6.12-stable review patch. If anyone has any objections, please let me know.
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From: Qu Wenruo wqu@suse.com
[ Upstream commit 0f7120266584490616f031873e7148495d77dd68 ]
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 Stable-dep-of: 8bf334beb349 ("btrfs: fix double accounting race when extent_writepage_io() failed") Signed-off-by: Sasha Levin sashal@kernel.org --- fs/btrfs/compression.c | 2 +- fs/btrfs/extent_io.c | 14 ++++++------- fs/btrfs/subpage.c | 46 +++++++++++++++++++++--------------------- fs/btrfs/subpage.h | 20 ++++++++++-------- 4 files changed, 43 insertions(+), 39 deletions(-)
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 64eaf74fbebc8..40332ab62f101 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -545,7 +545,7 @@ static noinline int add_ra_bio_pages(struct inode *inode, * subpage::readers and to unlock the page. */ if (fs_info->sectorsize < PAGE_SIZE) - btrfs_folio_set_writer_lock(fs_info, folio, cur, add_size); + btrfs_folio_set_lock(fs_info, folio, cur, add_size); folio_put(folio); cur += add_size; } diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 5d6b3b812593d..5a1bde8cc8b64 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -190,7 +190,7 @@ static void process_one_folio(struct btrfs_fs_info *fs_info, btrfs_folio_clamp_clear_writeback(fs_info, folio, start, len);
if (folio != locked_folio && (page_ops & PAGE_UNLOCK)) - btrfs_folio_end_writer_lock(fs_info, folio, start, len); + btrfs_folio_end_lock(fs_info, folio, start, len); }
static void __process_folios_contig(struct address_space *mapping, @@ -276,7 +276,7 @@ static noinline int lock_delalloc_folios(struct inode *inode, range_start = max_t(u64, folio_pos(folio), start); range_len = min_t(u64, folio_pos(folio) + folio_size(folio), end + 1) - range_start; - btrfs_folio_set_writer_lock(fs_info, folio, range_start, range_len); + btrfs_folio_set_lock(fs_info, folio, range_start, range_len);
processed_end = range_start + range_len - 1; } @@ -438,7 +438,7 @@ static void end_folio_read(struct folio *folio, bool uptodate, u64 start, u32 le if (!btrfs_is_subpage(fs_info, folio->mapping)) folio_unlock(folio); else - btrfs_folio_end_writer_lock(fs_info, folio, start, len); + btrfs_folio_end_lock(fs_info, folio, start, len); }
/* @@ -495,7 +495,7 @@ static void begin_folio_read(struct btrfs_fs_info *fs_info, struct folio *folio) return;
ASSERT(folio_test_private(folio)); - btrfs_folio_set_writer_lock(fs_info, folio, folio_pos(folio), PAGE_SIZE); + btrfs_folio_set_lock(fs_info, folio, folio_pos(folio), PAGE_SIZE); }
/* @@ -1187,7 +1187,7 @@ static noinline_for_stack int writepage_delalloc(struct btrfs_inode *inode, for_each_set_bit(bit, &bio_ctrl->submit_bitmap, fs_info->sectors_per_page) { u64 start = page_start + (bit << fs_info->sectorsize_bits);
- btrfs_folio_set_writer_lock(fs_info, folio, start, fs_info->sectorsize); + btrfs_folio_set_lock(fs_info, folio, start, fs_info->sectorsize); }
/* Lock all (subpage) delalloc ranges inside the folio first. */ @@ -1523,7 +1523,7 @@ static int extent_writepage(struct folio *folio, struct btrfs_bio_ctrl *bio_ctrl * Only unlock ranges that are submitted. As there can be some async * submitted ranges inside the folio. */ - btrfs_folio_end_writer_lock_bitmap(fs_info, folio, bio_ctrl->submit_bitmap); + btrfs_folio_end_lock_bitmap(fs_info, folio, bio_ctrl->submit_bitmap); ASSERT(ret <= 0); return ret; } @@ -2280,7 +2280,7 @@ void extent_write_locked_range(struct inode *inode, const struct folio *locked_f cur, cur_len, !ret); mapping_set_error(mapping, ret); } - btrfs_folio_end_writer_lock(fs_info, folio, cur, cur_len); + btrfs_folio_end_lock(fs_info, folio, cur, cur_len); if (ret < 0) found_error = true; next_page: diff --git a/fs/btrfs/subpage.c b/fs/btrfs/subpage.c index 0587a7d7b5e81..88a01d51ab11f 100644 --- a/fs/btrfs/subpage.c +++ b/fs/btrfs/subpage.c @@ -143,7 +143,7 @@ struct btrfs_subpage *btrfs_alloc_subpage(const struct btrfs_fs_info *fs_info, if (type == BTRFS_SUBPAGE_METADATA) atomic_set(&ret->eb_refs, 0); else - atomic_set(&ret->writers, 0); + atomic_set(&ret->nr_locked, 0); return ret; }
@@ -237,8 +237,8 @@ static void btrfs_subpage_clamp_range(struct folio *folio, u64 *start, u32 *len) orig_start + orig_len) - *start; }
-static bool btrfs_subpage_end_and_test_writer(const struct btrfs_fs_info *fs_info, - struct folio *folio, u64 start, u32 len) +static bool btrfs_subpage_end_and_test_lock(const struct btrfs_fs_info *fs_info, + struct folio *folio, u64 start, u32 len) { struct btrfs_subpage *subpage = folio_get_private(folio); const int start_bit = subpage_calc_start_bit(fs_info, folio, locked, start, len); @@ -256,9 +256,9 @@ static bool btrfs_subpage_end_and_test_writer(const struct btrfs_fs_info *fs_inf * extent_clear_unlock_delalloc() for compression path. * * This @locked_page is locked by plain lock_page(), thus its - * subpage::writers is 0. Handle them in a special way. + * subpage::locked is 0. Handle them in a special way. */ - if (atomic_read(&subpage->writers) == 0) { + if (atomic_read(&subpage->nr_locked) == 0) { spin_unlock_irqrestore(&subpage->lock, flags); return true; } @@ -267,8 +267,8 @@ static bool btrfs_subpage_end_and_test_writer(const struct btrfs_fs_info *fs_inf clear_bit(bit, subpage->bitmaps); cleared++; } - ASSERT(atomic_read(&subpage->writers) >= cleared); - last = atomic_sub_and_test(cleared, &subpage->writers); + ASSERT(atomic_read(&subpage->nr_locked) >= cleared); + last = atomic_sub_and_test(cleared, &subpage->nr_locked); spin_unlock_irqrestore(&subpage->lock, flags); return last; } @@ -289,8 +289,8 @@ static bool btrfs_subpage_end_and_test_writer(const struct btrfs_fs_info *fs_inf * bitmap, reduce the writer lock number, and unlock the page if that's * the last locked range. */ -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) { struct btrfs_subpage *subpage = folio_get_private(folio);
@@ -303,24 +303,24 @@ void btrfs_folio_end_writer_lock(const struct btrfs_fs_info *fs_info,
/* * For subpage case, there are two types of locked page. With or - * without writers number. + * without locked number. * - * Since we own the page lock, no one else could touch subpage::writers + * Since we own the page lock, no one else could touch subpage::locked * and we are safe to do several atomic operations without spinlock. */ - if (atomic_read(&subpage->writers) == 0) { - /* No writers, locked by plain lock_page(). */ + if (atomic_read(&subpage->nr_locked) == 0) { + /* No subpage lock, locked by plain lock_page(). */ folio_unlock(folio); return; }
btrfs_subpage_clamp_range(folio, &start, &len); - if (btrfs_subpage_end_and_test_writer(fs_info, folio, start, len)) + if (btrfs_subpage_end_and_test_lock(fs_info, folio, start, len)) folio_unlock(folio); }
-void btrfs_folio_end_writer_lock_bitmap(const struct btrfs_fs_info *fs_info, - struct folio *folio, unsigned long bitmap) +void btrfs_folio_end_lock_bitmap(const struct btrfs_fs_info *fs_info, + struct folio *folio, unsigned long bitmap) { struct btrfs_subpage *subpage = folio_get_private(folio); const int start_bit = fs_info->sectors_per_page * btrfs_bitmap_nr_locked; @@ -334,8 +334,8 @@ void btrfs_folio_end_writer_lock_bitmap(const struct btrfs_fs_info *fs_info, return; }
- if (atomic_read(&subpage->writers) == 0) { - /* No writers, locked by plain lock_page(). */ + if (atomic_read(&subpage->nr_locked) == 0) { + /* No subpage lock, locked by plain lock_page(). */ folio_unlock(folio); return; } @@ -345,8 +345,8 @@ void btrfs_folio_end_writer_lock_bitmap(const struct btrfs_fs_info *fs_info, if (test_and_clear_bit(bit + start_bit, subpage->bitmaps)) cleared++; } - ASSERT(atomic_read(&subpage->writers) >= cleared); - last = atomic_sub_and_test(cleared, &subpage->writers); + ASSERT(atomic_read(&subpage->nr_locked) >= cleared); + last = atomic_sub_and_test(cleared, &subpage->nr_locked); spin_unlock_irqrestore(&subpage->lock, flags); if (last) folio_unlock(folio); @@ -671,8 +671,8 @@ void btrfs_folio_assert_not_dirty(const struct btrfs_fs_info *fs_info, * This populates the involved subpage ranges so that subpage helpers can * properly unlock them. */ -void btrfs_folio_set_writer_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) { struct btrfs_subpage *subpage; unsigned long flags; @@ -691,7 +691,7 @@ void btrfs_folio_set_writer_lock(const struct btrfs_fs_info *fs_info, /* Target range should not yet be locked. */ ASSERT(bitmap_test_range_all_zero(subpage->bitmaps, start_bit, nbits)); bitmap_set(subpage->bitmaps, start_bit, nbits); - ret = atomic_add_return(nbits, &subpage->writers); + ret = atomic_add_return(nbits, &subpage->nr_locked); ASSERT(ret <= fs_info->sectors_per_page); spin_unlock_irqrestore(&subpage->lock, flags); } diff --git a/fs/btrfs/subpage.h b/fs/btrfs/subpage.h index 8488ea057b30b..44fff1f4eac48 100644 --- a/fs/btrfs/subpage.h +++ b/fs/btrfs/subpage.h @@ -54,8 +54,12 @@ 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[]; }; @@ -87,12 +91,12 @@ 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_folio_end_writer_lock(const struct btrfs_fs_info *fs_info, - struct folio *folio, u64 start, u32 len); -void btrfs_folio_set_writer_lock(const struct btrfs_fs_info *fs_info, - struct folio *folio, u64 start, u32 len); -void btrfs_folio_end_writer_lock_bitmap(const struct btrfs_fs_info *fs_info, - struct folio *folio, unsigned long bitmap); +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. *