[PATCH 5.3 182/197] Btrfs: add missing extents release on file extent cluster relocation error

From: Greg Kroah-Hartman
Date: Sun Oct 27 2019 - 17:26:16 EST

From: Filipe Manana <fdmanana@xxxxxxxx>

commit 44db1216efe37bf670f8d1019cdc41658d84baf5 upstream.

If we error out when finding a page at relocate_file_extent_cluster(), we
need to release the outstanding extents counter on the relocation inode,
set by the previous call to btrfs_delalloc_reserve_metadata(), otherwise
the inode's block reserve size can never decrease to zero and metadata
space is leaked. Therefore add a call to btrfs_delalloc_release_extents()
in case we can't find the target page.

Fixes: 8b62f87bad9c ("Btrfs: rework outstanding_extents")
CC: stable@xxxxxxxxxxxxxxx # 4.19+
Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

fs/btrfs/relocation.c | 2 ++
1 file changed, 2 insertions(+)

--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -3276,6 +3276,8 @@ static int relocate_file_extent_cluster(
if (!page) {
PAGE_SIZE, true);
+ btrfs_delalloc_release_extents(BTRFS_I(inode),
+ PAGE_SIZE, true);
ret = -ENOMEM;
goto out;