hammer_get_node
hammer_node_t hammer_get_node(hammer_transaction_t trans,
parent = hammer_get_node(trans, node->ondisk->parent, 0, errorp);
child = hammer_get_node(trans, elm->internal.subtree_offset,
child = hammer_get_node(cursor->trans,
child = hammer_get_node(cursor->trans,
node = hammer_get_node(trans, volume->ondisk->vol0_btree_root,
node = hammer_get_node(cursor->trans,
node = hammer_get_node(trans, node_offset, 1, errorp);