mirror of
https://github.com/torvalds/linux.git
synced 2025-11-04 02:30:34 +02:00
e55a0de185
Pages passed to __extent_writepage() are always locked, but they may be locked by different functions. There are two types of locked page for __extent_writepage(): - Page locked by plain lock_page() It should not have any subpage::writers count. Can be unlocked by unlock_page(). This is the most common locked page for __extent_writepage() called inside extent_write_cache_pages() or extent_write_full_page(). Rarer cases include the @locked_page from extent_write_locked_range(). - Page locked by lock_delalloc_pages() There is only one caller, all pages except @locked_page for extent_write_locked_range(). In this case, we have to call subpage helper to handle the case. So here we introduce a helper, btrfs_page_unlock_writer(), to allow __extent_writepage() to unlock different locked pages. And since for all other callers of __extent_writepage() their pages are ensured to be locked by lock_page(), also add an extra check for epd::extent_locked to unlock such pages directly. Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
156 lines
5.4 KiB
C
156 lines
5.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
|
|
#ifndef BTRFS_SUBPAGE_H
|
|
#define BTRFS_SUBPAGE_H
|
|
|
|
#include <linux/spinlock.h>
|
|
|
|
/*
|
|
* Extra info for subpapge bitmap.
|
|
*
|
|
* For subpage we pack all uptodate/error/dirty/writeback/ordered bitmaps into
|
|
* one larger bitmap.
|
|
*
|
|
* This structure records how they are organized in the bitmap:
|
|
*
|
|
* /- uptodate_offset /- error_offset /- dirty_offset
|
|
* | | |
|
|
* v v v
|
|
* |u|u|u|u|........|u|u|e|e|.......|e|e| ... |o|o|
|
|
* |<- bitmap_nr_bits ->|
|
|
* |<--------------- total_nr_bits ---------------->|
|
|
*/
|
|
struct btrfs_subpage_info {
|
|
/* Number of bits for each bitmap */
|
|
unsigned int bitmap_nr_bits;
|
|
|
|
/* Total number of bits for the whole bitmap */
|
|
unsigned int total_nr_bits;
|
|
|
|
/*
|
|
* *_start indicates where the bitmap starts, the length is always
|
|
* @bitmap_size, which is calculated from PAGE_SIZE / sectorsize.
|
|
*/
|
|
unsigned int uptodate_offset;
|
|
unsigned int error_offset;
|
|
unsigned int dirty_offset;
|
|
unsigned int writeback_offset;
|
|
unsigned int ordered_offset;
|
|
unsigned int checked_offset;
|
|
};
|
|
|
|
/*
|
|
* Structure to trace status of each sector inside a page, attached to
|
|
* page::private for both data and metadata inodes.
|
|
*/
|
|
struct btrfs_subpage {
|
|
/* Common members for both data and metadata pages */
|
|
spinlock_t lock;
|
|
/*
|
|
* Both data and metadata needs to track how many readers are for the
|
|
* page.
|
|
* Data relies on @readers to unlock the page when last reader finished.
|
|
* While metadata doesn't need page unlock, it needs to prevent
|
|
* page::private get cleared before the last end_page_read().
|
|
*/
|
|
atomic_t readers;
|
|
union {
|
|
/*
|
|
* Structures only used by metadata
|
|
*
|
|
* @eb_refs should only be operated under private_lock, as it
|
|
* manages whether the subpage can be detached.
|
|
*/
|
|
atomic_t eb_refs;
|
|
|
|
/* Structures only used by data */
|
|
atomic_t writers;
|
|
};
|
|
unsigned long bitmaps[];
|
|
};
|
|
|
|
enum btrfs_subpage_type {
|
|
BTRFS_SUBPAGE_METADATA,
|
|
BTRFS_SUBPAGE_DATA,
|
|
};
|
|
|
|
void btrfs_init_subpage_info(struct btrfs_subpage_info *subpage_info, u32 sectorsize);
|
|
int btrfs_attach_subpage(const struct btrfs_fs_info *fs_info,
|
|
struct page *page, enum btrfs_subpage_type type);
|
|
void btrfs_detach_subpage(const struct btrfs_fs_info *fs_info,
|
|
struct page *page);
|
|
|
|
/* Allocate additional data where page represents more than one sector */
|
|
struct btrfs_subpage *btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info,
|
|
enum btrfs_subpage_type type);
|
|
void btrfs_free_subpage(struct btrfs_subpage *subpage);
|
|
|
|
void btrfs_page_inc_eb_refs(const struct btrfs_fs_info *fs_info,
|
|
struct page *page);
|
|
void btrfs_page_dec_eb_refs(const struct btrfs_fs_info *fs_info,
|
|
struct page *page);
|
|
|
|
void btrfs_subpage_start_reader(const struct btrfs_fs_info *fs_info,
|
|
struct page *page, u64 start, u32 len);
|
|
void btrfs_subpage_end_reader(const struct btrfs_fs_info *fs_info,
|
|
struct page *page, u64 start, u32 len);
|
|
|
|
void btrfs_subpage_start_writer(const struct btrfs_fs_info *fs_info,
|
|
struct page *page, u64 start, u32 len);
|
|
bool btrfs_subpage_end_and_test_writer(const struct btrfs_fs_info *fs_info,
|
|
struct page *page, u64 start, u32 len);
|
|
int btrfs_page_start_writer_lock(const struct btrfs_fs_info *fs_info,
|
|
struct page *page, u64 start, u32 len);
|
|
void btrfs_page_end_writer_lock(const struct btrfs_fs_info *fs_info,
|
|
struct page *page, u64 start, u32 len);
|
|
|
|
/*
|
|
* Template for subpage related operations.
|
|
*
|
|
* btrfs_subpage_*() are for call sites where the page has subpage attached and
|
|
* the range is ensured to be inside the page.
|
|
*
|
|
* btrfs_page_*() are for call sites where the page can either be subpage
|
|
* specific or regular page. The function will handle both cases.
|
|
* But the range still needs to be inside the page.
|
|
*
|
|
* btrfs_page_clamp_*() are similar to btrfs_page_*(), except the range doesn't
|
|
* need to be inside the page. Those functions will truncate the range
|
|
* automatically.
|
|
*/
|
|
#define DECLARE_BTRFS_SUBPAGE_OPS(name) \
|
|
void btrfs_subpage_set_##name(const struct btrfs_fs_info *fs_info, \
|
|
struct page *page, u64 start, u32 len); \
|
|
void btrfs_subpage_clear_##name(const struct btrfs_fs_info *fs_info, \
|
|
struct page *page, u64 start, u32 len); \
|
|
bool btrfs_subpage_test_##name(const struct btrfs_fs_info *fs_info, \
|
|
struct page *page, u64 start, u32 len); \
|
|
void btrfs_page_set_##name(const struct btrfs_fs_info *fs_info, \
|
|
struct page *page, u64 start, u32 len); \
|
|
void btrfs_page_clear_##name(const struct btrfs_fs_info *fs_info, \
|
|
struct page *page, u64 start, u32 len); \
|
|
bool btrfs_page_test_##name(const struct btrfs_fs_info *fs_info, \
|
|
struct page *page, u64 start, u32 len); \
|
|
void btrfs_page_clamp_set_##name(const struct btrfs_fs_info *fs_info, \
|
|
struct page *page, u64 start, u32 len); \
|
|
void btrfs_page_clamp_clear_##name(const struct btrfs_fs_info *fs_info, \
|
|
struct page *page, u64 start, u32 len); \
|
|
bool btrfs_page_clamp_test_##name(const struct btrfs_fs_info *fs_info, \
|
|
struct page *page, u64 start, u32 len);
|
|
|
|
DECLARE_BTRFS_SUBPAGE_OPS(uptodate);
|
|
DECLARE_BTRFS_SUBPAGE_OPS(error);
|
|
DECLARE_BTRFS_SUBPAGE_OPS(dirty);
|
|
DECLARE_BTRFS_SUBPAGE_OPS(writeback);
|
|
DECLARE_BTRFS_SUBPAGE_OPS(ordered);
|
|
DECLARE_BTRFS_SUBPAGE_OPS(checked);
|
|
|
|
bool btrfs_subpage_clear_and_test_dirty(const struct btrfs_fs_info *fs_info,
|
|
struct page *page, u64 start, u32 len);
|
|
|
|
void btrfs_page_assert_not_dirty(const struct btrfs_fs_info *fs_info,
|
|
struct page *page);
|
|
void btrfs_page_unlock_writer(struct btrfs_fs_info *fs_info, struct page *page,
|
|
u64 start, u32 len);
|
|
|
|
#endif
|