[PATCH 1/3] btrfs: fix extent map leak in unexpected scenario at unpin_extent_cache()

[fdmanana@kernel.org]

From: Filipe Manana <fdmanana@suse.com>

At unpin_extent_cache() if we happen to find an extent map with an
unexpected start offset, we jump to the 'out' label and never release the
reference we added to the extent map through the call to
lookup_extent_mapping(), therefore resulting in a leak. So fix this by
moving the free_extent_map() under the 'out' label.

Fixes: c03c89f821e5 ("btrfs: handle errors returned from unpin_extent_cache()")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 fs/btrfs/extent_map.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 347ca13d15a9..e03953dbcd5e 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -340,9 +340,9 @@ int unpin_extent_cache(struct btrfs_inode *inode, u64 start, u64 len, u64 gen)
 		em->mod_len = em->len;
 	}
 
-	free_extent_map(em);
 out:
 	write_unlock(&tree->lock);
+	free_extent_map(em);
 	return ret;
 
 }
-- 
2.43.0