[PATCH] btrfs: fix the length of reserved qgroup to free

[iamhswang@gmail.com]

From: Haisu Wang <haisuwang@tencent.com>

The dealloc flag may be cleared and the extent won't reach the disk
in cow_file_range when errors path. The reserved qgroup space is
freed in commit 30479f31d44d ("btrfs: fix qgroup reserve leaks in
cow_file_range"). However, the length of untouched region to free
need to be adjusted with the region size.

Fixes: 30479f31d44d ("btrfs: fix qgroup reserve leaks in cow_file_range")
Signed-off-by: Haisu Wang <haisuwang@tencent.com>
---
 fs/btrfs/inode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index b0ad46b734c3..5eefa2318fa8 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1592,7 +1592,7 @@ static noinline int cow_file_range(struct btrfs_inode *inode,
 		clear_bits |= EXTENT_CLEAR_DATA_RESV;
 		extent_clear_unlock_delalloc(inode, start, end, locked_folio,
 					     &cached, clear_bits, page_ops);
-		btrfs_qgroup_free_data(inode, NULL, start, cur_alloc_size, NULL);
+		btrfs_qgroup_free_data(inode, NULL, start, end - start + 1, NULL);
 	}
 	return ret;
 }
-- 
2.39.3