Re: [syzbot] [nilfs?] WARNING in nilfs_btree_assign (3)

[Ryusuke Konishi]

Isolation test 2: the reproducers output a lot of
nilfs_btree_propagate messages, but the metadata corruption is not
escalated to the bmap layer, so test the effectiveness of that fix.

#syz test

diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c
index ef5061bb56da..8a280379e813 100644
--- a/fs/nilfs2/btree.c
+++ b/fs/nilfs2/btree.c
@@ -2103,11 +2103,14 @@ static int nilfs_btree_propagate(struct nilfs_bmap *btree,
 
 	ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1, 0);
 	if (ret < 0) {
-		if (unlikely(ret == -ENOENT))
+		if (unlikely(ret == -ENOENT)) {
 			nilfs_crit(btree->b_inode->i_sb,
 				   "writing node/leaf block does not appear in b-tree (ino=%lu) at key=%llu, level=%d",
 				   btree->b_inode->i_ino,
 				   (unsigned long long)key, level);
+			/* Notify bmap layer of metadata corruption */
+			ret = -EINVAL;
+		}
 		goto out;
 	}
 
-- 
2.43.0