[PATCH AUTOSEL 5.15 02/11] btrfs: raid56: properly handle the error when unable to find the missing stripe

[Sasha Levin]

From: Qu Wenruo <wqu@xxxxxxxx>

[ Upstream commit f15fb2cd979a07fbfc666e2f04b8b30ec9233b2a ]

In raid56_alloc_missing_rbio(), if we can not determine where the
missing device is inside the full stripe, we just BUG_ON().

This is not necessary especially the only caller inside scrub.c is
already properly checking the return value, and will treat it as a
memory allocation failure.

Fix the error handling by:

- Add an extra warning for the reason
  Although personally speaking it may be better to be an ASSERT().

- Properly free the allocated rbio

Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/btrfs/raid56.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index 3157a26ddf7e..5b27c289139a 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -2728,8 +2728,10 @@ raid56_alloc_missing_rbio(struct btrfs_fs_info *fs_info, struct bio *bio,
 
 	rbio->faila = find_logical_bio_stripe(rbio, bio);
 	if (rbio->faila == -1) {
-		BUG();
-		kfree(rbio);
+		btrfs_warn_rl(fs_info,
+	"can not determine the failed stripe number for full stripe %llu",
+			      bioc->raid_map[0]);
+		__free_raid_bio(rbio);
 		return NULL;
 	}
 
-- 
2.35.1