void __bch2_btree_and_journal_iter_init_node_iter(struct btree_and_journal_iter *iter,
						  struct bch_fs *c,
						  struct btree *b,
						  struct btree_node_iter node_iter,
						  struct bpos pos)
void __bch2_btree_and_journal_iter_init_node_iter(struct btree_trans *trans,
						  struct btree_and_journal_iter *iter,
						  struct btree *b,
						  struct btree_node_iter node_iter,
						  struct bpos pos)