unlock_up
unlock_up(p, level, lowest_unlock,
unlock_up(p, level, lowest_unlock, min_write_lock_level,
unlock_up(p, level, lowest_unlock, 0, NULL);
unlock_up(p, level, lowest_unlock, 0, NULL);
unlock_up(path, level, 1, 0, NULL);
unlock_up(path, 0, 1, 0, NULL);