Re: [PATCH net] ipv6: no need to return rt->dst.error if it is not null entry.

From: Cong Wang <xiyou.wangcong@gmail.com>
To: Hangbin Liu <liuhangbin@gmail.com>
Cc: network dev <netdev@vger.kernel.org>,
	Roopa Prabhu <roopa@cumulusnetworks.com>
Subject: Re: [PATCH net] ipv6: no need to return rt->dst.error if it is not null entry.
Date: Fri, 21 Jul 2017 11:42:46 -0700	[thread overview]
Message-ID: <CAM_iQpUM6m=GvUU0OfwZAFsOGsf1UZmTjmuM9FH2P1iOZP=Svw@mail.gmail.com> (raw)
In-Reply-To: <CAPwn2JTF+j84+Bv4Zn=pqju2tnMuuJrhTr9Un786-PZ0D6af3w@mail.gmail.com>

On Thu, Jul 20, 2017 at 8:23 AM, Hangbin Liu <liuhangbin@gmail.com> wrote:
> 2017-07-20 23:06 GMT+08:00 Hangbin Liu <liuhangbin@gmail.com>:
>>> +++ b/net/ipv6/route.c
>>> @@ -3637,12 +3637,6 @@ static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
>>>                 dst = ip6_route_lookup(net, &fl6, 0);
>>>
>>>         rt = container_of(dst, struct rt6_info, dst);
>>> -       if (rt->dst.error) {
>>> -               err = rt->dst.error;
>>> -               ip6_rt_put(rt);
>>> -               goto errout;
>>> -       }
>>
>> hmm... or instead of remove this check, should we check all the entry? Like
>> if ((rt->dst.error && rt != net->ipv6.ip6_null_entry && rt !=
>                                                     ^^ mistake here
>> net->ipv6.ip6_blk_hole_entry) ||
>>      rt == net->ipv6.ip6_null_entry )
>
> Sorry,  there should be no need to check ip6_null_entry since the
> error is already
> -ENETUNREACH. So how about

Hmm? All of these 3 entries have error set, right??
So we should only check dst.error...