From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xin Long Subject: [PATCH net] ip_gre: ipgre_tap device should keep dst Date: Thu, 28 Sep 2017 13:23:31 +0800 Message-ID: Cc: davem@davemloft.net, Dmitry Kozlov To: network dev Return-path: Received: from mail-pg0-f67.google.com ([74.125.83.67]:33270 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750943AbdI1FXk (ORCPT ); Thu, 28 Sep 2017 01:23:40 -0400 Received: by mail-pg0-f67.google.com with SMTP id u136so679613pgc.0 for ; Wed, 27 Sep 2017 22:23:40 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: Without keeping dst, the tunnel will not update any mtu/pmtu info, since it does not have a dst on the skb. Reproducer: client(ipgre_tap1 - eth1) <-----> (eth1 - ipgre_tap1)server After reducing eth1's mtu on client, then perforamnce became 0. This patch is to netif_keep_dst in gre_tap_init, as ipgre does. Reported-by: Jianlin Shi Signed-off-by: Xin Long --- net/ipv4/ip_gre.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index 0162fb9..8b837f6 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -1223,6 +1223,7 @@ static int gre_tap_init(struct net_device *dev) { __gre_tunnel_init(dev); dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; + netif_keep_dst(dev); return ip_tunnel_init(dev); } -- 2.1.0