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btrfs: zoned: fix double counting of split ordered extent

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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: d22002fd37 ("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>
This commit is contained in:
Naohiro Aota
2021-09-07 00:04:28 +09:00
committed by David Sterba
parent c124706900
commit f79645df80
1 changed files with 8 additions and 0 deletions
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8
fs/btrfs/ordered-data.c
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@@ -1049,6 +1049,7 @@ static int clone_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pos,
u64 len) u64 len)
{ {
struct inode *inode = ordered->inode; 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 file_offset = ordered->file_offset + pos;
u64 disk_bytenr = ordered->disk_bytenr + pos; u64 disk_bytenr = ordered->disk_bytenr + pos;
u64 num_bytes = len; u64 num_bytes = len;
@@ -1066,6 +1067,13 @@ static int clone_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pos,
else else
type = __ffs(flags_masked); 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)) { if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered->flags)) {
WARN_ON_ONCE(1); WARN_ON_ONCE(1);
ret = btrfs_add_ordered_extent_compress(BTRFS_I(inode), ret = btrfs_add_ordered_extent_compress(BTRFS_I(inode),