On Mon, Sep 25, 2017 at 5:56 PM, Martin KaFai Lau <ka...@fb.com> wrote:
> On Mon, Sep 25, 2017 at 05:35:22PM +0000, Wei Wang wrote:
>> From: Wei Wang <wei...@google.com>
>>
>> fib6_del() generates WARN_ON() when rt->dst.obsolete > 0. This does not
>> make sense because it is possible that the route passed in is already
>> deleted by some other thread and rt->dst.obsolete is set to
>> DST_OBSOLETE_DEAD.
>> So this commit deletes this WARN_ON() and also remove the
>> "#ifdef RT6_DEBUG >= 2" condition so that if the route is already
>> obsolete, we return right at the beginning of fib6_del().
>>
>>
>> diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
>> index e5308d7cbd75..693bcd7ef6d2 100644
>> --- a/net/ipv6/ip6_fib.c
>> +++ b/net/ipv6/ip6_fib.c
>> @@ -1592,13 +1592,7 @@ int fib6_del(struct rt6_info *rt, struct nl_info
>> *info)
>> struct net *net = info->nl_net;
>> struct rt6_info **rtp;
>>
>> -#if RT6_DEBUG >= 2
>> - if (rt->dst.obsolete > 0) {
>> - WARN_ON(fn);
> fn should have already been set to NULL if it is removed
> from the fib6 tree?
>
That is true. rt->rt6i_node (fn) should already be marked as NULL.
That means the check on rt->dst.obsolete is redundant.
I will remove it in v2.
Thanks Martin.
>> - return -ENOENT;
>> - }
>> -#endif
>> - if (!fn || rt == net->ipv6.ip6_null_entry)
>> + if (!fn || rt->dst.obsolete > 0 || rt == net->ipv6.ip6_null_entry)
>> return -ENOENT;
>>
>> WARN_ON(!(fn->fn_flags & RTN_RTINFO));
>> --
>> 2.14.1.821.g8fa685d3b7-goog
>>
