Btrfs: remove BUG() in raid56

This BUG() has been triggered by a fuzz testing image, which contains
an invalid chunk type, ie. a single stripe chunk has the raid6 type.

Btrfs can handle this gracefully by returning -EIO, so besides using
btrfs_warn to give us more debugging information rather than a single
BUG(), we can return error properly.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index cd8d302a1f61..d016d4a79864 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -2143,7 +2143,10 @@ int raid56_parity_recover(struct btrfs_root *root, struct bio *bio,
 
         rbio->faila = find_logical_bio_stripe(rbio, bio);
         if (rbio->faila == -1) {
-                BUG();
+                btrfs_warn(root->fs_info,
+        "%s could not find the bad stripe in raid56 so that we cannot recover any more (bio has logical %llu len %llu, bbio has map_type %llu)",
+                           __func__, (u64)bio->bi_iter.bi_sector << 9,
+                           (u64)bio->bi_iter.bi_size, bbio->map_type);
                 if (generic_io)
                         btrfs_put_bbio(bbio);
                 kfree(rbio);