Re: [PATCH] ipv6: fix rt6_update_expires

[Gao feng <gaofeng@cn.fujitsu.com>]

于 2012年04月16日 21:34, Jiri Bohac 写道:
> 
> Commit 1716a961 (ipv6: fix problem with expired dst cache) broke PMTU
> discovery. rt6_update_expires() calls dst_set_expires(), which only updates
> dst->expires if it has not been set previously (expires == 0) or if the new
> expires is earlier than the current dst->expires.
> 
> rt6_update_expires() needs to zero rt->dst.expires, otherwise it will contain
> ivalid data left over from rt->dst.from and will confuse dst_set_expires().
> 
> Signed-off-by: Jiri Bohac <jbohac@suse.cz>
> 
> diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
> index ad4126f..68c1f94 100644
> --- a/include/net/ip6_fib.h
> +++ b/include/net/ip6_fib.h
> @@ -143,8 +143,13 @@ static inline void rt6_set_expires(struct rt6_info *rt, unsigned long expires)
>  
>  static inline void rt6_update_expires(struct rt6_info *rt, int timeout)
>  {
> -	if (!(rt->rt6i_flags & RTF_EXPIRES) && rt->dst.from)
> -		dst_release(rt->dst.from);
> +	if (!(rt->rt6i_flags & RTF_EXPIRES)) {
> +		if (rt->dst.from)
> +			dst_release(rt->dst.from);
> +		/* dst_set_expires relies on expires == 0 
> +                  if it has not been set previously */
> +		rt->dst.expires = 0;
> +	}
>  
>  	dst_set_expires(&rt->dst, timeout);
>  	rt->rt6i_flags |= RTF_EXPIRES;
> 

looks good to me, thanks.