diff options
| -rw-r--r-- | fs/btrfs/subpage.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/fs/btrfs/subpage.c b/fs/btrfs/subpage.c index eae9e8a478f6..54736f6238e6 100644 --- a/fs/btrfs/subpage.c +++ b/fs/btrfs/subpage.c @@ -328,24 +328,34 @@ static void btrfs_subpage_start_writer(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); const int nbits = (len >> fs_info->sectorsize_bits); + unsigned long flags; int ret; btrfs_subpage_assert(fs_info, folio, start, len); + spin_lock_irqsave(&subpage->lock, flags); ASSERT(atomic_read(&subpage->readers) == 0); + 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); ASSERT(ret == nbits); + spin_unlock_irqrestore(&subpage->lock, flags); } static bool btrfs_subpage_end_and_test_writer(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); const int nbits = (len >> fs_info->sectorsize_bits); + unsigned long flags; + bool last; btrfs_subpage_assert(fs_info, folio, start, len); + spin_lock_irqsave(&subpage->lock, flags); /* * We have call sites passing @lock_page into * extent_clear_unlock_delalloc() for compression path. @@ -353,11 +363,18 @@ static bool btrfs_subpage_end_and_test_writer(const struct btrfs_fs_info *fs_inf * This @locked_page is locked by plain lock_page(), thus its * subpage::writers is 0. Handle them in a special way. */ - if (atomic_read(&subpage->writers) == 0) + if (atomic_read(&subpage->writers) == 0) { + spin_unlock_irqrestore(&subpage->lock, flags); return true; + } ASSERT(atomic_read(&subpage->writers) >= nbits); - return atomic_sub_and_test(nbits, &subpage->writers); + /* The target range should have been locked. */ + ASSERT(bitmap_test_range_all_set(subpage->bitmaps, start_bit, nbits)); + bitmap_clear(subpage->bitmaps, start_bit, nbits); + last = atomic_sub_and_test(nbits, &subpage->writers); + spin_unlock_irqrestore(&subpage->lock, flags); + return last; } /* |