From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH v3 net 1/5] ipv6: Refactor common ip6gre_tunnel_init codes Date: Fri, 11 Sep 2015 15:30:59 -0700 (PDT) Message-ID: <20150911.153059.459077104316140368.davem@davemloft.net> References: <1441994781-2718585-1-git-send-email-kafai@fb.com> <1441994781-2718585-2-git-send-email-kafai@fb.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com, hannes@stressinduktion.org, kernel-team@fb.com To: kafai@fb.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:50872 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752853AbbIKWbC (ORCPT ); Fri, 11 Sep 2015 18:31:02 -0400 In-Reply-To: <1441994781-2718585-2-git-send-email-kafai@fb.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Martin KaFai Lau Date: Fri, 11 Sep 2015 11:06:17 -0700 > @@ -1460,19 +1474,16 @@ static void ip6gre_netlink_parms(struct nlattr *data[], > static int ip6gre_tap_init(struct net_device *dev) > { > struct ip6_tnl *tunnel; > + int ret; > > - tunnel = netdev_priv(dev); > + ret = ip6gre_tunnel_init_common(dev); > + if (ret) > + return ret; > > - tunnel->dev = dev; > - tunnel->net = dev_net(dev); > - strcpy(tunnel->parms.name, dev->name); > + tunnel = netdev_priv(dev); > > ip6gre_tnl_link_config(tunnel, 1); > > - dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); > - if (!dev->tstats) > - return -ENOMEM; > - > return 0; > } Is this really equivalent? The existing code for GRE tap device initialization would use whatever ether_setup() left in the broadcast address, it would leave dev->dev_addr alone, and unconditionally use eth_header_ops. You are changing behavior here, and it's been like this has been this way long enough that I can't see clearly whether this is a valid change or not. It probably is not. Either way, even if it is valid, you have to document what is happening here and why it's ok.