bch_btree_node_write
bch_btree_node_write(new_nodes[i], &cl);
bch_btree_node_write(last->b, writes);
bch_btree_node_write(i->b, writes);
bch_btree_node_write(n2, &cl);
bch_btree_node_write(n1, &cl);
bch_btree_node_write(n3, &cl);
bch_btree_node_write(b, &cl);
bch_btree_node_write(b, &cl);
bch_btree_node_write(b, NULL);
void bch_btree_node_write(struct btree *b, struct closure *parent);
bch_btree_node_write(c->root, &cl);