Subject: Re: [PATCH net-next 8/8] net/dst: do not confirm neighbor for vxlan and geneve pmtu update

From: Guillaume Nault <[email-masked]>
Date: Thu, 19 Dec 2019 18:49:35 +0100

On Wed, Dec 18, 2019 at 07:53:13PM +0800, Hangbin Liu wrote:
> When do IPv6 tunnel PMTU update and calls __ip6_rt_update_pmtu() in the end,
> we should not call dst_confirm_neigh() as there is no two-way communication.
> 
> So disable the neigh confirm for vxlan and geneve pmtu update.
> 
> Signed-off-by: Hangbin Liu <[email-masked]>
> ---
>  include/net/dst.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/net/dst.h b/include/net/dst.h
> index 208e7c0c89d8..626cf614ad86 100644
> --- a/include/net/dst.h
> +++ b/include/net/dst.h
> @@ -535,7 +535,7 @@ static inline void skb_tunnel_check_pmtu(struct sk_buff *skb,
>  	u32 encap_mtu = dst_mtu(encap_dst);
>  
>  	if (skb->len > encap_mtu - headroom)
> -		skb_dst_update_pmtu(skb, encap_mtu - headroom);
> +		skb_dst_update_pmtu_no_confirm(skb, encap_mtu - headroom);
>  }
>  

Fixes: a93bf0ff4490 ("vxlan: update skb dst pmtu on tx path")
Fixes: 52a589d51f10 ("geneve: update skb dst pmtu on tx path")