find_prio_chains_parent
prio_chains_parent = find_prio_chains_parent(node, NULL);
if (ft && parent == find_prio_chains_parent(&ft->node, child))
prio_parent = find_prio_chains_parent(&prio->node, &child);
parent = find_prio_chains_parent(&prev_prio->node, &child);
prio_parent = find_prio_chains_parent(&prio->node, &child);