From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Frederic Sowa Subject: Re: [PATCH net-next] ipv6: recreate ipv6 link-local addresses when increasing MTU over IPV6_MIN_MTU Date: Mon, 26 Oct 2015 17:05:01 +0100 Message-ID: <1445875501.168420.420547673.4BB6C209@webmail.messagingengine.com> References: <1445870205-27202-1-git-send-email-hannes@stressinduktion.org> <562E4C26.3030501@gmail.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit To: Alexander Duyck , netdev@vger.kernel.org Return-path: Received: from out3-smtp.messagingengine.com ([66.111.4.27]:38012 "EHLO out3-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751475AbbJZQFC (ORCPT ); Mon, 26 Oct 2015 12:05:02 -0400 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id D47F3202CC for ; Mon, 26 Oct 2015 12:05:01 -0400 (EDT) In-Reply-To: <562E4C26.3030501@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: Hi Alex, On Mon, Oct 26, 2015, at 16:52, Alexander Duyck wrote: > On 10/26/2015 07:36 AM, Hannes Frederic Sowa wrote: > > Take into consideration that the interface might be disabled for IPv6, > > thus switch event type. > > > > Signed-off-by: Hannes Frederic Sowa > > --- > > net/ipv6/addrconf.c | 7 +++++-- > > 1 file changed, 5 insertions(+), 2 deletions(-) > > > > diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c > > index d0c685c..c2dcebe 100644 > > --- a/net/ipv6/addrconf.c > > +++ b/net/ipv6/addrconf.c > > @@ -3149,6 +3149,7 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, > > > > case NETDEV_UP: > > case NETDEV_CHANGE: > > +netdev_change: > > if (dev->flags & IFF_SLAVE) > > break; > > > > @@ -3244,8 +3245,10 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, > > > > if (!idev && dev->mtu >= IPV6_MIN_MTU) { > > idev = ipv6_add_dev(dev); > > - if (!IS_ERR(idev)) > > - break; > > + if (!IS_ERR(idev)) { > > + event = NETDEV_UP; > > + goto netdev_change; > > + } > > } > > > > /* > > Seems like this code isn't quite correct. You are calling ipv6_add_dev > for slave devices, and if I understand things correctly I don't believe > that was happening before and may be an unintended side effect. Hmm, could you quickly help me where I get into this situation? I made sure I enter the NETDEV_UP part before the IFF_SLAVE test and disable_ipv6 test. > You might want to instead just make it so that you only do the jump, and > perhaps change the code in the NETDEV_UP/NETDEV_CHANGE section so that > you test for NETDEV_CHANGE instead of NETDEV_UP. That should be enough > to get the effect you are looking for and I believe there would be no > change to behaviour other than adding IPv6 link-local addresses when the > MTU is increased. > > Give me a bit and I can submit an alternative that may actually work out > a bit better I think. If you go the NETDEV_CHANGE route instead of NETDEV_UP, you end up with the IF_READY flag already set from ipv6_add_dev and thus won't do any initialization of the device. Sure, I wait. Bye, Hannes