[PATCH 5.16 0272/1017] btrfs: fix unexpected error path when reflinking an inline extent

Greg Kroah-Hartman
2022-04-05T12:16:06Z

From: Filipe Manana <fdmanana@suse.com>

[ Upstream commit 1f4613cdbe7739ce291554b316bff8e551383389 ]

When reflinking an inline extent, we assert that its file offset is 0 and
that its uncompressed length is not greater than the sector size. We then
return an error if one of those conditions is not satisfied. However we
use a return statement, which results in returning from btrfs_clone()
without freeing the path and buffer that were allocated before, as well as
not clearing the flag BTRFS_INODE_NO_DELALLOC_FLUSH for the destination
inode.

Fix that by jumping to the 'out' label instead, and also add a WARN_ON()
for each condition so that in case assertions are disabled, we get to
known which of the unexpected conditions triggered the error.

Fixes: a61e1e0df9f321 ("Btrfs: simplify inline extent handling when doing reflinks")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/btrfs/reflink.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/reflink.c b/fs/btrfs/reflink.c
index e0f93b357548..157d72e330d6 100644
--- a/fs/btrfs/reflink.c
+++ b/fs/btrfs/reflink.c
@@ -505,8 +505,11 @@ static int btrfs_clone(struct inode *src, struct inode *inode,
*/
ASSERT(key.offset == 0);
ASSERT(datal <= fs_info->sectorsize);
- if (key.offset != 0 || datal > fs_info->sectorsize)
- return -EUCLEAN;
+ if (WARN_ON(key.offset != 0) ||
+ WARN_ON(datal > fs_info->sectorsize)) {
+ ret = -EUCLEAN;
+ goto out;
+ }

ret = clone_copy_inline_extent(inode, path, &new_key,
drop_start, datal, size,
--
2.34.1