Sub volumes handling in bch2_fsck_update_backpointers

[Arnaud Lecomte]

Hey everyone, in fsck.c, we have:
/*
 * Prefer to delete the first one, since that will be the one at the wrong
 * offset:
 * return value: 0 -> delete k1, 1 -> delete k2
 */
int bch2_fsck_update_backpointers(struct btree_trans *trans,
                                  struct snapshots_seen *s,
                                  const struct bch_hash_desc desc,
                                  struct bch_hash_info *hash_info,
                                  struct bkey_i *new)
{
        if (new->k.type != KEY_TYPE_dirent)
                return 0;

        struct bkey_i_dirent *d = bkey_i_to_dirent(new);
        struct inode_walker target = inode_walker_init();
        int ret = 0;

        if (d->v.d_type == DT_SUBVOL) {
                BUG();
        } else {
                ret = get_visible_inodes(trans, &target, s, 
le64_to_cpu(d->v.d_inum));
                if (ret)
                        goto err;

                darray_for_each(target.inodes, i) {
                        i->inode.bi_dir_offset = d->k.p.offset;
                        ret = __bch2_fsck_write_inode(trans, &i->inode);
                        if (ret)
                                goto err;
                }
        }
err:
        inode_walker_exit(&target);
        return ret;
}

What is the current state for handling subvolumes ? In someone already working 
on or it is something we don't want to implement
for some reasons ?

Regards,
Arnaud