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dm thin: detect metadata device resizing

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Allow the dm thin pool metadata device to be extended.

Whenever a pool is resumed, detect whether the size of the metadata
device has increased, and if so, extend the metadata to use the new
space.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Joe Thornber 2013-05-10 14:37:19 +01:00 committed by Alasdair G Kergon
parent 1921c56d95
commit 24347e9595
3 changed files with 64 additions and 3 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

12
drivers/md/dm-thin-metadata.c
View file

@ -1677,6 +1677,18 @@ int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
return r;
}
int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
{
int r = -EINVAL;
down_write(&pmd->root_lock);
if (!pmd->fail_io)
r = __resize_space_map(pmd->metadata_sm, new_count);
up_write(&pmd->root_lock);
return r;
}
void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)
{
down_write(&pmd->root_lock);

1
drivers/md/dm-thin-metadata.h
View file

@ -185,6 +185,7 @@ int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result);
* blocks would be lost.
*/
int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_size);
int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_size);
/*
* Flicks the underlying block manager into read only mode, so you know

54
drivers/md/dm-thin.c
View file

@ -1923,6 +1923,15 @@ static sector_t get_metadata_dev_size(struct block_device *bdev)
return metadata_dev_size;
}
static dm_block_t get_metadata_dev_size_in_blocks(struct block_device *bdev)
{
sector_t metadata_dev_size = get_metadata_dev_size(bdev);
sector_div(metadata_dev_size, THIN_METADATA_BLOCK_SIZE >> SECTOR_SHIFT);
return metadata_dev_size;
}
/*
* thin-pool <metadata dev> <data dev>
* <data block size (sectors)>
@ -2132,6 +2141,41 @@ static int maybe_resize_data_dev(struct dm_target *ti, bool *need_commit)
return 0;
}
static int maybe_resize_metadata_dev(struct dm_target *ti, bool *need_commit)
{
int r;
struct pool_c *pt = ti->private;
struct pool *pool = pt->pool;
dm_block_t metadata_dev_size, sb_metadata_dev_size;
*need_commit = false;
metadata_dev_size = get_metadata_dev_size(pool->md_dev);
r = dm_pool_get_metadata_dev_size(pool->pmd, &sb_metadata_dev_size);
if (r) {
DMERR("failed to retrieve data device size");
return r;
}
if (metadata_dev_size < sb_metadata_dev_size) {
DMERR("metadata device (%llu sectors) too small: expected %llu",
metadata_dev_size, sb_metadata_dev_size);
return -EINVAL;
} else if (metadata_dev_size > sb_metadata_dev_size) {
r = dm_pool_resize_metadata_dev(pool->pmd, metadata_dev_size);
if (r) {
DMERR("failed to resize metadata device");
return r;
}
*need_commit = true;
}
return 0;
}
/*
* Retrieves the number of blocks of the data device from
* the superblock and compares it to the actual device size,
@ -2146,7 +2190,7 @@ static int maybe_resize_data_dev(struct dm_target *ti, bool *need_commit)
static int pool_preresume(struct dm_target *ti)
{
int r;
bool need_commit1;
bool need_commit1, need_commit2;
struct pool_c *pt = ti->private;
struct pool *pool = pt->pool;
@ -2161,7 +2205,11 @@ static int pool_preresume(struct dm_target *ti)
if (r)
return r;
if (need_commit1)
r = maybe_resize_metadata_dev(ti, &need_commit2);
if (r)
return r;
if (need_commit1 || need_commit2)
(void) commit_or_fallback(pool);
return 0;
@ -2583,7 +2631,7 @@ static struct target_type pool_target = {
.name = "thin-pool",
.features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE |
DM_TARGET_IMMUTABLE,
.version = {1, 7, 0},
.version = {1, 8, 0},
.module = THIS_MODULE,
.ctr = pool_ctr,
.dtr = pool_dtr,