syztest

[Arnaud Lecomte]

#syz test

--- a/fs/bcachefs/fsck.c
+++ b/fs/bcachefs/fsck.c
@@ -976,7 +976,24 @@ int bch2_fsck_update_backpointers(struct btree_trans 
*trans,
        int ret = 0;
 
        if (d->v.d_type == DT_SUBVOL) {
-               BUG();
+               struct bch_subvolume subvol;
+
+               ret = bch2_subvolume_get(trans, 
le32_to_cpu(d->v.d_child_subvol),
+                                            false, &subvol);
+               if (ret && !bch2_err_matches(ret, ENOENT))
+                       goto err;
+
+               ret = get_visible_inodes(trans, &target, s, 
le64_to_cpu(subvol.inode));
+               if (ret)
+                       goto err;
+
+               if (target.inodes.nr) {
+                       target.inodes.data[0].inode.bi_dir_offset = 
d->k.p.offset;
+                       ret = __bch2_fsck_write_inode(trans, 
&target.inodes.data[0].inode);
+                       if (ret)
+                               goto err;
+               }
+
        } else {
                ret = get_visible_inodes(trans, &target, s, 
le64_to_cpu(d->v.d_inum));
                if (ret)
-- 
2.43.0