diff options
Diffstat (limited to 'fs/btrfs/subpage.h')
| -rw-r--r-- | fs/btrfs/subpage.h | 153 |
1 files changed, 95 insertions, 58 deletions
diff --git a/fs/btrfs/subpage.h b/fs/btrfs/subpage.h index b6dc013b0fdc..3042c5ea840a 100644 --- a/fs/btrfs/subpage.h +++ b/fs/btrfs/subpage.h @@ -5,10 +5,12 @@ #include <linux/spinlock.h> #include <linux/atomic.h> +#include <linux/sizes.h> +#include "btrfs_inode.h" +#include "fs.h" struct address_space; struct folio; -struct btrfs_fs_info; /* * Extra info for subpapge bitmap. @@ -18,39 +20,23 @@ struct btrfs_fs_info; * * This structure records how they are organized in the bitmap: * - * /- uptodate_offset /- dirty_offset /- ordered_offset + * /- uptodate /- dirty /- ordered * | | | * v v v * |u|u|u|u|........|u|u|d|d|.......|d|d|o|o|.......|o|o| - * |<- bitmap_nr_bits ->| - * |<----------------- total_nr_bits ------------------>| + * |< sectors_per_page >| + * + * Unlike regular macro-like enums, here we do not go upper-case names, as + * these names will be utilized in various macros to define function names. */ -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; - - /* - * *_offset indicates where the bitmap starts, the length is always - * @bitmap_size, which is calculated from PAGE_SIZE / sectorsize. - */ - unsigned int uptodate_offset; - unsigned int dirty_offset; - unsigned int writeback_offset; - unsigned int ordered_offset; - unsigned int checked_offset; - - /* - * For locked bitmaps, normally it's subpage representation for folio - * Locked flag, but metadata is different: - * - * - Metadata doesn't really lock the folio - * It's just to prevent page::private get cleared before the last - * end_page_read(). - */ - unsigned int locked_offset; +enum { + btrfs_bitmap_nr_uptodate = 0, + btrfs_bitmap_nr_dirty, + btrfs_bitmap_nr_writeback, + btrfs_bitmap_nr_ordered, + btrfs_bitmap_nr_checked, + btrfs_bitmap_nr_locked, + btrfs_bitmap_nr_max }; /* @@ -60,14 +46,6 @@ struct btrfs_subpage_info { 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 @@ -77,8 +55,12 @@ struct btrfs_subpage { */ atomic_t eb_refs; - /* Structures only used by data */ - atomic_t writers; + /* + * Structures only used by data, + * + * How many sectors inside the page is locked. + */ + atomic_t nr_locked; }; unsigned long bitmaps[]; }; @@ -88,31 +70,60 @@ enum btrfs_subpage_type { BTRFS_SUBPAGE_DATA, }; -bool btrfs_is_subpage(const struct btrfs_fs_info *fs_info, struct address_space *mapping); +#if PAGE_SIZE > BTRFS_MIN_BLOCKSIZE +/* + * Subpage support for metadata is more complex, as we can have dummy extent + * buffers, where folios have no mapping to determine the owning inode. + * + * Thankfully we only need to check if node size is smaller than page size. + * Even with larger folio support, we will only allocate a folio as large as + * node size. + * Thus if nodesize < PAGE_SIZE, we know metadata needs need to subpage routine. + */ +static inline bool btrfs_meta_is_subpage(const struct btrfs_fs_info *fs_info) +{ + return fs_info->nodesize < PAGE_SIZE; +} +static inline bool btrfs_is_subpage(const struct btrfs_fs_info *fs_info, + struct folio *folio) +{ + if (folio->mapping && folio->mapping->host) + ASSERT(is_data_inode(BTRFS_I(folio->mapping->host))); + return fs_info->sectorsize < folio_size(folio); +} +#else +static inline bool btrfs_meta_is_subpage(const struct btrfs_fs_info *fs_info) +{ + return false; +} +static inline bool btrfs_is_subpage(const struct btrfs_fs_info *fs_info, + struct folio *folio) +{ + if (folio->mapping && folio->mapping->host) + ASSERT(is_data_inode(BTRFS_I(folio->mapping->host))); + return false; +} +#endif -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 folio *folio, enum btrfs_subpage_type type); -void btrfs_detach_subpage(const struct btrfs_fs_info *fs_info, struct folio *folio); +void btrfs_detach_subpage(const struct btrfs_fs_info *fs_info, struct folio *folio, + enum btrfs_subpage_type type); /* 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); + size_t fsize, enum btrfs_subpage_type type); void btrfs_free_subpage(struct btrfs_subpage *subpage); void btrfs_folio_inc_eb_refs(const struct btrfs_fs_info *fs_info, struct folio *folio); void btrfs_folio_dec_eb_refs(const struct btrfs_fs_info *fs_info, struct folio *folio); -void btrfs_subpage_start_reader(const struct btrfs_fs_info *fs_info, - struct folio *folio, u64 start, u32 len); -void btrfs_subpage_end_reader(const struct btrfs_fs_info *fs_info, - struct folio *folio, u64 start, u32 len); - -int btrfs_folio_start_writer_lock(const struct btrfs_fs_info *fs_info, - struct folio *folio, u64 start, u32 len); -void btrfs_folio_end_writer_lock(const struct btrfs_fs_info *fs_info, - struct folio *folio, u64 start, u32 len); - +void btrfs_folio_end_lock(const struct btrfs_fs_info *fs_info, + struct folio *folio, u64 start, u32 len); +void btrfs_folio_set_lock(const struct btrfs_fs_info *fs_info, + struct folio *folio, u64 start, u32 len); +void btrfs_folio_end_lock_bitmap(const struct btrfs_fs_info *fs_info, + struct folio *folio, unsigned long bitmap); /* * Template for subpage related operations. * @@ -126,6 +137,13 @@ void btrfs_folio_end_writer_lock(const struct btrfs_fs_info *fs_info, * btrfs_folio_clamp_*() are similar to btrfs_folio_*(), except the range doesn't * need to be inside the page. Those functions will truncate the range * automatically. + * + * Both btrfs_folio_*() and btrfs_folio_clamp_*() are for data folios. + * + * For metadata, one should use btrfs_meta_folio_*() helpers instead, and there + * is no clamp version for metadata helpers, as we either go subpage + * (nodesize < PAGE_SIZE) or go regular folio helpers (nodesize >= PAGE_SIZE, + * and our folio is never larger than nodesize). */ #define DECLARE_BTRFS_SUBPAGE_OPS(name) \ void btrfs_subpage_set_##name(const struct btrfs_fs_info *fs_info, \ @@ -145,7 +163,10 @@ void btrfs_folio_clamp_set_##name(const struct btrfs_fs_info *fs_info, \ void btrfs_folio_clamp_clear_##name(const struct btrfs_fs_info *fs_info, \ struct folio *folio, u64 start, u32 len); \ bool btrfs_folio_clamp_test_##name(const struct btrfs_fs_info *fs_info, \ - struct folio *folio, u64 start, u32 len); + struct folio *folio, u64 start, u32 len); \ +void btrfs_meta_folio_set_##name(struct folio *folio, const struct extent_buffer *eb); \ +void btrfs_meta_folio_clear_##name(struct folio *folio, const struct extent_buffer *eb); \ +bool btrfs_meta_folio_test_##name(struct folio *folio, const struct extent_buffer *eb); DECLARE_BTRFS_SUBPAGE_OPS(uptodate); DECLARE_BTRFS_SUBPAGE_OPS(dirty); @@ -153,12 +174,28 @@ DECLARE_BTRFS_SUBPAGE_OPS(writeback); DECLARE_BTRFS_SUBPAGE_OPS(ordered); DECLARE_BTRFS_SUBPAGE_OPS(checked); +/* + * Helper for error cleanup, where a folio will have its dirty flag cleared, + * with writeback started and finished. + */ +static inline void btrfs_folio_clamp_finish_io(struct btrfs_fs_info *fs_info, + struct folio *locked_folio, + u64 start, u32 len) +{ + btrfs_folio_clamp_clear_dirty(fs_info, locked_folio, start, len); + btrfs_folio_clamp_set_writeback(fs_info, locked_folio, start, len); + btrfs_folio_clamp_clear_writeback(fs_info, locked_folio, start, len); +} + bool btrfs_subpage_clear_and_test_dirty(const struct btrfs_fs_info *fs_info, struct folio *folio, u64 start, u32 len); -void btrfs_folio_assert_not_dirty(const struct btrfs_fs_info *fs_info, struct folio *folio); -void btrfs_folio_unlock_writer(struct btrfs_fs_info *fs_info, - struct folio *folio, u64 start, u32 len); +void btrfs_folio_assert_not_dirty(const struct btrfs_fs_info *fs_info, + struct folio *folio, u64 start, u32 len); +bool btrfs_meta_folio_clear_and_test_dirty(struct folio *folio, const struct extent_buffer *eb); +void btrfs_get_subpage_dirty_bitmap(struct btrfs_fs_info *fs_info, + struct folio *folio, + unsigned long *ret_bitmap); void __cold btrfs_subpage_dump_bitmap(const struct btrfs_fs_info *fs_info, struct folio *folio, u64 start, u32 len); |