From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Ahern <dsa@cumulusnetworks.com>
Subject: Re: [PATCH net] ipv6: use rt6_info members when dst is set in
 rt6_fill_node
Date: Mon, 10 Sep 2018 20:39:34 -0600
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Cc: Xin Long <lucien.xin@gmail.com>,
        network dev <netdev@vger.kernel.org>,
        davem <davem@davemloft.net>,
        Roopa Prabhu <roopa@cumulusnetworks.com>
To: Hangbin Liu <liuhangbin@gmail.com>
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On 9/10/18 7:04 PM, Hangbin Liu wrote:

> diff --git a/net/ipv6/route.c b/net/ipv6/route.c
> index 18e00ce..62621b4 100644
> --- a/net/ipv6/route.c
> +++ b/net/ipv6/route.c
> @@ -998,6 +998,21 @@ static void ip6_rt_copy_init(struct rt6_info *rt, struct fib6_info *ort)
>  	rt->rt6i_prefsrc = ort->fib6_prefsrc;
>  }
>  
> +static void rt6_update_info(struct rt6_info *rt)
> +{
> +	struct fib6_info *from;
> +
> +	rcu_read_lock();
> +	from = rcu_dereference(rt->from);
> +	fib6_info_hold(from);
> +	rcu_read_unlock();
> +
> +	from->fib6_flags = rt->rt6i_flags;
> +	from->fib6_nh.nh_gw = rt->rt6i_gateway;

As I mentioned on your last patch, redirects do *not* update fib
entries. Exceptions, yes, but not core data of a fib entry.