err = fib6_del(rt, nlh, _rtattr);
err = fib6_del(rt, nlh, _rtattr, req);
int ip6_del_rt(struct rt6_info *rt, struct nlmsghdr *nlh, void *_rtattr){	int err;	write_lock_bh(&rt6_lock);	rt6_reset_dflt_pointer(NULL);	err = fib6_del(rt, nlh, _rtattr);	dst_release(&rt->u.dst);	write_unlock_bh(&rt6_lock);	return err;}