint for buffered IO from btrfs file system to block layer
by filling bi_write_hint of struct bio in alloc_new_bio().

There's an ongoing discussion which devices can use that,
https://lore.kernel.org/all/20240910150200.6589-6-joshi.k@samsung.com,
in SCSI there's support using sd_group_number() and
sd_setup_rw32_cmnd().

The hint goes from the application directly to the block device so it's
up to the application to set up everything properly to utilize the
different hint classes.

Link: https://lore.kernel.org/all/20240910150200.6589-6-joshi.k@samsung.com
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jing Xia <j.xia@samsung.com>
[ Add more context and use case. ]
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:21 +01:00
Anand Jain
3681dbe0af btrfs: print read policy on module load
Print the read read policy if set as module parameter (with
CONFIG_BTRFS_EXPERIMENTAL).

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:21 +01:00
Anand Jain
e426286cfa btrfs: configure read policy via module parameter
For testing purposes allow to configure the read policy via module
parameter from the beginning. Available only with CONFIG_BTRFS_EXPERIMENTAL

Examples:

- Set the RAID1 balancing method to round-robin with a custom
  min_contig_read of 4k:
  $ modprobe btrfs read_policy=round-robin:4096

- Set the round-robin balancing method with the default
  min_contiguous_read:
  $ modprobe btrfs read_policy=round-robin

- Set the "devid" balancing method, defaulting to the latest device:
  $ modprobe btrfs read_policy=devid

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:21 +01:00
Anand Jain
bb4715e967 btrfs: print status of experimental mode when loading module
Commit c9c49e8f157e ("btrfs: split out CONFIG_BTRFS_EXPERIMENTAL from
CONFIG_BTRFS_DEBUG") introduces a way to enable or disable experimental
features, print its status during module load, like:

  Btrfs loaded, experimental=on, debug=on, assert=on, zoned=yes, fsverity=yes

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:21 +01:00
Anand Jain
c86aae73bd btrfs: add read policy to set a preferred device
Add read policy that will force all reads to go to the given device
(specified by devid) on the RAID1 profiles.

This will be used for testing, e.g. to read from stale device. Users may
find other use cases.

Can be set in sysfs, the value format is "devid:<devid>" to the file

  /sys/fs/btrfs/FSID/read_policy

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:21 +01:00
Anand Jain
6d7a915495 btrfs: introduce RAID1 round-robin read balancing
Add round-robin read policy that balances reads over available devices
(all RAID1 block group profiles). Switch to the next devices is done
after a number of blocks is read, which is 256K by default and is
configurable in sysfs.

The format is "round-robin:<min-contig-read>" and can be set in file

  /sys/fs/btrfs/FSID/read_policy

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:21 +01:00
Anand Jain
22fb0d99c9 btrfs: add tracking of read blocks for read policy
Track number of read blocks in the whole filesystem. The counter is
initialized when devices are opened. The counter is increased at
btrfs_submit_dev_bio() if the stats tracking is enabled (depends on the
read policy).  Stats tracking is disabled by default and is enabled
through fs_devices::collect_fs_stats when required.

The code is not under the EXPERIMENTAL define, as stats can be expanded
to include write counts and other performance counters, with the user
interface independent of its internal use.

This is an in-memory-only feature, not related to the dev error stats.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:21 +01:00
Anand Jain
b6bed20ed3 btrfs: sysfs: handle value associated with read balancing policy
Enable specifying additional configuration values along the RAID1
balancing read policy in a single input string.

Update btrfs_read_policy_to_enum() to parse and handle a value
associated with the policy in the format "policy:value", the value part
if present is converted to 64-bit integer.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:21 +01:00
Anand Jain
38cae63137 btrfs: sysfs: add btrfs_read_policy_to_enum() helper and refactor read policy store
Introduce btrfs_read_policy_to_enum() helper to simplify the conversion
of a string read policy to its corresponding enum value. This reduces
duplication and improves code clarity in btrfs_read_policy_store().

The parameter is copied locally to allow modification, enabling the
separation of the method and its value. This prepares for the addition of
more functionality in subsequent patches.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:21 +01:00
Anand Jain
83be7f8b9c btrfs: sysfs: refactor output formatting in btrfs_read_policy_show()
Refactor the logic in btrfs_read_policy_show() for easier extension with
more balancing methods.  Streamline the space and bracket handling
around the active policy without altering the functional output.  This
is in preparation to add more methods.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:20 +01:00
Anand Jain
a5019b7070 btrfs: initialize fs_devices->fs_info earlier in btrfs_init_devices_late()
Currently, fs_devices->fs_info is initialized in btrfs_init_devices_late(),
but this occurs too late for find_live_mirror(), which is invoked by
load_super_root() much earlier than btrfs_init_devices_late().

Fix this by moving the initialization to open_ctree(), before load_super_root().

Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:20 +01:00
Filipe Manana
74973b45a6 btrfs: xattr: remove unnecessary call to btrfs_mark_buffer_dirty()
The call to btrfs_mark_buffer_dirty() at btrfs_setxattr() is not
necessary as we have a path setup for writing with btrfs_search_slot()
having a 'cow' argument set to 1.

This just makes the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove it.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:20 +01:00
Filipe Manana
1ca4e15f41 btrfs: volumes: remove unnecessary calls to btrfs_mark_buffer_dirty()
We have several places explicitly calling btrfs_mark_buffer_dirty() but
that is not necessarily since the target leaf came from a path that was
obtained for a btree search function that modifies the btree, something
like btrfs_insert_empty_item() or anything else that ends up calling
btrfs_search_slot() with a value of 1 for its 'cow' argument.

These just make the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove them.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:20 +01:00
Filipe Manana
c9a4390707 btrfs: uuid-tree: remove unnecessary call to btrfs_mark_buffer_dirty()
The call to btrfs_mark_buffer_dirty() at btrfs_uuid_tree_add() is not
necessary as we have a path setup for writing with btrfs_search_slot()
having a 'cow' argument set to 1 (through btrfs_insert_empty_item()).

This just makes the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove it.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:20 +01:00
Filipe Manana
65733e8d6c btrfs: root-tree: remove unnecessary calls to btrfs_mark_buffer_dirty()
We have several places explicitly calling btrfs_mark_buffer_dirty() but
that is not necessarily since the target leaf came from a path that was
obtained for a btree search function that modifies the btree, something
like btrfs_insert_empty_item() or anything else that ends up calling
btrfs_search_slot() with a value of 1 for its 'cow' argument.

These just make the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove them.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:20 +01:00
Filipe Manana
5a8293a1cc btrfs: relocation: remove unnecessary calls to btrfs_mark_buffer_dirty()
We have several places explicitly calling btrfs_mark_buffer_dirty() but
that is not necessarily since the target leaf came from a path that was
obtained for a btree search function that modifies the btree, something
like btrfs_insert_empty_item() or anything else that ends up calling
btrfs_search_slot() with a value of 1 for its 'cow' argument.

These just make the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove them.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:20 +01:00
Filipe Manana
bdf1660b22 btrfs: raid-stripe-tree: remove unnecessary call to btrfs_mark_buffer_dirty()
The call to btrfs_mark_buffer_dirty() at update_raid_extent_item() is not
necessary as we have a path setup for writing with btrfs_search_slot()
having a 'cow' argument set to 1.

This just makes the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove it.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:20 +01:00
Filipe Manana
d74a36f37e btrfs: qgroup: remove unnecessary calls to btrfs_mark_buffer_dirty()
We have several places explicitly calling btrfs_mark_buffer_dirty() but
that is not necessarily since the target leaf came from a path that was
obtained for a btree search function that modifies the btree, something
like btrfs_insert_empty_item() or anything else that ends up calling
btrfs_search_slot() with a value of 1 for its 'cow' argument.

These just make the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove them.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:20 +01:00
Filipe Manana
bd25bf9dcd btrfs: ioctl: remove unnecessary call to btrfs_mark_buffer_dirty()
The call to btrfs_mark_buffer_dirty() at btrfs_ioctl_default_subvol() is
not necessary as we have a path setup for writing with btrfs_search_slot()
having a 'cow' argument set to 1.

This just makes the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove it.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:20 +01:00
Filipe Manana
212e5f5cb8 btrfs: inode-item: remove unnecessary calls to btrfs_mark_buffer_dirty()
We have several places explicitly calling btrfs_mark_buffer_dirty() but
that is not necessarily since the target leaf came from a path that was
obtained for a btree search function that modifies the btree, something
like btrfs_insert_empty_item() or anything else that ends up calling
btrfs_search_slot() with a value of 1 for its 'cow' argument.

These just make the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove them.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:19 +01:00
Filipe Manana
5c7763312c btrfs: inode: remove unnecessary calls to btrfs_mark_buffer_dirty()
We have several places explicitly calling btrfs_mark_buffer_dirty() but
that is not necessarily since the target leaf came from a path that was
obtained for a btree search function that modifies the btree, something
like btrfs_insert_empty_item() or anything else that ends up calling
btrfs_search_slot() with a value of 1 for its 'cow' argument.

These just make the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove them.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:19 +01:00
Filipe Manana
038d6999ec btrfs: free-space-cache: remove unnecessary calls to btrfs_mark_buffer_dirty()
We have several places explicitly calling btrfs_mark_buffer_dirty() but
that is not necessarily since the target leaf came from a path that was
obtained for a btree search function that modifies the btree, something
like btrfs_insert_empty_item() or anything else that ends up calling
btrfs_search_slot() with a value of 1 for its 'cow' argument.

These just make the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove them.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:19 +01:00
Filipe Manana
5e887b5071 btrfs: file-item: remove unnecessary calls to btrfs_mark_buffer_dirty()
We have several places explicitly calling btrfs_mark_buffer_dirty() but
that is not necessarily since the target leaf came from a path that was
obtained for a btree search function that modifies the btree, something
like btrfs_insert_empty_item() or anything else that ends up calling
btrfs_search_slot() with a value of 1 for its 'cow' argument.

These just make the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove them.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:19 +01:00
Filipe Manana
49c318e4f7 btrfs: file: remove unnecessary calls to btrfs_mark_buffer_dirty()
We have several places explicitly calling btrfs_mark_buffer_dirty() but
that is not necessarily since the target leaf came from a path that was
obtained for a btree search function that modifies the btree, something
like btrfs_insert_empty_item() or anything else that ends up calling
btrfs_search_slot() with a value of 1 for its 'cow' argument.

These just make the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove them.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:19 +01:00
Filipe Manana
4866812020 btrfs: dir-item: remove unnecessary calls to btrfs_mark_buffer_dirty()
We have several places explicitly calling btrfs_mark_buffer_dirty() but
that is not necessarily since the target leaf came from a path that was
obtained for a btree search function that modifies the btree, something
like btrfs_insert_empty_item() or anything else that ends up calling
btrfs_search_slot() with a value of 1 for its 'cow' argument.

These just make the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove them.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:19 +01:00
Filipe Manana
7caa86c44b btrfs: dev-replace: remove unnecessary call to btrfs_mark_buffer_dirty()
The call to btrfs_mark_buffer_dirty() at btrfs_run_dev_replace() is not
necessary as we have a path setup for writing with btrfs_search_slot()
having a 'cow' argument set to 1.

This just makes the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove it.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:19 +01:00
Filipe Manana
a81ae6c31d btrfs: delayed-inode: remove unnecessary call to btrfs_mark_buffer_dirty()
The call to btrfs_mark_buffer_dirty() at __btrfs_update_delayed_inode() is
not necessary as we have a path setup for writing with btrfs_search_slot()
having a 'cow' argument set to 1.

This just makes the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove it.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:19 +01:00
Filipe Manana
ca9d907645 btrfs: block-group: remove unnecessary calls to btrfs_mark_buffer_dirty()
We have several places explicitly calling btrfs_mark_buffer_dirty() but
that is not necessarily since the target leaf came from a path that was
obtained for a btree search function that modifies the btree, something
like btrfs_insert_empty_item() or anything else that ends up calling
btrfs_search_slot() with a value of 1 for its 'cow' argument.

These just make the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove them.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:19 +01:00
Filipe Manana
1440fd2757 btrfs: extent-tree: remove unnecessary calls to btrfs_mark_buffer_dirty()
We have several places explicitly calling btrfs_mark_buffer_dirty() but
that is not necessarily since the target leaf came from a path that was
obtained for a btree search function that modifies the btree, something
like btrfs_insert_empty_item() or anything else that ends up calling
btrfs_search_slot() with a value of 1 for its 'cow' argument.

These just make the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove them.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:19 +01:00
Filipe Manana
63eb222387 btrfs: free-space-tree: remove unnecessary calls to btrfs_mark_buffer_dirty()
We have several places explicitly calling btrfs_mark_buffer_dirty() but
that is not necessarily since the target leaf came from a path that was
obtained for a btree search function that modifies the btree, something
ike btrfs_insert_empty_item() or anything else that ends up calling
btrfs_search_slot() with a value of 1 for its 'cow' argument.

These just make the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove them.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:19 +01:00
Filipe Manana
8787c36c63 btrfs: tree-log: remove unnecessary calls to btrfs_mark_buffer_dirty()
We have several places explicitly calling btrfs_mark_buffer_dirty() but
that is not necessarily since the target leaf came from a path that was
obtained for a btree search function that modifies the btree, something
like btrfs_insert_empty_item() or anything else that ends up calling
btrfs_search_slot() with a value of 1 for its 'cow' argument.

These just make the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove them.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:18 +01:00
Filipe Manana
097a7eef61 btrfs: uncollapse transaction aborts during renames
During renames we are grouping transaction aborts that can be due to a
failure of one of several function calls. While this makes the code less
verbose, it makes it harder to debug as we end up not knowing from which
function call we got an error.

So change this to trigger a transaction abort after each function call
failure, so that when we get a transaction abort message we know exactly
which function call failed, helping us to debug issues.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:18 +01:00
Qu Wenruo
2a9bb78cfd btrfs: validate system chunk array at btrfs_validate_super()
Currently btrfs_validate_super() only does a very basic check on the
array chunk size (not too large than the available space, but not too
small to contain no chunk).

The more comprehensive checks (the regular chunk checks and size check
inside the system chunk array) are all done inside btrfs_read_sys_array().

It's not a big deal, but it also means we do not do any validation on
the system chunk array at super block writeback time either.

Do the following modification to centralize the system chunk array
checks into btrfs_validate_super():

- Make chunk_err() helper accept stack chunk pointer
  If @leaf parameter is NULL, then the @chunk pointer will be a pointer
  to the chunk item, other than the offset inside the leaf.

  And since @leaf can be NULL, add a new @fs_info parameter for that
  case.

- Make btrfs_check_chunk_valid() handle stack chunk pointer
  The same as chunk_err(), a new @fs_info parameter, and if @leaf is
  NULL, then @chunk will be a pointer to a stack chunk.

  If @chunk is NULL, then all needed btrfs_chunk members will be read
  using the stack helper instead of the leaf helper.
  This means we need to read out all the needed member at the beginning
  of the function.

  Furthermore, at super block read time, fs_info->sectorsize is not yet
  initialized, we need one extra @sectorsize parameter to grab the
  correct sectorsize.

- Introduce a helper validate_sys_chunk_array()
  * Validate the disk key.
  * Validate the size before we access the full chunk items.
  * Do the full chunk item validation.

- Call validate_sys_chunk_array() at btrfs_validate_super()

- Simplify the checks inside btrfs_read_sys_array()
  Now the checks will be converted to an ASSERT().

- Simplify the checks inside read_one_chunk()
  Now that all chunk items inside system chunk array and chunk tree are
  verified, there is no need to verify them again inside read_one_chunk().

This change has the following advantages:

- More comprehensive checks at write time
  And unlike the sys_chunk_array read routine, this time we do not need
  to allocate a dummy extent buffer to do the check.
  All the checks done here require no new memory allocation.

- Slightly improved readability when iterating the system chunk array

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:18 +01:00
Roger L. Beckermeyer III
4e4d058e21 btrfs: update tree_insert() to use rb helpers
Update tree_insert() to use rb_find_add_cached().
add cmp_refs_node in rb_find_add_cached() to compare.

Since we're here, also make comp_data_refs() and comp_refs() accept
both parameters as const.

Signed-off-by: Roger L. Beckermeyer III <beckerlee3@gmail.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:18 +01:00
Roger L. Beckermeyer III
287373c701 btrfs: update btrfs_add_chunk_map() to use rb helpers
Update btrfs_add_chunk_map() to use rb_find_add_cached().

Signed-off-by: Roger L. Beckermeyer III <beckerlee3@gmail.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:18 +01:00
Roger L. Beckermeyer III
0877597dc3 btrfs: update __btrfs_add_delayed_item() to use rb helper
Update __btrfs_add_delayed_item() to use rb_find_add_cached().

Signed-off-by: Roger L. Beckermeyer III <beckerlee3@gmail.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:18 +01:00
Roger L. Beckermeyer III
14ae60c712 btrfs: update prelim_ref_insert() to use rb helpers
Update prelim_ref_insert() to use rb_find_add_cached().

There is a special change that the existing prelim_ref_compare() is
called with the first parameter as the existing ref in the rbtree.

But the newer rb_find_add_cached() expects the cmp() function to have
the first parameter as the to-be-added node, thus the new helper
prelim_ref_rb_add_cmp() need to adapt this new order.

Signed-off-by: Roger L. Beckermeyer III <beckerlee3@gmail.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:18 +01:00
Roger L. Beckermeyer III
372484f2c2 btrfs: update btrfs_add_block_group_cache() to use rb helper
Update fs/btrfs/block-group.c to use rb_find_add_cached().

Suggested-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Roger L. Beckermeyer III <beckerlee3@gmail.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:18 +01:00
Wolfram Sang
57e421867b btrfs: don't include linux/rwlock_types.h directly
The header clearly states that it does not want to be included directly,
only via linux/spinlock_types.h. Drop this as we can simply use the
spinlock.h which is already included.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:18 +01:00
Qu Wenruo
882af9f13e btrfs: handle free space tree rebuild in multiple transactions
During free space tree rebuild, we're holding a transaction handle for
the whole rebuild process.

This can lead to blocked task warning, e.g. btrfs-transaction kthread
(which is already created before btrfs_start_pre_rw_mount()) can be
waked up to join and commit the current transaction.

But the free space tree rebuild process may need to go through thousands
block groups, this will block btrfs-transaction kthread for a long time.

Fix the problem by calling btrfs_should_end_transaction() after each
block group, so that we won't hold the transaction handle too long.

And since the free-space-tree rebuild can be split into
multiple transactions, we need to consider the safety when the rebuild
process is interrupted.

Thankfully since we only set the FREE_SPACE_TREE compat_ro flag without
FREE_SPACE_TREE_VALID flag, even if the rebuild is interrupted, on the
next RW mount, we will still go rebuild the free space tree, by deleting
any items we have and re-starting the rebuild from scratch.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:18 +01:00
Filipe Manana
6a2b3d7a36 btrfs: use uuid_is_null() to verify if an uuid is empty
At btrfs_is_empty_uuid() we have our custom code to check if an uuid is
empty, however there a kernel uuid library that has a function named
uuid_is_null() which does the same and probably more efficient.

So change btrfs_is_empty_uuid() to use uuid_is_null(), which is almost
a directly replacement, it just wraps the necessary casting since our
uuid types are u8 arrays while the uuid kernel library uses the uuid_t
type, which is just a typedef of an u8 array of 16 elements as well.

Also since the function is now to trivial, make it a static inline
function in fs.h.

Suggested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:17 +01:00
Filipe Manana
de9c8265b7 btrfs: remove pointless comment from ctree.h
It's pointless to have a comment above the prototype declarations of
btrfs_ctree_init() and btrfs_ctree_exit() mentioning that they are
declared in ctree.c. This is from the old days when ctree.h was used
to place anything that didn't fit in any other file. So remove it.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:17 +01:00
Filipe Manana
07174a3429 btrfs: move extent-tree function declarations out of ctree.h
We have 3 functions that have their prototypes declared in ctree.h but
they are defined at extent-tree.c and they are unrelated to the btree
data structure. Move the prototypes out of ctree.h and into extent-tree.h.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:17 +01:00
Filipe Manana
378f25d3fc btrfs: move btrfs_alloc_write_mask() into fs.h
Currently btrfs_alloc_write_mask() is defined in ctree.h but it's not
related at all to the btree data structure, so move it into fs.h.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:17 +01:00
Filipe Manana
a4545b74e2 btrfs: move BTRFS_BYTES_TO_BLKS() into fs.h
Currently BTRFS_BYTES_TO_BLKS() is defined in ctree.h but it's not related
at all to the btree data structure, so move it into fs.h.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:17 +01:00
Filipe Manana
2205302298 btrfs: move the folio ordered helpers from ctree.h into fs.h
The folio ordered helper macros are defined at ctree.h but this is not
the best place since ctree.{h,c} is all about the btree data structure
implementation and not a generic module. So move these macros into the
fs.h header.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:17 +01:00
Filipe Manana
a5b3f117da btrfs: move btrfs_is_empty_uuid() from ioctl.c into fs.c
It's a generic helper not specific to ioctls and used in several places,
so move it out from ioctl.c and into fs.c. While at it change its return
type from int to bool and declare the loop variable in the loop itself.

This also slightly reduces the module's size.

Before this change:

  $ size fs/btrfs/btrfs.ko
     text	   data	    bss	    dec	    hex	filename
  1781492	 161037	  16920	1959449	 1de619	fs/btrfs/btrfs.ko

After this change:

  $ size fs/btrfs/btrfs.ko
     text	   data	    bss	    dec	    hex	filename
  1781340	 161037	  16920	1959297	 1de581	fs/btrfs/btrfs.ko

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:17 +01:00
Filipe Manana
0b93369104 btrfs: move the exclusive operation functions into fs.c
The declarations for the exclusive operation functions are located at fs.h
but their definitions are in ioctl.c, which doesn't make much sense since
(most of them) are used in several files other than ioctl.c. Since they
are used in several files and they are generic enough, move them out of
ioctl.c and into fs.c, even the ones that are currently only used at
ioctl.c, for the sake of having them all in the same C file.

This also reduces the module's size.

Before this change:

  $ size fs/btrfs/btrfs.ko
     text	   data	    bss	    dec	    hex	filename
  1782094	 161045	  16920	1960059	 1de87b	fs/btrfs/btrfs.ko

After this change:

  $ size fs/btrfs/btrfs.ko
     text	   data	    bss	    dec	    hex	filename
  1781492	 161037	  16920	1959449	 1de619	fs/btrfs/btrfs.ko

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:17 +01:00
Filipe Manana
a6f0bcf9b1 btrfs: move csum related functions from ctree.c into fs.c
The ctree module is about the implementation of the btree data structure
and not a place holder for generic filesystem things like the csum
algorithm details. Move the functions related to the csum algorithm
details away from ctree.c and into fs.c, which is a far better place for
them. Also fix missing punctuation in comments and change one multiline
comment to a single line comment since everything fits in under 80
characters.

For some reason this also slightly reduces the module's size.

Before this change:

  $ size fs/btrfs/btrfs.ko
     text	   data	    bss	    dec	    hex	filename
  1782126	 161045	  16920	1960091	 1de89b	fs/btrfs/btrfs.ko

After this change:

  $ size fs/btrfs/btrfs.ko
     text	   data	    bss	    dec	    hex	filename
  1782094	 161045	  16920	1960059	 1de87b	fs/btrfs/btrfs.ko

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:17 +01:00
Filipe Manana
b815a78e17 btrfs: move abort_should_print_stack() to transaction.h
The function abort_should_print_stack() is declared in transaction.h but
its definition is in ctree.c, which doesn't make sense since ctree.c is
the btree implementation and the function is related to the transaction
code. Move its definition into transaction.h as an inline function since
it's a very short and trivial function, and also add the 'btrfs_' prefix
into its name.

This change also reduces the module size.

Before this change:

  $ size fs/btrfs/btrfs.ko
     text	   data	    bss	    dec	    hex	filename
  1783148	 161137	  16920	1961205	 1decf5	fs/btrfs/btrfs.ko

After this change:

  $ size fs/btrfs/btrfs.ko
     text	   data	    bss	    dec	    hex	filename
  1782126	 161045	  16920	1960091	 1de89b	fs/btrfs/btrfs.ko

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:17 +01:00
Johannes Thumshirn
63e5f9df7c btrfs: pass btrfs_io_geometry to is_single_device_io
Now that we have the stripe tree decision saved in struct
btrfs_io_geometry we can pass it into is_single_device_io() and get rid of
another call to btrfs_need_raid_stripe_tree_update().

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:16 +01:00
Johannes Thumshirn
9c48bcec47 btrfs: cache RAID stripe tree decision in btrfs_io_context
Cache the decision if a particular I/O needs to update RAID stripe tree
entries in struct btrfs_io_context.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:16 +01:00
Johannes Thumshirn
68ab9825a6 btrfs: cache stripe tree usage in struct btrfs_io_geometry
Cache the return of btrfs_need_stripe_tree_update() in struct
btrfs_io_geometry starting from btrfs_map_block().

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:16 +01:00
Filipe Manana
88694f74f4 btrfs: add assertions and comment about path expectations to btrfs_cross_ref_exist()
We should always call check_delayed_ref() with a path having a locked leaf
from the extent tree where either the extent item is located or where it
should be located in case it doesn't exist yet (when there's a pending
unflushed delayed ref to do it), as we need to lock any existing delayed
ref head while holding such leaf locked in order to avoid races with
flushing delayed references, which could make us think an extent is not
shared when it really is.

So add some assertions and a comment about such expectations to
btrfs_cross_ref_exist(), which is the only caller of check_delayed_ref().

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:16 +01:00
Filipe Manana
2747c55595 btrfs: add function comment for check_committed_ref()
There are some not immediately obvious details about the operation of
check_committed_ref(), namely that when it returns 0 it must return with
the path having a locked leaf from the extent tree that contains the
extent's extent item, so that we can later check for delayed refs when
calling check_delayed_ref() in a way that doesn't race with a task running
delayed references. For similar reasons, it must also return with a locked
leaf when the extent item is not found, and that leaf is where the extent
item should be located, because we may have delayed references that are
going to create the extent item. Also document that the function can
return false positives in order to not be too slow, and that the most
important is to not return false negatives.

So add a function comment to check_committed_ref().

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:16 +01:00
Filipe Manana
9e0d43ea4e btrfs: simplify arguments for btrfs_cross_ref_exist()
Instead of passing a root and an objectid which matches an inode number,
pass the inode instead, since the root is always the root associated to
the inode and the objectid is the number of that inode.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:16 +01:00
Filipe Manana
adf7da3f26 btrfs: simplify return logic at check_committed_ref()
Instead of setting the value to return in a local variable 'ret' and then
jumping into a label named 'out' that does nothing but return that value,
simplify everything by getting rid of the label and directly returning a
value.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:16 +01:00
Filipe Manana
78cdfba85d btrfs: avoid redundant call to get inline ref type at check_committed_ref()
At check_committed_ref() we are calling btrfs_get_extent_inline_ref_type()
twice, once before we check if have an inline extent owner ref (for simple
qgroups) and then once again sometime after that check. This second call
is redundant when we have simple quotas disabled or we found an inline ref
that is not of the owner ref type. So avoid this second call unless we
have simple quotas enabled and found an owner ref, saving a function call
that does inline ref validation again.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:16 +01:00
Filipe Manana
4f000a87fb btrfs: remove the snapshot check from check_committed_ref()
At check_committed_ref() we have this check to see if the data extent was
created in a generation lower than or equals to the generation where the
last snapshot for the root was created, and if so we return immediately
with 1, since it's very likely the extent is shared, referenced by other
root.

The only call chain for check_committed_ref() is the following:

   can_nocow_file_extent()
      btrfs_cross_ref_exist()
         check_committed_ref()

And we already do that snapshot check at can_nocow_file_extent(), before
we call btrfs_cross_ref_exist(). This makes the check done at
check_committed_ref() redundant, so remove it.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:16 +01:00
Filipe Manana
6c44075524 btrfs: remove no longer needed strict argument from can_nocow_extent()
All callers of can_nocow_extent() now pass a value of false for its
'strict' argument, making it redundant. So remove the argument from
can_nocow_extent() as well as can_nocow_file_extent(),
btrfs_cross_ref_exist() and check_committed_ref(), because this
argument was used just to influence the behavior of check_committed_ref().
Also remove the 'strict' field from struct can_nocow_file_extent_args,
which is now always false as well, as its value is taken from the
argument to can_nocow_extent().

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:16 +01:00
Johannes Thumshirn
4016358e85 btrfs: remove unused variable length in btrfs_insert_one_raid_extent()
Remove the variable length in btrfs_insert_one_raid_extent() as it is
unused.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:16 +01:00
Qu Wenruo
d0f038104f btrfs: output the reason for open_ctree() failure
There is a recent ML report that mounting a large fs backed by hardware
RAID56 controller (with one device missing) took too much time, and
systemd seems to kill the mount attempt.

In that case, the only error message is:

  BTRFS error (device sdj): open_ctree failed

There is no reason on why the failure happened, making it very hard to
understand the reason.

At least output the error number (in the particular case it should be
-EINTR) to provide some clue.

Link: https://lore.kernel.org/linux-btrfs/9b9c4d2810abcca2f9f76e32220ed9a90febb235.camel@scientia.org/
Reported-by: Christoph Anton Mitterer <calestyo@scientia.org>
Cc: stable@vger.kernel.org
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:15 +01:00
Qu Wenruo
a883120b2d btrfs: open-code btrfs_copy_from_user()
The function btrfs_copy_from_user() handles the folio dirtying for
buffered write. The original design is to allow that function to handle
multiple folios, but since commit c87c299776 ("btrfs: make buffered
write to copy one page a time") there is no need to support multiple
folios.

So here open-code btrfs_copy_from_user() to
copy_folio_from_iter_atomic() and flush_dcache_folio() calls.

The short-copy check and revert are still kept as-is.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:15 +01:00
Qu Wenruo
c0def46dec btrfs: improve the warning and error message for btrfs_remove_qgroup()
[WARNING]
There are several warnings about the recently introduced qgroup
auto-removal that it triggers WARN_ON() for the non-zero rfer/excl
numbers, e.g:

 ------------[ cut here ]------------
 WARNING: CPU: 67 PID: 2882 at fs/btrfs/qgroup.c:1854 btrfs_remove_qgroup+0x3df/0x450
 CPU: 67 UID: 0 PID: 2882 Comm: btrfs-cleaner Kdump: loaded Not tainted 6.11.6-300.fc41.x86_64 #1
 RIP: 0010:btrfs_remove_qgroup+0x3df/0x450
 Call Trace:
  <TASK>
  btrfs_qgroup_cleanup_dropped_subvolume+0x97/0xc0
  btrfs_drop_snapshot+0x44e/0xa80
  btrfs_clean_one_deleted_snapshot+0xc3/0x110
  cleaner_kthread+0xd8/0x130
  kthread+0xd2/0x100
  ret_from_fork+0x34/0x50
  ret_from_fork_asm+0x1a/0x30
  </TASK>
 ---[ end trace 0000000000000000 ]---
 BTRFS warning (device sda): to be deleted qgroup 0/319 has non-zero numbers, rfer 258478080 rfer_cmpr 258478080 excl 0 excl_cmpr 0

[CAUSE]
Although the root cause is still unclear, as if qgroup is consistent a
fully dropped subvolume (with extra transaction committed) should lead
to all zero numbers for the qgroup.

My current guess is the subvolume drop triggered the new subtree drop
threshold thus marked qgroup inconsistent, then rescan cleared it but
some corner case is not properly handled during subvolume dropping.

But at least for this particular case, since it's only the rfer/excl not
properly reset to 0, and qgroup is already marked inconsistent, there is
nothing to be worried for the end users.

The user space tool utilizing qgroup would queue a rescan to handle
everything, so the kernel wanring is a little overkilled.

[ENHANCEMENT]
Enhance the warning inside btrfs_remove_qgroup() by:

- Only do WARN() if CONFIG_BTRFS_DEBUG is enabled
  As explained the kernel can handle inconsistent qgroups by simply do a
  rescan, there is nothing to bother the end users.

- Treat the reserved space leak the same as non-zero numbers
  By outputting the values and trigger a WARN() if it's a debug build.
  So far I haven't experienced any case related to reserved space so I
  hope we will never need to bother them.

Fixes: 839d6ea4f8 ("btrfs: automatically remove the subvolume qgroup")
Link: https://github.com/kdave/btrfs-progs/issues/922
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:15 +01:00
Josef Bacik
f974bc3c9a btrfs: remove detached list from struct btrfs_backref_cache
We don't ever look at this list, remove it.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:15 +01:00
Josef Bacik
b61e0eb037 btrfs: remove the ->lowest and ->leaves members from struct btrfs_backref_node
Before we were keeping all of our nodes on various lists in order to
make sure everything got cleaned up correctly.  We used node->lowest to
indicate that node->lower was linked into the cache->leaves list.  Now
that we do cleanup based on the rb-tree both the list and the flag are
useless, so delete them both.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:15 +01:00
Josef Bacik
29e74a12a3 btrfs: simplify btrfs_backref_release_cache()
We rely on finding all our nodes on the various lists in the backref
cache, when they are all also in the rbtree.  Instead just search
through the rbtree and free everything.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:15 +01:00
Josef Bacik
4eb8064dc9 btrfs: do not handle non-shareable roots in backref cache
Now that we handle relocation for non-shareable roots without using the
backref cache, remove the ->cowonly field from the backref nodes and
update the handling to throw an error.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:15 +01:00
Josef Bacik
46bb6765d3 btrfs: don't build backref tree for COW-only blocks
We already determine the owner for any blocks we find when we're
relocating, and for COW-only blocks (and the data reloc tree) we COW
down to the block and call it good enough.  However we still build a
whole backref tree for them, even though we're not going to use it, and
then just don't put these blocks in the cache.

Rework the code to check if the block belongs to a COW-only root or the
data reloc root, and then just cow down to the block, skipping the
backref cache generation.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:15 +01:00
Josef Bacik
0097422c0d btrfs: remove clone_backref_node() from relocation
Since we no longer maintain backref cache across transactions, and this
is only called when we're creating the reloc root for a newly created
snapshot in the transaction critical section, we will end up doing a
bunch of work that will just get thrown away when we start the
transaction in the relocation loop.  Delete this code as it no longer
does anything for us.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:15 +01:00
Josef Bacik
551d04a32a btrfs: simplify loop in select_reloc_root()
We have this setup as a loop, but in reality we will never walk back up
the backref tree, if we do then it's a bug.  Get rid of the loop and
handle the case where we have node->new_bytenr set at all.  Previous
check was only if node->new_bytenr != root->node->start, but if it did
then we would hit the WARN_ON() and walk back up the tree.

Instead we want to just return error if ->new_bytenr is set, and then do
the normal updating of the node for the reloc root and carry on.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:15 +01:00
Josef Bacik
cb7de8ee9c btrfs: add a comment for new_bytenr in backref_cache_node
Add a comment for this field so we know what it is used for.  Previously
we used it to update the backref cache, so people may mistakenly think
it is useless, but in fact exists to make sure the backref cache makes
sense.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:15 +01:00
Josef Bacik
b1d4d5d1d8 btrfs: remove the changed list for backref cache
Now that we're not updating the backref cache when we switch transids we
can remove the changed list.

We're going to keep the new_bytenr field because it serves as a good
sanity check for the backref cache and relocation, and can prevent us
from making extent tree corruption worse.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:14 +01:00
Josef Bacik
6a4730b325 btrfs: convert BUG_ON in btrfs_reloc_cow_block() to proper error handling
This BUG_ON is meant to catch backref cache problems, but these can
arise from either bugs in the backref cache or corruption in the extent
tree.  Fix it to be a proper error.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:14 +01:00
Hao-ran Zheng
5324c4e10e btrfs: fix data race when accessing the inode's disk_i_size at btrfs_drop_extents()
A data race occurs when the function `insert_ordered_extent_file_extent()`
and the function `btrfs_inode_safe_disk_i_size_write()` are executed
concurrently. The function `insert_ordered_extent_file_extent()` is not
locked when reading inode->disk_i_size, causing
`btrfs_inode_safe_disk_i_size_write()` to cause data competition when
writing inode->disk_i_size, thus affecting the value of `modify_tree`.

The specific call stack that appears during testing is as follows:

  ============DATA_RACE============
   btrfs_drop_extents+0x89a/0xa060 [btrfs]
   insert_reserved_file_extent+0xb54/0x2960 [btrfs]
   insert_ordered_extent_file_extent+0xff5/0x1760 [btrfs]
   btrfs_finish_one_ordered+0x1b85/0x36a0 [btrfs]
   btrfs_finish_ordered_io+0x37/0x60 [btrfs]
   finish_ordered_fn+0x3e/0x50 [btrfs]
   btrfs_work_helper+0x9c9/0x27a0 [btrfs]
   process_scheduled_works+0x716/0xf10
   worker_thread+0xb6a/0x1190
   kthread+0x292/0x330
   ret_from_fork+0x4d/0x80
   ret_from_fork_asm+0x1a/0x30
  ============OTHER_INFO============
   btrfs_inode_safe_disk_i_size_write+0x4ec/0x600 [btrfs]
   btrfs_finish_one_ordered+0x24c7/0x36a0 [btrfs]
   btrfs_finish_ordered_io+0x37/0x60 [btrfs]
   finish_ordered_fn+0x3e/0x50 [btrfs]
   btrfs_work_helper+0x9c9/0x27a0 [btrfs]
   process_scheduled_works+0x716/0xf10
   worker_thread+0xb6a/0x1190
   kthread+0x292/0x330
   ret_from_fork+0x4d/0x80
   ret_from_fork_asm+0x1a/0x30
  =================================

The main purpose of the check of the inode's disk_i_size is to avoid
taking write locks on a btree path when we have a write at or beyond
EOF, since in these cases we don't expect to find extent items in the
root to drop. However if we end up taking write locks due to a data
race on disk_i_size, everything is still correct, we only add extra
lock contention on the tree in case there's concurrency from other tasks.
If the race causes us to not take write locks when we actually need them,
then everything is functionally correct as well, since if we find out we
have extent items to drop and we took read locks (modify_tree set to 0),
we release the path and retry again with write locks.

Since this data race does not affect the correctness of the function,
it is a harmless data race, use data_race() to check inode->disk_i_size.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Hao-ran Zheng <zhenghaoran154@gmail.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:14 +01:00
Johannes Thumshirn
f6f0da564c btrfs: don't BUG_ON() in btrfs_drop_extents()
btrfs_drop_extents() calls BUG_ON() in case the counter of to be deleted
extents is greater than 0. But all of these code paths can handle errors,
so there's no need to crash the kernel. Instead WARN() that the condition
has been met and gracefully bail out.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:14 +01:00
Naohiro Aota
453a73c306 btrfs: zoned: reclaim unused zone by zone resetting
On the zoned mode, once used and freed region is still not reusable after the
freeing. The underlying zone needs to be reset before reusing. Btrfs resets a
zone when it removes a block group, and then new block group is allocated on
the zones to reuse the zones. But, it is sometime too late to catch up with a
write side.

This commit introduces a new space-info reclaim method ZONE_RESET. That will
pick a block group from the unused list and reset its zone to reuse the
zone_unusable space. It is faster than removing the block group and re-creating
a new block group on the same zones.

For the first implementation, the ZONE_RESET is only applied to a block group
whose region is fully zone_unusable. Reclaiming partial zone_unusable block
group could be implemented later.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:14 +01:00
Naohiro Aota
7de9ca1f30 btrfs: drop fs_info argument from btrfs_update_space_info_*()
Since commit e1e577aafe41 ("btrfs: store fs_info in space_info"), we have
the fs_info in a space_info. So, we can drop fs_info argument from
btrfs_update_space_info_*. There is no behavior change.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:14 +01:00
Naohiro Aota
3704db1013 btrfs: factor out btrfs_return_free_space()
Factor out a part of unpin_extent_range() that returns space back to the
space info, prioritizing global block reserve.  Also, move the "len"
variable into the loop to clarify we don't need to carry it beyond an
iteration.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:14 +01:00
Allison Karlitskaya
bfcf6d04f8 btrfs: handle FS_IOC_READ_VERITY_METADATA ioctl
Commit 146054090b ("btrfs: initial fsverity support") introduced
fs-verity support for btrfs, but didn't add support for
FS_IOC_READ_VERITY_METADATA to directly query the Merkle tree,
descriptor and signature blocks for fs-verity enabled files.

Add the (trival) implementation: we just need to wire it through to the
fs-verity code, the same way as is done in the other two filesystems
which support this ioctl (ext4, f2fs). The fs-verity code already has
access to the required data.

This is also safe to backport to older stable trees (5.15+) if needed.

Signed-off-by: Allison Karlitskaya <allison.karlitskaya@redhat.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:14 +01:00
Colin Ian King
d0ad40d730 btrfs: send: remove redundant assignments to variable ret
The variable ret is being initialized to zero and also later re-assigned
to zero. In both cases the assignment is redundant since the value is
never read after the assignment and hence they can be removed.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:14 +01:00
Qu Wenruo
27602f1d1b btrfs: use PTR_ERR() instead of PTR_ERR_OR_ZERO() for btrfs_get_extent()
The function btrfs_get_extent() will only return an PTR_ERR() or a valid
extent map pointer. It will not return NULL.

Thus the usage of PTR_ERR_OR_ZERO() inside submit_one_sector() is not
needed, use plain PTR_ERR() instead, and that is the only usage of
PTR_ERR_OR_ZERO() after btrfs_get_extent().

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:14 +01:00
Josef Bacik
2b34879d97 btrfs: selftests: add delayed ref self test cases
The recent fix for a stupid mistake I made uncovered the fact that we
don't have adequate testing in the delayed refs code, as it took a
pretty extensive and long running stress test to uncover something that
a unit test would have uncovered right away.

Fix this by adding a delayed refs self test suite.  This will validate
that the btrfs_ref transformation does the correct thing, that we do the
correct thing when merging delayed refs, and that we get the delayed
refs in the order that we expect.  These are all crucial to how the
delayed refs operate.

I introduced various bugs (including the original bug) into the delayed
refs code to validate that these tests caught all of the shenanigans
that I could think of.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:13 +01:00
Josef Bacik
5473aeedff btrfs: move select_delayed_ref() and export it
This helper is how we select the delayed ref to run once we've selected
the delayed ref head.  I need this exported to add a unit test for
delayed refs, and it's more natural home is in delayed-ref.c.  Rename it
to btrfs_select_delayed_ref and move it into delayed-ref.c.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-13 14:53:13 +01:00
Linus Torvalds
643e2e259c for-6.13-rc6-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmd/7dYACgkQxWXV+ddt
 WDuX7Q//UkrNtVh7UEiyNyujLjjvczfMXhpD1fAdVU0zMon6ux3RQ3JSs3xvAGrb
 jFFa9c9+Db8/kWzdWp5n1u9Q/+sy4XBaeKGuzPRLPPGT1yXfKEa4mrm1sCrWRJoS
 c8b07Kfuepldcim80x8WSa2qhr5gmDmSZBgvjKt63ppp5/jaNKCZg+d3BhwqhHbI
 XA9JjIk9j0ZsAYauYflQTwgUpkyvXV1a9YyeKv4U6mYA1r+rXl2aolcndNkS1U/D
 dDGuiDpOjKtIUecRi4YbOkt2zvwREDdQCbRV/QLsZajHxqeHV5QH0TBI/URikx2z
 1shwYMzLfLtQIW0+PhHCGKiftMIb4NliyMUxxviPdN78nCFmocrR/ZkPx+a5M9Io
 d7oqwS/8U3pFGeB4bAey8WvMzQI5BtCCYJY+3HreNTDkiubqcRtTCtJ9dNDTAMFH
 FMZ6DA8wTsqSA2e9Q8OwKNjvMCLAKevXn/4wiJi5b75Fiu5ZB/imTfJ+geEMUZCR
 3uq9oybFCKti7lestM0z06K19AKtmPWLoq5YJ1Hg69DsafS2aR3CBeYOi7uQ+56D
 7uwAFjVrGPrxOgGkCohYpPLCUikJ0y3Nl/k5fnybsnLPWr0cenLroUeP7Rao4fFU
 8hLzMSv3ImL+Io0RjH0XBAM8YLN+xO3CLYCv6D8d42AlQTgAIVw=
 =QYC1
 -----END PGP SIGNATURE-----

Merge tag 'for-6.13-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "A few more fixes.

  Besides the one-liners in Btrfs there's fix to the io_uring and
  encoded read integration (added in this development cycle). The update
  to io_uring provides more space for the ongoing command that is then
  used in Btrfs to handle some cases.

   - io_uring and encoded read:
       - provide stable storage for io_uring command data
       - make a copy of encoded read ioctl call, reuse that in case the
         call would block and will be called again

   - properly initialize zlib context for hardware compression on s390

   - fix max extent size calculation on filesystems with non-zoned
     devices

   - fix crash in scrub on crafted image due to invalid extent tree"

* tag 'for-6.13-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: zlib: fix avail_in bytes for s390 zlib HW compression path
  btrfs: zoned: calculate max_extent_size properly on non-zoned setup
  btrfs: avoid NULL pointer dereference if no valid extent tree
  btrfs: don't read from userspace twice in btrfs_uring_encoded_read()
  io_uring: add io_uring_cmd_get_async_data helper
  io_uring/cmd: add per-op data to struct io_uring_cmd_data
  io_uring/cmd: rename struct uring_cache to io_uring_cmd_data
2025-01-09 10:16:45 -08:00
Mikhail Zaslonko
0ee4736c00 btrfs: zlib: fix avail_in bytes for s390 zlib HW compression path
Since the input data length passed to zlib_compress_folios() can be
arbitrary, always setting strm.avail_in to a multiple of PAGE_SIZE may
cause read-in bytes to exceed the input range. Currently this triggers
an assert in btrfs_compress_folios() on the debug kernel (see below).
Fix strm.avail_in calculation for S390 hardware acceleration path.

  assertion failed: *total_in <= orig_len, in fs/btrfs/compression.c:1041
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/compression.c:1041!
  monitor event: 0040 ilc:2 [#1] PREEMPT SMP
  CPU: 16 UID: 0 PID: 325 Comm: kworker/u273:3 Not tainted 6.13.0-20241204.rc1.git6.fae3b21430ca.300.fc41.s390x+debug #1
  Hardware name: IBM 3931 A01 703 (z/VM 7.4.0)
  Workqueue: btrfs-delalloc btrfs_work_helper
  Krnl PSW : 0704d00180000000 0000021761df6538 (btrfs_compress_folios+0x198/0x1a0)
             R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:1 PM:0 RI:0 EA:3
  Krnl GPRS: 0000000080000000 0000000000000001 0000000000000047 0000000000000000
             0000000000000006 ffffff01757bb000 000001976232fcc0 000000000000130c
             000001976232fcd0 000001976232fcc8 00000118ff4a0e30 0000000000000001
             00000111821ab400 0000011100000000 0000021761df6534 000001976232fb58
  Krnl Code: 0000021761df6528: c020006f5ef4        larl    %r2,0000021762be2310
             0000021761df652e: c0e5ffbd09d5        brasl   %r14,00000217615978d8
            #0000021761df6534: af000000            mc      0,0
            >0000021761df6538: 0707                bcr     0,%r7
             0000021761df653a: 0707                bcr     0,%r7
             0000021761df653c: 0707                bcr     0,%r7
             0000021761df653e: 0707                bcr     0,%r7
             0000021761df6540: c004004bb7ec        brcl    0,000002176276d518
  Call Trace:
   [<0000021761df6538>] btrfs_compress_folios+0x198/0x1a0
  ([<0000021761df6534>] btrfs_compress_folios+0x194/0x1a0)
   [<0000021761d97788>] compress_file_range+0x3b8/0x6d0
   [<0000021761dcee7c>] btrfs_work_helper+0x10c/0x160
   [<0000021761645760>] process_one_work+0x2b0/0x5d0
   [<000002176164637e>] worker_thread+0x20e/0x3e0
   [<000002176165221a>] kthread+0x15a/0x170
   [<00000217615b859c>] __ret_from_fork+0x3c/0x60
   [<00000217626e72d2>] ret_from_fork+0xa/0x38
  INFO: lockdep is turned off.
  Last Breaking-Event-Address:
   [<0000021761597924>] _printk+0x4c/0x58
  Kernel panic - not syncing: Fatal exception: panic_on_oops

Fixes: fd1e75d010 ("btrfs: make compression path to be subpage compatible")
CC: stable@vger.kernel.org # 6.12+
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-06 16:32:43 +01:00
Christoph Hellwig
7467bc5959 btrfs: zoned: calculate max_extent_size properly on non-zoned setup
Since commit 559218d43e ("block: pre-calculate max_zone_append_sectors"),
queue_limits's max_zone_append_sectors is default to be 0 and it is only
updated when there is a zoned device. So, we have
lim->max_zone_append_sectors = 0 when there is no zoned device in the
filesystem.

That leads to fs_info->max_zone_append_size and thus
fs_info->max_extent_size to be 0, which is wrong and can for example
lead to a divide by zero in count_max_extents().

Fix this by only capping fs_info->max_extent_size to
fs_info->max_zone_append_size when it is non-zero.

Based on a patch from Naohiro Aota <naohiro.aota@wdc.com>, from which
much of this commit message is stolen as well.

Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: 559218d43e ("block: pre-calculate max_zone_append_sectors")
Tested-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-06 16:32:35 +01:00
Qu Wenruo
6aecd91a5c btrfs: avoid NULL pointer dereference if no valid extent tree
[BUG]
Syzbot reported a crash with the following call trace:

  BTRFS info (device loop0): scrub: started on devid 1
  BUG: kernel NULL pointer dereference, address: 0000000000000208
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 106e70067 P4D 106e70067 PUD 107143067 PMD 0
  Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI
  CPU: 1 UID: 0 PID: 689 Comm: repro Kdump: loaded Tainted: G           O       6.13.0-rc4-custom+ #206
  Tainted: [O]=OOT_MODULE
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022
  RIP: 0010:find_first_extent_item+0x26/0x1f0 [btrfs]
  Call Trace:
   <TASK>
   scrub_find_fill_first_stripe+0x13d/0x3b0 [btrfs]
   scrub_simple_mirror+0x175/0x260 [btrfs]
   scrub_stripe+0x5d4/0x6c0 [btrfs]
   scrub_chunk+0xbb/0x170 [btrfs]
   scrub_enumerate_chunks+0x2f4/0x5f0 [btrfs]
   btrfs_scrub_dev+0x240/0x600 [btrfs]
   btrfs_ioctl+0x1dc8/0x2fa0 [btrfs]
   ? do_sys_openat2+0xa5/0xf0
   __x64_sys_ioctl+0x97/0xc0
   do_syscall_64+0x4f/0x120
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
   </TASK>

[CAUSE]
The reproducer is using a corrupted image where extent tree root is
corrupted, thus forcing to use "rescue=all,ro" mount option to mount the
image.

Then it triggered a scrub, but since scrub relies on extent tree to find
where the data/metadata extents are, scrub_find_fill_first_stripe()
relies on an non-empty extent root.

But unfortunately scrub_find_fill_first_stripe() doesn't really expect
an NULL pointer for extent root, it use extent_root to grab fs_info and
triggered a NULL pointer dereference.

[FIX]
Add an extra check for a valid extent root at the beginning of
scrub_find_fill_first_stripe().

The new error path is introduced by 42437a6386 ("btrfs: introduce
mount option rescue=ignorebadroots"), but that's pretty old, and later
commit b979547513 ("btrfs: scrub: introduce helper to find and fill
sector info for a scrub_stripe") changed how we do scrub.

So for kernels older than 6.6, the fix will need manual backport.

Reported-by: syzbot+339e9dbe3a2ca419b85d@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/67756935.050a0220.25abdd.0a12.GAE@google.com/
Fixes: 42437a6386 ("btrfs: introduce mount option rescue=ignorebadroots")
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-06 16:32:31 +01:00
Mark Harmstone
c21b89d495 btrfs: don't read from userspace twice in btrfs_uring_encoded_read()
If we return -EAGAIN the first time because we need to block,
btrfs_uring_encoded_read() will get called twice. Take a copy of args,
the iovs, and the iter the first time, as by the time we are called the
second time these may have gone out of scope.

Reported-by: Jens Axboe <axboe@kernel.dk>
Fixes: 34310c442e ("btrfs: add io_uring command for encoded reads (ENCODED_READ ioctl)")
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2025-01-06 13:59:29 +01:00
Linus Torvalds
c059361673 for-6.13-rc4-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmdw8AgACgkQxWXV+ddt
 WDsL4w/+Ib5WGmd2Rjn1+1X9U5dzrEb+/072UBAhwwaqOOUTlBofeyRSdYqFB0oZ
 aucRMXdXPpVe1xrXsj0WsOZmPsuZT46Eh2ALqqZP5fO1sgBkJ2WmQF0Ei7uypfb+
 abQwiEO2IaMMwt2XgDNzbpZS7oVNGEXHzoHF0R/deL4FoBDNMsbCfRnW+L9++tWU
 dUSpafLhgMMwivJN07VJYwU4ZVXsBhmKv2qI8WpJ5w9kJb1ssN692CvBOVjhuSYd
 A8IMV84dW2KO37fmPqN36QAWotz4mKpv8yrhjJvrix7nAOcXe3TXFUhaFBh1Vmzg
 G5bhkqYcNP6UHT7CIcLZE1mdv6ZAKTp0zSNCh2Uu51+MJL2tIQVjTaUQhbkYLnLN
 9DS2dXz4ksm9ISrjr2tmPe4kgyNQIrp5TCdwXu3CYs+AaU7yKeEBukZ7mXcp/e/W
 TdLKvzPRLMED8mGlFBwg2QbOvcJJ663UW2esyv6DvC61F3tXyiV2RXSC/1qF+RyZ
 FBJvvEevensQlASn1NScuQV+iEQpMo2lMURnRjSG8dGhwMmHpW3wifa2TJDyBzWS
 AH0MriQA9nsYQTkPGPnqr46/BAhFG2vEfVlX20Sk9S0PTBLu8YRy/o2evcV67J8v
 zGaa5pa7fQPbEjRv4Rthdb4R2VIFkZTOtIZSZfjHkPDjtvS7ahU=
 =NwGH
 -----END PGP SIGNATURE-----

Merge tag 'for-6.13-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "A few more fixes that accumulated over the last two weeks, fixing some
  user reported problems:

   - swapfile fixes:
       - conditional reschedule in the activation loop
       - fix race with memory mapped file when activating
       - make activation loop interruptible
       - rework and fix extent sharing checks

   - folio fixes:
       - in send, recheck folio mapping after unlock
       - in relocation, recheck folio mapping after unlock

   - fix waiting for encoded read io_uring requests

   - fix transaction atomicity when enabling simple quotas

   - move COW block trace point before the block gets freed

   - print various sizes in sysfs with correct endianity"

* tag 'for-6.13-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: sysfs: fix direct super block member reads
  btrfs: fix transaction atomicity bug when enabling simple quotas
  btrfs: avoid monopolizing a core when activating a swap file
  btrfs: allow swap activation to be interruptible
  btrfs: fix swap file activation failure due to extents that used to be shared
  btrfs: fix race with memory mapped writes when activating swap file
  btrfs: check folio mapping after unlock in put_file_data()
  btrfs: check folio mapping after unlock in relocate_one_folio()
  btrfs: fix use-after-free when COWing tree bock and tracing is enabled
  btrfs: fix use-after-free waiting for encoded read endios
2024-12-29 09:34:34 -08:00
Qu Wenruo
fca432e73d btrfs: sysfs: fix direct super block member reads
The following sysfs entries are reading super block member directly,
which can have a different endian and cause wrong values:

- sys/fs/btrfs/<uuid>/nodesize
- sys/fs/btrfs/<uuid>/sectorsize
- sys/fs/btrfs/<uuid>/clone_alignment

Thankfully those values (nodesize and sectorsize) are always aligned
inside the btrfs_super_block, so it won't trigger unaligned read errors,
just endian problems.

Fix them by using the native cached members instead.

Fixes: df93589a17 ("btrfs: export more from FS_INFO to sysfs")
CC: stable@vger.kernel.org
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-23 22:06:44 +01:00
Julian Sun
f2363e6fcc btrfs: fix transaction atomicity bug when enabling simple quotas
Set squota incompat bit before committing the transaction that enables
the feature.

With the config CONFIG_BTRFS_ASSERT enabled, an assertion
failure occurs regarding the simple quota feature.

  [5.596534] assertion failed: btrfs_fs_incompat(fs_info, SIMPLE_QUOTA), in fs/btrfs/qgroup.c:365
  [5.597098] ------------[ cut here ]------------
  [5.597371] kernel BUG at fs/btrfs/qgroup.c:365!
  [5.597946] CPU: 1 UID: 0 PID: 268 Comm: mount Not tainted 6.13.0-rc2-00031-gf92f4749861b #146
  [5.598450] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
  [5.599008] RIP: 0010:btrfs_read_qgroup_config+0x74d/0x7a0
  [5.604303]  <TASK>
  [5.605230]  ? btrfs_read_qgroup_config+0x74d/0x7a0
  [5.605538]  ? exc_invalid_op+0x56/0x70
  [5.605775]  ? btrfs_read_qgroup_config+0x74d/0x7a0
  [5.606066]  ? asm_exc_invalid_op+0x1f/0x30
  [5.606441]  ? btrfs_read_qgroup_config+0x74d/0x7a0
  [5.606741]  ? btrfs_read_qgroup_config+0x74d/0x7a0
  [5.607038]  ? try_to_wake_up+0x317/0x760
  [5.607286]  open_ctree+0xd9c/0x1710
  [5.607509]  btrfs_get_tree+0x58a/0x7e0
  [5.608002]  vfs_get_tree+0x2e/0x100
  [5.608224]  fc_mount+0x16/0x60
  [5.608420]  btrfs_get_tree+0x2f8/0x7e0
  [5.608897]  vfs_get_tree+0x2e/0x100
  [5.609121]  path_mount+0x4c8/0xbc0
  [5.609538]  __x64_sys_mount+0x10d/0x150

The issue can be easily reproduced using the following reproducer:

  root@q:linux# cat repro.sh
  set -e

  mkfs.btrfs -q -f /dev/sdb
  mount /dev/sdb /mnt/btrfs
  btrfs quota enable -s /mnt/btrfs
  umount /mnt/btrfs
  mount /dev/sdb /mnt/btrfs

The issue is that when enabling quotas, at btrfs_quota_enable(), we set
BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE at fs_info->qgroup_flags and persist
it in the quota root in the item with the key BTRFS_QGROUP_STATUS_KEY, but
we only set the incompat bit BTRFS_FEATURE_INCOMPAT_SIMPLE_QUOTA after we
commit the transaction used to enable simple quotas.

This means that if after that transaction commit we unmount the filesystem
without starting and committing any other transaction, or we have a power
failure, the next time we mount the filesystem we will find the flag
BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE set in the item with the key
BTRFS_QGROUP_STATUS_KEY but we will not find the incompat bit
BTRFS_FEATURE_INCOMPAT_SIMPLE_QUOTA set in the superblock, triggering an
assertion failure at:

  btrfs_read_qgroup_config() -> qgroup_read_enable_gen()

To fix this issue, set the BTRFS_FEATURE_INCOMPAT_SIMPLE_QUOTA flag
immediately after setting the BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE.
This ensures that both flags are flushed to disk within the same
transaction.

Fixes: 182940f4f4 ("btrfs: qgroup: add new quota mode for simple quotas")
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Julian Sun <sunjunchao2870@gmail.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-23 22:05:05 +01:00
Filipe Manana
2c8507c63f btrfs: avoid monopolizing a core when activating a swap file
During swap activation we iterate over the extents of a file and we can
have many thousands of them, so we can end up in a busy loop monopolizing
a core. Avoid this by doing a voluntary reschedule after processing each
extent.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-23 22:04:48 +01:00
Filipe Manana
9a45022a0e btrfs: allow swap activation to be interruptible
During swap activation we iterate over the extents of a file, then do
several checks for each extent, some of which may take some significant
time such as checking if an extent is shared. Since a file can have
many thousands of extents, this can be a very slow operation and it's
currently not interruptible. I had a bug during development of a previous
patch that resulted in an infinite loop when iterating the extents, so
a core was busy looping and I couldn't cancel the operation, which is very
annoying and requires a reboot. So make the loop interruptible by checking
for fatal signals at the end of each iteration and stopping immediately if
there is one.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-23 22:04:38 +01:00
Filipe Manana
03018e5d85 btrfs: fix swap file activation failure due to extents that used to be shared
When activating a swap file, to determine if an extent is shared we use
can_nocow_extent(), which ends up at btrfs_cross_ref_exist(). That helper
is meant to be quick because it's used in the NOCOW write path, when
flushing delalloc and when doing a direct IO write, however it does return
some false positives, meaning it may indicate that an extent is shared
even if it's no longer the case. For the write path this is fine, we just
do a unnecessary COW operation instead of doing a more rigorous check
which would be too heavy (calling btrfs_is_data_extent_shared()).

However when activating a swap file, the false positives simply result
in a failure, which is confusing for users/applications. One particular
case where this happens is when a data extent only has 1 reference but
that reference is not inlined in the extent item located in the extent
tree - this happens when we create more than 33 references for an extent
and then delete those 33 references plus every other non-inline reference
except one. The function check_committed_ref() assumes that if the size
of an extent item doesn't match the size of struct btrfs_extent_item
plus the size of an inline reference (plus an owner reference in case
simple quotas are enabled), then the extent is shared - that is not the
case however, we can have a single reference but it's not inlined - the
reason we do this is to be fast and avoid inspecting non-inline references
which may be located in another leaf of the extent tree, slowing down
write paths.

The following test script reproduces the bug:

   $ cat test.sh
   #!/bin/bash

   DEV=/dev/sdi
   MNT=/mnt/sdi
   NUM_CLONES=50

   umount $DEV &> /dev/null

   run_test()
   {
        local sync_after_add_reflinks=$1
        local sync_after_remove_reflinks=$2

        mkfs.btrfs -f $DEV > /dev/null
        #mkfs.xfs -f $DEV > /dev/null
        mount $DEV $MNT

        touch $MNT/foo
        chmod 0600 $MNT/foo
   	# On btrfs the file must be NOCOW.
        chattr +C $MNT/foo &> /dev/null
        xfs_io -s -c "pwrite -b 1M 0 1M" $MNT/foo
        mkswap $MNT/foo

        for ((i = 1; i <= $NUM_CLONES; i++)); do
            touch $MNT/foo_clone_$i
            chmod 0600 $MNT/foo_clone_$i
            # On btrfs the file must be NOCOW.
            chattr +C $MNT/foo_clone_$i &> /dev/null
            cp --reflink=always $MNT/foo $MNT/foo_clone_$i
        done

        if [ $sync_after_add_reflinks -ne 0 ]; then
            # Flush delayed refs and commit current transaction.
            sync -f $MNT
        fi

        # Remove the original file and all clones except the last.
        rm -f $MNT/foo
        for ((i = 1; i < $NUM_CLONES; i++)); do
            rm -f $MNT/foo_clone_$i
        done

        if [ $sync_after_remove_reflinks -ne 0 ]; then
            # Flush delayed refs and commit current transaction.
            sync -f $MNT
        fi

        # Now use the last clone as a swap file. It should work since
        # its extent are not shared anymore.
        swapon $MNT/foo_clone_${NUM_CLONES}
        swapoff $MNT/foo_clone_${NUM_CLONES}

        umount $MNT
   }

   echo -e "\nTest without sync after creating and removing clones"
   run_test 0 0

   echo -e "\nTest with sync after creating clones"
   run_test 1 0

   echo -e "\nTest with sync after removing clones"
   run_test 0 1

   echo -e "\nTest with sync after creating and removing clones"
   run_test 1 1

Running the test:

   $ ./test.sh
   Test without sync after creating and removing clones
   wrote 1048576/1048576 bytes at offset 0
   1 MiB, 1 ops; 0.0017 sec (556.793 MiB/sec and 556.7929 ops/sec)
   Setting up swapspace version 1, size = 1020 KiB (1044480 bytes)
   no label, UUID=a6b9c29e-5ef4-4689-a8ac-bc199c750f02
   swapon: /mnt/sdi/foo_clone_50: swapon failed: Invalid argument
   swapoff: /mnt/sdi/foo_clone_50: swapoff failed: Invalid argument

   Test with sync after creating clones
   wrote 1048576/1048576 bytes at offset 0
   1 MiB, 1 ops; 0.0036 sec (271.739 MiB/sec and 271.7391 ops/sec)
   Setting up swapspace version 1, size = 1020 KiB (1044480 bytes)
   no label, UUID=5e9008d6-1f7a-4948-a1b4-3f30aba20a33
   swapon: /mnt/sdi/foo_clone_50: swapon failed: Invalid argument
   swapoff: /mnt/sdi/foo_clone_50: swapoff failed: Invalid argument

   Test with sync after removing clones
   wrote 1048576/1048576 bytes at offset 0
   1 MiB, 1 ops; 0.0103 sec (96.665 MiB/sec and 96.6651 ops/sec)
   Setting up swapspace version 1, size = 1020 KiB (1044480 bytes)
   no label, UUID=916c2740-fa9f-4385-9f06-29c3f89e4764

   Test with sync after creating and removing clones
   wrote 1048576/1048576 bytes at offset 0
   1 MiB, 1 ops; 0.0031 sec (314.268 MiB/sec and 314.2678 ops/sec)
   Setting up swapspace version 1, size = 1020 KiB (1044480 bytes)
   no label, UUID=06aab1dd-4d90-49c0-bd9f-3a8db4e2f912
   swapon: /mnt/sdi/foo_clone_50: swapon failed: Invalid argument
   swapoff: /mnt/sdi/foo_clone_50: swapoff failed: Invalid argument

Fix this by reworking btrfs_swap_activate() to instead of using extent
maps and checking for shared extents with can_nocow_extent(), iterate
over the inode's file extent items and use the accurate
btrfs_is_data_extent_shared().

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-23 22:04:17 +01:00
Filipe Manana
0525064bb8 btrfs: fix race with memory mapped writes when activating swap file
When activating the swap file we flush all delalloc and wait for ordered
extent completion, so that we don't miss any delalloc and extents before
we check that the file's extent layout is usable for a swap file and
activate the swap file. We are called with the inode's VFS lock acquired,
so we won't race with buffered and direct IO writes, however we can still
race with memory mapped writes since they don't acquire the inode's VFS
lock. The race window is between flushing all delalloc and locking the
whole file's extent range, since memory mapped writes lock an extent range
with the length of a page.

Fix this by acquiring the inode's mmap lock before we flush delalloc.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-23 22:03:43 +01:00
Boris Burkov
0fba7be1ca btrfs: check folio mapping after unlock in put_file_data()
When we call btrfs_read_folio() we get an unlocked folio, so it is possible
for a different thread to concurrently modify folio->mapping. We must
check that this hasn't happened once we do have the lock.

CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-23 22:00:07 +01:00
Boris Burkov
3e74859ee3 btrfs: check folio mapping after unlock in relocate_one_folio()
When we call btrfs_read_folio() to bring a folio uptodate, we unlock the
folio. The result of that is that a different thread can modify the
mapping (like remove it with invalidate) before we call folio_lock().
This results in an invalid page and we need to try again.

In particular, if we are relocating concurrently with aborting a
transaction, this can result in a crash like the following:

  BUG: kernel NULL pointer dereference, address: 0000000000000000
  PGD 0 P4D 0
  Oops: 0000 [#1] SMP
  CPU: 76 PID: 1411631 Comm: kworker/u322:5
  Workqueue: events_unbound btrfs_reclaim_bgs_work
  RIP: 0010:set_page_extent_mapped+0x20/0xb0
  RSP: 0018:ffffc900516a7be8 EFLAGS: 00010246
  RAX: ffffea009e851d08 RBX: ffffea009e0b1880 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: ffffc900516a7b90 RDI: ffffea009e0b1880
  RBP: 0000000003573000 R08: 0000000000000001 R09: ffff88c07fd2f3f0
  R10: 0000000000000000 R11: 0000194754b575be R12: 0000000003572000
  R13: 0000000003572fff R14: 0000000000100cca R15: 0000000005582fff
  FS:  0000000000000000(0000) GS:ffff88c07fd00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000000 CR3: 000000407d00f002 CR4: 00000000007706f0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  PKRU: 55555554
  Call Trace:
  <TASK>
  ? __die+0x78/0xc0
  ? page_fault_oops+0x2a8/0x3a0
  ? __switch_to+0x133/0x530
  ? wq_worker_running+0xa/0x40
  ? exc_page_fault+0x63/0x130
  ? asm_exc_page_fault+0x22/0x30
  ? set_page_extent_mapped+0x20/0xb0
  relocate_file_extent_cluster+0x1a7/0x940
  relocate_data_extent+0xaf/0x120
  relocate_block_group+0x20f/0x480
  btrfs_relocate_block_group+0x152/0x320
  btrfs_relocate_chunk+0x3d/0x120
  btrfs_reclaim_bgs_work+0x2ae/0x4e0
  process_scheduled_works+0x184/0x370
  worker_thread+0xc6/0x3e0
  ? blk_add_timer+0xb0/0xb0
  kthread+0xae/0xe0
  ? flush_tlb_kernel_range+0x90/0x90
  ret_from_fork+0x2f/0x40
  ? flush_tlb_kernel_range+0x90/0x90
  ret_from_fork_asm+0x11/0x20
  </TASK>

This occurs because cleanup_one_transaction() calls
destroy_delalloc_inodes() which calls invalidate_inode_pages2() which
takes the folio_lock before setting mapping to NULL. We fail to check
this, and subsequently call set_extent_mapping(), which assumes that
mapping != NULL (in fact it asserts that in debug mode)

Note that the "fixes" patch here is not the one that introduced the
race (the very first iteration of this code from 2009) but a more recent
change that made this particular crash happen in practice.

Fixes: e7f1326cc2 ("btrfs: set page extent mapped after read_folio in relocate_one_page")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-23 22:00:07 +01:00
Filipe Manana
44f52bbe96 btrfs: fix use-after-free when COWing tree bock and tracing is enabled
When a COWing a tree block, at btrfs_cow_block(), and we have the
tracepoint trace_btrfs_cow_block() enabled and preemption is also enabled
(CONFIG_PREEMPT=y), we can trigger a use-after-free in the COWed extent
buffer while inside the tracepoint code. This is because in some paths
that call btrfs_cow_block(), such as btrfs_search_slot(), we are holding
the last reference on the extent buffer @buf so btrfs_force_cow_block()
drops the last reference on the @buf extent buffer when it calls
free_extent_buffer_stale(buf), which schedules the release of the extent
buffer with RCU. This means that if we are on a kernel with preemption,
the current task may be preempted before calling trace_btrfs_cow_block()
and the extent buffer already released by the time trace_btrfs_cow_block()
is called, resulting in a use-after-free.

Fix this by moving the trace_btrfs_cow_block() from btrfs_cow_block() to
btrfs_force_cow_block() before the COWed extent buffer is freed.
This also has a side effect of invoking the tracepoint in the tree defrag
code, at defrag.c:btrfs_realloc_node(), since btrfs_force_cow_block() is
called there, but this is fine and it was actually missing there.

Reported-by: syzbot+8517da8635307182c8a5@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/6759a9b9.050a0220.1ac542.000d.GAE@google.com/
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-23 21:59:32 +01:00
Johannes Thumshirn
d29662695e btrfs: fix use-after-free waiting for encoded read endios
Fix a use-after-free in the I/O completion path for encoded reads by
using a completion instead of a wait_queue for synchronizing the
destruction of 'struct btrfs_encoded_read_private'.

Fixes: 1881fba89b ("btrfs: add BTRFS_IOC_ENCODED_READ ioctl")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-23 21:55:06 +01:00
Linus Torvalds
eabcdba3ad for-6.13-rc3-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmdhyQAACgkQxWXV+ddt
 WDuveg//bJSuXHrA7jkijst8rdoAFrceiUXuQPZ6bqb9QrSqlDZlP5/XQpdXZ3yU
 qJh/aE13cy0zWTQ2+fMcc770WSvU1cRW/f5BZ+fdXgvO8lS516suXGYd2Q06Cl9/
 DriAKGKtRfJn1BrEEv8+fjKS/chxZg6IR/W4kN6AinW31myY9jE5mEDAn+vyTDgQ
 8USZ/ar/3KuWo+wO5h5JzrvGnhzK0W0HRs/A0NZ3gG8J5T4yj+8zG0VJR4Gf93AL
 iBlsnAR8VzAYJOZCi36SD3j3/eDxJio5GhDYsdt28tk1bL8FqSuI4Yxt+LuiZ2Fg
 Cq/31lELEkyEH8AoVFm9pX3HNyRmV6JhpvDXiyofHaOUZ3VeivVE59gOShLUUMkn
 f9Pl/uh5/t/ioWWHBnCMyRpI9GZUGCvW24k7HjT7QZhsDGFLTm07diCiRgZ7eaOu
 LZRKMOL5jifAnfxNSvIJV19H4lQLTZfbdjmJyb6Il39tIU/1U9pXicgih3iyidW2
 N5n4pHf3OQFwG8kNw1mR1g1CPBALP62ja8kMv//IgH4YXXnm1Mo7B3CcJogAAmo4
 HB9f/gFqZ8kWaiuIUJKfPZkkLFt5x0TNZQyyOhVUd7V4mFdtEzVtZRWo3juYuLGk
 7Shp/MTlYokwnEropiWHU5ab3Bb9vLxlh8daGK/OmwBz01DaApI=
 =AAmb
 -----END PGP SIGNATURE-----

Merge tag 'for-6.13-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - tree-checker catches invalid number of inline extent references

 - zoned mode fixes:
    - enhance zone append IO command so it also detects emulated writes
    - handle bio splitting at sectorsize boundary

 - when deleting a snapshot, fix a condition for visiting nodes in reloc
   trees

* tag 'for-6.13-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: tree-checker: reject inline extent items with 0 ref count
  btrfs: split bios to the fs sector size boundary
  btrfs: use bio_is_zone_append() in the completion handler
  btrfs: fix improper generation check in snapshot delete
2024-12-18 14:17:21 -08:00
Qu Wenruo
dfb92681a1 btrfs: tree-checker: reject inline extent items with 0 ref count
[BUG]
There is a bug report in the mailing list where btrfs_run_delayed_refs()
failed to drop the ref count for logical 25870311358464 num_bytes
2113536.

The involved leaf dump looks like this:

  item 166 key (25870311358464 168 2113536) itemoff 10091 itemsize 50
    extent refs 1 gen 84178 flags 1
    ref#0: shared data backref parent 32399126528000 count 0 <<<
    ref#1: shared data backref parent 31808973717504 count 1

Notice the count number is 0.

[CAUSE]
There is no concrete evidence yet, but considering 0 -> 1 is also a
single bit flipped, it's possible that hardware memory bitflip is
involved, causing the on-disk extent tree to be corrupted.

[FIX]
To prevent us reading such corrupted extent item, or writing such
damaged extent item back to disk, enhance the handling of
BTRFS_EXTENT_DATA_REF_KEY and BTRFS_SHARED_DATA_REF_KEY keys for both
inlined and key items, to detect such 0 ref count and reject them.

CC: stable@vger.kernel.org # 5.4+
Link: https://lore.kernel.org/linux-btrfs/7c69dd49-c346-4806-86e7-e6f863a66f48@app.fastmail.com/
Reported-by: Frankie Fisher <frankie@terrorise.me.uk>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-17 19:54:32 +01:00
Christoph Hellwig
be691b5e59 btrfs: split bios to the fs sector size boundary
Btrfs like other file systems can't really deal with I/O not aligned to
it's internal block size (which strangely is called sector size in
btrfs, for historical reasons), but the block layer split helper doesn't
even know about that.

Round down the split boundary so that all I/Os are aligned.

Fixes: d5e4377d50 ("btrfs: split zone append bios in btrfs_submit_bio")
CC: stable@vger.kernel.org # 6.12
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-17 19:54:32 +01:00
Christoph Hellwig
6c3864e055 btrfs: use bio_is_zone_append() in the completion handler
Otherwise it won't catch bios turned into regular writes by the block
level zone write plugging. The additional test it adds is for emulated
zone append.

Fixes: 9b1ce7f0c6 ("block: Implement zone append emulation")
CC: stable@vger.kernel.org # 6.12
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-17 19:54:32 +01:00
Josef Bacik
d75d72a858 btrfs: fix improper generation check in snapshot delete
We have been using the following check

   if (generation <= root->root_key.offset)

to make decisions about whether or not to visit a node during snapshot
delete.  This is because for normal subvolumes this is set to 0, and for
snapshots it's set to the creation generation.  The idea being that if
the generation of the node is less than or equal to our creation
generation then we don't need to visit that node, because it doesn't
belong to us, we can simply drop our reference and move on.

However reloc roots don't have their generation stored in
root->root_key.offset, instead that is the objectid of their
corresponding fs root.  This means we can incorrectly not walk into
nodes that need to be dropped when deleting a reloc root.

There are a variety of consequences to making the wrong choice in two
distinct areas.

visit_node_for_delete()

1. False positive.  We think we are newer than the block when we really
   aren't.  We don't visit the node and drop our reference to the node
   and carry on.  This would result in leaked space.
2. False negative.  We do decide to walk down into a block that we
   should have just dropped our reference to.  However this means that
   the child node will have refs > 1, so we will switch to
   UPDATE_BACKREF, and then the subsequent walk_down_proc() will notice
   that btrfs_header_owner(node) != root->root_key.objectid and it'll
   break out of the loop, and then walk_up_proc() will drop our reference,
   so this appears to be ok.

do_walk_down()

1. False positive.  We are in UPDATE_BACKREF and incorrectly decide that
   we are done and don't need to update the backref for our lower nodes.
   This is another case that simply won't happen with relocation, as we
   only have to do UPDATE_BACKREF if the node below us was shared and
   didn't have FULL_BACKREF set, and since we don't own that node
   because we're a reloc root we actually won't end up in this case.
2. False negative.  Again this is tricky because as described above, we
   simply wouldn't be here from relocation, because we don't own any of
   the nodes because we never set btrfs_header_owner() to the reloc root
   objectid, and we always use FULL_BACKREF, we never actually need to
   set FULL_BACKREF on any children.

Having spent a lot of time stressing relocation/snapshot delete recently
I've not seen this pop in practice.  But this is objectively incorrect,
so fix this to get the correct starting generation based on the root
we're dropping to keep me from thinking there's a problem here.

CC: stable@vger.kernel.org
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-17 19:54:32 +01:00
Josef Bacik
5121711eb8 fs: enable pre-content events on supported file systems
Now that all the code has been added for pre-content events, and the
various file systems that need the page fault hooks for fsnotify have
been updated, add SB_I_ALLOW_HSM to the supported file systems.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/46960dcb2725fa0317895ed66a8409ba1c306a82.1731684329.git.josef@toxicpanda.com
2024-12-11 17:28:41 +01:00
Josef Bacik
b722e40be2 btrfs: disable defrag on pre-content watched files
We queue up inodes to be defrag'ed asynchronously, which means we do not
have their original file for readahead.  This means that the code to
skip readahead on pre-content watched files will not run, and we could
potentially read in empty pages.

Handle this corner case by disabling defrag on files that are currently
being watched for pre-content events.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/4cc5bcea13db7904174353d08e85157356282a59.1731684329.git.josef@toxicpanda.com
2024-12-11 17:28:41 +01:00
Linus Torvalds
5a087a6b17 for-6.13-rc2-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmdYzmoACgkQxWXV+ddt
 WDv5GxAAnCsGctNax89x/VpCDZynRghrkxlzu/4kG/pqxsJyzlgXDFtzHAEewSMs
 MYL+WCZLYpeKB5FpZq98mDJVLGNMG+9wqkx1bH/xy2ajBGZTeQe5pnkXMNlv9U1O
 SX34t8nzOdTCENDnQeRc5I2vTcsQRhgHoVjJkAYdWdhcD9fs6xHKZRe+himlstSn
 46ioKzEKSR3ztEUW4ycPF379g7d4kTR0hkk3pu5Nxe7ER8iq+jNSWXj0mzKg7mpJ
 KxP56VgY0OrsiUcJr2qFZ1hQIp810puaAuM4C1lLgRplECHxtLbP9JvL9Rr7a8Ox
 68tuThyLEpQtR59078jIX3RK6CwVi15rKb/ZkLZkW19TNSAAfM5qrB146hLBUM4T
 16WaiJ0x9lVkH2oYQv8zbNZiqDxPhPUdS/JArNAcQYk9ma+C1hCsxPQ/N5yoWH/C
 OABJddNR83sm4VTXu3Nci1EB8QuEoOuihYO6CdRkJ3PPNDuQiG6gwnoA2zqSihhy
 L5fQaLSWAUsLczarHZrvAi9Y0rfG66QzqGR+A1K/8qMTQ8pSCupd+LfqVa21QpI1
 Awx/wVFzsAm7z9CrnPTRJe+JSlBDQdeXWX7pDhhkXgwbCsMVSf3dbBweCD3o1EiM
 BVI7SfEgImlbatd0QvDp9FcsnEqp90SCi+99U+zZCmQ1SW8CEC0=
 =+DUB
 -----END PGP SIGNATURE-----

Merge tag 'for-6.13-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "A few more fixes. Apart from the one liners and updated bio splitting
  error handling there's a fix for subvolume mount with different flags.
  This was known and fixed for some time but I've delayed it to give it
  more testing.

   - fix unbalanced locking when swapfile activation fails when the
     subvolume gets deleted in the meantime

   - add btrfs error handling after bio_split() calls that got error
     handling recently

   - during unmount, flush delalloc workers at the right time before the
     cleaner thread is shut down

   - fix regression in buffered write folio conversion, explicitly wait
     for writeback as FGP_STABLE flag is currently a no-op on btrfs

   - handle race in subvolume mount with different flags, the conversion
     to the new mount API did not handle the case where multiple
     subvolumes get mounted in parallel, which is a distro use case"

* tag 'for-6.13-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: flush delalloc workers queue before stopping cleaner kthread during unmount
  btrfs: handle bio_split() errors
  btrfs: properly wait for writeback before buffered write
  btrfs: fix missing snapshot drew unlock when root is dead during swap activation
  btrfs: fix mount failure due to remount races
2024-12-10 18:18:01 -08:00
Filipe Manana
f10bef73fb btrfs: flush delalloc workers queue before stopping cleaner kthread during unmount
During the unmount path, at close_ctree(), we first stop the cleaner
kthread, using kthread_stop() which frees the associated task_struct, and
then stop and destroy all the work queues. However after we stopped the
cleaner we may still have a worker from the delalloc_workers queue running
inode.c:submit_compressed_extents(), which calls btrfs_add_delayed_iput(),
which in turn tries to wake up the cleaner kthread - which was already
destroyed before, resulting in a use-after-free on the task_struct.

Syzbot reported this with the following stack traces:

  BUG: KASAN: slab-use-after-free in __lock_acquire+0x78/0x2100 kernel/locking/lockdep.c:5089
  Read of size 8 at addr ffff8880259d2818 by task kworker/u8:3/52

  CPU: 1 UID: 0 PID: 52 Comm: kworker/u8:3 Not tainted 6.13.0-rc1-syzkaller-00002-gcdd30ebb1b9f #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
  Workqueue: btrfs-delalloc btrfs_work_helper
  Call Trace:
   <TASK>
   __dump_stack lib/dump_stack.c:94 [inline]
   dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
   print_address_description mm/kasan/report.c:378 [inline]
   print_report+0x169/0x550 mm/kasan/report.c:489
   kasan_report+0x143/0x180 mm/kasan/report.c:602
   __lock_acquire+0x78/0x2100 kernel/locking/lockdep.c:5089
   lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
   __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
   _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
   class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline]
   try_to_wake_up+0xc2/0x1470 kernel/sched/core.c:4205
   submit_compressed_extents+0xdf/0x16e0 fs/btrfs/inode.c:1615
   run_ordered_work fs/btrfs/async-thread.c:288 [inline]
   btrfs_work_helper+0x96f/0xc40 fs/btrfs/async-thread.c:324
   process_one_work kernel/workqueue.c:3229 [inline]
   process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310
   worker_thread+0x870/0xd30 kernel/workqueue.c:3391
   kthread+0x2f0/0x390 kernel/kthread.c:389
   ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
   ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
   </TASK>

  Allocated by task 2:
   kasan_save_stack mm/kasan/common.c:47 [inline]
   kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
   unpoison_slab_object mm/kasan/common.c:319 [inline]
   __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
   kasan_slab_alloc include/linux/kasan.h:250 [inline]
   slab_post_alloc_hook mm/slub.c:4104 [inline]
   slab_alloc_node mm/slub.c:4153 [inline]
   kmem_cache_alloc_node_noprof+0x1d9/0x380 mm/slub.c:4205
   alloc_task_struct_node kernel/fork.c:180 [inline]
   dup_task_struct+0x57/0x8c0 kernel/fork.c:1113
   copy_process+0x5d1/0x3d50 kernel/fork.c:2225
   kernel_clone+0x223/0x870 kernel/fork.c:2807
   kernel_thread+0x1bc/0x240 kernel/fork.c:2869
   create_kthread kernel/kthread.c:412 [inline]
   kthreadd+0x60d/0x810 kernel/kthread.c:767
   ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
   ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

  Freed by task 24:
   kasan_save_stack mm/kasan/common.c:47 [inline]
   kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
   kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582
   poison_slab_object mm/kasan/common.c:247 [inline]
   __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
   kasan_slab_free include/linux/kasan.h:233 [inline]
   slab_free_hook mm/slub.c:2338 [inline]
   slab_free mm/slub.c:4598 [inline]
   kmem_cache_free+0x195/0x410 mm/slub.c:4700
   put_task_struct include/linux/sched/task.h:144 [inline]
   delayed_put_task_struct+0x125/0x300 kernel/exit.c:227
   rcu_do_batch kernel/rcu/tree.c:2567 [inline]
   rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823
   handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:554
   run_ksoftirqd+0xca/0x130 kernel/softirq.c:943
   smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164
   kthread+0x2f0/0x390 kernel/kthread.c:389
   ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
   ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

  Last potentially related work creation:
   kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
   __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:544
   __call_rcu_common kernel/rcu/tree.c:3086 [inline]
   call_rcu+0x167/0xa70 kernel/rcu/tree.c:3190
   context_switch kernel/sched/core.c:5372 [inline]
   __schedule+0x1803/0x4be0 kernel/sched/core.c:6756
   __schedule_loop kernel/sched/core.c:6833 [inline]
   schedule+0x14b/0x320 kernel/sched/core.c:6848
   schedule_timeout+0xb0/0x290 kernel/time/sleep_timeout.c:75
   do_wait_for_common kernel/sched/completion.c:95 [inline]
   __wait_for_common kernel/sched/completion.c:116 [inline]
   wait_for_common kernel/sched/completion.c:127 [inline]
   wait_for_completion+0x355/0x620 kernel/sched/completion.c:148
   kthread_stop+0x19e/0x640 kernel/kthread.c:712
   close_ctree+0x524/0xd60 fs/btrfs/disk-io.c:4328
   generic_shutdown_super+0x139/0x2d0 fs/super.c:642
   kill_anon_super+0x3b/0x70 fs/super.c:1237
   btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2112
   deactivate_locked_super+0xc4/0x130 fs/super.c:473
   cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373
   task_work_run+0x24f/0x310 kernel/task_work.c:239
   ptrace_notify+0x2d2/0x380 kernel/signal.c:2503
   ptrace_report_syscall include/linux/ptrace.h:415 [inline]
   ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline]
   syscall_exit_work+0xc7/0x1d0 kernel/entry/common.c:173
   syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline]
   __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline]
   syscall_exit_to_user_mode+0x24a/0x340 kernel/entry/common.c:218
   do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
   entry_SYSCALL_64_after_hwframe+0x77/0x7f

  The buggy address belongs to the object at ffff8880259d1e00
   which belongs to the cache task_struct of size 7424
  The buggy address is located 2584 bytes inside of
   freed 7424-byte region [ffff8880259d1e00, ffff8880259d3b00)

  The buggy address belongs to the physical page:
  page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x259d0
  head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
  memcg:ffff88802f4b56c1
  flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
  page_type: f5(slab)
  raw: 00fff00000000040 ffff88801bafe500 dead000000000100 dead000000000122
  raw: 0000000000000000 0000000000040004 00000001f5000000 ffff88802f4b56c1
  head: 00fff00000000040 ffff88801bafe500 dead000000000100 dead000000000122
  head: 0000000000000000 0000000000040004 00000001f5000000 ffff88802f4b56c1
  head: 00fff00000000003 ffffea0000967401 ffffffffffffffff 0000000000000000
  head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
  page dumped because: kasan: bad access detected
  page_owner tracks the page as allocated
  page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 12, tgid 12 (kworker/u8:1), ts 7328037942, free_ts 0
   set_page_owner include/linux/page_owner.h:32 [inline]
   post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556
   prep_new_page mm/page_alloc.c:1564 [inline]
   get_page_from_freelist+0x3651/0x37a0 mm/page_alloc.c:3474
   __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4751
   alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
   alloc_slab_page+0x6a/0x140 mm/slub.c:2408
   allocate_slab+0x5a/0x2f0 mm/slub.c:2574
   new_slab mm/slub.c:2627 [inline]
   ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3815
   __slab_alloc+0x58/0xa0 mm/slub.c:3905
   __slab_alloc_node mm/slub.c:3980 [inline]
   slab_alloc_node mm/slub.c:4141 [inline]
   kmem_cache_alloc_node_noprof+0x269/0x380 mm/slub.c:4205
   alloc_task_struct_node kernel/fork.c:180 [inline]
   dup_task_struct+0x57/0x8c0 kernel/fork.c:1113
   copy_process+0x5d1/0x3d50 kernel/fork.c:2225
   kernel_clone+0x223/0x870 kernel/fork.c:2807
   user_mode_thread+0x132/0x1a0 kernel/fork.c:2885
   call_usermodehelper_exec_work+0x5c/0x230 kernel/umh.c:171
   process_one_work kernel/workqueue.c:3229 [inline]
   process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310
   worker_thread+0x870/0xd30 kernel/workqueue.c:3391
  page_owner free stack trace missing

  Memory state around the buggy address:
   ffff8880259d2700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
   ffff8880259d2780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  >ffff8880259d2800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                              ^
   ffff8880259d2880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
   ffff8880259d2900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ==================================================================

Fix this by flushing the delalloc workers queue before stopping the
cleaner kthread.

Reported-by: syzbot+b7cf50a0c173770dcb14@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/674ed7e8.050a0220.48a03.0031.GAE@google.com/
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-06 15:04:18 +01:00
Johannes Thumshirn
c7c97ceff9 btrfs: handle bio_split() errors
Commit e546fe1da9 ("block: Rework bio_split() return value") changed
bio_split() so that it can return errors.

Add error handling for it in btrfs_split_bio() and ultimately
btrfs_submit_chunk(). As the bio is not submitted, the bio counter must
be decremented to pair btrfs_bio_counter_inc_blocked().

Reviewed-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-06 15:04:13 +01:00
Qu Wenruo
c83d77eb0f btrfs: properly wait for writeback before buffered write
[BUG]
Before commit e820dbeb6a ("btrfs: convert btrfs_buffered_write() to
use folios"), function prepare_one_folio() will always wait for folio
writeback to finish before returning the folio.

However commit e820dbeb6a ("btrfs: convert btrfs_buffered_write() to
use folios") changed to use FGP_STABLE to do the writeback wait, but
FGP_STABLE is calling folio_wait_stable(), which only calls
folio_wait_writeback() if the address space has AS_STABLE_WRITES, which
is not set for btrfs inodes.

This means we will not wait for the folio writeback at all.

[CAUSE]
The cause is FGP_STABLE is not waiting for writeback unconditionally, but
only for address spaces with AS_STABLE_WRITES, normally such flag is set
when the super block has SB_I_STABLE_WRITES flag.

Such super block flag is set when the block device has hardware digest
support or has internal checksum requirement.

I'd argue btrfs should set such super block due to its default data
checksum behavior, but it is not set yet, so this means FGP_STABLE flag
will have no effect at all.

(For NODATASUM inodes, we can skip the waiting in theory but that should
be an optimization in the future.)

This can lead to data checksum mismatch, as we can modify the folio
while it's still under writeback, this will make the contents differ
from the contents at submission and checksum calculation.

[FIX]
Instead of fully relying on FGP_STABLE, manually do the folio writeback
waiting, until we set the address space or super flag.

Fixes: e820dbeb6a ("btrfs: convert btrfs_buffered_write() to use folios")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-06 15:04:07 +01:00
Filipe Manana
9c803c474c btrfs: fix missing snapshot drew unlock when root is dead during swap activation
When activating a swap file we acquire the root's snapshot drew lock and
then check if the root is dead, failing and returning with -EPERM if it's
dead but without unlocking the root's snapshot lock. Fix this by adding
the missing unlock.

Fixes: 60021bd754 ("btrfs: prevent subvol with swapfile from being deleted")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-03 20:27:02 +01:00
Qu Wenruo
951a3f59d2 btrfs: fix mount failure due to remount races
[BUG]
The following reproducer can cause btrfs mount to fail:

  dev="/dev/test/scratch1"
  mnt1="/mnt/test"
  mnt2="/mnt/scratch"

  mkfs.btrfs -f $dev
  mount $dev $mnt1
  btrfs subvolume create $mnt1/subvol1
  btrfs subvolume create $mnt1/subvol2
  umount $mnt1

  mount $dev $mnt1 -o subvol=subvol1
  while mount -o remount,ro $mnt1; do mount -o remount,rw $mnt1; done &
  bg=$!

  while mount $dev $mnt2 -o subvol=subvol2; do umount $mnt2; done

  kill $bg
  wait
  umount -R $mnt1
  umount -R $mnt2

The script will fail with the following error:

  mount: /mnt/scratch: /dev/mapper/test-scratch1 already mounted on /mnt/test.
        dmesg(1) may have more information after failed mount system call.
  umount: /mnt/test: target is busy.
  umount: /mnt/scratch/: not mounted

And there is no kernel error message.

[CAUSE]
During the btrfs mount, to support mounting different subvolumes with
different RO/RW flags, we need to detect that and retry if needed:

  Retry with matching RO flags if the initial mount fail with -EBUSY.

The problem is, during that retry we do not hold any super block lock
(s_umount), this means there can be a remount process changing the RO
flags of the original fs super block.

If so, we can have an EBUSY error during retry.  And this time we treat
any failure as an error, without any retry and cause the above EBUSY
mount failure.

[FIX]
The current retry behavior is racy because we do not have a super block
thus no way to hold s_umount to prevent the race with remount.

Solve the root problem by allowing fc->sb_flags to mismatch from the
sb->s_flags at btrfs_get_tree_super().

Then at the re-entry point btrfs_get_tree_subvol(), manually check the
fc->s_flags against sb->s_flags, if it's a RO->RW mismatch, then
reconfigure with s_umount lock hold.

Reported-by: Enno Gotthold <egotthold@suse.com>
Reported-by: Fabian Vogt <fvogt@suse.com>
[ Special thanks for the reproducer and early analysis pointing to btrfs. ]
Fixes: f044b31867 ("btrfs: handle the ro->rw transition for mounting different subvolumes")
Link: https://bugzilla.suse.com/show_bug.cgi?id=1231836
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-12-03 20:26:49 +01:00
Linus Torvalds
feffde684a for-6.13-rc1-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmdPMbMACgkQxWXV+ddt
 WDtFSA/+Kd61BPKaiZFF0yjOsjBOlu8WMHFLO5xa2ZRqV3HUzm6rdO4wUSq3Eyqg
 lrFszPfLA0REZIEdY2rqDKJduk1MZZg6NY7Pvn+/ByGOorM0Ym1BJoydtlUN5o2Y
 AWeaDxs6LBMwRqpai0+AkikufK/jK7QfhHci+Oo2XmOv1C39DQbkXO76SYh/yERt
 CcZNaSjm9DUlLxOOpkefxYvpPW4Uv4NSBfh9aymX/u1VxXqeuMuzPZqwZO+nwl/p
 M1yr9fcbrqh3yKC+JjhD7xmOJM3x4c2PmzSkQTdepOuAlQvuQ/iFD+Zc1YjY0XlT
 Fl938rdTKULgCarR5rdsXqdlFRnOprlgt0J1Pdf+GipTVU0EY3WU343HCz6h8pmG
 F/NPvlCahkEtk1UCguL92NOBeAf0adWhuYfKjkuxYuL5ZTvzsOl2ymF6Vlja0Y39
 VK4exjG4ilDESxweinJe53k3QLDwvUc2h0D291QVoo2X06dhXda8oOVK+6lR5mij
 zDtXqurjlCybT1W7op6RcWMY0TaA8IR3Bo9oU1YbVcctuc86/X8SERv1G8MQtXhh
 tevOVb/cKy7gEw9q73OtrH/J2EAklnsesnpH2sdt7WUEzOQPw9BIwEa/NRbjvoqn
 n2ts5KktBhNjM1s0elHBf7o4+OaTrTlTrp0HelXyONZucPrzDQ4=
 =4mFO
 -----END PGP SIGNATURE-----

Merge tag 'for-6.13-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - add lockdep annotations for io_uring/encoded read integration, inode
   lock is held when returning to userspace

 - properly reflect experimental config option to sysfs

 - handle NULL root in case the rescue mode accepts invalid/damaged tree
   roots (rescue=ibadroot)

 - regression fix of a deadlock between transaction and extent locks

 - fix pending bio accounting bug in encoded read ioctl

 - fix NOWAIT mode when checking references for NOCOW files

 - fix use-after-free in a rb-tree cleanup in ref-verify debugging tool

* tag 'for-6.13-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix lockdep warnings on io_uring encoded reads
  btrfs: ref-verify: fix use-after-free after invalid ref action
  btrfs: add a sanity check for btrfs root in btrfs_search_slot()
  btrfs: don't loop for nowait writes when checking for cross references
  btrfs: sysfs: advertise experimental features only if CONFIG_BTRFS_EXPERIMENTAL=y
  btrfs: fix deadlock between transaction commits and extent locks
  btrfs: fix use-after-free in btrfs_encoded_read_endio()
2024-12-03 11:02:17 -08:00
Mark Harmstone
22d2e48e31 btrfs: fix lockdep warnings on io_uring encoded reads
Lockdep doesn't like the fact that btrfs_uring_read_extent() returns to
userspace still holding the inode lock, even though we release it once
the I/O finishes. Add calls to rwsem_release() and rwsem_acquire_read() to
work round this.

Reported-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
34310c442e ("btrfs: add io_uring command for encoded reads (ENCODED_READ ioctl)")
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-29 16:56:38 +01:00
Filipe Manana
7c4e39f9d2 btrfs: ref-verify: fix use-after-free after invalid ref action
At btrfs_ref_tree_mod() after we successfully inserted the new ref entry
(local variable 'ref') into the respective block entry's rbtree (local
variable 'be'), if we find an unexpected action of BTRFS_DROP_DELAYED_REF,
we error out and free the ref entry without removing it from the block
entry's rbtree. Then in the error path of btrfs_ref_tree_mod() we call
btrfs_free_ref_cache(), which iterates over all block entries and then
calls free_block_entry() for each one, and there we will trigger a
use-after-free when we are called against the block entry to which we
added the freed ref entry to its rbtree, since the rbtree still points
to the block entry, as we didn't remove it from the rbtree before freeing
it in the error path at btrfs_ref_tree_mod(). Fix this by removing the
new ref entry from the rbtree before freeing it.

Syzbot report this with the following stack traces:

   BTRFS error (device loop0 state EA):   Ref action 2, root 5, ref_root 0, parent 8564736, owner 0, offset 0, num_refs 18446744073709551615
      __btrfs_mod_ref+0x7dd/0xac0 fs/btrfs/extent-tree.c:2523
      update_ref_for_cow+0x9cd/0x11f0 fs/btrfs/ctree.c:512
      btrfs_force_cow_block+0x9f6/0x1da0 fs/btrfs/ctree.c:594
      btrfs_cow_block+0x35e/0xa40 fs/btrfs/ctree.c:754
      btrfs_search_slot+0xbdd/0x30d0 fs/btrfs/ctree.c:2116
      btrfs_insert_empty_items+0x9c/0x1a0 fs/btrfs/ctree.c:4314
      btrfs_insert_empty_item fs/btrfs/ctree.h:669 [inline]
      btrfs_insert_orphan_item+0x1f1/0x320 fs/btrfs/orphan.c:23
      btrfs_orphan_add+0x6d/0x1a0 fs/btrfs/inode.c:3482
      btrfs_unlink+0x267/0x350 fs/btrfs/inode.c:4293
      vfs_unlink+0x365/0x650 fs/namei.c:4469
      do_unlinkat+0x4ae/0x830 fs/namei.c:4533
      __do_sys_unlinkat fs/namei.c:4576 [inline]
      __se_sys_unlinkat fs/namei.c:4569 [inline]
      __x64_sys_unlinkat+0xcc/0xf0 fs/namei.c:4569
      do_syscall_x64 arch/x86/entry/common.c:52 [inline]
      do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
      entry_SYSCALL_64_after_hwframe+0x77/0x7f
   BTRFS error (device loop0 state EA):   Ref action 1, root 5, ref_root 5, parent 0, owner 260, offset 0, num_refs 1
      __btrfs_mod_ref+0x76b/0xac0 fs/btrfs/extent-tree.c:2521
      update_ref_for_cow+0x96a/0x11f0
      btrfs_force_cow_block+0x9f6/0x1da0 fs/btrfs/ctree.c:594
      btrfs_cow_block+0x35e/0xa40 fs/btrfs/ctree.c:754
      btrfs_search_slot+0xbdd/0x30d0 fs/btrfs/ctree.c:2116
      btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:411
      __btrfs_update_delayed_inode+0x1e7/0xb90 fs/btrfs/delayed-inode.c:1030
      btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1114 [inline]
      __btrfs_commit_inode_delayed_items+0x2318/0x24a0 fs/btrfs/delayed-inode.c:1137
      __btrfs_run_delayed_items+0x213/0x490 fs/btrfs/delayed-inode.c:1171
      btrfs_commit_transaction+0x8a8/0x3740 fs/btrfs/transaction.c:2313
      prepare_to_relocate+0x3c4/0x4c0 fs/btrfs/relocation.c:3586
      relocate_block_group+0x16c/0xd40 fs/btrfs/relocation.c:3611
      btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4081
      btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3377
      __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4161
      btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4538
   BTRFS error (device loop0 state EA):   Ref action 2, root 5, ref_root 0, parent 8564736, owner 0, offset 0, num_refs 18446744073709551615
      __btrfs_mod_ref+0x7dd/0xac0 fs/btrfs/extent-tree.c:2523
      update_ref_for_cow+0x9cd/0x11f0 fs/btrfs/ctree.c:512
      btrfs_force_cow_block+0x9f6/0x1da0 fs/btrfs/ctree.c:594
      btrfs_cow_block+0x35e/0xa40 fs/btrfs/ctree.c:754
      btrfs_search_slot+0xbdd/0x30d0 fs/btrfs/ctree.c:2116
      btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:411
      __btrfs_update_delayed_inode+0x1e7/0xb90 fs/btrfs/delayed-inode.c:1030
      btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1114 [inline]
      __btrfs_commit_inode_delayed_items+0x2318/0x24a0 fs/btrfs/delayed-inode.c:1137
      __btrfs_run_delayed_items+0x213/0x490 fs/btrfs/delayed-inode.c:1171
      btrfs_commit_transaction+0x8a8/0x3740 fs/btrfs/transaction.c:2313
      prepare_to_relocate+0x3c4/0x4c0 fs/btrfs/relocation.c:3586
      relocate_block_group+0x16c/0xd40 fs/btrfs/relocation.c:3611
      btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4081
      btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3377
      __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4161
      btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4538
   ==================================================================
   BUG: KASAN: slab-use-after-free in rb_first+0x69/0x70 lib/rbtree.c:473
   Read of size 8 at addr ffff888042d1af38 by task syz.0.0/5329

   CPU: 0 UID: 0 PID: 5329 Comm: syz.0.0 Not tainted 6.12.0-rc7-syzkaller #0
   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
   Call Trace:
    <TASK>
    __dump_stack lib/dump_stack.c:94 [inline]
    dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
    print_address_description mm/kasan/report.c:377 [inline]
    print_report+0x169/0x550 mm/kasan/report.c:488
    kasan_report+0x143/0x180 mm/kasan/report.c:601
    rb_first+0x69/0x70 lib/rbtree.c:473
    free_block_entry+0x78/0x230 fs/btrfs/ref-verify.c:248
    btrfs_free_ref_cache+0xa3/0x100 fs/btrfs/ref-verify.c:917
    btrfs_ref_tree_mod+0x139f/0x15e0 fs/btrfs/ref-verify.c:898
    btrfs_free_extent+0x33c/0x380 fs/btrfs/extent-tree.c:3544
    __btrfs_mod_ref+0x7dd/0xac0 fs/btrfs/extent-tree.c:2523
    update_ref_for_cow+0x9cd/0x11f0 fs/btrfs/ctree.c:512
    btrfs_force_cow_block+0x9f6/0x1da0 fs/btrfs/ctree.c:594
    btrfs_cow_block+0x35e/0xa40 fs/btrfs/ctree.c:754
    btrfs_search_slot+0xbdd/0x30d0 fs/btrfs/ctree.c:2116
    btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:411
    __btrfs_update_delayed_inode+0x1e7/0xb90 fs/btrfs/delayed-inode.c:1030
    btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1114 [inline]
    __btrfs_commit_inode_delayed_items+0x2318/0x24a0 fs/btrfs/delayed-inode.c:1137
    __btrfs_run_delayed_items+0x213/0x490 fs/btrfs/delayed-inode.c:1171
    btrfs_commit_transaction+0x8a8/0x3740 fs/btrfs/transaction.c:2313
    prepare_to_relocate+0x3c4/0x4c0 fs/btrfs/relocation.c:3586
    relocate_block_group+0x16c/0xd40 fs/btrfs/relocation.c:3611
    btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4081
    btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3377
    __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4161
    btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4538
    btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3673
    vfs_ioctl fs/ioctl.c:51 [inline]
    __do_sys_ioctl fs/ioctl.c:907 [inline]
    __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893
    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
    entry_SYSCALL_64_after_hwframe+0x77/0x7f
   RIP: 0033:0x7f996df7e719
   RSP: 002b:00007f996ede7038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
   RAX: ffffffffffffffda RBX: 00007f996e135f80 RCX: 00007f996df7e719
   RDX: 0000000020000180 RSI: 00000000c4009420 RDI: 0000000000000004
   RBP: 00007f996dff139e R08: 0000000000000000 R09: 0000000000000000
   R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
   R13: 0000000000000000 R14: 00007f996e135f80 R15: 00007fff79f32e68
    </TASK>

   Allocated by task 5329:
    kasan_save_stack mm/kasan/common.c:47 [inline]
    kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
    poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
    __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
    kasan_kmalloc include/linux/kasan.h:257 [inline]
    __kmalloc_cache_noprof+0x19c/0x2c0 mm/slub.c:4295
    kmalloc_noprof include/linux/slab.h:878 [inline]
    kzalloc_noprof include/linux/slab.h:1014 [inline]
    btrfs_ref_tree_mod+0x264/0x15e0 fs/btrfs/ref-verify.c:701
    btrfs_free_extent+0x33c/0x380 fs/btrfs/extent-tree.c:3544
    __btrfs_mod_ref+0x7dd/0xac0 fs/btrfs/extent-tree.c:2523
    update_ref_for_cow+0x9cd/0x11f0 fs/btrfs/ctree.c:512
    btrfs_force_cow_block+0x9f6/0x1da0 fs/btrfs/ctree.c:594
    btrfs_cow_block+0x35e/0xa40 fs/btrfs/ctree.c:754
    btrfs_search_slot+0xbdd/0x30d0 fs/btrfs/ctree.c:2116
    btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:411
    __btrfs_update_delayed_inode+0x1e7/0xb90 fs/btrfs/delayed-inode.c:1030
    btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1114 [inline]
    __btrfs_commit_inode_delayed_items+0x2318/0x24a0 fs/btrfs/delayed-inode.c:1137
    __btrfs_run_delayed_items+0x213/0x490 fs/btrfs/delayed-inode.c:1171
    btrfs_commit_transaction+0x8a8/0x3740 fs/btrfs/transaction.c:2313
    prepare_to_relocate+0x3c4/0x4c0 fs/btrfs/relocation.c:3586
    relocate_block_group+0x16c/0xd40 fs/btrfs/relocation.c:3611
    btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4081
    btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3377
    __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4161
    btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4538
    btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3673
    vfs_ioctl fs/ioctl.c:51 [inline]
    __do_sys_ioctl fs/ioctl.c:907 [inline]
    __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893
    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

   Freed by task 5329:
    kasan_save_stack mm/kasan/common.c:47 [inline]
    kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
    kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
    poison_slab_object mm/kasan/common.c:247 [inline]
    __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
    kasan_slab_free include/linux/kasan.h:230 [inline]
    slab_free_hook mm/slub.c:2342 [inline]
    slab_free mm/slub.c:4579 [inline]
    kfree+0x1a0/0x440 mm/slub.c:4727
    btrfs_ref_tree_mod+0x136c/0x15e0
    btrfs_free_extent+0x33c/0x380 fs/btrfs/extent-tree.c:3544
    __btrfs_mod_ref+0x7dd/0xac0 fs/btrfs/extent-tree.c:2523
    update_ref_for_cow+0x9cd/0x11f0 fs/btrfs/ctree.c:512
    btrfs_force_cow_block+0x9f6/0x1da0 fs/btrfs/ctree.c:594
    btrfs_cow_block+0x35e/0xa40 fs/btrfs/ctree.c:754
    btrfs_search_slot+0xbdd/0x30d0 fs/btrfs/ctree.c:2116
    btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:411
    __btrfs_update_delayed_inode+0x1e7/0xb90 fs/btrfs/delayed-inode.c:1030
    btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1114 [inline]
    __btrfs_commit_inode_delayed_items+0x2318/0x24a0 fs/btrfs/delayed-inode.c:1137
    __btrfs_run_delayed_items+0x213/0x490 fs/btrfs/delayed-inode.c:1171
    btrfs_commit_transaction+0x8a8/0x3740 fs/btrfs/transaction.c:2313
    prepare_to_relocate+0x3c4/0x4c0 fs/btrfs/relocation.c:3586
    relocate_block_group+0x16c/0xd40 fs/btrfs/relocation.c:3611
    btrfs_relocate_block_group+0x77d/0xd90 fs/btrfs/relocation.c:4081
    btrfs_relocate_chunk+0x12c/0x3b0 fs/btrfs/volumes.c:3377
    __btrfs_balance+0x1b0f/0x26b0 fs/btrfs/volumes.c:4161
    btrfs_balance+0xbdc/0x10c0 fs/btrfs/volumes.c:4538
    btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3673
    vfs_ioctl fs/ioctl.c:51 [inline]
    __do_sys_ioctl fs/ioctl.c:907 [inline]
    __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893
    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

   The buggy address belongs to the object at ffff888042d1af00
    which belongs to the cache kmalloc-64 of size 64
   The buggy address is located 56 bytes inside of
    freed 64-byte region [ffff888042d1af00, ffff888042d1af40)

   The buggy address belongs to the physical page:
   page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x42d1a
   anon flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
   page_type: f5(slab)
   raw: 04fff00000000000 ffff88801ac418c0 0000000000000000 dead000000000001
   raw: 0000000000000000 0000000000200020 00000001f5000000 0000000000000000
   page dumped because: kasan: bad access detected
   page_owner tracks the page as allocated
   page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5055, tgid 5055 (dhcpcd-run-hook), ts 40377240074, free_ts 40376848335
    set_page_owner include/linux/page_owner.h:32 [inline]
    post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1541
    prep_new_page mm/page_alloc.c:1549 [inline]
    get_page_from_freelist+0x3649/0x3790 mm/page_alloc.c:3459
    __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4735
    alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
    alloc_slab_page+0x6a/0x140 mm/slub.c:2412
    allocate_slab+0x5a/0x2f0 mm/slub.c:2578
    new_slab mm/slub.c:2631 [inline]
    ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818
    __slab_alloc+0x58/0xa0 mm/slub.c:3908
    __slab_alloc_node mm/slub.c:3961 [inline]
    slab_alloc_node mm/slub.c:4122 [inline]
    __do_kmalloc_node mm/slub.c:4263 [inline]
    __kmalloc_noprof+0x25a/0x400 mm/slub.c:4276
    kmalloc_noprof include/linux/slab.h:882 [inline]
    kzalloc_noprof include/linux/slab.h:1014 [inline]
    tomoyo_encode2 security/tomoyo/realpath.c:45 [inline]
    tomoyo_encode+0x26f/0x540 security/tomoyo/realpath.c:80
    tomoyo_realpath_from_path+0x59e/0x5e0 security/tomoyo/realpath.c:283
    tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
    tomoyo_check_open_permission+0x255/0x500 security/tomoyo/file.c:771
    security_file_open+0x777/0x990 security/security.c:3109
    do_dentry_open+0x369/0x1460 fs/open.c:945
    vfs_open+0x3e/0x330 fs/open.c:1088
    do_open fs/namei.c:3774 [inline]
    path_openat+0x2c84/0x3590 fs/namei.c:3933
   page last free pid 5055 tgid 5055 stack trace:
    reset_page_owner include/linux/page_owner.h:25 [inline]
    free_pages_prepare mm/page_alloc.c:1112 [inline]
    free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2642
    free_pipe_info+0x300/0x390 fs/pipe.c:860
    put_pipe_info fs/pipe.c:719 [inline]
    pipe_release+0x245/0x320 fs/pipe.c:742
    __fput+0x23f/0x880 fs/file_table.c:431
    __do_sys_close fs/open.c:1567 [inline]
    __se_sys_close fs/open.c:1552 [inline]
    __x64_sys_close+0x7f/0x110 fs/open.c:1552
    do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

   Memory state around the buggy address:
    ffff888042d1ae00: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
    ffff888042d1ae80: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
   >ffff888042d1af00: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                                           ^
    ffff888042d1af80: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
    ffff888042d1b000: 00 00 00 00 00 fc fc 00 00 00 00 00 fc fc 00 00

Reported-by: syzbot+7325f164162e200000c1@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/673723eb.050a0220.1324f8.00a8.GAE@google.com/T/#u
Fixes: fd708b81d9 ("Btrfs: add a extent ref verify tool")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-29 16:52:29 +01:00
Lizhi Xu
3ed51857a5 btrfs: add a sanity check for btrfs root in btrfs_search_slot()
Syzbot reports a null-ptr-deref in btrfs_search_slot().

The reproducer is using rescue=ibadroots, and the extent tree root is
corrupted thus the extent tree is NULL.

When scrub tries to search the extent tree to gather the needed extent
info, btrfs_search_slot() doesn't check if the target root is NULL or
not, resulting the null-ptr-deref.

Add sanity check for btrfs root before using it in btrfs_search_slot().

Reported-by: syzbot+3030e17bd57a73d39bd7@syzkaller.appspotmail.com
Fixes: 42437a6386 ("btrfs: introduce mount option rescue=ignorebadroots")
Link: https://syzkaller.appspot.com/bug?extid=3030e17bd57a73d39bd7
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Tested-by: syzbot+3030e17bd57a73d39bd7@syzkaller.appspotmail.com
Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-29 16:50:40 +01:00
Filipe Manana
ed67f2a913 btrfs: don't loop for nowait writes when checking for cross references
When checking for delayed refs when verifying if there are cross
references for a data extent, we stop if the path has nowait set and we
can't try lock the delayed ref head's mutex, returning -EAGAIN with the
goal of making a write fallback to a blocking context. However we ignore
the -EAGAIN at btrfs_cross_ref_exist() when check_delayed_ref() returns
it, and keep looping instead of immediately returning the -EAGAIN to the
caller.

Fix this by not looping if we get -EAGAIN and we have a nowait path.

Fixes: 26ce911446 ("btrfs: make can_nocow_extent nowait compatible")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-29 16:46:47 +01:00
Filipe Manana
b188ad7791 btrfs: sysfs: advertise experimental features only if CONFIG_BTRFS_EXPERIMENTAL=y
We are advertising experimental features through sysfs if
CONFIG_BTRFS_DEBUG is set, without looking if CONFIG_BTRFS_EXPERIMENTAL
is set. This is wrong as it will result in reporting experimental
features as supported when CONFIG_BTRFS_EXPERIMENTAL is not set but
CONFIG_BTRFS_DEBUG is set.

Fix this by checking for CONFIG_BTRFS_EXPERIMENTAL instead of
CONFIG_BTRFS_DEBUG.

Fixes: 67cd3f2217 ("btrfs: split out CONFIG_BTRFS_EXPERIMENTAL from CONFIG_BTRFS_DEBUG")
Reviewed-by: Neal Gompa <neal@gompa.dev>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-28 20:46:59 +01:00
Filipe Manana
7d6872ccbd btrfs: fix deadlock between transaction commits and extent locks
When running a workload with fsstress and duperemove (generic/561) we can
hit a deadlock related to transaction commits and locking extent ranges,
as described below.

Task A hanging during a transaction commit, waiting for all other writers
to complete:

  [178317.334817] INFO: task fsstress:555623 blocked for more than 120 seconds.
  [178317.335693]       Not tainted 6.12.0-rc6-btrfs-next-179+ #1
  [178317.336528] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [178317.337673] task:fsstress        state:D stack:0     pid:555623 tgid:555623 ppid:555620 flags:0x00004002
  [178317.337679] Call Trace:
  [178317.337681]  <TASK>
  [178317.337685]  __schedule+0x364/0xbe0
  [178317.337691]  schedule+0x26/0xa0
  [178317.337695]  btrfs_commit_transaction+0x5c5/0x1050 [btrfs]
  [178317.337769]  ? start_transaction+0xc4/0x800 [btrfs]
  [178317.337815]  ? __pfx_autoremove_wake_function+0x10/0x10
  [178317.337819]  btrfs_mksubvol+0x381/0x640 [btrfs]
  [178317.337878]  btrfs_mksnapshot+0x7a/0xb0 [btrfs]
  [178317.337935]  __btrfs_ioctl_snap_create+0x1bb/0x1d0 [btrfs]
  [178317.337995]  btrfs_ioctl_snap_create_v2+0x103/0x130 [btrfs]
  [178317.338053]  btrfs_ioctl+0x29b/0x2a90 [btrfs]
  [178317.338118]  ? kmem_cache_alloc_noprof+0x5f/0x2c0
  [178317.338126]  ? getname_flags+0x45/0x1f0
  [178317.338133]  ? _raw_spin_unlock+0x15/0x30
  [178317.338145]  ? __x64_sys_ioctl+0x88/0xc0
  [178317.338149]  __x64_sys_ioctl+0x88/0xc0
  [178317.338152]  do_syscall_64+0x4a/0x110
  [178317.338160]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
  [178317.338190] RIP: 0033:0x7f13c28e271b

Which corresponds to line 2361 of transaction.c:

  $ cat -n fs/btrfs/transaction.c
  (...)
  2162  int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
  2163  {
  (...)
  2349          spin_lock(&fs_info->trans_lock);
  2350          add_pending_snapshot(trans);
  2351          cur_trans->state = TRANS_STATE_COMMIT_DOING;
  2352          spin_unlock(&fs_info->trans_lock);
  2353
  2354          /*
  2355           * The thread has started/joined the transaction thus it holds the
  2356           * lockdep map as a reader. It has to release it before acquiring the
  2357           * lockdep map as a writer.
  2358           */
  2359          btrfs_lockdep_release(fs_info, btrfs_trans_num_writers);
  2360          btrfs_might_wait_for_event(fs_info, btrfs_trans_num_writers);
  2361          wait_event(cur_trans->writer_wait,
  2362                     atomic_read(&cur_trans->num_writers) == 1);
  (...)

The transaction is in the TRANS_STATE_COMMIT_DOING state and so it's
waiting for all other existing writers to complete and release their
transaction handle.

Task B is running ordered extent completion and blocked waiting to lock an
extent range in an inode's io tree:

  [178317.327411] INFO: task kworker/u48:8:554545 blocked for more than 120 seconds.
  [178317.328630]       Not tainted 6.12.0-rc6-btrfs-next-179+ #1
  [178317.329635] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [178317.330872] task:kworker/u48:8   state:D stack:0     pid:554545 tgid:554545 ppid:2      flags:0x00004000
  [178317.330878] Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
  [178317.330944] Call Trace:
  [178317.330945]  <TASK>
  [178317.330947]  __schedule+0x364/0xbe0
  [178317.330952]  schedule+0x26/0xa0
  [178317.330955]  __lock_extent+0x337/0x3a0 [btrfs]
  [178317.331014]  ? __pfx_autoremove_wake_function+0x10/0x10
  [178317.331017]  btrfs_finish_one_ordered+0x47a/0xaa0 [btrfs]
  [178317.331074]  ? psi_group_change+0x132/0x2d0
  [178317.331078]  btrfs_work_helper+0xbd/0x370 [btrfs]
  [178317.331140]  process_scheduled_works+0xd3/0x460
  [178317.331144]  ? __pfx_worker_thread+0x10/0x10
  [178317.331146]  worker_thread+0x121/0x250
  [178317.331149]  ? __pfx_worker_thread+0x10/0x10
  [178317.331151]  kthread+0xe9/0x120
  [178317.331154]  ? __pfx_kthread+0x10/0x10
  [178317.331157]  ret_from_fork+0x2d/0x50
  [178317.331159]  ? __pfx_kthread+0x10/0x10
  [178317.331162]  ret_from_fork_asm+0x1a/0x30

This extent range locking happens after joining the current transaction,
so task A is waiting for task B to release its transaction handle
(decrementing the transaction's num_writers counter).

Task C while doing a fiemap it tries to join the current transaction:

  [242682.812815] task:pool            state:D stack:0     pid:560767 tgid:560724 ppid:555622 flags:0x00004006
  [242682.812827] Call Trace:
  [242682.812856]  <TASK>
  [242682.812864]  __schedule+0x364/0xbe0
  [242682.812879]  ? _raw_spin_unlock_irqrestore+0x23/0x40
  [242682.812897]  schedule+0x26/0xa0
  [242682.812909]  wait_current_trans+0xd6/0x130 [btrfs]
  [242682.813148]  ? __pfx_autoremove_wake_function+0x10/0x10
  [242682.813162]  start_transaction+0x3d4/0x800 [btrfs]
  [242682.813399]  btrfs_is_data_extent_shared+0xd2/0x440 [btrfs]
  [242682.813723]  fiemap_process_hole+0x2a2/0x300 [btrfs]
  [242682.813995]  extent_fiemap+0x9b8/0xb80 [btrfs]
  [242682.814249]  btrfs_fiemap+0x78/0xc0 [btrfs]
  [242682.814501]  do_vfs_ioctl+0x2db/0xa50
  [242682.814519]  __x64_sys_ioctl+0x6a/0xc0
  [242682.814531]  do_syscall_64+0x4a/0x110
  [242682.814544]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
  [242682.814556] RIP: 0033:0x7efff595e71b

It tries to join the current transaction, but it can't because the
transaction is in the TRANS_STATE_COMMIT_DOING state, so
join_transaction() returns -EBUSY to start_transaction() and makes it
wait for the current transaction to complete. And while it's waiting
for the transaction to complete, it's holding an extent range locked
in the same inode that task B is operating, which causes a deadlock
between these 3 tasks. The extent range for the inode was locked at
the start of the fiemap operation, early at extent_fiemap().

In short these tasks deadlock because:

1) Task A is waiting for task B to release its transaction handle;

2) Task B is waiting to lock an extent range for an inode while holding a
   transaction handle open;

3) Task C is waiting for the current transaction to complete (for task A
   to finish the transaction commit) while holding the extent range for
   the inode locked, so task B can't progress and release its transaction
   handle.

This results in an ABBA deadlock involving transaction commits and extent
locks. Extent locks are higher level locks, like inode VFS locks, and
should always be acquired before joining or starting a transaction, but
recently commit 2206265f41 ("btrfs: remove code duplication in ordered
extent finishing") accidentally changed btrfs_finish_one_ordered() to do
the transaction join before locking the extent range.

Fix this by making sure that btrfs_finish_one_ordered() always locks the
extent before joining a transaction and add an explicit comment about the
need for this order.

Fixes: 2206265f41 ("btrfs: remove code duplication in ordered extent finishing")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-28 20:46:40 +01:00
Johannes Thumshirn
05b36b04d7 btrfs: fix use-after-free in btrfs_encoded_read_endio()
Shinichiro reported the following use-after free that sometimes is
happening in our CI system when running fstests' btrfs/284 on a TCMU
runner device:

  BUG: KASAN: slab-use-after-free in lock_release+0x708/0x780
  Read of size 8 at addr ffff888106a83f18 by task kworker/u80:6/219

  CPU: 8 UID: 0 PID: 219 Comm: kworker/u80:6 Not tainted 6.12.0-rc6-kts+ #15
  Hardware name: Supermicro Super Server/X11SPi-TF, BIOS 3.3 02/21/2020
  Workqueue: btrfs-endio btrfs_end_bio_work [btrfs]
  Call Trace:
   <TASK>
   dump_stack_lvl+0x6e/0xa0
   ? lock_release+0x708/0x780
   print_report+0x174/0x505
   ? lock_release+0x708/0x780
   ? __virt_addr_valid+0x224/0x410
   ? lock_release+0x708/0x780
   kasan_report+0xda/0x1b0
   ? lock_release+0x708/0x780
   ? __wake_up+0x44/0x60
   lock_release+0x708/0x780
   ? __pfx_lock_release+0x10/0x10
   ? __pfx_do_raw_spin_lock+0x10/0x10
   ? lock_is_held_type+0x9a/0x110
   _raw_spin_unlock_irqrestore+0x1f/0x60
   __wake_up+0x44/0x60
   btrfs_encoded_read_endio+0x14b/0x190 [btrfs]
   btrfs_check_read_bio+0x8d9/0x1360 [btrfs]
   ? lock_release+0x1b0/0x780
   ? trace_lock_acquire+0x12f/0x1a0
   ? __pfx_btrfs_check_read_bio+0x10/0x10 [btrfs]
   ? process_one_work+0x7e3/0x1460
   ? lock_acquire+0x31/0xc0
   ? process_one_work+0x7e3/0x1460
   process_one_work+0x85c/0x1460
   ? __pfx_process_one_work+0x10/0x10
   ? assign_work+0x16c/0x240
   worker_thread+0x5e6/0xfc0
   ? __pfx_worker_thread+0x10/0x10
   kthread+0x2c3/0x3a0
   ? __pfx_kthread+0x10/0x10
   ret_from_fork+0x31/0x70
   ? __pfx_kthread+0x10/0x10
   ret_from_fork_asm+0x1a/0x30
   </TASK>

  Allocated by task 3661:
   kasan_save_stack+0x30/0x50
   kasan_save_track+0x14/0x30
   __kasan_kmalloc+0xaa/0xb0
   btrfs_encoded_read_regular_fill_pages+0x16c/0x6d0 [btrfs]
   send_extent_data+0xf0f/0x24a0 [btrfs]
   process_extent+0x48a/0x1830 [btrfs]
   changed_cb+0x178b/0x2ea0 [btrfs]
   btrfs_ioctl_send+0x3bf9/0x5c20 [btrfs]
   _btrfs_ioctl_send+0x117/0x330 [btrfs]
   btrfs_ioctl+0x184a/0x60a0 [btrfs]
   __x64_sys_ioctl+0x12e/0x1a0
   do_syscall_64+0x95/0x180
   entry_SYSCALL_64_after_hwframe+0x76/0x7e

  Freed by task 3661:
   kasan_save_stack+0x30/0x50
   kasan_save_track+0x14/0x30
   kasan_save_free_info+0x3b/0x70
   __kasan_slab_free+0x4f/0x70
   kfree+0x143/0x490
   btrfs_encoded_read_regular_fill_pages+0x531/0x6d0 [btrfs]
   send_extent_data+0xf0f/0x24a0 [btrfs]
   process_extent+0x48a/0x1830 [btrfs]
   changed_cb+0x178b/0x2ea0 [btrfs]
   btrfs_ioctl_send+0x3bf9/0x5c20 [btrfs]
   _btrfs_ioctl_send+0x117/0x330 [btrfs]
   btrfs_ioctl+0x184a/0x60a0 [btrfs]
   __x64_sys_ioctl+0x12e/0x1a0
   do_syscall_64+0x95/0x180
   entry_SYSCALL_64_after_hwframe+0x76/0x7e

  The buggy address belongs to the object at ffff888106a83f00
   which belongs to the cache kmalloc-rnd-07-96 of size 96
  The buggy address is located 24 bytes inside of
   freed 96-byte region [ffff888106a83f00, ffff888106a83f60)

  The buggy address belongs to the physical page:
  page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888106a83800 pfn:0x106a83
  flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff)
  page_type: f5(slab)
  raw: 0017ffffc0000000 ffff888100053680 ffffea0004917200 0000000000000004
  raw: ffff888106a83800 0000000080200019 00000001f5000000 0000000000000000
  page dumped because: kasan: bad access detected

  Memory state around the buggy address:
   ffff888106a83e00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
   ffff888106a83e80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
  >ffff888106a83f00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                              ^
   ffff888106a83f80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
   ffff888106a84000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  ==================================================================

Further analyzing the trace and the crash dump's vmcore file shows that
the wake_up() call in btrfs_encoded_read_endio() is calling wake_up() on
the wait_queue that is in the private data passed to the end_io handler.

Commit 4ff47df40447 ("btrfs: move priv off stack in
btrfs_encoded_read_regular_fill_pages()") moved 'struct
btrfs_encoded_read_private' off the stack.

Before that commit one can see a corruption of the private data when
analyzing the vmcore after a crash:

*(struct btrfs_encoded_read_private *)0xffff88815626eec8 = {
	.wait = (wait_queue_head_t){
		.lock = (spinlock_t){
			.rlock = (struct raw_spinlock){
				.raw_lock = (arch_spinlock_t){
					.val = (atomic_t){
						.counter = (int)-2005885696,
					},
					.locked = (u8)0,
					.pending = (u8)157,
					.locked_pending = (u16)40192,
					.tail = (u16)34928,
				},
				.magic = (unsigned int)536325682,
				.owner_cpu = (unsigned int)29,
				.owner = (void *)__SCT__tp_func_btrfs_transaction_commit+0x0 = 0x0,
				.dep_map = (struct lockdep_map){
					.key = (struct lock_class_key *)0xffff8881575a3b6c,
					.class_cache = (struct lock_class *[2]){ 0xffff8882a71985c0, 0xffffea00066f5d40 },
					.name = (const char *)0xffff88815626f100 = "",
					.wait_type_outer = (u8)37,
					.wait_type_inner = (u8)178,
					.lock_type = (u8)154,
				},
			},
			.__padding = (u8 [24]){ 0, 157, 112, 136, 50, 174, 247, 31, 29 },
			.dep_map = (struct lockdep_map){
				.key = (struct lock_class_key *)0xffff8881575a3b6c,
				.class_cache = (struct lock_class *[2]){ 0xffff8882a71985c0, 0xffffea00066f5d40 },
				.name = (const char *)0xffff88815626f100 = "",
				.wait_type_outer = (u8)37,
				.wait_type_inner = (u8)178,
				.lock_type = (u8)154,
			},
		},
		.head = (struct list_head){
			.next = (struct list_head *)0x112cca,
			.prev = (struct list_head *)0x47,
		},
	},
	.pending = (atomic_t){
		.counter = (int)-1491499288,
	},
	.status = (blk_status_t)130,
}

Here we can see several indicators of in-memory data corruption, e.g. the
large negative atomic values of ->pending or
->wait->lock->rlock->raw_lock->val, as well as the bogus spinlock magic
0x1ff7ae32 (decimal 536325682 above) instead of 0xdead4ead or the bogus
pointer values for ->wait->head.

To fix this, change atomic_dec_return() to atomic_dec_and_test() to fix the
corruption, as atomic_dec_return() is defined as two instructions on
x86_64, whereas atomic_dec_and_test() is defined as a single atomic
operation. This can lead to a situation where counter value is already
decremented but the if statement in btrfs_encoded_read_endio() is not
completely processed, i.e. the 0 test has not completed. If another thread
continues executing btrfs_encoded_read_regular_fill_pages() the
atomic_dec_return() there can see an already updated ->pending counter and
continues by freeing the private data. Continuing in the endio handler the
test for 0 succeeds and the wait_queue is woken up, resulting in a
use-after-free.

Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Suggested-by: Damien Le Moal <Damien.LeMoal@wdc.com>
Fixes: 1881fba89b ("btrfs: add BTRFS_IOC_ENCODED_READ ioctl")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-28 20:45:43 +01:00
Linus Torvalds
563cb0b1e7 cxl changes for v6.13
- Constify range_contains() input parameters to prevent changes.
 - Add support for displaying RCD capabilities in sysfs to support lspci for CXL device.
 - Downgrade warning message to debug in cxl_probe_component_regs().
 - Add support for adding a printf specifier '$pra' to emit 'struct range' content.
   - Add sanity tests for 'struct resource'.
   - Add documentation for special case.
   - Add %pra for 'struct range'.
   - Add %pra usage in CXL code.
 - Add preparation code for DCD support
   - Add range_overlaps().
   - Add CDAT DSMAS table shared and read only flag in ACPICA.
   - Add documentation to 'struct dev_dax_range'.
   - Delay event buffer allocation in CXL PCI code until needed.
   - Use guard() in cxl_dpa_set_mode().
   - Refactor create region code to consolidate common code.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEE5DAy15EJMCV1R6v9YGjFFmlTOEoFAmc84dMACgkQYGjFFmlT
 OEoGTg//cSJlQ9X7+xZDbngnzpJwcLzQkR/FXDfe3obtmgs7woDJgNNcYnKSlgyf
 wal47Q0UM/1Hv8Dtfrt62Ay1fmOvDL2GSpey35NVJGCEpIsfOqqk1zTCgfgwRHTO
 MZJLnOSFUIlDYlVz8ljLNHnNqPjr7dCoUh9tdBefvkw59FqbkHNcWI8hG1lh1SR4
 2frtJcqVg54S6vJa2eeWmNVpxz7RZvPFrb8TJzhdrGM8PkTMNFA2oJINAf0j00Ev
 8/T6HXTxXvFtNhBH0dtMO1MFh1d6Qr/zFnX/gmrnPWl1l/12HFDMBIZIzq/Whjpo
 +7hQ5xK3cwkMevFgFrAhwdZMj8maR84x1dbFItoThaoeDIQ4sGfyQEMPsbkZP/Sc
 67i5hQFIBZc+ORLB0W+z9Da52ZFGyVw/xsCmDRzXCw4s7N2twpydIoA7Pvu9NN1X
 3JVF35NrsRZ+PyuGWEitNjo0Rj6swNpBC5Xv/T1mgFtSgvVuk1T2QtSHJcPoQyzQ
 zbijsCKmvJYbdJBnPiotdrBs1BUxBsP9dBT9IxWzMy6lcEpTJrYpUheRCk2tSHFa
 Kk8O8IYNiBKZaSpN9UHKaGzr43H8gNbLf4svSIiu1lZJTSSdtWqfZZYjXFBgB1Vb
 l2gBCDmPJ0y7WKZSCa53UmQiOusr+l3Pi+OflZEfCy6JxbSqTTM=
 =GNlu
 -----END PGP SIGNATURE-----

Merge tag 'cxl-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

Pull cxl updates from Dave Jiang:

 - Constify range_contains() input parameters to prevent changes

 - Add support for displaying RCD capabilities in sysfs to support lspci
   for CXL device

 - Downgrade warning message to debug in cxl_probe_component_regs()

 - Add support for adding a printf specifier '%pra' to emit 'struct
   range' content:
     - Add sanity tests for 'struct resource'
     - Add documentation for special case
     - Add %pra for 'struct range'
     - Add %pra usage in CXL code

 - Add preparation code for DCD support:
     - Add range_overlaps()
     - Add CDAT DSMAS table shared and read only flag in ACPICA
     - Add documentation to 'struct dev_dax_range'
     - Delay event buffer allocation in CXL PCI code until needed
     - Use guard() in cxl_dpa_set_mode()
     - Refactor create region code to consolidate common code

* tag 'cxl-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl:
  cxl/region: Refactor common create region code
  cxl/hdm: Use guard() in cxl_dpa_set_mode()
  cxl/pci: Delay event buffer allocation
  dax: Document struct dev_dax_range
  ACPI/CDAT: Add CDAT/DSMAS shared and read only flag values
  range: Add range_overlaps()
  cxl/cdat: Use %pra for dpa range outputs
  printf: Add print format (%pra) for struct range
  Documentation/printf: struct resource add start == end special case
  test printf: Add very basic struct resource tests
  cxl: downgrade a warning message to debug level in cxl_probe_component_regs()
  cxl/pci: Add sysfs attribute for CXL 1.1 device link status
  cxl/core/regs: Add rcd_pcie_cap initialization
  kernel/range: Const-ify range_contains parameters
2024-11-22 12:33:52 -08:00
Linus Torvalds
77a0cfafa9 for-6.13/block-20241118
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAmc7S40QHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgpjHVD/43rDZ8ehs+IAAr6S0RemNX1SRG0mK2UOEb
 kMoNogS7StO/c4JYW3JuzCyLRn5ZsgeWV/muqxwDEWQrmTGrvi+V45KikrZPwm3k
 p0ump33qV9EU2jiR1MKZjtwK2P0CI7/DD3W8ww6IOvKbTT7RcqQcdHznvXArFBtc
 xCuQPpayFG7ZasC+N9VaBwtiUEVgU3Ek9AFT7UVZRWajjHPNalQwaooJWayO0rEG
 KdoW5yG0ryLrgCY2ACSvRLS+2s14EJtb8hgT08WKHTNgd5LxhSKxfsTapamua+7U
 FdVS6Ij0tEkgu2jpvgj7QKO0Uw10Cnep2gj7RHts/LVewvkliS6XcheOzqRS1jWU
 I2EI+UaGOZ11OUiw52VIveEVS5zV/NWhgy5BSP9LYEvXw0BUAHRDYGMem8o5G1V1
 SWqjIM1UWvcQDlAnMF9FDVzojvjVUmYWvcAlFFztO8J0B7SavHR3NcfHwEf57reH
 rNoUbi/9c4/wjJJF33gejiR5pU+ewy/Mk75GrtX3xpEqlztfRbf9/FbPCMEAO1KR
 DF/b3lkUV9i2/BRW6a0SpZ5RDSmSYMnateel6TrPyVSRnpiSSFO8FrbynwUOa17b
 6i49YDFWzzXOrR1YWDg6IEtTrcmBEmvi7F6aoDs020qUnL0hwLn1ZuoIxuiFEpor
 Z0iFF1B/nw==
 =PWTH
 -----END PGP SIGNATURE-----

Merge tag 'for-6.13/block-20241118' of git://git.kernel.dk/linux

Pull block updates from Jens Axboe:

 - NVMe updates via Keith:
      - Use uring_cmd helper (Pavel)
      - Host Memory Buffer allocation enhancements (Christoph)
      - Target persistent reservation support (Guixin)
      - Persistent reservation tracing (Guixen)
      - NVMe 2.1 specification support (Keith)
      - Rotational Meta Support (Matias, Wang, Keith)
      - Volatile cache detection enhancment (Guixen)

 - MD updates via Song:
      - Maintainers update
      - raid5 sync IO fix
      - Enhance handling of faulty and blocked devices
      - raid5-ppl atomic improvement
      - md-bitmap fix

 - Support for manually defining embedded partition tables

 - Zone append fixes and cleanups

 - Stop sending the queued requests in the plug list to the driver
   ->queue_rqs() handle in reverse order.

 - Zoned write plug cleanups

 - Cleanups disk stats tracking and add support for disk stats for
   passthrough IO

 - Add preparatory support for file system atomic writes

 - Add lockdep support for queue freezing. Already found a bunch of
   issues, and some fixes for that are in here. More will be coming.

 - Fix race between queue stopping/quiescing and IO queueing

 - ublk recovery improvements

 - Fix ublk mmap for 64k pages

 - Various fixes and cleanups

* tag 'for-6.13/block-20241118' of git://git.kernel.dk/linux: (118 commits)
  MAINTAINERS: Update git tree for mdraid subsystem
  block: make struct rq_list available for !CONFIG_BLOCK
  block/genhd: use seq_put_decimal_ull for diskstats decimal values
  block: don't reorder requests in blk_mq_add_to_batch
  block: don't reorder requests in blk_add_rq_to_plug
  block: add a rq_list type
  block: remove rq_list_move
  virtio_blk: reverse request order in virtio_queue_rqs
  nvme-pci: reverse request order in nvme_queue_rqs
  btrfs: validate queue limits
  block: export blk_validate_limits
  nvmet: add tracing of reservation commands
  nvme: parse reservation commands's action and rtype to string
  nvmet: report ns's vwc not present
  md/raid5: Increase r5conf.cache_name size
  block: remove the ioprio field from struct request
  block: remove the write_hint field from struct request
  nvme: check ns's volatile write cache not present
  nvme: add rotational support
  nvme: use command set independent id ns if available
  ...
2024-11-18 16:50:08 -08:00
Linus Torvalds
c14a8a4c04 for-6.13-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmc0zT4ACgkQxWXV+ddt
 WDtThRAAhzSSiHcJqTfCL5nHh7w85MNEVw28o1ETgXSYJmx0JOWLE7Znlp2FV7jj
 IbYkFfF2gXJzYvRZkcXB/TAHV9KJG5yZIBZfccbM+9db9f8xkImVKMuqQRXPU41R
 ppSCmqZTeujtt8ucsaJkMpm6pzECKJCJaGOsMJ8fiqKpo89dKO3eGAVboSbpPF4C
 r0YmppiBwSP/cCXQCqWxZRbqPGN+lUgZpIGNRi157kehfmRHlVVJTO1pgqK8PCXb
 uIT09Kulppfez8+1A10CPcniDTyinLik/qLTNlzdWoDBL4iNJMg0A0wsA04AJVf0
 PdOS0REusiv3QcEIO6PefuRFRRfXcSLPpPDUceltJT5O0uM2gUqf2C7dEHXUGU3o
 TdgYlbQpsJWpZ7VGWQDZeGGV04lOPQvu0LGLPgEerUQd5H9ABa0dX8Fn0sPhKsa8
 whpAcdfE4rdNxB2OJFnqQeFq0z3cSjP/rvKlluCmAj97QYI+kiu3QyhemcT1YSC9
 U7n5Ya9IzIYCN3ml54q3hEgyD0IVGGG20GuUmqC9XSP9mrQRC8I1g7v26AiOTrrk
 VhgSdtMmphDxXudifsnYMaQ0Z1QqiUrW1SM/prAEOnBYCo75+HDsTgrq9ithgHoI
 4xz4YXJyMRs18qfTJctXC1wmGuz5plTdQrwarHdNsELN5HEyqX4=
 =aAcf
 -----END PGP SIGNATURE-----

Merge tag 'for-6.13-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "Changes outside of btrfs: add io_uring command flag to track a dying
  task (the rest will go via the block git tree).

  User visible changes:

   - wire encoded read (ioctl) to io_uring commands, this can be used on
     itself, in the future this will allow 'send' to be asynchronous. As
     a consequence, the encoded read ioctl can also work in non-blocking
     mode

   - new ioctl to wait for cleaned subvolumes, no need to use the
     generic and root-only SEARCH_TREE ioctl, will be used by "btrfs
     subvol sync"

   - recognize different paths/symlinks for the same devices and don't
     report them during rescanning, this can be observed with LVM or DM

   - seeding device use case change, the sprout device (the one
     capturing new writes) will not clear the read-only status of the
     super block; this prevents accumulating space from deleted
     snapshots

  Performance improvements:

   - reduce lock contention when traversing extent buffers

   - reduce extent tree lock contention when searching for inline
     backref

   - switch from rb-trees to xarray for delayed ref tracking,
     improvements due to better cache locality, branching factors and
     more compact data structures

   - enable extent map shrinker again (prevent memory exhaustion under
     some types of IO load), reworked to run in a single worker thread
     (there used to be problems causing long stalls under memory
     pressure)

  Core changes:

   - raid-stripe-tree feature updates:
       - make device replace and scrub work
       - implement partial deletion of stripe extents
       - new selftests

   - split the config option BTRFS_DEBUG and add EXPERIMENTAL for
     features that are experimental or with known problems so we don't
     misuse debugging config for that

   - subpage mode updates (sector < page):
       - update compression implementations
       - update writepage, writeback

   - continued folio API conversions:
       - buffered writes

   - make buffered write copy one page at a time, preparatory work for
     future integration with large folios, may cause performance drop

   - proper locking of root item regarding starting send

   - error handling improvements

   - code cleanups and refactoring:
       - dead code removal
       - unused parameter reduction
       - lockdep assertions"

* tag 'for-6.13-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (119 commits)
  btrfs: send: check for read-only send root under critical section
  btrfs: send: check for dead send root under critical section
  btrfs: remove check for NULL fs_info at btrfs_folio_end_lock_bitmap()
  btrfs: fix warning on PTR_ERR() against NULL device at btrfs_control_ioctl()
  btrfs: fix a typo in btrfs_use_zone_append
  btrfs: avoid superfluous calls to free_extent_map() in btrfs_encoded_read()
  btrfs: simplify logic to decrement snapshot counter at btrfs_mksnapshot()
  btrfs: remove hole from struct btrfs_delayed_node
  btrfs: update stale comment for struct btrfs_delayed_ref_node::add_list
  btrfs: add new ioctl to wait for cleaned subvolumes
  btrfs: simplify range tracking in cow_file_range()
  btrfs: remove conditional path allocation in btrfs_read_locked_inode()
  btrfs: push cleanup into btrfs_read_locked_inode()
  io_uring/cmd: let cmds to know about dying task
  btrfs: add struct io_btrfs_cmd as type for io_uring_cmd_to_pdu()
  btrfs: add io_uring command for encoded reads (ENCODED_READ ioctl)
  btrfs: move priv off stack in btrfs_encoded_read_regular_fill_pages()
  btrfs: don't sleep in btrfs_encoded_read() if IOCB_NOWAIT is set
  btrfs: change btrfs_encoded_read() so that reading of extent is done by caller
  btrfs: remove pointless iocb::ki_pos addition in btrfs_encoded_read()
  ...
2024-11-18 16:37:41 -08:00
Linus Torvalds
0f25f0e4ef the bulk of struct fd memory safety stuff
Making sure that struct fd instances are destroyed in the same
 scope where they'd been created, getting rid of reassignments
 and passing them by reference, converting to CLASS(fd{,_pos,_raw}).
 
 We are getting very close to having the memory safety of that stuff
 trivial to verify.
 
 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCZzdikAAKCRBZ7Krx/gZQ
 69nJAQCmbQHK3TGUbQhOw6MJXOK9ezpyEDN3FZb4jsu38vTIdgEA6OxAYDO2m2g9
 CN18glYmD3wRyU6Bwl4vGODouSJvDgA=
 =gVH3
 -----END PGP SIGNATURE-----

Merge tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull 'struct fd' class updates from Al Viro:
 "The bulk of struct fd memory safety stuff

  Making sure that struct fd instances are destroyed in the same scope
  where they'd been created, getting rid of reassignments and passing
  them by reference, converting to CLASS(fd{,_pos,_raw}).

  We are getting very close to having the memory safety of that stuff
  trivial to verify"

* tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits)
  deal with the last remaing boolean uses of fd_file()
  css_set_fork(): switch to CLASS(fd_raw, ...)
  memcg_write_event_control(): switch to CLASS(fd)
  assorted variants of irqfd setup: convert to CLASS(fd)
  do_pollfd(): convert to CLASS(fd)
  convert do_select()
  convert vfs_dedupe_file_range().
  convert cifs_ioctl_copychunk()
  convert media_request_get_by_fd()
  convert spu_run(2)
  switch spufs_calls_{get,put}() to CLASS() use
  convert cachestat(2)
  convert do_preadv()/do_pwritev()
  fdget(), more trivial conversions
  fdget(), trivial conversions
  privcmd_ioeventfd_assign(): don't open-code eventfd_ctx_fdget()
  o2hb_region_dev_store(): avoid goto around fdget()/fdput()
  introduce "fd_pos" class, convert fdget_pos() users to it.
  fdget_raw() users: switch to CLASS(fd_raw)
  convert vmsplice() to CLASS(fd)
  ...
2024-11-18 12:24:06 -08:00
Linus Torvalds
56be9aaf98 vfs-6.13.pagecache
-----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZzcUQAAKCRCRxhvAZXjc
 onEpAQCUdwIBHpwmSIFvJFA9aNGpbLzi0dDSEIxuWYtp5qVuogD+ImccwqpG3kEi
 Zq9vokdPpB1zbahxKl1mkvBG4G0GFQE=
 =LbP6
 -----END PGP SIGNATURE-----

Merge tag 'vfs-6.13.pagecache' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs pagecache updates from Christian Brauner:
 "Cleanup filesystem page flag usage: This continues the work to make
  the mappedtodisk/owner_2 flag available to filesystems which don't use
  buffer heads. Further patches remove uses of Private2. This brings us
  very close to being rid of it entirely"

* tag 'vfs-6.13.pagecache' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  migrate: Remove references to Private2
  ceph: Remove call to PagePrivate2()
  btrfs: Switch from using the private_2 flag to owner_2
  mm: Remove PageMappedToDisk
  nilfs2: Convert nilfs_copy_buffer() to use folios
  fs: Move clearing of mappedtodisk to buffer.c
2024-11-18 09:54:32 -08:00
Linus Torvalds
70e7730c2a vfs-6.13.misc
-----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZzcToAAKCRCRxhvAZXjc
 osL9AP948FFumJRC28gDJ4xp+X4eohNOfkgoEG8FTbF2zU6ulwD+O0pr26FqpFli
 pqlG+38UdATImpfqqWjPbb72sBYcfQg=
 =wLUh
 -----END PGP SIGNATURE-----

Merge tag 'vfs-6.13.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "Features:

   - Fixup and improve NLM and kNFSD file lock callbacks

     Last year both GFS2 and OCFS2 had some work done to make their
     locking more robust when exported over NFS. Unfortunately, part of
     that work caused both NLM (for NFS v3 exports) and kNFSD (for
     NFSv4.1+ exports) to no longer send lock notifications to clients

     This in itself is not a huge problem because most NFS clients will
     still poll the server in order to acquire a conflicted lock

     It's important for NLM and kNFSD that they do not block their
     kernel threads inside filesystem's file_lock implementations
     because that can produce deadlocks. We used to make sure of this by
     only trusting that posix_lock_file() can correctly handle blocking
     lock calls asynchronously, so the lock managers would only setup
     their file_lock requests for async callbacks if the filesystem did
     not define its own lock() file operation

     However, when GFS2 and OCFS2 grew the capability to correctly
     handle blocking lock requests asynchronously, they started
     signalling this behavior with EXPORT_OP_ASYNC_LOCK, and the check
     for also trusting posix_lock_file() was inadvertently dropped, so
     now most filesystems no longer produce lock notifications when
     exported over NFS

     Fix this by using an fop_flag which greatly simplifies the problem
     and grooms the way for future uses by both filesystems and lock
     managers alike

   - Add a sysctl to delete the dentry when a file is removed instead of
     making it a negative dentry

     Commit 681ce86235 ("vfs: Delete the associated dentry when
     deleting a file") introduced an unconditional deletion of the
     associated dentry when a file is removed. However, this led to
     performance regressions in specific benchmarks, such as
     ilebench.sum_operations/s, prompting a revert in commit
     4a4be1ad3a ("Revert "vfs: Delete the associated dentry when
     deleting a file""). This reintroduces the concept conditionally
     through a sysctl

   - Expand the statmount() system call:

       * Report the filesystem subtype in a new fs_subtype field to
         e.g., report fuse filesystem subtypes

       * Report the superblock source in a new sb_source field

       * Add a new way to return filesystem specific mount options in an
         option array that returns filesystem specific mount options
         separated by zero bytes and unescaped. This allows caller's to
         retrieve filesystem specific mount options and immediately pass
         them to e.g., fsconfig() without having to unescape or split
         them

       * Report security (LSM) specific mount options in a separate
         security option array. We don't lump them together with
         filesystem specific mount options as security mount options are
         generic and most users aren't interested in them

         The format is the same as for the filesystem specific mount
         option array

   - Support relative paths in fsconfig()'s FSCONFIG_SET_STRING command

   - Optimize acl_permission_check() to avoid costly {g,u}id ownership
     checks if possible

   - Use smp_mb__after_spinlock() to avoid full smp_mb() in evict()

   - Add synchronous wakeup support for ep_poll_callback.

     Currently, epoll only uses wake_up() to wake up task. But sometimes
     there are epoll users which want to use the synchronous wakeup flag
     to give a hint to the scheduler, e.g., the Android binder driver.
     So add a wake_up_sync() define, and use wake_up_sync() when sync is
     true in ep_poll_callback()

  Fixes:

   - Fix kernel documentation for inode_insert5() and iget5_locked()

   - Annotate racy epoll check on file->f_ep

   - Make F_DUPFD_QUERY associative

   - Avoid filename buffer overrun in initramfs

   - Don't let statmount() return empty strings

   - Add a cond_resched() to dump_user_range() to avoid hogging the CPU

   - Don't query the device logical blocksize multiple times for hfsplus

   - Make filemap_read() check that the offset is positive or zero

  Cleanups:

   - Various typo fixes

   - Cleanup wbc_attach_fdatawrite_inode()

   - Add __releases annotation to wbc_attach_and_unlock_inode()

   - Add hugetlbfs tracepoints

   - Fix various vfs kernel doc parameters

   - Remove obsolete TODO comment from io_cancel()

   - Convert wbc_account_cgroup_owner() to take a folio

   - Fix comments for BANDWITH_INTERVAL and wb_domain_writeout_add()

   - Reorder struct posix_acl to save 8 bytes

   - Annotate struct posix_acl with __counted_by()

   - Replace one-element array with flexible array member in freevxfs

   - Use idiomatic atomic64_inc_return() in alloc_mnt_ns()"

* tag 'vfs-6.13.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (35 commits)
  statmount: retrieve security mount options
  vfs: make evict() use smp_mb__after_spinlock instead of smp_mb
  statmount: add flag to retrieve unescaped options
  fs: add the ability for statmount() to report the sb_source
  writeback: wbc_attach_fdatawrite_inode out of line
  writeback: add a __releases annoation to wbc_attach_and_unlock_inode
  fs: add the ability for statmount() to report the fs_subtype
  fs: don't let statmount return empty strings
  fs:aio: Remove TODO comment suggesting hash or array usage in io_cancel()
  hfsplus: don't query the device logical block size multiple times
  freevxfs: Replace one-element array with flexible array member
  fs: optimize acl_permission_check()
  initramfs: avoid filename buffer overrun
  fs/writeback: convert wbc_account_cgroup_owner to take a folio
  acl: Annotate struct posix_acl with __counted_by()
  acl: Realign struct posix_acl to save 8 bytes
  epoll: Add synchronous wakeup support for ep_poll_callback
  coredump: add cond_resched() to dump_user_range
  mm/page-writeback.c: Fix comment of wb_domain_writeout_add()
  mm/page-writeback.c: Update comment for BANDWIDTH_INTERVAL
  ...
2024-11-18 09:35:30 -08:00
Linus Torvalds
6ac81fd55e vfs-6.13.mgtime
-----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCZzcScQAKCRCRxhvAZXjc
 oj+5AP4k822a77wc/3iPFk379naIvQ4dsrgemh0/Pb6ZvzvkFQEAi3vFCfzCDR2x
 SkJF/RwXXKZv6U31QXMRt2Qo6wfBuAc=
 =nVlm
 -----END PGP SIGNATURE-----

Merge tag 'vfs-6.13.mgtime' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs multigrain timestamps from Christian Brauner:
 "This is another try at implementing multigrain timestamps. This time
  with significant help from the timekeeping maintainers to reduce the
  performance impact.

  Thomas provided a base branch that contains the required timekeeping
  interfaces for the VFS. It serves as the base for the multi-grain
  timestamp work:

   - Multigrain timestamps allow the kernel to use fine-grained
     timestamps when an inode's attributes is being actively observed
     via ->getattr(). With this support, it's possible for a file to get
     a fine-grained timestamp, and another modified after it to get a
     coarse-grained stamp that is earlier than the fine-grained time. If
     this happens then the files can appear to have been modified in
     reverse order, which breaks VFS ordering guarantees.

     To prevent this, a floor value is maintained for multigrain
     timestamps. Whenever a fine-grained timestamp is handed out, record
     it, and when later coarse-grained stamps are handed out, ensure
     they are not earlier than that value. If the coarse-grained
     timestamp is earlier than the fine-grained floor, return the floor
     value instead.

     The timekeeper changes add a static singleton atomic64_t into
     timekeeper.c that is used to keep track of the latest fine-grained
     time ever handed out. This is tracked as a monotonic ktime_t value
     to ensure that it isn't affected by clock jumps. Because it is
     updated at different times than the rest of the timekeeper object,
     the floor value is managed independently of the timekeeper via a
     cmpxchg() operation, and sits on its own cacheline.

     Two new public timekeeper interfaces are added:

      (1) ktime_get_coarse_real_ts64_mg() fills a timespec64 with the
          later of the coarse-grained clock and the floor time

      (2) ktime_get_real_ts64_mg() gets the fine-grained clock value,
          and tries to swap it into the floor. A timespec64 is filled
          with the result.

   - The VFS has always used coarse-grained timestamps when updating the
     ctime and mtime after a change. This has the benefit of allowing
     filesystems to optimize away a lot metadata updates, down to around
     1 per jiffy, even when a file is under heavy writes.

     Unfortunately, this has always been an issue when we're exporting
     via NFSv3, which relies on timestamps to validate caches. A lot of
     changes can happen in a jiffy, so timestamps aren't sufficient to
     help the client decide when to invalidate the cache. Even with
     NFSv4, a lot of exported filesystems don't properly support a
     change attribute and are subject to the same problems with
     timestamp granularity. Other applications have similar issues with
     timestamps (e.g backup applications).

     If we were to always use fine-grained timestamps, that would
     improve the situation, but that becomes rather expensive, as the
     underlying filesystem would have to log a lot more metadata
     updates.

     This adds a way to only use fine-grained timestamps when they are
     being actively queried. Use the (unused) top bit in
     inode->i_ctime_nsec as a flag that indicates whether the current
     timestamps have been queried via stat() or the like. When it's set,
     we allow the kernel to use a fine-grained timestamp iff it's
     necessary to make the ctime show a different value.

     This solves the problem of being able to distinguish the timestamp
     between updates, but introduces a new problem: it's now possible
     for a file being changed to get a fine-grained timestamp. A file
     that is altered just a bit later can then get a coarse-grained one
     that appears older than the earlier fine-grained time. This
     violates timestamp ordering guarantees.

     This is where the earlier mentioned timkeeping interfaces help. A
     global monotonic atomic64_t value is kept that acts as a timestamp
     floor. When we go to stamp a file, we first get the latter of the
     current floor value and the current coarse-grained time. If the
     inode ctime hasn't been queried then we just attempt to stamp it
     with that value.

     If it has been queried, then first see whether the current coarse
     time is later than the existing ctime. If it is, then we accept
     that value. If it isn't, then we get a fine-grained time and try to
     swap that into the global floor. Whether that succeeds or fails, we
     take the resulting floor time, convert it to realtime and try to
     swap that into the ctime.

     We take the result of the ctime swap whether it succeeds or fails,
     since either is just as valid.

     Filesystems can opt into this by setting the FS_MGTIME fstype flag.
     Others should be unaffected (other than being subject to the same
     floor value as multigrain filesystems)"

* tag 'vfs-6.13.mgtime' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  fs: reduce pointer chasing in is_mgtime() test
  tmpfs: add support for multigrain timestamps
  btrfs: convert to multigrain timestamps
  ext4: switch to multigrain timestamps
  xfs: switch to multigrain timestamps
  Documentation: add a new file documenting multigrain timestamps
  fs: add percpu counters for significant multigrain timestamp events
  fs: tracepoints around multigrain timestamp events
  fs: handle delegated timestamps in setattr_copy_mgtime
  timekeeping: Add percpu counter for tracking floor swap events
  timekeeping: Add interfaces for handling timestamps with a floor value
  fs: have setattr_copy handle multigrain timestamps appropriately
  fs: add infrastructure for multigrain timestamps
2024-11-18 09:15:39 -08:00
Linus Torvalds
c9dd4571ad for-6.12-rc7-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmc2aGIACgkQxWXV+ddt
 WDu0AQ/9FLfC/e3X2GjZ0auna/7A/rF8MPoATUdAyHn75Md6Hc8PXpi1YvMph+ba
 pvoufOqrU66/g0UNeacgsp6rF4rKJHg0q9Id+7wueLnDr41g9paXjsLYItq4j26w
 GusDiZvUDwuDmb70vlTXrgAfnjooIdSwqJTlIzJxvl4wrNzOiUlUJtTMzmUrwn/9
 Lf/iByWlGcPKKBc+1ZzFz4HlVOZZSt9YePeJw2/Aul2OMtuI3RTTAL/NtjaFIlYc
 pb+NHVqFrrfgC+xo68hLBmnsBfS41EGR58rYRjEuQo0+hARa8WbxL3DNA/E/Vi5X
 dsq/wQVlD7IVIWCoF9J94/iyDdwlDOGFMoL6FUrJwDtPGN/v/xxtA6ruvuC7k5zy
 bHCR8ZVrJWVaxE7u0Gtl+hFPpDTwNTR7SfvK69gxPfci1cN0m2wCNK02SEUJwV09
 N82N2ENGGwyWS+nOl/ERB+7A0QxViMr3JpUrPzSYqsmn8bwDvovSjK2fFouJoSey
 bpAzbFWj+OS0O9nnRqabTJDM/Tk9O0s0Ye76aUS+Vfk9d5EuVfAg6pHiOBcFDhsK
 UEG9QbPltfh6LPDHCdV93HOOsC0uNxCTCSpbQ9LFGKBICQsPIX/vZeV45fNFJDLX
 j5kEtHFVU3snU+jA97nvYXPRANDnnNx/EzXv7zo0Ye8L+plecBs=
 =ssYj
 -----END PGP SIGNATURE-----

Merge tag 'for-6.12-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fix from David Sterba:
 "One more fix that seems urgent and good to have in 6.12 final.

  It could potentially lead to unexpected transaction aborts, due to
  wrong comparison and order of processing of delayed refs"

* tag 'for-6.12-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix incorrect comparison for delayed refs
2024-11-15 09:45:32 -08:00
Josef Bacik
7d493a5ecc btrfs: fix incorrect comparison for delayed refs
When I reworked delayed ref comparison in cf4f04325b ("btrfs: move
->parent and ->ref_root into btrfs_delayed_ref_node"), I made a mistake
and returned -1 for the case where ref1->ref_root was > than
ref2->ref_root.  This is a subtle bug that can result in improper
delayed ref running order, which can result in transaction aborts.

Fixes: cf4f04325b ("btrfs: move ->parent and ->ref_root into btrfs_delayed_ref_node")
CC: stable@vger.kernel.org # 6.10+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-14 16:11:02 +01:00
Christoph Hellwig
e559ee0226 btrfs: validate queue limits
Call blk_validate_limits on the queue limits used for zone append
splitting so that calculated values get filled in and any stacking
conflicts get cought.

Without this there isn't a max_zone_append_sectors limits as of commit
559218d43e ("block: pre-calculate max_zone_append_sectors").

Fixes: 559218d43e ("block: pre-calculate max_zone_append_sectors")
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20241113084541.34315-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-11-13 11:40:11 -07:00
Filipe Manana
e82c936293 btrfs: send: check for read-only send root under critical section
We're checking if the send root is read-only without being under the
protection of the root's root_item_lock spinlock, which is what protects
the root's flags when clearing the read-only flag, done at
btrfs_ioctl_subvol_setflags(). Furthermore, it should be done in the
same critical section that increments the root's send_in_progress counter,
as btrfs_ioctl_subvol_setflags() clears the read-only flag in the same
critical section that checks the counter's value.

So fix this by moving the read-only check under the critical section
delimited by the root's root_item_lock which also increments the root's
send_in_progress counter.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:23 +01:00
Filipe Manana
dc058f5fda btrfs: send: check for dead send root under critical section
We're checking if the send root is dead without the protection of the
root's root_item_lock spinlock, which is what protects the root's flags.
The inverse, setting the dead flag on a root, is done under the protection
of that lock, at btrfs_delete_subvolume(). Also checking and updating the
root's send_in_progress counter is supposed to be done in the same
critical section as checking for or setting the root dead flag, so that
these operations are done atomically as a single step (which is correctly
done by btrfs_delete_subvolume()).

So fix this by checking if the send root is dead in the same critical
section that updates the send_in_progress counter, which is protected by
the root's root_item_lock spinlock.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:23 +01:00
Filipe Manana
722d343f12 btrfs: remove check for NULL fs_info at btrfs_folio_end_lock_bitmap()
Smatch complains about possibly dereferencing a NULL fs_info at
btrfs_folio_end_lock_bitmap():

  fs/btrfs/subpage.c:332 btrfs_folio_end_lock_bitmap() warn: variable dereferenced before check 'fs_info' (see line 326)

because we access fs_info to set the 'start_bit' variable before doing the
check for a NULL fs_info.

However fs_info is never NULL, since in the only caller of
btrfs_folio_end_lock_bitmap() is extent_writepage(), where we have an
inode which always as a non-NULL fs_info.

So remove the check for a NULL fs_info at btrfs_folio_end_lock_bitmap().

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:22 +01:00
Filipe Manana
2342d6595b btrfs: fix warning on PTR_ERR() against NULL device at btrfs_control_ioctl()
Smatch complains about calling PTR_ERR() against a NULL pointer:

  fs/btrfs/super.c:2272 btrfs_control_ioctl() warn: passing zero to 'PTR_ERR'

Fix this by calling PTR_ERR() against the device pointer only if it
contains an error.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:22 +01:00
Christoph Hellwig
80b3695538 btrfs: fix a typo in btrfs_use_zone_append
REQ_OP_ZONE_APPNED -> REQ_OP_ZONE_APPEND.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:22 +01:00
Mark Harmstone
08fdca9eee btrfs: avoid superfluous calls to free_extent_map() in btrfs_encoded_read()
Change the control flow of btrfs_encoded_read() so that it doesn't call
free_extent_map() when we know that this has already been done.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Suggested-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:22 +01:00
Filipe Manana
e36d114990 btrfs: simplify logic to decrement snapshot counter at btrfs_mksnapshot()
There's no point in having a 'snapshot_force_cow' variable to track if we
need to decrement the root->snapshot_force_cow counter, as we never jump
to the 'out' label after incrementing the counter. Simplify this by
removing the variable and always decrementing the counter before the 'out'
label, right after the call to btrfs_mksubvol().

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:22 +01:00
Filipe Manana
a20725e1e7 btrfs: remove hole from struct btrfs_delayed_node
On x86_64 and a release kernel, there's a 4 bytes hole in the structure
after the ref count field:

  struct btrfs_delayed_node {
          u64                        inode_id;             /*     0     8 */
          u64                        bytes_reserved;       /*     8     8 */
          struct btrfs_root *        root;                 /*    16     8 */
          struct list_head           n_list;               /*    24    16 */
          struct list_head           p_list;               /*    40    16 */
          struct rb_root_cached      ins_root;             /*    56    16 */
          /* --- cacheline 1 boundary (64 bytes) was 8 bytes ago --- */
          struct rb_root_cached      del_root;             /*    72    16 */
          struct mutex               mutex;                /*    88    32 */
          struct btrfs_inode_item    inode_item;           /*   120   160 */
          /* --- cacheline 4 boundary (256 bytes) was 24 bytes ago --- */
          refcount_t                 refs;                 /*   280     4 */

          /* XXX 4 bytes hole, try to pack */

          u64                        index_cnt;            /*   288     8 */
          long unsigned int          flags;                /*   296     8 */
          int                        count;                /*   304     4 */
          u32                        curr_index_batch_size; /*   308     4 */
          u32                        index_item_leaves;    /*   312     4 */

          /* size: 320, cachelines: 5, members: 15 */
          /* sum members: 312, holes: 1, sum holes: 4 */
          /* padding: 4 */
  };

Move the 'count' field, which is 4 bytes long, to just below the ref count
field, so we eliminate the hole and reduce the structure size from 320
bytes down to 312 bytes:

  struct btrfs_delayed_node {
          u64                        inode_id;             /*     0     8 */
          u64                        bytes_reserved;       /*     8     8 */
          struct btrfs_root *        root;                 /*    16     8 */
          struct list_head           n_list;               /*    24    16 */
          struct list_head           p_list;               /*    40    16 */
          struct rb_root_cached      ins_root;             /*    56    16 */
          /* --- cacheline 1 boundary (64 bytes) was 8 bytes ago --- */
          struct rb_root_cached      del_root;             /*    72    16 */
          struct mutex               mutex;                /*    88    32 */
          struct btrfs_inode_item    inode_item;           /*   120   160 */
          /* --- cacheline 4 boundary (256 bytes) was 24 bytes ago --- */
          refcount_t                 refs;                 /*   280     4 */
          int                        count;                /*   284     4 */
          u64                        index_cnt;            /*   288     8 */
          long unsigned int          flags;                /*   296     8 */
          u32                        curr_index_batch_size; /*   304     4 */
          u32                        index_item_leaves;    /*   308     4 */

          /* size: 312, cachelines: 5, members: 15 */
          /* last cacheline: 56 bytes */
  };

This now allows to have 13 delayed nodes per 4K page instead of 12.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:22 +01:00
Filipe Manana
dd0896e77d btrfs: update stale comment for struct btrfs_delayed_ref_node::add_list
The comment refers to a list in the respective delayed ref head that no
longer exists (ref_list), it was replaced with a rbtree (ref_tree) in
commit 0e0adbcfdc ("btrfs: track refs in a rb_tree instead of a list").

So update the stale comment to refer to the rbtree instead of the old
list.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:22 +01:00
David Sterba
6c83d153ed btrfs: add new ioctl to wait for cleaned subvolumes
Add a new unprivileged ioctl that will let the command
'btrfs subvolume sync' work without the (privileged) SEARCH_TREE ioctl.

There are several modes of operation, where the most common ones are to
wait on a specific subvolume or all currently queued for cleaning. This
is utilized e.g. in backup applications that delete subvolumes and wait
until they're cleaned to check for remaining space.

The other modes are for flexibility, e.g. for monitoring or
checkpoints in the queue of deleted subvolumes, again without the need
to use SEARCH_TREE.

Notes:

- waiting is interruptible, the timeout is set to 1 second and is not
  configurable

- repeated calls to the ioctl see a different state, so this is
  inherently racy when using e.g. the count or peek next/last

Use cases:

- a subvolume A was deleted, wait for cleaning (WAIT_FOR_ONE)

- a bunch of subvolumes were deleted, wait for all (WAIT_FOR_QUEUED or
  PEEK_LAST + WAIT_FOR_ONE)

- count how many are queued (not blocking), for monitoring purposes

- report progress (PEEK_NEXT), may miss some if cleaning is quick

- own waiting in user space (PEEK_LAST until it's 0)

Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:22 +01:00
Haisu Wang
5599f39356 btrfs: simplify range tracking in cow_file_range()
Simplify tracking of the range processed by using cur_alloc_size only to
store the reserved part that may fail to the allocated extent. Remove
the ram_size as well since it is always equal to cur_alloc_size in the
context. Advance the start in normal path until extent allocation
succeeds and keep the start unchanged in the error handling path.

Passed the fstest generic/475 test for a hundred times with quota
enabled. And a modified generic/475 test by removing the sleep time
for a hundred times. About one tenth of the tests do enter the error
handling path due to fail to reserve extent.

Suggested-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Haisu Wang <haisuwang@tencent.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:22 +01:00
Leo Martins
7c855e16ab btrfs: remove conditional path allocation in btrfs_read_locked_inode()
Remove conditional path allocation from btrfs_read_locked_inode(). Add
an ASSERT(path) to indicate it should never be called with a NULL path.

Call btrfs_read_locked_inode() directly from btrfs_iget(). This causes
code duplication between btrfs_iget() and btrfs_iget_path(), but I
think this is justifiable as it removes the need for conditionally
allocating the path inside of btrfs_read_locked_inode(). This makes the
code easier to reason about and makes it clear who has the
responsibility of allocating and freeing the path.

Signed-off-by: Leo Martins <loemra.dev@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:22 +01:00
Leo Martins
69673992b1 btrfs: push cleanup into btrfs_read_locked_inode()
Move btrfs_add_inode_to_root() so it can be called from
btrfs_read_locked_inode(), no changes were made to the function.

Move cleanup code from btrfs_iget_path() to btrfs_read_locked_inode.
This improves readability and improves a leaky abstraction. Previously
btrfs_iget_path() had to handle a positive error case as a result of a
call to btrfs_search_slot(), but it makes more sense to handle this
closer to the source of the call.

Signed-off-by: Leo Martins <loemra.dev@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:21 +01:00
Mark Harmstone
1cc86aeada btrfs: add struct io_btrfs_cmd as type for io_uring_cmd_to_pdu()
Add struct io_btrfs_cmd as a wrapper type for io_uring_cmd_to_pdu(),
rather than using a raw pointer.

Suggested-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:21 +01:00
Mark Harmstone
34310c442e btrfs: add io_uring command for encoded reads (ENCODED_READ ioctl)
Add an io_uring command for encoded reads, using the same interface as
the existing BTRFS_IOC_ENCODED_READ ioctl.

btrfs_uring_encoded_read() is an io_uring version of
btrfs_ioctl_encoded_read(), which validates the user input and calls
btrfs_encoded_read() to read the appropriate metadata. If we determine
that we need to read an extent from disk, we call
btrfs_encoded_read_regular_fill_pages() through
btrfs_uring_read_extent() to prepare the bio.

The existing btrfs_encoded_read_regular_fill_pages() is changed so that
if it is passed a valid uring_ctx, rather than waking up any waiting
threads it calls btrfs_uring_read_extent_endio(). This in turn copies
the read data back to userspace, and calls io_uring_cmd_done() to
complete the io_uring command.

Because we're potentially doing a non-blocking read,
btrfs_uring_read_extent() doesn't clean up after itself if it returns
-EIOCBQUEUED. Instead, it allocates a priv struct, populates the fields
there that we will need to unlock the inode and free our allocations,
and defers this to the btrfs_uring_read_finished() that gets called when
the bio completes.

Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:21 +01:00
Mark Harmstone
68d3b27e05 btrfs: move priv off stack in btrfs_encoded_read_regular_fill_pages()
Change btrfs_encoded_read_regular_fill_pages() so that the priv struct
is allocated rather than stored on the stack, in preparation for adding
an asynchronous mode to the function.

Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:21 +01:00
Mark Harmstone
973a432637 btrfs: don't sleep in btrfs_encoded_read() if IOCB_NOWAIT is set
Change btrfs_encoded_read() so that it returns -EAGAIN rather than sleeps
if IOCB_NOWAIT is set in iocb->ki_flags. The conditions that require
sleeping are: inode lock, writeback, extent lock, ordered range.

Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:21 +01:00
Mark Harmstone
26efd44796 btrfs: change btrfs_encoded_read() so that reading of extent is done by caller
Change the behaviour of btrfs_encoded_read() so that if it needs to read
an extent from disk, it leaves the extent and inode locked and returns
-EIOCBQUEUED. The caller is then responsible for doing the I/O via
btrfs_encoded_read_regular() and unlocking the extent and inode.

Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:21 +01:00
Mark Harmstone
4bca7412b8 btrfs: remove pointless iocb::ki_pos addition in btrfs_encoded_read()
iocb->ki_pos isn't used after this function, so there's no point in
changing its value.

Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:21 +01:00
Filipe Manana
7f13360ef9 btrfs: remove no longer used delayed ref head search functionality
After the previous patch, which converted the rb-tree used to track
delayed ref heads into an xarray, the find_ref_head() function is now
used only by one caller which always passes false to the 'return_bigger'
argument. So remove the 'return_bigger' logic, simplifying the function,
and move all the function code to the single caller.

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:21 +01:00
Filipe Manana
928ed1349d btrfs: track delayed ref heads in an xarray
Currently we use a red black tree (rb-tree) to track the delayed ref
heads (in struct btrfs_delayed_ref_root::href_root). This however is not
very efficient when the number of delayed ref heads is large (and it's
very common to be at least in the order of thousands) since rb-trees are
binary trees. For example for 10K delayed ref heads, the tree has a depth
of 13. Besides that, inserting into the tree requires navigating through
it and pulling useless cache lines in the process since the red black tree
nodes are embedded within the delayed ref head structure - on the other
hand, by being embedded, it requires no extra memory allocations.

We can improve this by using an xarray instead which has a much higher
branching factor than a red black tree (binary balanced tree) and is more
cache friendly and behaves like a resizable array, with a much better
search and insertion complexity than a red black tree. This only has one
small disadvantage which is that insertion will sometimes require
allocating memory for the xarray - which may fail (not that often since
it uses a kmem_cache) - but on the other hand we can reduce the delayed
ref head structure size by 24 bytes (from 152 down to 128 bytes) after
removing the embedded red black tree node, meaning than we can now fit
32 delayed ref heads per 4K page instead of 26, and that gain compensates
for the occasional memory allocations needed for the xarray nodes. We
also end up using only 2 cache lines instead of 3 per delayed ref head.

Running the following fs_mark test showed some improvements:

    $ cat test.sh
    #!/bin/bash

    DEV=/dev/nullb0
    MNT=/mnt/nullb0
    MOUNT_OPTIONS="-o ssd"
    FILES=100000
    THREADS=$(nproc --all)

    echo "performance" | \
        tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor

    mkfs.btrfs -f $DEV
    mount $MOUNT_OPTIONS $DEV $MNT

    OPTS="-S 0 -L 5 -n $FILES -s 0 -t $THREADS -k"
    for ((i = 1; i <= $THREADS; i++)); do
        OPTS="$OPTS -d $MNT/d$i"
    done

    fs_mark $OPTS

    umount $MNT

Before this patch:

   FSUse%        Count         Size    Files/sec     App Overhead
       10      1200000            0     171845.7         12253839
       16      2400000            0     230898.7         12308254
       23      3600000            0     212292.9         12467768
       30      4800000            0     195737.8         12627554
       46      6000000            0     171055.2         12783329

After this patch:

   FSUse%        Count         Size    Files/sec     App Overhead
       10      1200000            0     173835.0         12246131
       16      2400000            0     233537.8         12271746
       23      3600000            0     220398.7         12307737
       30      4800000            0     204483.6         12392318
       40      6000000            0     182923.3         12771843

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:21 +01:00
Filipe Manana
d3aaeea771 btrfs: add comments regarding locking to struct btrfs_delayed_ref_root
Add some comments to struct btrfs_delayed_ref_root's fields to mention
what its spinlock protects.

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:21 +01:00
Filipe Manana
a8985ac6be btrfs: assert delayed refs lock is held at add_delayed_ref_head()
The delayed refs lock must be held when calling add_delayed_ref_head(),
so assert that it's being held.

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:20 +01:00
Filipe Manana
64a71f0b8a btrfs: assert delayed refs lock is held at find_first_ref_head()
The delayed refs lock must be held when calling find_first_ref_head(), so
assert that it's being held.

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:20 +01:00
Filipe Manana
7226ed7d44 btrfs: assert delayed refs lock is held at find_ref_head()
We have 3 callers for find_ref_head() so assert at find_ref_head() that we
have the delayed refs lock held, removing the assertion from one of its
callers (btrfs_find_delayed_ref_head()).

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:20 +01:00
Filipe Manana
5f54384c73 btrfs: pass fs_info to btrfs_delete_ref_head()
One of the following patches in the series will need to access fs_info at
btrfs_delete_ref_head(), so pass a fs_info argument to it.

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:20 +01:00
Filipe Manana
765f828902 btrfs: pass fs_info to functions that search for delayed ref heads
One of the following patches in the series will need to access fs_info in
the function find_ref_head(), so pass a fs_info argument to it as well as
to the functions btrfs_select_ref_head() and btrfs_find_delayed_ref_head()
which call find_ref_head().

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:20 +01:00
Filipe Manana
58a4391810 btrfs: move delayed ref head unselection to delayed-ref.c
The unselect_delayed_ref_head() at extent-tree.c doesn't really belong in
that file as it's a delayed refs specific detail and therefore should be
at delayed-ref.c. Further its inverse, btrfs_select_ref_head(), is at
delayed-ref.c, so it only makes sense to have it there too.

So move unselect_delayed_ref_head() into delayed-ref.c and rename it to
btrfs_unselect_ref_head() so that its name closely matches its inverse
(btrfs_select_ref_head()).

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:20 +01:00
Filipe Manana
a98048e10d btrfs: simplify obtaining a delayed ref head
Instead of doing it in two steps outside of delayed-ref.c, leaking low
level details such as locking, move the logic entirely to delayed-ref.c
under btrfs_select_ref_head(), reducing code and making things simpler
for the caller.

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:20 +01:00
Filipe Manana
7ef3604886 btrfs: change return type of btrfs_delayed_ref_lock() to boolean
The function only returns 0, meaning it was able to lock the delayed ref
head, or -EAGAIN in case it wasn't able to lock it. So simplify this and
use a boolean return type instead, returning true if it was able to lock
and false otherwise.

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:20 +01:00
Filipe Manana
f7d4b4924d btrfs: remove num_entries atomic counter from delayed ref root
The atomic counter 'num_entries' is not used anymore, we increment it
and decrement it but then we don't ever read it to use for any logic.
Its last use was removed with commit 61a56a992f ("btrfs: delayed refs
pre-flushing should only run the heads we have"). So remove it.

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:20 +01:00
Filipe Manana
055903c4e7 btrfs: use helper to find first ref head at btrfs_destroy_delayed_refs()
Instead of open coding it, use the find_first_ref_head() helper at
btrfs_destroy_delayed_refs(). This avoids duplicating the logic,
specially with the upcoming changes in subsequent patches.

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:20 +01:00
Filipe Manana
8d07a8f4c6 btrfs: remove duplicated code to drop delayed ref during transaction abort
When destroying delayed refs during a transaction abort, we have open
coded the removal of a delayed ref, which is also done by the static
helper function drop_delayed_ref(). So remove that duplicated code and
use drop_delayed_ref() instead.

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:20 +01:00
Filipe Manana
c3a5888e0f btrfs: remove fs_info parameter from btrfs_cleanup_one_transaction()
The fs_info parameter is redundant because it can be extracted from the
transaction given as another parameter. So remove it and use the fs_info
accessible from the transaction.

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:19 +01:00
Filipe Manana
2f6e05a5cc btrfs: remove fs_info parameter from btrfs_destroy_delayed_refs()
The fs_info parameter is redundant because it can be extracted from the
transaction given as another parameter. So remove it and use the fs_info
accessible from the transaction.

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:19 +01:00
Filipe Manana
22a0ae1889 btrfs: move btrfs_destroy_delayed_refs() to delayed-ref.c
It's better suited at delayed-ref.c since it's about delayed refs and
contains logic to iterate over them (using the red black tree, doing all
the locking, freeing, etc), so move it from disk-io.c, which is pretty
big, into delayed-ref.c, hiding implementation details of how delayed
refs are tracked and managed. This also facilitates the next patches in
the series.

This change moves the code between files but also does the following
simple cleanups:

1) Rename the 'cache' variable to 'bg', since it's a block group
   (the 'cache' logic comes from old days where the block group
   structure was named 'btrfs_block_group_cache');

2) Move the 'ref' variable declaration to the scope of the inner
   while loop, since it's not used outside that loop.

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:19 +01:00
Filipe Manana
00f529661b btrfs: remove BUG_ON() at btrfs_destroy_delayed_refs()
At btrfs_destroy_delayed_refs() it's unexpected to not find the block
group to which a delayed reference's extent belongs to, so we have this
BUG_ON(), not just because it's highly unexpected but also because we
don't know what to do there.

Since we are in the transaction abort path, there's nothing we can do
other than proceed and cleanup all used resources we can. So remove
the BUG_ON() and deal with a missing block group by logging an error
message and continuing to cleanup all we can related to the current
delayed ref head and moving to other delayed refs.

Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:19 +01:00
Robbie Ko
1d16c2761b btrfs: reduce extent tree lock contention when searching for inline backref
When inserting extent backref, in order to check whether refs other than
inline refs are used, we always use path keep locks for tree search, which
will increase the lock contention of extent tree.

We do not need the parent node every time to determine whether normal
refs are used.  It is only needed when the extent item is the last item
in a leaf.

Therefore, we change it to first use keep_locks=0 for search.  If the
extent item happens to be the last item in the leaf, we then change to
keep_locks=1 for the second search to reduce lock contention.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:19 +01:00
Johannes Thumshirn
6e6ecdec22 btrfs: tests: implement case for partial RAID stripe-tree delete
Implement self-tests for partial deletion of RAID stripe-tree entries.

These two new tests cover both the deletion of the front of a RAID
stripe-tree stripe extent as well as truncation of an item to make it
smaller.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:19 +01:00
Johannes Thumshirn
6aea95ee31 btrfs: implement partial deletion of RAID stripe extents
In our CI system, the RAID stripe tree configuration sometimes fails with
the following ASSERT():

  assertion failed: found_start >= start && found_end <= end, in fs/btrfs/raid-stripe-tree.c:64

This ASSERT()ion triggers, because for the initial design of RAID
stripe-tree, I had the "one ordered-extent equals one bio" rule of zoned
btrfs in mind.

But for a RAID stripe-tree based system, that is not hosted on a zoned
storage device, but on a regular device this rule doesn't apply.

So in case the range we want to delete starts in the middle of the
previous item, grab the item and "truncate" it's length. That is, clone
the item, subtract the deleted portion from the key's offset, delete the
old item and insert the new one.

In case the range to delete ends in the middle of an item, we have to
adjust both the item's key as well as the stripe extents and then
re-insert the modified clone into the tree after deleting the old stripe
extent.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:19 +01:00
Anand Jain
d07eaa9995 btrfs: use filemap_get_folio() helper
When fgp_flags and gfp_flags are zero, use filemap_get_folio(A, B)
instead of __filemap_get_folio(A, B, 0, 0)—no need for the extra
arguments 0, 0.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:19 +01:00
Qu Wenruo
e820dbeb6a btrfs: convert btrfs_buffered_write() to use folios
The buffered write path is still heavily utilizing the page interface.
Since we have converted it to do a page-by-page copying, it's much easier
to convert all involved functions to folio interface, this involves:

- btrfs_copy_from_user()
- btrfs_drop_folio()
- prepare_uptodate_page()
- prepare_one_page()
- lock_and_cleanup_extent_if_need()
- btrfs_dirty_page()

All function are changed to accept a folio parameter, and if the word
"page" is in the function name, change that to "folio" too.

The function btrfs_dirty_page() is exported for v1 space cache, convert
v1 cache call site to convert its page to folio for the new interface.

And there is a small enhancement for prepare_one_folio(), instead of
manually waiting for the page writeback, let __filemap_get_folio() to
handle that by using FGP_WRITEBEGIN, which implies
(FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE).

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:19 +01:00
Qu Wenruo
c87c299776 btrfs: make buffered write to copy one page a time
Currently the btrfs_buffered_write() is preparing multiple page a time,
allowing a better performance.

But the current trend is to support larger folio as an optimization,
instead of implementing own multi-page optimization.

This is inspired by generic_perform_write(), which is copying one folio
a time.

Such change will prepare us to migrate to implement the write_begin()
and write_end() callbacks, and make every involved function a little
easier.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:19 +01:00
Mark Harmstone
b1c5f6eda2 btrfs: fix wrong sizeof in btrfs_do_encoded_write()
btrfs_do_encoded_write() was converted to use folios in 400b172b8c,
but we're still allocating based on sizeof(struct page *) rather than
sizeof(struct folio *). There's no functional change.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Mark Harmstone <maharmstone@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:18 +01:00
Thorsten Blum
4f285a7752 btrfs: use str_yes_no() helper function in btrfs_dump_free_space()
Remove hard-coded strings by using the str_yes_no() and str_no_yes()
helper functions.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:18 +01:00
Qu Wenruo
0f71202665 btrfs: rename btrfs_folio_(set|start|end)_writer_lock()
Since there is no user of reader locks, rename the writer locks into a
more generic name, by removing the "_writer" part from the name.

And also rename btrfs_subpage::writer into btrfs_subpage::locked.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:18 +01:00
Qu Wenruo
336e69f302 btrfs: unify to use writer locks for subpage locking
Since commit d7172f52e9 ("btrfs: use per-buffer locking for
extent_buffer reading"), metadata read no longer relies on the subpage
reader locking.

This means we do not need to maintain a different metadata/data split
for locking, so we can convert the existing reader lock users by:

- add_ra_bio_pages()
  Convert to btrfs_folio_set_writer_lock()

- end_folio_read()
  Convert to btrfs_folio_end_writer_lock()

- begin_folio_read()
  Convert to btrfs_folio_set_writer_lock()

- folio_range_has_eb()
  Remove the subpage->readers checks, since it is always 0.

- Remove btrfs_subpage_start_reader() and btrfs_subpage_end_reader()

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:18 +01:00
Qu Wenruo
8511074c42 btrfs: remove unused btrfs_folio_start_writer_lock()
This function is not really suitable to lock a folio, as it lacks the
proper mapping checks, thus the locked folio may not even belong to
btrfs.

And due to the above reason, the last user inside lock_delalloc_folios()
is already removed, and we can remove this function.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:18 +01:00
Boris Burkov
70958a949d btrfs: do not clear read-only when adding sprout device
If you follow the seed/sprout wiki, it suggests the following workflow:

btrfstune -S 1 seed_dev
mount seed_dev mnt
btrfs device add sprout_dev
mount -o remount,rw mnt

The first mount mounts the FS readonly, which results in not setting
BTRFS_FS_OPEN, and setting the readonly bit on the sb. The device add
somewhat surprisingly clears the readonly bit on the sb (though the
mount is still practically readonly, from the users perspective...).
Finally, the remount checks the readonly bit on the sb against the flag
and sees no change, so it does not run the code intended to run on
ro->rw transitions, leaving BTRFS_FS_OPEN unset.

As a result, when the cleaner_kthread runs, it sees no BTRFS_FS_OPEN and
does no work. This results in leaking deleted snapshots until we run out
of space.

I propose fixing it at the first departure from what feels reasonable:
when we clear the readonly bit on the sb during device add.

A new fstest I have written reproduces the bug and confirms the fix.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:18 +01:00
Filipe Manana
4b5c1200f7 btrfs: remove local generation variable from read_block_for_search()
It's redundant to have the 'gen' variable since we already have the same
value in the local btrfs_tree_parent_check structure. So remove it and
instead use the structure's field.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:18 +01:00
Filipe Manana
b8e63ea405 btrfs: remove redundant initializations for struct btrfs_tree_parent_check
It's pointless to initialize the has_first_key field of the stack local
btrfs_tree_parent_check structure at btrfs_tree_parent_check() and at
btrfs_qgroup_trace_subtree() since all fields not explicitly initialized
are zeroed out. In the case of the first function it's a bit odd because
we are assigning 0 and the field is of type bool, however not incorrect
since a 0 is converted to false.

Just remove the explicit initializations due to their redundancy.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:18 +01:00
Filipe Manana
c88ebf1db5 btrfs: simplify arguments for btrfs_verify_level_key()
The only caller of btrfs_verify_level_key() is read_block_for_search() and
it's passing 3 arguments to it that can be extracted from its on stack
variable of type struct btrfs_tree_parent_check.

So change btrfs_verify_level_key() to accept an argument of type
struct btrfs_tree_parent_check instead of level, first key and parent
transid arguments.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:18 +01:00
Filipe Manana
2b1ef80d68 btrfs: remove redundant level argument from read_block_for_search()
The level parameter passed to read_block_for_search() always matches the
level of the extent buffer passed in the "eb_ret" parameter, which we are
also extracting into the "parent_level" local variable.

So remove the level parameter and instead use the "parent_level" variable
which in fact has a better name (it's the level of the parent node from
which we are reading a child node/leaf).

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:18 +01:00
Filipe Manana
a8371fccf0 btrfs: re-enable the extent map shrinker
Now that the extent map shrinker can only be run by a single task and runs
asynchronously as a work queue job, enable it as it can no longer cause
stalls on tasks allocating memory and entering the extent map shrinker
through the fs shrinker (implemented by btrfs_free_cached_objects()).

This is crucial to prevent exhaustion of memory due to unbounded extent
map creation, primarily with direct IO but also for buffered IO on files
with holes. This problem, for the direct IO case, was first reported in
the Link tag below. That report was added to a Link tag of the first patch
that introduced the extent map shrinker, commit 956a17d9d0 ("btrfs: add
a shrinker for extent maps"), however the Link tag disappeared somehow
from the committed patch (but was included in the submitted patch to the
mailing list), so adding it below for future reference.

Link: https://lore.kernel.org/linux-btrfs/13f94633dcf04d29aaf1f0a43d42c55e@amazon.com/
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:18 +01:00
Filipe Manana
e7fa845010 btrfs: rename extent map shrinker members from struct btrfs_fs_info
The names for the members of struct btrfs_fs_info related to the extent
map shrinker are a bit too long, so rename them to be shorter by replacing
the "extent_map_" prefix with the "em_" prefix.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:17 +01:00
Filipe Manana
70a5f9e266 btrfs: simplify tracking progress for the extent map shrinker
Now that the extent map shrinker can only be run by a single task (as a
work queue item) there is no need to keep the progress of the shrinker
protected by a spinlock and passing the progress to trace events as
parameters. So remove the lock and simplify the arguments for the trace
events.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:17 +01:00
Filipe Manana
1020443840 btrfs: make the extent map shrinker run asynchronously as a work queue job
Currently the extent map shrinker is run synchronously for kswapd tasks
that end up calling the fs shrinker (fs/super.c:super_cache_scan()).
This has some disadvantages and for some heavy workloads with memory
pressure it can cause some delays and stalls that make a machine
unresponsive for some periods. This happens because:

1) We can have several kswapd tasks on machines with multiple NUMA zones,
   and running the extent map shrinker concurrently can cause high
   contention on some spin locks, namely the spin locks that protect
   the radix tree that tracks roots, the per root xarray that tracks
   open inodes and the list of delayed iputs. This not only delays the
   shrinker but also causes high CPU consumption and makes the task
   running the shrinker monopolize a core, resulting in the symptoms
   of an unresponsive system. This was noted in previous commits such as
   commit ae1e766f62 ("btrfs: only run the extent map shrinker from
   kswapd tasks");

2) The extent map shrinker's iteration over inodes can often be slow, even
   after changing the data structure that tracks open inodes for a root
   from a red black tree (up to kernel 6.10) to an xarray (kernel 6.10+).
   The transition to the xarray while it made things a bit faster, it's
   still somewhat slow - for example in a test scenario with 10000 inodes
   that have no extent maps loaded, the extent map shrinker took between
   5ms to 8ms, using a release, non-debug kernel. Iterating over the
   extent maps of an inode can also be slow if have an inode with many
   thousands of extent maps, since we use a red black tree to track and
   search extent maps. So having the extent map shrinker run synchronously
   adds extra delay for other things a kswapd task does.

So make the extent map shrinker run asynchronously as a job for the
system unbounded workqueue, just like what we do for data and metadata
space reclaim jobs.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:17 +01:00
Filipe Manana
03ba050583 btrfs: add and use helper to remove extent map from its inode's tree
Move the common code to remove an extent map from its inode's tree into a
helper function and use it, reducing duplicated code.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:17 +01:00
Robbie Ko
99785998ed btrfs: reduce lock contention when eb cache miss for btree search
When crawling btree, if an eb cache miss occurs, we change to use the eb
read lock and release all previous locks (including the parent lock) to
reduce lock contention.

If an eb cache miss occurs in a leaf and needs to execute IO, before this
change we released locks only from level 2 and up and we read a leaf's
content from disk while holding a lock on its parent (level 1), causing
the unnecessary lock contention on the parent, after this change we
release locks from level 1 and up, but we lock level 0, and read leaf's
content from disk.

Because we have prepared the check parameters and the read lock of eb we
hold, we can ensure that no race will occur during the check and cause
unexpected errors.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:17 +01:00
David Sterba
a9c50c9756 btrfs: drop unused parameter level from alloc_heuristic_ws()
The compression heuristic pass does not need a level, so we can drop the
parameter.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:17 +01:00
David Sterba
8c7cd2b6c9 btrfs: drop unused parameter fs_info from btrfs_match_dir_item_name()
Cascaded removal of fs_info that is not needed in several functions.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:17 +01:00
David Sterba
d12a1a2a30 btrfs: drop unused parameter transaction from alloc_log_tree()
The function got split in commit 6ab6ebb760 ("btrfs: split
alloc_log_tree()") and since then transaction parameter has been unused.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:17 +01:00
David Sterba
01c5db782e btrfs: drop unused parameter data from btrfs_fill_super()
The only caller passes NULL, we can drop the parameter. This is since
the new mount option parser done in 3bb17a25bc ("btrfs: add get_tree
callback for new mount API").

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:17 +01:00
David Sterba
87cbab8636 btrfs: drop unused parameter options from open_ctree()
Since the new mount option parser in commit ad21f15b0f ("btrfs:
switch to the new mount API") we don't pass the options like that
anymore.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:17 +01:00
David Sterba
ec315b4b9f btrfs: drop unused parameter fs_info from folio_range_has_eb()
The parameter was added in 8ff8466d29 ("btrfs: support subpage for
extent buffer page release") for page but hasn't been used since, so we
can drop it.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:17 +01:00
David Sterba
2decc288eb btrfs: drop unused parameter mask from try_release_extent_state()
The mask parameter used for allocations got unified to GFP_NOFS and
removed from relevant functions in 1d12680044 ("btrfs: drop gfp from
parameter extent state helpers").

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:16 +01:00
David Sterba
f8c4d59de2 btrfs: drop unused parameter refs from visit_node_for_delete()
The parameter duplicates what can be effectively obtained from
wc->refs[level - 1] and this is what's actually used inside. Added in
commit 2b73c7e761 ("btrfs: unify logic to decide if we need to walk
down into a node during snapshot delete").

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:16 +01:00
David Sterba
cc5fe81aa6 btrfs: drop unused parameter iov_iter from btrfs_write_check()
The parameter 'from' has never been used since commit b8d8e1fd57
("btrfs: introduce btrfs_write_check()"), this is for buffered write.
Direct io write needs it so it was probably an interface thing, but we
can drop it.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:16 +01:00
David Sterba
590168edbe btrfs: drop unused parameter file_offset from btrfs_encoded_read_regular_fill_pages()
The file_offset parameter used to be passed to encoded read struct but
was removed in commit b665affe93 ("btrfs: remove unused members from
struct btrfs_encoded_read_private").

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:16 +01:00
David Sterba
e469da5d84 btrfs: drop unused parameter offset from __cow_file_range_inline()
We don't need offset for inline extents, they always start from 0.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:16 +01:00
David Sterba
372e5f88af btrfs: drop unused parameter inode from read_inline_extent()
We don't need the inode pointer to read inline extent, it's all
accessible from the path pointer.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:16 +01:00
David Sterba
fd68c60048 btrfs: drop unused parameter argp from btrfs_ioctl_quota_rescan_wait()
We don't need the user passed parameter, rescan is a filesystem
operation so fs_info is sufficient.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:16 +01:00
David Sterba
3f4b1bc1c0 btrfs: lzo: drop unused paramter level from lzo_alloc_workspace()
The LZO compression has only one level, we don't need to pass the
parameter.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:16 +01:00
David Sterba
d7f4b4efaa btrfs: drop unused transaction parameter from btrfs_qgroup_add_swapped_blocks()
The caller replace_path() runs under transaction but we don't need it in
btrfs_qgroup_add_swapped_blocks().

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:16 +01:00
David Sterba
2651f43274 btrfs: qgroup: drop unused parameter fs_info from __del_qgroup_rb()
We don't need fs_info here, everything is reachable from qgroup.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:16 +01:00
David Sterba
887d417f0a btrfs: drop unused parameter map from scrub_simple_mirror()
The parameter map used to be passed to scrub_extent() until
e02ee89baa ("btrfs: scrub: switch scrub_simple_mirror() to
scrub_stripe infrastructure"), where the scrub implementation was
completely reworked.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:16 +01:00
David Sterba
f2c144fba7 btrfs: scrub: drop unused parameter sctx from scrub_submit_extent_sector_read()
The parameter is unused and we can reach sctx from scrub stripe if
needed.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:15 +01:00
David Sterba
a86a735d03 btrfs: send: drop unused parameter index from iterate_inode_ref_t callbacks
None of the ref iteration callbacks needs the index parameter (this is
for the directory item iteration), so we can drop it.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:15 +01:00
David Sterba
a1e76e362f btrfs: send: drop unused parameter num from iterate_inode_ref_t callbacks
None of the ref iteration callbacks needs the num parameter (this is for
the directory item iteration), so we can drop it.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:15 +01:00
David Sterba
343a63594b btrfs: drop unused parameter fs_info from do_reclaim_sweep()
The parameter is unused and we can get it from space info if needed.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:15 +01:00
David Sterba
a6563fa06a btrfs: drop unused parameter fs_info from wait_reserve_ticket()
The parameter is not used, we can also reach it from the space info if
needed in the future.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:15 +01:00
David Sterba
2d5903dd5b btrfs: drop unused parameter ctx from batch_delete_dir_index_items()
The ctx parameter is not used, we can drop it.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:15 +01:00
David Sterba
25a1399a6d btrfs: drop unused parameter path from btrfs_tree_mod_log_rewind()
The path parameter was used for our own locking, that got converted to
rwsem eventually. Last usage in ac5887c8e0 ("btrfs: locking: remove
all the blocking helpers").

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:15 +01:00
David Sterba
2fac7e163d btrfs: zstd: assert the timer pointer in callback
Make sure we got the right timer struct for the zstd workspace reclaim
work.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:15 +01:00
Qu Wenruo
0fcaf926ad btrfs: remove btrfs_set_range_writeback()
The function btrfs_set_range_writeback() was originally a callback for
metadata and data, to mark a range with writeback flag.

Then it was converted into a common function call for both metadata and
data.

From the very beginning, the function had been only called on a full page,
later converted to handle range inside a page.

But it never needed to handle multiple pages, and since commit
8189197425 ("btrfs: refactor __extent_writepage_io() to do
sector-by-sector submission") the function was only called on a
sector-by-sector basis.

This makes the function unnecessary, and can be converted to a simple
btrfs_folio_set_writeback() call instead.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:15 +01:00
Filipe Manana
dd4028315e btrfs: qgroup: run delayed iputs after ordered extent completion
When trying to flush qgroups in order to release space we run delayed
iputs in order to release space from recently deleted files (their link
counted reached zero), and then we start delalloc and wait for any
existing ordered extents to complete.

However there's a time window here where we end up not doing the final
iput on a deleted file which could release necessary space:

1) An unlink operation starts;

2) During the unlink, or right before it completes, delalloc is flushed
   and an ordered extent is created;

3) When the ordered extent is created, the inode's ref count is
   incremented (with igrab() at alloc_ordered_extent());

4) When the unlink finishes it doesn't drop the last reference on the
   inode and so it doesn't trigger inode eviction to delete all of
   the inode's items in its root and drop all references on its data
   extents;

5) Another task enters try_flush_qgroup() to try to release space,
   it runs all delayed iputs, but there's no delayed iput yet for that
   deleted file because the ordered extent hasn't completed yet;

6) Then at try_flush_qgroup() we wait for the ordered extent to complete
   and that results in adding a delayed iput at btrfs_put_ordered_extent()
   when called from btrfs_finish_one_ordered();

7) Adding the delayed iput results in waking the cleaner kthread if it's
   not running already. However it may take some time for it to be
   scheduled, or it may be running but busy running auto defrag, dropping
   deleted snapshots or doing other work, so by the time we return from
   try_flush_qgroup() the space for deleted file isn't released.

Improve on this by running delayed iputs only after flushing delalloc
and waiting for ordered extent completion.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:15 +01:00
Johannes Thumshirn
9fde8a67b9 btrfs: scrub: skip initial RST lookup errors
Performing the initial extent sector read on a RAID stripe-tree backed
filesystem with pre-allocated extents will cause the RAID stripe-tree
lookup code to return ENODATA, as pre-allocated extents do not have any
on-disk bytes and thus no RAID stripe-tree entries.

But the current scrub read code marks these extents as errors, because
the lookup fails.

If btrfs_map_block() returns -ENODATA, it means that the call to
btrfs_get_raid_extent_offset() returned -ENODATA, because there is no
entry for the corresponding range in the RAID stripe-tree. But as this
range is in the extent tree it means we've hit a pre-allocated extent. In
this case, don't mark the sector in the stripe's error bitmaps as faulty
and carry on to the next.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:15 +01:00
Johannes Thumshirn
5e72aabc1f btrfs: return ENODATA in case RST lookup fails
In case a lookup in the RAID stripe-tree fails, return ENODATA instead of
ENOENT to better distinguish stripe-tree lookups from other code paths
where we return ENOENT.

Suggested-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:14 +01:00
Johannes Thumshirn
61b4d75e3c btrfs: handle empty list of NOCOW ordered extents with checksum list
Currently we BUG_ON() in btrfs_finish_one_ordered() if we are finishing
an ordered extent that is flagged as NOCOW, but it's checksum list is
not empty.

This is clearly a logic error which we can recover from by aborting the
transaction.

For developer builds which enable CONFIG_BTRFS_ASSERT, also ASSERT()
that the list is empty.

Suggested-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:14 +01:00
Qu Wenruo
7f91c6a78a btrfs: simplify the page uptodate preparation for prepare_pages()
Currently inside prepare_pages(), we handle the leading and tailing page
differently, and skip the middle pages (if any).  This is to avoid
reading pages which are fully covered by the dirty range.

Refactor the code by moving all checks (alignment check, range check,
force read check) into prepare_uptodate_page().

So that prepare_pages() only needs to iterate all the pages
unconditionally.

And since we're here, also update prepare_uptodate_page() to use
folio API other than the old page API.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:14 +01:00
Qu Wenruo
00c5135dce btrfs: remove the dirty_page local variable
Inside btrfs_buffered_write(), we have a local variable @dirty_pages,
recording the number of pages we dirtied in the current iteration.

However we do not really need that variable, since it can be calculated
from @pos and @copied.

In fact there is already a problem inside the short copy path, where we
use @dirty_pages to calculate the range we need to release.
But that usage assumes sectorsize == PAGE_SIZE, which is no longer true.

Instead of keeping @dirty_pages and cause incorrect usage, just
calculate the number of dirtied pages inside btrfs_dirty_pages().

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:14 +01:00
Dr. David Alan Gilbert
b628c13951 btrfs: remove unused btrfs_try_tree_write_lock()
btrfs_try_tree_write_lock() has been unused since commit
50b21d7a06 ("btrfs: submit a writeback bio per extent_buffer").
Remove it as we don't need it anymore.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:14 +01:00
Dr. David Alan Gilbert
441ffe8a98 btrfs: remove unused btrfs_is_parity_mirror()
btrfs_is_parity_mirror() has been unused since commit 4886ff7b50
("btrfs: introduce a new helper to submit write bio for repair").
Remove it as the code was refactored and we don't need the helper
anymore.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:14 +01:00
Dr. David Alan Gilbert
004641bd06 btrfs: remove unused btrfs_free_squota_rsv()
btrfs_free_squota_rsv() was added in commit
e85a0adacf ("btrfs: ensure releasing squota reserve on head refs")
but has remained unused since then.
Remove it as we don't seem to need it and was probably a leftover.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:14 +01:00
Johannes Thumshirn
506be4d565 btrfs: tests: add selftests for raid-stripe-tree
Add first stash of very basic self tests for the RAID stripe-tree.

More test cases will follow exercising the tree.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:14 +01:00
Shen Lichuan
2144e1f23f btrfs: correct typos in multiple comments across various files
Fix some confusing spelling errors that were currently identified,
the details are as follows:

	block-group.c: 2800: 	uncompressible 	==> incompressible
	extent-tree.c: 3131:	EXTEMT		==> EXTENT
	extent_io.c: 3124: 	utlizing 	==> utilizing
	extent_map.c: 1323: 	ealier		==> earlier
	extent_map.c: 1325:	possiblity	==> possibility
	fiemap.c: 189:		emmitted	==> emitted
	fiemap.c: 197:		emmitted	==> emitted
	fiemap.c: 203:		emmitted	==> emitted
	transaction.h: 36:	trasaction	==> transaction
	volumes.c: 5312:	filesysmte	==> filesystem
	zoned.c: 1977:		trasnsaction	==> transaction

Signed-off-by: Shen Lichuan <shenlichuan@vivo.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:14 +01:00
Youling Tang
fa984c9e62 btrfs: remove unused page_to_inode and page_to_fs_info macros
This macro is no longer used after the "btrfs: Cleaned up folio->page
conversion" series patch [1] was applied, so remove it.

[1]: https://patchwork.kernel.org/project/linux-btrfs/cover/20240828182908.3735344-1-lizetao1@huawei.com/

Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Youling Tang <tangyouling@kylinos.cn>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:14 +01:00
Riyan Dhiman
522945b342 btrfs: remove redundant stop_loop variable in scrub_stripe()
The variable stop_loop was originally introduced in commit 625f1c8dc6
("Btrfs: improve the loop of scrub_stripe"). It was initialized to 0 in
commit 3b080b2564 ("Btrfs: scrub raid56 stripes in the right way").
However, in a later commit 18d30ab961 ("btrfs: scrub: use
scrub_simple_mirror() to handle RAID56 data stripe scrub"), the code
that modified stop_loop was removed, making the variable redundant.

Currently, stop_loop is only initialized with 0 and is never used or
modified within the scrub_stripe() function. As a result, this patch
removes the stop_loop variable to clean up the code and eliminate
unnecessary redundancy.

This change has no impact on functionality, as stop_loop was never
utilized in any meaningful way in the final version of the code.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Riyan Dhiman <riyandhiman14@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:13 +01:00
Filipe Manana
287d1cf303 btrfs: remove pointless initialization at btrfs_qgroup_trace_extent()
The qgroup record was allocated with kzalloc(), so it's pointless to set
its old_roots member to NULL. Remove the assignment.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:13 +01:00
Filipe Manana
db58e152a2 btrfs: always use delayed_refs local variable at btrfs_qgroup_trace_extent()
Instead of dereferencing the delayed refs from the transaction multiple
times, store it early in the local variable and then always use the
variable.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:13 +01:00
Filipe Manana
c5e2680224 btrfs: remove unnecessary delayed refs locking at btrfs_qgroup_trace_extent()
There's no need to hold the delayed refs spinlock when calling
btrfs_qgroup_trace_extent_nolock() from btrfs_qgroup_trace_extent(), since
it doesn't change anything in delayed refs and it only changes the xarray
used to track qgroup extent records, which is protected by the xarray's
lock.

Holding the lock is only adding unnecessary lock contention with other
tasks that actually need to take the lock to add/remove/change delayed
references. So remove the locking.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:13 +01:00
Filipe Manana
fad884b0c8 btrfs: store fs_info in a local variable at btrfs_qgroup_trace_extent_post()
Instead of extracting fs_info from the transaction multiples times, store
it in a local variable and use it.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:13 +01:00
Filipe Manana
c28b97f53b btrfs: qgroups: remove bytenr field from struct btrfs_qgroup_extent_record
Now that we track qgroup extent records in a xarray we don't need to have
a "bytenr" field in  struct btrfs_qgroup_extent_record, since we can get
it from the index of the record in the xarray.

So remove the field and grab the bytenr from either the index key or any
other place where it's available (delayed refs). This reduces the size of
struct btrfs_qgroup_extent_record from 40 bytes down to 32 bytes, meaning
that we now can store 128 instances of this structure instead of 102 per
4K page.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:13 +01:00
Johannes Thumshirn
2206265f41 btrfs: remove code duplication in ordered extent finishing
Remove the duplicated transaction joining, block reserve setting and raid
extent inserting in btrfs_finish_ordered_extent().

While at it, also abort the transaction in case inserting a RAID
stripe-tree entry fails.

Suggested-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:13 +01:00
Qu Wenruo
7e06de7c83 btrfs: canonicalize the device path before adding it
[PROBLEM]
Currently btrfs accepts any file path for its device, resulting some
weird situation:

 # ./mount_by_fd /dev/test/scratch1  /mnt/btrfs/

The program has the following source code:

 #include <fcntl.h>
 #include <stdio.h>
 #include <sys/mount.h>

 int main(int argc, char *argv[]) {
	int fd = open(argv[1], O_RDWR);
	char path[256];
	snprintf(path, sizeof(path), "/proc/self/fd/%d", fd);
	return mount(path, argv[2], "btrfs", 0, NULL);
 }

Then we can have the following weird device path:

 BTRFS: device fsid 2378be81-fe12-46d2-a9e8-68cf08dd98d5 devid 1 transid 7 /proc/self/fd/3 (253:2) scanned by mount_by_fd (18440)

Normally it's not a big deal, and later udev can trigger a device path
rename. But if udev didn't trigger, the device path "/proc/self/fd/3"
will show up in mtab.

[CAUSE]
For filename "/proc/self/fd/3", it means the opened file descriptor 3.
In above case, it's exactly the device we want to open, aka points to
"/dev/test/scratch1" which is another symlink pointing to "/dev/dm-2".

Inside kernel we solve the mount source using LOOKUP_FOLLOW, which
follows the symbolic link and grab the proper block device.

But inside btrfs we also save the filename into btrfs_device::name, and
utilize that member to report our mount source, which leads to the above
situation.

[FIX]
Instead of unconditionally trust the path, check if the original file
(not following the symbolic link) is inside "/dev/", if not, then
manually lookup the path to its final destination, and use that as our
device path.

This allows us to still use symbolic links, like
"/dev/mapper/test-scratch" from LVM2, which is required for fstests runs
with LVM2 setup.

And for really weird names, like the above case, we solve it to
"/dev/dm-2" instead.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Link: https://bugzilla.suse.com/show_bug.cgi?id=1230641
Reported-by: Fabian Vogt <fvogt@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:13 +01:00
Qu Wenruo
2e8b6bc0ab btrfs: avoid unnecessary device path update for the same device
[PROBLEM]
It is very common for udev to trigger device scan, and every time a
mounted btrfs device got re-scan from different soft links, we will get
some of unnecessary device path updates, this is especially common
for LVM based storage:

 # lvs
  scratch1 test -wi-ao---- 10.00g
  scratch2 test -wi-a----- 10.00g
  scratch3 test -wi-a----- 10.00g
  scratch4 test -wi-a----- 10.00g
  scratch5 test -wi-a----- 10.00g
  test     test -wi-a----- 10.00g

 # mkfs.btrfs -f /dev/test/scratch1
 # mount /dev/test/scratch1 /mnt/btrfs
 # dmesg -c
 [  205.705234] BTRFS: device fsid 7be2602f-9e35-4ecf-a6ff-9e91d2c182c9 devid 1 transid 6 /dev/mapper/test-scratch1 (253:4) scanned by mount (1154)
 [  205.710864] BTRFS info (device dm-4): first mount of filesystem 7be2602f-9e35-4ecf-a6ff-9e91d2c182c9
 [  205.711923] BTRFS info (device dm-4): using crc32c (crc32c-intel) checksum algorithm
 [  205.713856] BTRFS info (device dm-4): using free-space-tree
 [  205.722324] BTRFS info (device dm-4): checking UUID tree

So far so good, but even if we just touched any soft link of
"dm-4", we will get quite some unnecessary device path updates.

 # touch /dev/mapper/test-scratch1
 # dmesg -c
 [  469.295796] BTRFS info: devid 1 device path /dev/mapper/test-scratch1 changed to /dev/dm-4 scanned by (udev-worker) (1221)
 [  469.300494] BTRFS info: devid 1 device path /dev/dm-4 changed to /dev/mapper/test-scratch1 scanned by (udev-worker) (1221)

Such device path rename is unnecessary and can lead to random path
change due to the udev race.

[CAUSE]
Inside device_list_add(), we are using a very primitive way checking if
the device has changed, strcmp().

Which can never handle links well, no matter if it's hard or soft links.

So every different link of the same device will be treated as a different
device, causing the unnecessary device path update.

[FIX]
Introduce a helper, is_same_device(), and use path_equal() to properly
detect the same block device.
So that the different soft links won't trigger the rename race.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Link: https://bugzilla.suse.com/show_bug.cgi?id=1230641
Reported-by: Fabian Vogt <fvogt@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:13 +01:00
Qu Wenruo
1d2fbb7f1f btrfs: allow compression even if the range is not page aligned
Previously for btrfs with sector size smaller than page size (subpage),
we only allow compression if the range is fully page aligned.

This is to work around the asynchronous submission of compressed range,
which delayed the page unlock and writeback into a workqueue,
furthermore asynchronous submission can lock multiple sector range
across page boundary.

Such asynchronous submission makes it very hard to co-operate with other
regular writes.

With the recent changes to the subpage folio unlock path, now
asynchronous submission of compressed pages can co-operate with regular
submission, so enable sector perfect compression if it's an experimental
build.

The ETA for moving this feature out of experimental is 6.15, and I hope
all remaining corner cases can be exposed before that.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:13 +01:00
Qu Wenruo
c96d0e3921 btrfs: mark all dirty sectors as locked inside writepage_delalloc()
Currently we only mark sectors as locked if there is a *NEW* delalloc
range for it.

But NEW delalloc range is not the same as dirty sectors we want to
submit, e.g:

        0       32K      64K      96K       128K
        |       |////////||///////|    |////|
                                       120K

For above 64K page size case, writepage_delalloc() for page 0 will find
and lock the delalloc range [32K, 96K), which is beyond the page
boundary.

Then when writepage_delalloc() is called for the page 64K, since [64K,
96K) is already locked, only [120K, 128K) will be locked.

This means, although range [64K, 96K) is dirty and will be submitted
later by extent_writepage_io(), it will not be marked as locked.

This is fine for now, as we call btrfs_folio_end_writer_lock_bitmap() to
free every non-compressed sector, and compression is only allowed for
full page range.

But this is not safe for future sector perfect compression support, as
this can lead to double folio unlock:

              Thread A                 |           Thread B
---------------------------------------+--------------------------------
                                       | submit_one_async_extent()
				       | |- extent_clear_unlock_delalloc()
extent_writepage()                     |    |- btrfs_folio_end_writer_lock()
|- btrfs_folio_end_writer_lock_bitmap()|       |- btrfs_subpage_end_and_test_writer()
   |                                   |       |  |- atomic_sub_and_test()
   |                                   |       |     /* Now the atomic value is 0 */
   |- if (atomic_read() == 0)          |       |
   |- folio_unlock()                   |       |- folio_unlock()

The root cause is the above range [64K, 96K) is dirtied and should also
be locked but it isn't.

So to make everything more consistent and prepare for the incoming
sector perfect compression, mark all dirty sectors as locked.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:13 +01:00
Qu Wenruo
2bca8eb077 btrfs: move the delalloc range bitmap search into extent_io.c
Currently for subpage (sector size < page size) cases, we reuse subpage
locked bitmap to find out all delalloc ranges we have locked, and run
all those found ranges.

However such reuse is not perfect, e.g.:

    0       32K      64K      96K       128K
    |       |////////||///////|    |////|
                                   120K

For above range, writepage_delalloc() for page 0 will handle the range
[32K, 96k), note delalloc range can be beyond the page boundary.

But writepage_delalloc() for page 64K will only handle range [120K,
128K), as the previous run on page 0 has already handled range [64K,
96K).
Meanwhile for the writeback we should expect range [64K, 96K) to also be
locked, this leads to the mismatch from locked bitmap and delalloc
range.

This is not causing problems yet, but it's still an inconsistent
behavior.

So instead of relying on the subpage locked bitmap, move the delalloc
range search using local @delalloc_bitmap, so that we can remove the
existing btrfs_folio_find_writer_locked().

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:12 +01:00
Qu Wenruo
928b4de66e btrfs: do not assume the full page range is not dirty in extent_writepage_io()
The function extent_writepage_io() will submit the dirty sectors inside
the page for the write.

But recently to co-operate with the incoming subpage compression
enhancement, a new bitmap is introduced to
btrfs_bio_ctrl::submit_bitmap, to only avoid a subset of the dirty
range.

This is because we can have the following cases with 64K page size:

    0      16K       32K       48K       64K
    |      |/////////|         |/|
                                 52K

For range [16K, 32K), we queue the dirty range for compression, which is
ran in a delayed workqueue.
Then for range [48K, 52K), we go through the regular submission path.

In that case, our btrfs_bio_ctrl::submit_bitmap will exclude the range
[16K, 32K).

The dirty flags for the range [16K, 32K) is only cleared when the
compression is done, by the extent_clear_unlock_delalloc() call inside
submit_one_async_extent().

This patch fix the false alert by removing the
btrfs_folio_assert_not_dirty() check, since it's no longer correct for
subpage compression cases.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:12 +01:00
Qu Wenruo
a4ef54dbb5 btrfs: make extent_range_clear_dirty_for_io() to handle sector size < page size cases
For btrfs with sector size < page size (e.g. 4K sector size, 64K page
size), and enable the sector perfect compression support, then the
following dirty range can lead to problems:

   0     32K     64K     96K    128K
   |     |///////||//////|    |/|
                              124K

In above case, if we start writeback for that inode, the last dirty
range [124K, 128K) will not be submitted and cause reserved space
leakage:

- Start writeback for page 0
  We find the range [32K, 96K) is suitable for compression, and queue it
  into a workqueue to do the delayed compression and submission.

- Compression happens for range [32K, 96K)
  Function extent_range_clear_dirty_for_io() is called, however it is
  only doing full page handling, not considering any the extra bitmaps
  for subpage cases.

  That function will clear page dirty for both page 0 and page 64K.

- Writeback for the inode is done
  Because page 64K has its dirty flag cleared, it will not be considered
  as a writeback target.

This means the range [124K, 128K) will not be submitted, and reserved
space for it will be leaked.

Fix this problem by using the subpage helper to clear the dirty flag.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:12 +01:00
Qu Wenruo
a8706d0271 btrfs: wait for writeback if sector size is smaller than page size
[PROBLEM]
If sector perfect compression is enabled for sector size < page size
case, the following case can lead dirty ranges not being written back:

     0     32K     64K     96K     128K
     |     |///////||//////|     |/|
                                 124K

In above example, the page size is 64K, and we need to write back above
two pages.

- Submit for page 0 (main thread)
  We found delalloc range [32K, 96K), which can be compressed.
  So we queue an async range for [32K, 96K).
  This means, the page unlock/clearing dirty/setting writeback will
  all happen in a workqueue context.

- The compression is done, and compressed range is submitted (workqueue)
  Since the compression is done in asynchronously, the compression can
  be done before the main thread to submit for page 64K.

  Now the whole range [32K, 96K), involving two pages, will be marked
  writeback.

- Submit for page 64K (main thread)
  extent_write_cache_pages() got its wbc->sync_mode is WB_SYNC_NONE,
  so it skips the writeback wait.

  And unlock the page and exit. This means the dirty range [124K, 128K)
  will never be submitted, until next writeback happens for page 64K.

This will never happen for previous kernels because:

- For sector size == page size case
  Since one page is one sector, if a page is marked writeback it will
  not have dirty flags.
  So this corner case will never hit.

- For sector size < page size case
  We never do subpage compression, a range can only be submitted for
  compression if the range is fully page aligned.
  This change makes the subpage behavior mostly the same as non-subpage
  cases.

[ENHANCEMENT]
Instead of relying WB_SYNC_NONE check only, if it's a subpage case, then
always wait for writeback flags.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:12 +01:00
Qu Wenruo
dd5e276254 btrfs: compression: add an ASSERT() to ensure the read-in length is sane
There are already two bugs (one in zlib, one in zstd) that involved
compression path is not handling sector size < page size cases well.

So it makes more sense to make sure that btrfs_compress_folios() returns

Since we already have two bugs (one in zlib, one in zstd) in the
compression path resulting the @total_in be to larger than the
to-be-compressed range length, there is enough reason to add an ASSERT()
to make sure the total read-in length doesn't exceed the input length.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:12 +01:00
Qu Wenruo
90275a7762 btrfs: zstd: make the compression path to handle sector size < page size
Inside zstd_compress_folios(), after exhausted one input page, we need
to switch to the next page as input.

However when counting the total input bytes (@tot_in), we always increase
it by PAGE_SIZE.

For the following case, it can cause incorrect value:

        0          32K         64K          96K
        |          |///////////||///////////|

After compressing range [32K, 64K), we switch to the next page, and
increasing @tot_in by 64K, while we only read 32K.

This will cause the @total_in to return a value larger than the input
length.

Fix it by only increase @tot_in by the input size.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:12 +01:00
Qu Wenruo
f6ebedb09b btrfs: zlib: make the compression path to handle sector size < page size
Inside zlib_compress_folios(), each time we switch the input page cache,
the @start is increased by PAGE_SIZE.

But for the incoming compression support for sector size < page size
(previously we support compression only when the range is fully page
aligned), this is not going to handle the following case:

    0          32K         64K          96K
    |          |///////////||///////////|

@start has the initial value 32K, indicating the start filepos of the
to-be-compressed range.

And when grabbing the first page as input, we always call "start +=
PAGE_SIZE;".

But since @start is starting at 32K, it will be increased by 64K,
resulting it to be 96K for the next range, causing incorrect input range
and corruption for the future subpage compression.

Fix it by only increase @start by the input size.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:12 +01:00
Qu Wenruo
67cd3f2217 btrfs: split out CONFIG_BTRFS_EXPERIMENTAL from CONFIG_BTRFS_DEBUG
Currently CONFIG_BTRFS_EXPERIMENTAL is not only for the extra debugging
output, but also for experimental features.

This is not ideal to distinguish planned but not yet stable features
from those purely designed for debugging.

This patch splits the following features into CONFIG_BTRFS_EXPERIMENTAL:

- Extent map shrinker
  This seems to be the first one to exit experimental.

- Extent tree v2
  This seems to be the last one to graduate from experimental.

- Raid stripe tree
- Csum offload mode
- Send protocol v3

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:12 +01:00
Qu Wenruo
c186345a6b btrfs: make assert_rbio() to only check CONFIG_BTRFS_ASSERT
According to the description, CONFIG_BTRFS_DEBUG is only for extra
debug info, meanwhile sanity checks should be managed by
CONFIG_BTRFS_ASSERT.

There is no need to check both to enable assert_rbio().

Just remove the check for CONFIG_BTRFS_DEBUG.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:12 +01:00
Johannes Thumshirn
8cca35cb29 btrfs: don't take dev_replace rwsem on task already holding it
Running fstests btrfs/011 with MKFS_OPTIONS="-O rst" to force the usage of
the RAID stripe-tree, we get the following splat from lockdep:

 BTRFS info (device sdd): dev_replace from /dev/sdd (devid 1) to /dev/sdb started

 ============================================
 WARNING: possible recursive locking detected
 6.11.0-rc3-btrfs-for-next #599 Not tainted
 --------------------------------------------
 btrfs/2326 is trying to acquire lock:
 ffff88810f215c98 (&fs_info->dev_replace.rwsem){++++}-{3:3}, at: btrfs_map_block+0x39f/0x2250

 but task is already holding lock:
 ffff88810f215c98 (&fs_info->dev_replace.rwsem){++++}-{3:3}, at: btrfs_map_block+0x39f/0x2250

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&fs_info->dev_replace.rwsem);
   lock(&fs_info->dev_replace.rwsem);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 1 lock held by btrfs/2326:
  #0: ffff88810f215c98 (&fs_info->dev_replace.rwsem){++++}-{3:3}, at: btrfs_map_block+0x39f/0x2250

 stack backtrace:
 CPU: 1 UID: 0 PID: 2326 Comm: btrfs Not tainted 6.11.0-rc3-btrfs-for-next #599
 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
 Call Trace:
  <TASK>
  dump_stack_lvl+0x5b/0x80
  __lock_acquire+0x2798/0x69d0
  ? __pfx___lock_acquire+0x10/0x10
  ? __pfx___lock_acquire+0x10/0x10
  lock_acquire+0x19d/0x4a0
  ? btrfs_map_block+0x39f/0x2250
  ? __pfx_lock_acquire+0x10/0x10
  ? find_held_lock+0x2d/0x110
  ? lock_is_held_type+0x8f/0x100
  down_read+0x8e/0x440
  ? btrfs_map_block+0x39f/0x2250
  ? __pfx_down_read+0x10/0x10
  ? do_raw_read_unlock+0x44/0x70
  ? _raw_read_unlock+0x23/0x40
  btrfs_map_block+0x39f/0x2250
  ? btrfs_dev_replace_by_ioctl+0xd69/0x1d00
  ? btrfs_bio_counter_inc_blocked+0xd9/0x2e0
  ? __kasan_slab_alloc+0x6e/0x70
  ? __pfx_btrfs_map_block+0x10/0x10
  ? __pfx_btrfs_bio_counter_inc_blocked+0x10/0x10
  ? kmem_cache_alloc_noprof+0x1f2/0x300
  ? mempool_alloc_noprof+0xed/0x2b0
  btrfs_submit_chunk+0x28d/0x17e0
  ? __pfx_btrfs_submit_chunk+0x10/0x10
  ? bvec_alloc+0xd7/0x1b0
  ? bio_add_folio+0x171/0x270
  ? __pfx_bio_add_folio+0x10/0x10
  ? __kasan_check_read+0x20/0x20
  btrfs_submit_bio+0x37/0x80
  read_extent_buffer_pages+0x3df/0x6c0
  btrfs_read_extent_buffer+0x13e/0x5f0
  read_tree_block+0x81/0xe0
  read_block_for_search+0x4bd/0x7a0
  ? __pfx_read_block_for_search+0x10/0x10
  btrfs_search_slot+0x78d/0x2720
  ? __pfx_btrfs_search_slot+0x10/0x10
  ? lock_is_held_type+0x8f/0x100
  ? kasan_save_track+0x14/0x30
  ? __kasan_slab_alloc+0x6e/0x70
  ? kmem_cache_alloc_noprof+0x1f2/0x300
  btrfs_get_raid_extent_offset+0x181/0x820
  ? __pfx_lock_acquire+0x10/0x10
  ? __pfx_btrfs_get_raid_extent_offset+0x10/0x10
  ? down_read+0x194/0x440
  ? __pfx_down_read+0x10/0x10
  ? do_raw_read_unlock+0x44/0x70
  ? _raw_read_unlock+0x23/0x40
  btrfs_map_block+0x5b5/0x2250
  ? __pfx_btrfs_map_block+0x10/0x10
  scrub_submit_initial_read+0x8fe/0x11b0
  ? __pfx_scrub_submit_initial_read+0x10/0x10
  submit_initial_group_read+0x161/0x3a0
  ? lock_release+0x20e/0x710
  ? __pfx_submit_initial_group_read+0x10/0x10
  ? __pfx_lock_release+0x10/0x10
  scrub_simple_mirror.isra.0+0x3eb/0x580
  scrub_stripe+0xe4d/0x1440
  ? lock_release+0x20e/0x710
  ? __pfx_scrub_stripe+0x10/0x10
  ? __pfx_lock_release+0x10/0x10
  ? do_raw_read_unlock+0x44/0x70
  ? _raw_read_unlock+0x23/0x40
  scrub_chunk+0x257/0x4a0
  scrub_enumerate_chunks+0x64c/0xf70
  ? __mutex_unlock_slowpath+0x147/0x5f0
  ? __pfx_scrub_enumerate_chunks+0x10/0x10
  ? bit_wait_timeout+0xb0/0x170
  ? __up_read+0x189/0x700
  ? scrub_workers_get+0x231/0x300
  ? up_write+0x490/0x4f0
  btrfs_scrub_dev+0x52e/0xcd0
  ? create_pending_snapshots+0x230/0x250
  ? __pfx_btrfs_scrub_dev+0x10/0x10
  btrfs_dev_replace_by_ioctl+0xd69/0x1d00
  ? lock_acquire+0x19d/0x4a0
  ? __pfx_btrfs_dev_replace_by_ioctl+0x10/0x10
  ? lock_release+0x20e/0x710
  ? btrfs_ioctl+0xa09/0x74f0
  ? __pfx_lock_release+0x10/0x10
  ? do_raw_spin_lock+0x11e/0x240
  ? __pfx_do_raw_spin_lock+0x10/0x10
  btrfs_ioctl+0xa14/0x74f0
  ? lock_acquire+0x19d/0x4a0
  ? find_held_lock+0x2d/0x110
  ? __pfx_btrfs_ioctl+0x10/0x10
  ? lock_release+0x20e/0x710
  ? do_sigaction+0x3f0/0x860
  ? __pfx_do_vfs_ioctl+0x10/0x10
  ? do_raw_spin_lock+0x11e/0x240
  ? lockdep_hardirqs_on_prepare+0x270/0x3e0
  ? _raw_spin_unlock_irq+0x28/0x50
  ? do_sigaction+0x3f0/0x860
  ? __pfx_do_sigaction+0x10/0x10
  ? __x64_sys_rt_sigaction+0x18e/0x1e0
  ? __pfx___x64_sys_rt_sigaction+0x10/0x10
  ? __x64_sys_close+0x7c/0xd0
  __x64_sys_ioctl+0x137/0x190
  do_syscall_64+0x71/0x140
  entry_SYSCALL_64_after_hwframe+0x76/0x7e
 RIP: 0033:0x7f0bd1114f9b
 Code: Unable to access opcode bytes at 0x7f0bd1114f71.
 RSP: 002b:00007ffc8a8c3130 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f0bd1114f9b
 RDX: 00007ffc8a8c35e0 RSI: 00000000ca289435 RDI: 0000000000000003
 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000007
 R10: 0000000000000008 R11: 0000000000000246 R12: 00007ffc8a8c6c85
 R13: 00000000398e72a0 R14: 0000000000004361 R15: 0000000000000004
  </TASK>

This happens because on RAID stripe-tree filesystems we recurse back into
btrfs_map_block() on scrub to perform the logical to device physical
mapping.

But as the device replace task is already holding the dev_replace::rwsem
we deadlock.

So don't take the dev_replace::rwsem in case our task is the task performing
the device replace.

Suggested-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-11 14:34:12 +01:00
Linus Torvalds
9183e033ec for-6.12-rc6-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmct+40ACgkQxWXV+ddt
 WDvCtRAAp0rheEu14hpVvWE2//+6u9Gx7Wfjzbj0+o4zBRWdg7BigFxfeb6JsH/E
 2TjuWdcoP/OMV9ghCBQAQxySAPtsxH7skkyNy2UcMk5byBIrNvhw9auP5GXXlrhK
 jSKDD4yfOMb++8LhrLevgTrijNyjLqaKXruw9a1Pmc3gxpdNmnMEySsQaF62o2Sm
 YC3jwi0KpNAhu2qyJ6TnPgd5zf3BTM0JAeuB019IZW4WoeRTOdcPe7S7gqqJwZ+e
 lL0D2/lfIE1lKvLE266Fab4FAQiJV07rozYj25XHiDpqThCxnJVOZCEHasOQ1PRy
 d6j3RmGPqJYAYfQL1L+FH2hsS1BVZfVyCV1V7A/cN+lAffBfnROnf13C3gJ15Nbx
 3lTyjBPQQw2WpfdmeyF3ikbrjZ8AfahChQO+mMnLN7oAWdIwWX5MRB+cwfWTxzA/
 P8upz6HSTpSwy8nXdq264q1KkyCjx0Wv+8iyU7LirN2fCcEchA12HAIaOBeHedgh
 PrGZDqrkZccQQxAvU5H7hQv0hZkGK8qba381oYHO09g72VM6ysuBU7tGrPZrlZYB
 CvYTCwNZ/lqI8ikrcHOyUO1SPR9SaaWej1mWgBJ69ZIfg+ZuMtOMl171DU4S/i2V
 iYgYoN8eCqTQWdaX5kk+3LWmK8fSU7F/KSDtJtT1KxkaSwCacfY=
 =TQzP
 -----END PGP SIGNATURE-----

Merge tag 'for-6.12-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "A few more one-liners that fix some user visible problems:

   - use correct range when clearing qgroup reservations after COW

   - properly reset freed delayed ref list head

   - fix ro/rw subvolume mounts to be backward compatible with old and
     new mount API"

* tag 'for-6.12-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix the length of reserved qgroup to free
  btrfs: reinitialize delayed ref list after deleting it from the list
  btrfs: fix per-subvolume RO/RW flags with new mount API
2024-11-08 07:31:03 -10:00
Ira Weiny
06cf321aad range: Add range_overlaps()
Code to support CXL Dynamic Capacity devices will have extent ranges
which need to be compared for intersection not a subset as is being
checked in range_contains().

range_overlaps() is defined in btrfs with a different meaning from what
is required in the standard range code.  Dan Williams pointed this out
in [1].  Adjust the btrfs call according to his suggestion there.

Then add a generic range_overlaps().

Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: David Sterba <dsterba@suse.com>
Cc: linux-btrfs@vger.kernel.org
Link: https://lore.kernel.org/all/65949f79ef908_8dc68294f2@dwillia2-xfh.jf.intel.com.notmuch/ [1]
Acked-by: David Sterba <dsterba@suse.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Fan Ni <fan.ni@samsung.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://patch.msgid.link/20241107-dcd-type2-upstream-v7-1-56a84e66bc36@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-11-08 09:36:29 -07:00
Haisu Wang
2b084d8205 btrfs: fix the length of reserved qgroup to free
The dealloc flag may be cleared and the extent won't reach the disk in
cow_file_range when errors path. The reserved qgroup space is freed in
commit 30479f31d4 ("btrfs: fix qgroup reserve leaks in
cow_file_range"). However, the length of untouched region to free needs
to be adjusted with the correct remaining region size.

Fixes: 30479f31d4 ("btrfs: fix qgroup reserve leaks in cow_file_range")
CC: stable@vger.kernel.org # 6.11+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Haisu Wang <haisuwang@tencent.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-07 02:08:29 +01:00
Filipe Manana
c9a75ec45f btrfs: reinitialize delayed ref list after deleting it from the list
At insert_delayed_ref() if we need to update the action of an existing
ref to BTRFS_DROP_DELAYED_REF, we delete the ref from its ref head's
ref_add_list using list_del(), which leaves the ref's add_list member
not reinitialized, as list_del() sets the next and prev members of the
list to LIST_POISON1 and LIST_POISON2, respectively.

If later we end up calling drop_delayed_ref() against the ref, which can
happen during merging or when destroying delayed refs due to a transaction
abort, we can trigger a crash since at drop_delayed_ref() we call
list_empty() against the ref's add_list, which returns false since
the list was not reinitialized after the list_del() and as a consequence
we call list_del() again at drop_delayed_ref(). This results in an
invalid list access since the next and prev members are set to poison
pointers, resulting in a splat if CONFIG_LIST_HARDENED and
CONFIG_DEBUG_LIST are set or invalid poison pointer dereferences
otherwise.

So fix this by deleting from the list with list_del_init() instead.

Fixes: 1d57ee9416 ("btrfs: improve delayed refs iterations")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-07 02:07:53 +01:00
Qu Wenruo
cda7163d4e btrfs: fix per-subvolume RO/RW flags with new mount API
[BUG]
With util-linux 2.40.2, the 'mount' utility is already utilizing the new
mount API. e.g:

  # strace  mount -o subvol=subv1,ro /dev/test/scratch1 /mnt/test/
  ...
  fsconfig(3, FSCONFIG_SET_STRING, "source", "/dev/mapper/test-scratch1", 0) = 0
  fsconfig(3, FSCONFIG_SET_STRING, "subvol", "subv1", 0) = 0
  fsconfig(3, FSCONFIG_SET_FLAG, "ro", NULL, 0) = 0
  fsconfig(3, FSCONFIG_CMD_CREATE, NULL, NULL, 0) = 0
  fsmount(3, FSMOUNT_CLOEXEC, 0)          = 4
  mount_setattr(4, "", AT_EMPTY_PATH, {attr_set=MOUNT_ATTR_RDONLY, attr_clr=0, propagation=0 /* MS_??? */, userns_fd=0}, 32) = 0
  move_mount(4, "", AT_FDCWD, "/mnt/test", MOVE_MOUNT_F_EMPTY_PATH) = 0

But this leads to a new problem, that per-subvolume RO/RW mount no
longer works, if the initial mount is RO:

  # mount -o subvol=subv1,ro /dev/test/scratch1 /mnt/test
  # mount -o rw,subvol=subv2 /dev/test/scratch1  /mnt/scratch
  # mount | grep mnt
  /dev/mapper/test-scratch1 on /mnt/test type btrfs (ro,relatime,discard=async,space_cache=v2,subvolid=256,subvol=/subv1)
  /dev/mapper/test-scratch1 on /mnt/scratch type btrfs (ro,relatime,discard=async,space_cache=v2,subvolid=257,subvol=/subv2)
  # touch /mnt/scratch/foobar
  touch: cannot touch '/mnt/scratch/foobar': Read-only file system

This is a common use cases on distros.

[CAUSE]
We have a workaround for remount to handle the RO->RW change, but if the
mount is using the new mount API, we do not do that, and rely on the
mount tool NOT to set the ro flag.

But that's not how the mount tool is doing for the new API:

  fsconfig(3, FSCONFIG_SET_STRING, "source", "/dev/mapper/test-scratch1", 0) = 0
  fsconfig(3, FSCONFIG_SET_STRING, "subvol", "subv1", 0) = 0
  fsconfig(3, FSCONFIG_SET_FLAG, "ro", NULL, 0) = 0       <<<< Setting RO flag for super block
  fsconfig(3, FSCONFIG_CMD_CREATE, NULL, NULL, 0) = 0
  fsmount(3, FSMOUNT_CLOEXEC, 0)          = 4
  mount_setattr(4, "", AT_EMPTY_PATH, {attr_set=MOUNT_ATTR_RDONLY, attr_clr=0, propagation=0 /* MS_??? */, userns_fd=0}, 32) = 0
  move_mount(4, "", AT_FDCWD, "/mnt/test", MOVE_MOUNT_F_EMPTY_PATH) = 0

This means we will set the super block RO at the first mount.

Later RW mount will not try to reconfigure the fs to RW because the
mount tool is already using the new API.

This totally breaks the per-subvolume RO/RW mount behavior.

[FIX]
Do not skip the reconfiguration even if using the new API.  The old
comments are just expecting any mount tool to properly skip the RO flag
set even if we specify "ro", which is not the reality.

Update the comments regarding the backward compatibility on the kernel
level so it works with old and new mount utilities.

CC: stable@vger.kernel.org # 6.8+
Fixes: f044b31867 ("btrfs: handle the ro->rw transition for mounting different subvolumes")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-11-07 02:07:45 +01:00
Al Viro
6348be02ee fdget(), trivial conversions
fdget() is the first thing done in scope, all matching fdput() are
immediately followed by leaving the scope.

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-11-03 01:28:06 -05:00
Linus Torvalds
6b4926494e for-6.12-rc5-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmck8eQACgkQxWXV+ddt
 WDu05g/6AwrnvPkivC4iVOv4Wkzrpk4gm76smx91Y9B8tSDLI1pHaS27CvJz9iWl
 vBKXPN3PQVQHwo6SPn+NjsFOSMkXlbBOVKpPU+MlZwH9Tuw66qcC+EnUCK2wEuAy
 3TN7cUGIA4r/j+SkhgIz+Irlr5pjdb1KkPIMBEVGcVFqDIuvDaTEGBqTn2i/V5aa
 dMn+gK+9rfngTOJ68t/pEFaX7SEWCvgMIcBpBB4/vs1gHm3ve2bcc1sBAdMxb1Se
 SrxgZfq+Rc5tkMn540JaWGwkb0rLzwXlurK6ygTKDKCpH0IMX+pBvDkexh9Zj0ux
 jejlRxiuDzTx3z2a7FjHDyp2sdZWMpq3sPsowpJ1Dsgi5EtSxTy4irmQuSAZY1Uj
 /uo6YwV9aTGeiNDwZeKqKc/wOuAttaMZLr14s37pro9KxndFJ/XZBxeyB+euUCOw
 B8AvAQVVIJAYQLyWINWruNKppqlgiO2RaN15RvvT2pX01d0TOx1KX1XFQku7YFxb
 M/8ZNXzJ96XtkeyHL3euo3zj7N5jWtnCvPINugUG1ADQa+bc8aX336gld1neD6fs
 QqIFIgzZG0l4N95viJilACrI6tW9zFnBqMyNFRhucKiX9aP9glOvhSfxfjcpDuQ/
 i/LIyxVLwp8M3hPNvv8tC345+1C2ug9AD0OyhWjjIYPuiOxtTWs=
 =alpB
 -----END PGP SIGNATURE-----

Merge tag 'for-6.12-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "A few more stability fixes. There's one patch adding export of MIPS
  cmpxchg helper, used in the error propagation fix.

   - fix error propagation from split bios to the original btrfs bio

   - fix merging of adjacent extents (normal operation, defragmentation)

   - fix potential use after free after freeing btrfs device structures"

* tag 'for-6.12-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix defrag not merging contiguous extents due to merged extent maps
  btrfs: fix extent map merging not happening for adjacent extents
  btrfs: fix use-after-free of block device file in __btrfs_free_extra_devids()
  btrfs: fix error propagation of split bios
  MIPS: export __cmpxchg_small()
2024-11-01 07:31:47 -10:00
Filipe Manana
77b0d113ee btrfs: fix defrag not merging contiguous extents due to merged extent maps
When running defrag (manual defrag) against a file that has extents that
are contiguous and we already have the respective extent maps loaded and
merged, we end up not defragging the range covered by those contiguous
extents. This happens when we have an extent map that was the result of
merging multiple extent maps for contiguous extents and the length of the
merged extent map is greater than or equals to the defrag threshold
length.

The script below reproduces this scenario:

   $ cat test.sh
   #!/bin/bash

   DEV=/dev/sdi
   MNT=/mnt/sdi

   mkfs.btrfs -f $DEV
   mount $DEV $MNT

   # Create a 256K file with 4 extents of 64K each.
   xfs_io -f -c "falloc 0 64K" \
             -c "pwrite 0 64K" \
             -c "falloc 64K 64K" \
             -c "pwrite 64K 64K" \
             -c "falloc 128K 64K" \
             -c "pwrite 128K 64K" \
             -c "falloc 192K 64K" \
             -c "pwrite 192K 64K" \
             $MNT/foo

   umount $MNT
   echo -n "Initial number of file extent items: "
   btrfs inspect-internal dump-tree -t 5 $DEV | grep EXTENT_DATA | wc -l

   mount $DEV $MNT
   # Read the whole file in order to load and merge extent maps.
   cat $MNT/foo > /dev/null

   btrfs filesystem defragment -t 128K $MNT/foo
   umount $MNT
   echo -n "Number of file extent items after defrag with 128K threshold: "
   btrfs inspect-internal dump-tree -t 5 $DEV | grep EXTENT_DATA | wc -l

   mount $DEV $MNT
   # Read the whole file in order to load and merge extent maps.
   cat $MNT/foo > /dev/null

   btrfs filesystem defragment -t 256K $MNT/foo
   umount $MNT
   echo -n "Number of file extent items after defrag with 256K threshold: "
   btrfs inspect-internal dump-tree -t 5 $DEV | grep EXTENT_DATA | wc -l

Running it:

   $ ./test.sh
   Initial number of file extent items: 4
   Number of file extent items after defrag with 128K threshold: 4
   Number of file extent items after defrag with 256K threshold: 4

The 4 extents don't get merged because we have an extent map with a size
of 256K that is the result of merging the individual extent maps for each
of the four 64K extents and at defrag_lookup_extent() we have a value of
zero for the generation threshold ('newer_than' argument) since this is a
manual defrag. As a consequence we don't call defrag_get_extent() to get
an extent map representing a single file extent item in the inode's
subvolume tree, so we end up using the merged extent map at
defrag_collect_targets() and decide not to defrag.

Fix this by updating defrag_lookup_extent() to always discard extent maps
that were merged and call defrag_get_extent() regardless of the minimum
generation threshold ('newer_than' argument).

A test case for fstests will be sent along soon.

CC: stable@vger.kernel.org # 6.1+
Fixes: 199257a78b ("btrfs: defrag: don't use merged extent map for their generation check")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-31 16:46:41 +01:00
Filipe Manana
a0f0625390 btrfs: fix extent map merging not happening for adjacent extents
If we have 3 or more adjacent extents in a file, that is, consecutive file
extent items pointing to adjacent extents, within a contiguous file range
and compatible flags, we end up not merging all the extents into a single
extent map.

For example:

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt/sdc

  $ xfs_io -f -d -c "pwrite -b 64K 0 64K" \
                 -c "pwrite -b 64K 64K 64K" \
                 -c "pwrite -b 64K 128K 64K" \
                 -c "pwrite -b 64K 192K 64K" \
                 /mnt/sdc/foo

After all the ordered extents complete we unpin the extent maps and try
to merge them, but instead of getting a single extent map we get two
because:

1) When the first ordered extent completes (file range [0, 64K)) we
   unpin its extent map and attempt to merge it with the extent map for
   the range [64K, 128K), but we can't because that extent map is still
   pinned;

2) When the second ordered extent completes (file range [64K, 128K)), we
   unpin its extent map and merge it with the previous extent map, for
   file range [0, 64K), but we can't merge with the next extent map, for
   the file range [128K, 192K), because this one is still pinned.

   The merged extent map for the file range [0, 128K) gets the flag
   EXTENT_MAP_MERGED set;

3) When the third ordered extent completes (file range [128K, 192K)), we
   unpin its extent map and attempt to merge it with the previous extent
   map, for file range [0, 128K), but we can't because that extent map
   has the flag EXTENT_MAP_MERGED set (mergeable_maps() returns false
   due to different flags) while the extent map for the range [128K, 192K)
   doesn't have that flag set.

   We also can't merge it with the next extent map, for file range
   [192K, 256K), because that one is still pinned.

   At this moment we have 3 extent maps:

   One for file range [0, 128K), with the flag EXTENT_MAP_MERGED set.
   One for file range [128K, 192K).
   One for file range [192K, 256K) which is still pinned;

4) When the fourth and final extent completes (file range [192K, 256K)),
   we unpin its extent map and attempt to merge it with the previous
   extent map, for file range [128K, 192K), which succeeds since none
   of these extent maps have the EXTENT_MAP_MERGED flag set.

   So we end up with 2 extent maps:

   One for file range [0, 128K), with the flag EXTENT_MAP_MERGED set.
   One for file range [128K, 256K), with the flag EXTENT_MAP_MERGED set.

   Since after merging extent maps we don't attempt to merge again, that
   is, merge the resulting extent map with the one that is now preceding
   it (and the one following it), we end up with those two extent maps,
   when we could have had a single extent map to represent the whole file.

Fix this by making mergeable_maps() ignore the EXTENT_MAP_MERGED flag.
While this doesn't present any functional issue, it prevents the merging
of extent maps which allows to save memory, and can make defrag not
merging extents too (that will be addressed in the next patch).

Fixes: 199257a78b ("btrfs: defrag: don't use merged extent map for their generation check")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-31 16:45:16 +01:00
Zhihao Cheng
aec8e6bf83 btrfs: fix use-after-free of block device file in __btrfs_free_extra_devids()
Mounting btrfs from two images (which have the same one fsid and two
different dev_uuids) in certain executing order may trigger an UAF for
variable 'device->bdev_file' in __btrfs_free_extra_devids(). And
following are the details:

1. Attach image_1 to loop0, attach image_2 to loop1, and scan btrfs
   devices by ioctl(BTRFS_IOC_SCAN_DEV):

             /  btrfs_device_1 → loop0
   fs_device
             \  btrfs_device_2 → loop1
2. mount /dev/loop0 /mnt
   btrfs_open_devices
    btrfs_device_1->bdev_file = btrfs_get_bdev_and_sb(loop0)
    btrfs_device_2->bdev_file = btrfs_get_bdev_and_sb(loop1)
   btrfs_fill_super
    open_ctree
     fail: btrfs_close_devices // -ENOMEM
	    btrfs_close_bdev(btrfs_device_1)
             fput(btrfs_device_1->bdev_file)
	      // btrfs_device_1->bdev_file is freed
	    btrfs_close_bdev(btrfs_device_2)
             fput(btrfs_device_2->bdev_file)

3. mount /dev/loop1 /mnt
   btrfs_open_devices
    btrfs_get_bdev_and_sb(&bdev_file)
     // EIO, btrfs_device_1->bdev_file is not assigned,
     // which points to a freed memory area
    btrfs_device_2->bdev_file = btrfs_get_bdev_and_sb(loop1)
   btrfs_fill_super
    open_ctree
     btrfs_free_extra_devids
      if (btrfs_device_1->bdev_file)
       fput(btrfs_device_1->bdev_file) // UAF !

Fix it by setting 'device->bdev_file' as 'NULL' after closing the
btrfs_device in btrfs_close_one_device().

Fixes: 1423881941 ("btrfs: do not background blkdev_put()")
CC: stable@vger.kernel.org # 4.19+
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219408
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-29 21:59:25 +01:00
Christoph Hellwig
2f5a65ef30 block: add a bdev_limits helper
Add a helper to get the queue_limits from the bdev without having to
poke into the request_queue.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20241029141937.249920-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29 09:15:00 -06:00
Pankaj Raghav
30dac24e14
fs/writeback: convert wbc_account_cgroup_owner to take a folio
Most of the callers of wbc_account_cgroup_owner() are converting a folio
to page before calling the function. wbc_account_cgroup_owner() is
converting the page back to a folio to call mem_cgroup_css_from_folio().

Convert wbc_account_cgroup_owner() to take a folio instead of a page,
and convert all callers to pass a folio directly except f2fs.

Convert the page to folio for all the callers from f2fs as they were the
only callers calling wbc_account_cgroup_owner() with a page. As f2fs is
already in the process of converting to folios, these call sites might
also soon be calling wbc_account_cgroup_owner() with a folio directly in
the future.

No functional changes. Only compile tested.

Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Link: https://lore.kernel.org/r/20240926140121.203821-1-kernel@pankajraghav.com
Acked-by: David Sterba <dsterba@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-10-28 13:26:54 +01:00
Linus Torvalds
4e46774408 for-6.12-rc4-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmcZGqsACgkQxWXV+ddt
 WDsZTg//dSLAAswT3dTAvWDt7rGxPhJC1V+gnzWdj/0Q3CUimNaw7zHp1QHtJDFT
 S+3TVvJJ2JDvOnbi3u24s/bL5YdkWcvIyy87oVE4trJMbQPc/E45pkYFqF3TRQAH
 wEYAVEnO9f9WUY+ekxX2XBzhmKp3xol93j9BBHDXOF9kHsDC5lI0D5YVYEhRY8Qu
 D4GcqAhqUj5Hj6I6ppiqO47NCJBNzw1Se9QsgruPpmItRbB0/LYJFhUfevwosTKg
 xVpkRVntFqQjkIdIdBfBv/ZGWfxJyM7K4M49QwLUqUQfxugu7BiGYuEjkBkiy07a
 pZDEOF9s8wUZsxvRVohqKlhL0zHBF+/pAANowYuhKNW1sqKt4GVCdN3V34AbH8ST
 JIbPvC2g1tUzIc2wckE8GO/NnsNR4r3k6iPB53MdCHrIo3jnENOeb9wF0GiVDb6s
 OrhCa3ph2ps80YC1aCnc4Jr/yV2ONebSivnqvHCIUQEZfpjtAc07atm0i946/7nx
 eiBE+9zSVJZB0LoooIVz2I3HX3lRnm3Wwi4nj8U/sNL/IbGaHNCurIETR23NivYP
 yWVql2njwE+yMc8q9YZXs4MBdKsSGP6eGJW3ZwKi6ru2PJdf5eIib+ffvR4bLqXD
 UUDfMyC1esGsQB24sc8wppk97wmmMrdqQUj9WnmNlTP8FUFggvQ=
 =sYxX
 -----END PGP SIGNATURE-----

Merge tag 'for-6.12-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - mount option fixes:
     - fix handling of compression mount options on remount
     - reject rw remount in case there are options that don't work
       in read-write mode (like rescue options)

 - fix zone accounting of unusable space

 - fix in-memory corruption when merging extent maps

 - fix delalloc range locking for sector < page

 - use more convenient default value of drop subtree threshold, clean
   more subvolumes without the fallback to marking quotas inconsistent

 - fix smatch warning about incorrect value passed to ERR_PTR

* tag 'for-6.12-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix passing 0 to ERR_PTR in btrfs_search_dir_index_item()
  btrfs: reject ro->rw reconfiguration if there are hard ro requirements
  btrfs: fix read corruption due to race with extent map merging
  btrfs: fix the delalloc range locking if sector size < page size
  btrfs: qgroup: set a more sane default value for subtree drop threshold
  btrfs: clear force-compress on remount when compress mount option is given
  btrfs: zoned: fix zone unusable accounting for freed reserved extent
2024-10-24 13:04:15 -07:00
Naohiro Aota
d48e1dea39 btrfs: fix error propagation of split bios
The purpose of btrfs_bbio_propagate_error() shall be propagating an error
of split bio to its original btrfs_bio, and tell the error to the upper
layer. However, it's not working well on some cases.

* Case 1. Immediate (or quick) end_bio with an error

When btrfs sends btrfs_bio to mirrored devices, btrfs calls
btrfs_bio_end_io() when all the mirroring bios are completed. If that
btrfs_bio was split, it is from btrfs_clone_bioset and its end_io function
is btrfs_orig_write_end_io. For this case, btrfs_bbio_propagate_error()
accesses the orig_bbio's bio context to increase the error count.

That works well in most cases. However, if the end_io is called enough
fast, orig_bbio's (remaining part after split) bio context may not be
properly set at that time. Since the bio context is set when the orig_bbio
(the last btrfs_bio) is sent to devices, that might be too late for earlier
split btrfs_bio's completion.  That will result in NULL pointer
dereference.

That bug is easily reproducible by running btrfs/146 on zoned devices [1]
and it shows the following trace.

[1] You need raid-stripe-tree feature as it create "-d raid0 -m raid1" FS.

  BUG: kernel NULL pointer dereference, address: 0000000000000020
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 0 P4D 0
  Oops: Oops: 0000 [#1] PREEMPT SMP PTI
  CPU: 1 UID: 0 PID: 13 Comm: kworker/u32:1 Not tainted 6.11.0-rc7-BTRFS-ZNS+ #474
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  Workqueue: writeback wb_workfn (flush-btrfs-5)
  RIP: 0010:btrfs_bio_end_io+0xae/0xc0 [btrfs]
  BTRFS error (device dm-0): bdev /dev/mapper/error-test errs: wr 2, rd 0, flush 0, corrupt 0, gen 0
  RSP: 0018:ffffc9000006f248 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff888005a7f080 RCX: ffffc9000006f1dc
  RDX: 0000000000000000 RSI: 000000000000000a RDI: ffff888005a7f080
  RBP: ffff888011dfc540 R08: 0000000000000000 R09: 0000000000000001
  R10: ffffffff82e508e0 R11: 0000000000000005 R12: ffff88800ddfbe58
  R13: ffff888005a7f080 R14: ffff888005a7f158 R15: ffff888005a7f158
  FS:  0000000000000000(0000) GS:ffff88803ea80000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000020 CR3: 0000000002e22006 CR4: 0000000000370ef0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   <TASK>
   ? __die_body.cold+0x19/0x26
   ? page_fault_oops+0x13e/0x2b0
   ? _printk+0x58/0x73
   ? do_user_addr_fault+0x5f/0x750
   ? exc_page_fault+0x76/0x240
   ? asm_exc_page_fault+0x22/0x30
   ? btrfs_bio_end_io+0xae/0xc0 [btrfs]
   ? btrfs_log_dev_io_error+0x7f/0x90 [btrfs]
   btrfs_orig_write_end_io+0x51/0x90 [btrfs]
   dm_submit_bio+0x5c2/0xa50 [dm_mod]
   ? find_held_lock+0x2b/0x80
   ? blk_try_enter_queue+0x90/0x1e0
   __submit_bio+0xe0/0x130
   ? ktime_get+0x10a/0x160
   ? lockdep_hardirqs_on+0x74/0x100
   submit_bio_noacct_nocheck+0x199/0x410
   btrfs_submit_bio+0x7d/0x150 [btrfs]
   btrfs_submit_chunk+0x1a1/0x6d0 [btrfs]
   ? lockdep_hardirqs_on+0x74/0x100
   ? __folio_start_writeback+0x10/0x2c0
   btrfs_submit_bbio+0x1c/0x40 [btrfs]
   submit_one_bio+0x44/0x60 [btrfs]
   submit_extent_folio+0x13f/0x330 [btrfs]
   ? btrfs_set_range_writeback+0xa3/0xd0 [btrfs]
   extent_writepage_io+0x18b/0x360 [btrfs]
   extent_write_locked_range+0x17c/0x340 [btrfs]
   ? __pfx_end_bbio_data_write+0x10/0x10 [btrfs]
   run_delalloc_cow+0x71/0xd0 [btrfs]
   btrfs_run_delalloc_range+0x176/0x500 [btrfs]
   ? find_lock_delalloc_range+0x119/0x260 [btrfs]
   writepage_delalloc+0x2ab/0x480 [btrfs]
   extent_write_cache_pages+0x236/0x7d0 [btrfs]
   btrfs_writepages+0x72/0x130 [btrfs]
   do_writepages+0xd4/0x240
   ? find_held_lock+0x2b/0x80
   ? wbc_attach_and_unlock_inode+0x12c/0x290
   ? wbc_attach_and_unlock_inode+0x12c/0x290
   __writeback_single_inode+0x5c/0x4c0
   ? do_raw_spin_unlock+0x49/0xb0
   writeback_sb_inodes+0x22c/0x560
   __writeback_inodes_wb+0x4c/0xe0
   wb_writeback+0x1d6/0x3f0
   wb_workfn+0x334/0x520
   process_one_work+0x1ee/0x570
   ? lock_is_held_type+0xc6/0x130
   worker_thread+0x1d1/0x3b0
   ? __pfx_worker_thread+0x10/0x10
   kthread+0xee/0x120
   ? __pfx_kthread+0x10/0x10
   ret_from_fork+0x30/0x50
   ? __pfx_kthread+0x10/0x10
   ret_from_fork_asm+0x1a/0x30
   </TASK>
  Modules linked in: dm_mod btrfs blake2b_generic xor raid6_pq rapl
  CR2: 0000000000000020

* Case 2. Earlier completion of orig_bbio for mirrored btrfs_bios

btrfs_bbio_propagate_error() assumes the end_io function for orig_bbio is
called last among split bios. In that case, btrfs_orig_write_end_io() sets
the bio->bi_status to BLK_STS_IOERR by seeing the bioc->error [2].
Otherwise, the increased orig_bio's bioc->error is not checked by anyone
and return BLK_STS_OK to the upper layer.

[2] Actually, this is not true. Because we only increases orig_bioc->errors
by max_errors, the condition "atomic_read(&bioc->error) > bioc->max_errors"
is still not met if only one split btrfs_bio fails.

* Case 3. Later completion of orig_bbio for un-mirrored btrfs_bios

In contrast to the above case, btrfs_bbio_propagate_error() is not working
well if un-mirrored orig_bbio is completed last. It sets
orig_bbio->bio.bi_status to the btrfs_bio's error. But, that is easily
over-written by orig_bbio's completion status. If the status is BLK_STS_OK,
the upper layer would not know the failure.

* Solution

Considering the above cases, we can only save the error status in the
orig_bbio (remaining part after split) itself as it is always
available. Also, the saved error status should be propagated when all the
split btrfs_bios are finished (i.e, bbio->pending_ios == 0).

This commit introduces "status" to btrfs_bbio and saves the first error of
split bios to original btrfs_bio's "status" variable. When all the split
bios are finished, the saved status is loaded into original btrfs_bio's
status.

With this commit, btrfs/146 on zoned devices does not hit the NULL pointer
dereference anymore.

Fixes: 852eee62d3 ("btrfs: allow btrfs_submit_bio to split bios")
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-23 18:17:43 +02:00
Yue Haibing
75f49c3dc7 btrfs: fix passing 0 to ERR_PTR in btrfs_search_dir_index_item()
The ret may be zero in btrfs_search_dir_index_item() and should not
passed to ERR_PTR(). Now btrfs_unlink_subvol() is the only caller to
this, reconstructed it to check ERR_PTR(-ENOENT) while ret >= 0.

This fixes smatch warnings:

fs/btrfs/dir-item.c:353
  btrfs_search_dir_index_item() warn: passing zero to 'ERR_PTR'

Fixes: 9dcbe16fcc ("btrfs: use btrfs_for_each_slot in btrfs_search_dir_index_item")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-22 16:10:55 +02:00
Qu Wenruo
3c36a72c1d btrfs: reject ro->rw reconfiguration if there are hard ro requirements
[BUG]
Syzbot reports the following crash:

  BTRFS info (device loop0 state MCS): disabling free space tree
  BTRFS info (device loop0 state MCS): clearing compat-ro feature flag for FREE_SPACE_TREE (0x1)
  BTRFS info (device loop0 state MCS): clearing compat-ro feature flag for FREE_SPACE_TREE_VALID (0x2)
  Oops: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN NOPTI
  KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
  RIP: 0010:backup_super_roots fs/btrfs/disk-io.c:1691 [inline]
  RIP: 0010:write_all_supers+0x97a/0x40f0 fs/btrfs/disk-io.c:4041
  Call Trace:
   <TASK>
   btrfs_commit_transaction+0x1eae/0x3740 fs/btrfs/transaction.c:2530
   btrfs_delete_free_space_tree+0x383/0x730 fs/btrfs/free-space-tree.c:1312
   btrfs_start_pre_rw_mount+0xf28/0x1300 fs/btrfs/disk-io.c:3012
   btrfs_remount_rw fs/btrfs/super.c:1309 [inline]
   btrfs_reconfigure+0xae6/0x2d40 fs/btrfs/super.c:1534
   btrfs_reconfigure_for_mount fs/btrfs/super.c:2020 [inline]
   btrfs_get_tree_subvol fs/btrfs/super.c:2079 [inline]
   btrfs_get_tree+0x918/0x1920 fs/btrfs/super.c:2115
   vfs_get_tree+0x90/0x2b0 fs/super.c:1800
   do_new_mount+0x2be/0xb40 fs/namespace.c:3472
   do_mount fs/namespace.c:3812 [inline]
   __do_sys_mount fs/namespace.c:4020 [inline]
   __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3997
   do_syscall_x64 arch/x86/entry/common.c:52 [inline]
   do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
   entry_SYSCALL_64_after_hwframe+0x77/0x7f

[CAUSE]
To support mounting different subvolume with different RO/RW flags for
the new mount APIs, btrfs introduced two workaround to support this feature:

- Skip mount option/feature checks if we are mounting a different
  subvolume

- Reconfigure the fs to RW if the initial mount is RO

Combining these two, we can have the following sequence:

- Mount the fs ro,rescue=all,clear_cache,space_cache=v1
  rescue=all will mark the fs as hard read-only, so no v2 cache clearing
  will happen.

- Mount a subvolume rw of the same fs.
  We go into btrfs_get_tree_subvol(), but fc_mount() returns EBUSY
  because our new fc is RW, different from the original fs.

  Now we enter btrfs_reconfigure_for_mount(), which switches the RO flag
  first so that we can grab the existing fs_info.
  Then we reconfigure the fs to RW.

- During reconfiguration, option/features check is skipped
  This means we will restart the v2 cache clearing, and convert back to
  v1 cache.
  This will trigger fs writes, and since the original fs has "rescue=all"
  option, it skips the csum tree read.

  And eventually causing NULL pointer dereference in super block
  writeback.

[FIX]
For reconfiguration caused by different subvolume RO/RW flags, ensure we
always run btrfs_check_options() to ensure we have proper hard RO
requirements met.

In fact the function btrfs_check_options() doesn't really do many
complex checks, but hard RO requirement and some feature dependency
checks, thus there is no special reason not to do the check for mount
reconfiguration.

Reported-by: syzbot+56360f93efa90ff15870@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/0000000000008c5d090621cb2770@google.com/
Fixes: f044b31867 ("btrfs: handle the ro->rw transition for mounting different subvolumes")
CC: stable@vger.kernel.org # 6.8+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-22 16:10:51 +02:00
Boris Burkov
7a2339058e btrfs: fix read corruption due to race with extent map merging
In debugging some corrupt squashfs files, we observed symptoms of
corrupt page cache pages but correct on-disk contents. Further
investigation revealed that the exact symptom was a correct page
followed by an incorrect, duplicate, page. This got us thinking about
extent maps.

commit ac05ca913e ("Btrfs: fix race between using extent maps and merging them")
enforces a reference count on the primary `em` extent_map being merged,
as that one gets modified.

However, since,
commit 3d2ac99224 ("btrfs: introduce new members for extent_map")
both 'em' and 'merge' get modified, which started modifying 'merge'
and thus introduced the same race.

We were able to reproduce this by looping the affected squashfs workload
in parallel on a bunch of separate btrfs-es while also dropping caches.
We are still working on a simple enough reproducer to make into an fstest.

The simplest fix is to stop modifying 'merge', which is not essential,
as it is dropped immediately after the merge. This behavior is simply
a consequence of the order of the two extent maps being important in
computing the new values. Modify merge_ondisk_extents to take prev and
next by const* and also take a third merged parameter that it puts the
results in. Note that this introduces the rather odd behavior of passing
'em' to merge_ondisk_extents as a const * and as a regular ptr.

Fixes: 3d2ac99224 ("btrfs: introduce new members for extent_map")
CC: stable@vger.kernel.org # 6.11+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-22 16:10:13 +02:00
Qu Wenruo
f10f59f91a btrfs: fix the delalloc range locking if sector size < page size
Inside lock_delalloc_folios(), there are several problems related to
sector size < page size handling:

- Set the writer locks without checking if the folio is still valid
  We call btrfs_folio_start_writer_lock() just like it's folio_lock().
  But since the folio may not even be the folio of the current mapping,
  we can easily screw up the folio->private.

- The range is not clamped inside the page
  This means we can over write other bitmaps if the start/len is not
  properly handled, and trigger the btrfs_subpage_assert().

- @processed_end is always rounded up to page end
  If the delalloc range is not page aligned, and we need to retry
  (returning -EAGAIN), then we will unlock to the page end.

  Thankfully this is not a huge problem, as now
  btrfs_folio_end_writer_lock() can handle range larger than the locked
  range, and only unlock what is already locked.

Fix all these problems by:

- Lock and check the folio first, then call
  btrfs_folio_set_writer_lock()
  So that if we got a folio not belonging to the inode, we won't
  touch folio->private.

- Properly truncate the range inside the page

- Update @processed_end to the locked range end

Fixes: 1e1de38792 ("btrfs: make process_one_page() to handle subpage locking")
CC: stable@vger.kernel.org # 6.1+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-22 16:09:44 +02:00
Qu Wenruo
5f9062a48d btrfs: qgroup: set a more sane default value for subtree drop threshold
Since commit 011b46c304 ("btrfs: skip subtree scan if it's too high to
avoid low stall in btrfs_commit_transaction()"), btrfs qgroup can
automatically skip large subtree scan at the cost of marking qgroup
inconsistent.

It's designed to address the final performance problem of snapshot drop
with qgroup enabled, but to be safe the default value is
BTRFS_MAX_LEVEL, requiring a user space daemon to set a different value
to make it work.

I'd say it's not a good idea to rely on user space tool to set this
default value, especially when some operations (snapshot dropping) can
be triggered immediately after mount, leaving a very small window to
that that sysfs interface.

So instead of disabling this new feature by default, enable it with a
low threshold (3), so that large subvolume tree drop at mount time won't
cause huge qgroup workload.

CC: stable@vger.kernel.org # 6.1
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-22 16:09:11 +02:00
Filipe Manana
3510e684b8 btrfs: clear force-compress on remount when compress mount option is given
After the migration to use fs context for processing mount options we had
a slight change in the semantics for remounting a filesystem that was
mounted with compress-force. Before we could clear compress-force by
passing only "-o compress[=algo]" during a remount, but after that change
that does not work anymore, force-compress is still present and one needs
to pass "-o compress-force=no,compress[=algo]" to the mount command.

Example, when running on a kernel 6.8+:

  $ mount -o compress-force=zlib:9 /dev/sdi /mnt/sdi
  $ mount | grep sdi
  /dev/sdi on /mnt/sdi type btrfs (rw,relatime,compress-force=zlib:9,discard=async,space_cache=v2,subvolid=5,subvol=/)

  $ mount -o remount,compress=zlib:5 /mnt/sdi
  $ mount | grep sdi
  /dev/sdi on /mnt/sdi type btrfs (rw,relatime,compress-force=zlib:5,discard=async,space_cache=v2,subvolid=5,subvol=/)

On a 6.7 kernel (or older):

  $ mount -o compress-force=zlib:9 /dev/sdi /mnt/sdi
  $ mount | grep sdi
  /dev/sdi on /mnt/sdi type btrfs (rw,relatime,compress-force=zlib:9,discard=async,space_cache=v2,subvolid=5,subvol=/)

  $ mount -o remount,compress=zlib:5 /mnt/sdi
  $ mount | grep sdi
  /dev/sdi on /mnt/sdi type btrfs (rw,relatime,compress=zlib:5,discard=async,space_cache=v2,subvolid=5,subvol=/)

So update btrfs_parse_param() to clear "compress-force" when "compress" is
given, providing the same semantics as kernel 6.7 and older.

Reported-by: Roman Mamedov <rm@romanrm.net>
Link: https://lore.kernel.org/linux-btrfs/20241014182416.13d0f8b0@nvm/
CC: stable@vger.kernel.org # 6.8+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-22 16:07:53 +02:00
Naohiro Aota
bf9821ba47 btrfs: zoned: fix zone unusable accounting for freed reserved extent
When btrfs reserves an extent and does not use it (e.g, by an error), it
calls btrfs_free_reserved_extent() to free the reserved extent. In the
process, it calls btrfs_add_free_space() and then it accounts the region
bytes as block_group->zone_unusable.

However, it leaves the space_info->bytes_zone_unusable side not updated. As
a result, ENOSPC can happen while a space_info reservation succeeded. The
reservation is fine because the freed region is not added in
space_info->bytes_zone_unusable, leaving that space as "free". OTOH,
corresponding block group counts it as zone_unusable and its allocation
pointer is not rewound, we cannot allocate an extent from that block group.
That will also negate space_info's async/sync reclaim process, and cause an
ENOSPC error from the extent allocation process.

Fix that by returning the space to space_info->bytes_zone_unusable.
Ideally, since a bio is not submitted for this reserved region, we should
return the space to free space and rewind the allocation pointer. But, it
needs rework on extent allocation handling, so let it work in this way for
now.

Fixes: 169e0da91a ("btrfs: zoned: track unusable bytes for zones")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-17 16:16:46 +02:00
Linus Torvalds
667b1d41b2 for-6.12-rc3-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmcPxtAACgkQxWXV+ddt
 WDu9lA//WfB88fwEKnqBYDRo6aiSMIAzLDuXkJ9i8d7rcjZO1OIZkEnMOsxhvTcZ
 KxgjNjkgzoTyUwoAUlG+ZpvMeSNMhBdr2NFkXmYzN9oanFE4zplpZiWx6tGSApRU
 0ilngjXBsr8p03HmB88Yb05DVYQ2elMP6Jx3VETDBa0CNyp4//tGKzusNhZdA7KM
 XLZmkKRk3ZKabNo+p2J5t8UGJCl2L18U0o/EphfSkODKadUnsBbAPZUt2EGQCZwv
 uZhDFAUkgTFBkeRO7JwTfDrNi51M4zwmh+kEduzg4Ny4TdFb1UapU7K1N330WMru
 4Qa953Met9I4NB/kKI+fZP1lN4NGuD2qEU6yoZVSy4UiqRp1gEg8kOUfVGFbNJa1
 VFYcwdrBad0I4PjnQc5bpZVjzqJT5wWiZxjlWrB7VyIfdmnvQxe5h4DBwBhN5FJr
 +MEtuY2QNFygjDAZ5z0Ss8hegqI+FYi562Cjy9QRLhb3qGD8STF2BIChaILIn3oA
 UVJUlUP6CUmCu1RZRMFB4/WkeHO46FmZxJErGfFeXqJInThf0/rdSZOQgIP0JsUq
 N8FINEgXFAMCkK1PT7MNvAYkSP0tR7B0JjGKcSlGS3v3F0URCNGvHSiqbLedAtXT
 lc1MdXTZxub8h6xhIvgY1j7HRAFGrunn7LD6MIKRWX1SZPWwAGI=
 =DEUA
 -----END PGP SIGNATURE-----

Merge tag 'for-6.12-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - regression fix: dirty extents tracked in xarray for qgroups must be
   adjusted for 32bit platforms

 - fix potentially freeing uninitialized name in fscrypt structure

 - fix warning about unneeded variable in a send callback

* tag 'for-6.12-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix uninitialized pointer free on read_alloc_one_name() error
  btrfs: send: cleanup unneeded return variable in changed_verity()
  btrfs: fix uninitialized pointer free in add_inode_ref()
  btrfs: use sector numbers as keys for the dirty extents xarray
2024-10-16 09:30:20 -07:00
Roi Martin
2ab5e243c2 btrfs: fix uninitialized pointer free on read_alloc_one_name() error
The function read_alloc_one_name() does not initialize the name field of
the passed fscrypt_str struct if kmalloc fails to allocate the
corresponding buffer.  Thus, it is not guaranteed that
fscrypt_str.name is initialized when freeing it.

This is a follow-up to the linked patch that fixes the remaining
instances of the bug introduced by commit e43eec81c5 ("btrfs: use
struct qstr instead of name and namelen pairs").

Link: https://lore.kernel.org/linux-btrfs/20241009080833.1355894-1-jroi.martin@gmail.com/
Fixes: e43eec81c5 ("btrfs: use struct qstr instead of name and namelen pairs")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Roi Martin <jroi.martin@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-11 19:55:04 +02:00
Christian Heusel
a0af4936e4 btrfs: send: cleanup unneeded return variable in changed_verity()
As all changed_* functions need to return something, just return 0
directly here, as the verity status is passed via the context.

Reported by LKP: fs/btrfs/send.c:6877:5-8: Unneeded variable: "ret". Return "0" on line 6883

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202410092305.WbyqspH8-lkp@intel.com/
Signed-off-by: Christian Heusel <christian@heusel.eu>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-11 19:54:58 +02:00
Roi Martin
66691c6e2f btrfs: fix uninitialized pointer free in add_inode_ref()
The add_inode_ref() function does not initialize the "name" struct when
it is declared.  If any of the following calls to "read_one_inode()
returns NULL,

	dir = read_one_inode(root, parent_objectid);
	if (!dir) {
		ret = -ENOENT;
		goto out;
	}

	inode = read_one_inode(root, inode_objectid);
	if (!inode) {
		ret = -EIO;
		goto out;
	}

then "name.name" would be freed on "out" before being initialized.

out:
	...
	kfree(name.name);

This issue was reported by Coverity with CID 1526744.

Fixes: e43eec81c5 ("btrfs: use struct qstr instead of name and namelen pairs")
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Roi Martin <jroi.martin@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-11 19:54:52 +02:00
Filipe Manana
97420be7bd btrfs: use sector numbers as keys for the dirty extents xarray
We are using the logical address ("bytenr") of an extent as the key for
qgroup records in the dirty extents xarray. This is a problem because the
xarrays use "unsigned long" for keys/indices, meaning that on a 32 bits
platform any extent starting at or beyond 4G is truncated, which is a too
low limitation as virtually everyone is using storage with more than 4G of
space. This means a "bytenr" of 4G gets truncated to 0, and so does 8G and
16G for example, resulting in incorrect qgroup accounting.

Fix this by using sector numbers as keys instead, that is, using keys that
match the logical address right shifted by fs_info->sectorsize_bits, which
is what we do for the fs_info->buffer_radix that tracks extent buffers
(radix trees also use an "unsigned long" type for keys). This also makes
the index space more dense which helps optimize the xarray (as mentioned
at Documentation/core-api/xarray.rst).

Fixes: 3cce39a8ca ("btrfs: qgroup: use xarray to track dirty extents in transaction")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-11 18:33:35 +02:00
Linus Torvalds
eb952c47d1 for-6.12-rc2-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAmcH4qAACgkQxWXV+ddt
 WDtDig//czntfO+iRvDERZWTIB6vdVExfLd3r3ZNYlO1pIvgCuvqx3iYva+0ZhGW
 8A+gcRax7cz0jCaxDp/+5lIRfdNxZH6/LwjZsDgU8Ly7himeRmwhtn2fCgNeiH/K
 bUl92+ZMo2vwqTKXYa3xF1g3Hz6cRXVW7gJrMwNhb1hpPTGx+lgYJU02m/Io/vjK
 1jcrZ84OEPIOY5uiAoDyO2hgsT/zVEeuuOiSTpKSzrghPbo0vmjLiYJ5T+CE5Uw3
 u3w7/Fqnw49NwucqtncvyFFDXY9EWNuQhowi3hqJgOYTInqwwJigIpQV0hDDwYxb
 ohGUGjazGfAEf/cy1jZXMbwCVgg8/Nj9x0eDKKhfs19VYUbMkEYQ8LKRTUlCeBwS
 H/2AmqpqHEEO+tPY3P+w6MVwkNho8JNpWPdP5OzJs7XrD067IViOjD06HPM/k5ci
 TU3zp9NYvgHVtmfZK1Aqsg9OYVhI1klVXejmlAzOLxejRPWXK/1hBw3kXbC6I+k1
 50l0Yh1dgEnclMI3yWsKoj8IYUAkh2eudt0pNsot4a5vICMY++NVS2eukdz5UcEz
 ix7hcpYcCcmzoOaelyEgmdAncWVGJT5w2Nzy85YaOp+Z1C65Ywb41utU+sSY+swB
 kZfwl9vrsfu754vX7UKBherCvvYo+Lnj3GeX8Oe+1LoT2BP0TPk=
 =lTqc
 -----END PGP SIGNATURE-----

Merge tag 'for-6.12-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - update fstrim loop and add more cancellation points, fix reported
   delayed or blocked suspend if there's a huge chunk queued

 - fix error handling in recent qgroup xarray conversion

 - in zoned mode, fix warning printing device path without RCU
   protection

 - again fix invalid extent xarray state (6252690f7e), lost due to
   refactoring

* tag 'for-6.12-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix clear_dirty and writeback ordering in submit_one_sector()
  btrfs: zoned: fix missing RCU locking in error message when loading zone info
  btrfs: fix missing error handling when adding delayed ref with qgroups enabled
  btrfs: add cancellation points to trim loops
  btrfs: split remaining space to discard in chunks
2024-10-10 10:02:59 -07:00
Christian Brauner
b40508ca5d
Merge patch series "timekeeping/fs: multigrain timestamp redux"
Jeff Layton <jlayton@kernel.org> says:

The VFS has always used coarse-grained timestamps when updating the
ctime and mtime after a change. This has the benefit of allowing
filesystems to optimize away a lot metadata updates, down to around 1
per jiffy, even when a file is under heavy writes.

Unfortunately, this has always been an issue when we're exporting via
NFSv3, which relies on timestamps to validate caches. A lot of changes
can happen in a jiffy, so timestamps aren't sufficient to help the
client decide when to invalidate the cache. Even with NFSv4, a lot of
exported filesystems don't properly support a change attribute and are
subject to the same problems with timestamp granularity. Other
applications have similar issues with timestamps (e.g backup
applications).

If we were to always use fine-grained timestamps, that would improve the
situation, but that becomes rather expensive, as the underlying
filesystem would have to log a lot more metadata updates.

What we need is a way to only use fine-grained timestamps when they are
being actively queried. Use the (unused) top bit in inode->i_ctime_nsec
as a flag that indicates whether the current timestamps have been
queried via stat() or the like. When it's set, we allow the kernel to
use a fine-grained timestamp iff it's necessary to make the ctime show
a different value.

This solves the problem of being able to distinguish the timestamp
between updates, but introduces a new problem: it's now possible for a
file being changed to get a fine-grained timestamp. A file that is
altered just a bit later can then get a coarse-grained one that appears
older than the earlier fine-grained time. This violates timestamp
ordering guarantees.

To remedy this, keep a global monotonic atomic64_t value that acts as a
timestamp floor.  When we go to stamp a file, we first get the latter of
the current floor value and the current coarse-grained time. If the
inode ctime hasn't been queried then we just attempt to stamp it with
that value.

If it has been queried, then first see whether the current coarse time
is later than the existing ctime. If it is, then we accept that value.
If it isn't, then we get a fine-grained time and try to swap that into
the global floor. Whether that succeeds or fails, we take the resulting
floor time, convert it to realtime and try to swap that into the ctime.

We take the result of the ctime swap whether it succeeds or fails, since
either is just as valid.

Filesystems can opt into this by setting the FS_MGTIME fstype flag.
Others should be unaffected (other than being subject to the same floor
value as multigrain filesystems).

* patches from https://lore.kernel.org/r/20241002-mgtime-v10-0-d1c4717f5284@kernel.org:
  tmpfs: add support for multigrain timestamps
  btrfs: convert to multigrain timestamps
  ext4: switch to multigrain timestamps
  xfs: switch to multigrain timestamps
  Documentation: add a new file documenting multigrain timestamps
  fs: add percpu counters for significant multigrain timestamp events
  fs: tracepoints around multigrain timestamp events
  fs: handle delegated timestamps in setattr_copy_mgtime
  fs: have setattr_copy handle multigrain timestamps appropriately
  fs: add infrastructure for multigrain timestamps

Link: https://lore.kernel.org/r/20241002-mgtime-v10-0-d1c4717f5284@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-10-10 10:20:57 +02:00
Jeff Layton
e2e801d6e6
btrfs: convert to multigrain timestamps
Enable multigrain timestamps, which should ensure that there is an
apparent change to the timestamp whenever it has been written after
being actively observed via getattr.

Beyond enabling the FS_MGTIME flag, this patch eliminates
update_time_for_write, which goes to great pains to avoid in-memory
stores. Just have it overwrite the timestamps unconditionally.

Note that this also drops the IS_I_VERSION check and unconditionally
bumps the change attribute, since SB_I_VERSION is always set on btrfs.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # documentation bits
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20241002-mgtime-v10-11-d1c4717f5284@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-10-10 10:20:53 +02:00
Naohiro Aota
e761be2a07 btrfs: fix clear_dirty and writeback ordering in submit_one_sector()
This commit is a replay of commit 6252690f7e ("btrfs: fix invalid
mapping of extent xarray state"). We need to call
btrfs_folio_clear_dirty() before btrfs_set_range_writeback(), so that
xarray DIRTY tag is cleared.

With a refactoring commit 8189197425 ("btrfs: refactor
__extent_writepage_io() to do sector-by-sector submission"), it screwed
up and the order is reversed and causing the same hang. Fix the ordering
now in submit_one_sector().

Fixes: 8189197425 ("btrfs: refactor __extent_writepage_io() to do sector-by-sector submission")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-09 13:23:51 +02:00