From: Naohiro Aota naohiro.aota@wdc.com
commit f79645df806565a03abb2847a1d20e6930b25e7e upstream.
btrfs_add_ordered_extent_*() add num_bytes to fs_info->ordered_bytes. Then, splitting an ordered extent will call btrfs_add_ordered_extent_*() again for split extents, leading to double counting of the region of a split extent. These leaked bytes are finally reported at unmount time as follow:
BTRFS info (device dm-1): at unmount dio bytes count 364544
Fix the double counting by subtracting split extent's size from fs_info->ordered_bytes.
Fixes: d22002fd37bd ("btrfs: zoned: split ordered extent when bio is sent") CC: stable@vger.kernel.org # 5.12+ Reviewed-by: Johannes Thumshirn johannes.thumshirn@wdc.com Signed-off-by: Naohiro Aota naohiro.aota@wdc.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/ordered-data.c | 8 ++++++++ 1 file changed, 8 insertions(+)
--- a/fs/btrfs/ordered-data.c +++ b/fs/btrfs/ordered-data.c @@ -1052,6 +1052,7 @@ static int clone_ordered_extent(struct b u64 len) { struct inode *inode = ordered->inode; + struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; u64 file_offset = ordered->file_offset + pos; u64 disk_bytenr = ordered->disk_bytenr + pos; u64 num_bytes = len; @@ -1069,6 +1070,13 @@ static int clone_ordered_extent(struct b else type = __ffs(flags_masked);
+ /* + * The splitting extent is already counted and will be added again + * in btrfs_add_ordered_extent_*(). Subtract num_bytes to avoid + * double counting. + */ + percpu_counter_add_batch(&fs_info->ordered_bytes, -num_bytes, + fs_info->delalloc_batch); if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered->flags)) { WARN_ON_ONCE(1); ret = btrfs_add_ordered_extent_compress(BTRFS_I(inode),