From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nikolay Aleksandrov Subject: Re: [net-next,1/3] bonding: fix vlan 0 addition and removal Date: Tue, 06 Aug 2013 10:16:04 +0200 Message-ID: <5200B0C4.2020101@redhat.com> References: <1375709304-16778-2-git-send-email-nikolay@redhat.com> <20130805215126.GB3859@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, fubar@us.ibm.com, andy@greyhouse.net, davem@davemloft.net, kaber@trash.net To: Veaceslav Falico Return-path: Received: from mx1.redhat.com ([209.132.183.28]:52252 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753993Ab3HFIQP (ORCPT ); Tue, 6 Aug 2013 04:16:15 -0400 In-Reply-To: <20130805215126.GB3859@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On 08/05/2013 11:51 PM, Veaceslav Falico wrote: > On Mon, Aug 05, 2013 at 03:28:22PM +0200, nikolay@redhat.com wrote: > ...snip... >> This is fixed by forbidding the addition/removal of vlan 0 through the >> bond's ndo_vlan_rx_add/kill_vid functions, and adding/removing it only when >> vlan 0 is in fact being created (or destroyed) on top of a bond interface >> in the bond's netdev handling function. > > Isn't that a bit too intrusive/hacky? I don't think we should treat vlan id > 0 somehow differently in terms of adding/removing, though I might be > wrong... > I didn't want to touch the vlan code, so I solved the problem entirely in the bonding, mind you there's still a bug when loading the 8021q module we'll bump up every slave's vlan 0 refcnt without adding the vlan, and it won't get bumped down. In my patch that problem still persists but only when an actual vlan 0 is being created. > Maybe we should just fix the bond_vlan_used() function? Something like > this (I've done only basic testing, can do more thorough if needed), though > it's also not a really clean fix: > Yes, that would be optimal and I agree. > From 1c89abefebe90568ed52d2df59fcfdd650bc4696 Mon Sep 17 00:00:00 2001 > From: Veaceslav Falico > Date: Mon, 5 Aug 2013 23:29:12 +0200 > Subject: [PATCH] bonding: add vlan_uses_dev_rcu() and make bond_vlan_used() > use it > > Currently, bond_vlan_used() looks for any vlan, including the pseudo-vlan > id 0, and always returns true if 8021q is loaded. This creates several bad > situations - some warnings in __bond_release_one() because it thinks that > we still have vlans while removing, sending LB packets with vlan id 0 and, > possibly, other caused by vlan id 0. > > Fix it by adding a new call, vlan_uses_dev_rcu(), which is the same as > vlan_uses_dev(), but uses rcu_dereference() instead of rtnl, and thus we > can use it in bond_vlan_used() wrapped in rcu_read_lock(). > > Also, use the pure vlan_uses_dev() in __bond_release_one() cause the rtnl > lock is held there. > > CC: Jay Vosburgh > CC: Andy Gospodarek > CC: Patrick McHardy > CC: "David S. Miller" > Signed-off-by: Veaceslav Falico > --- I'm okay with this fix, if Dave is also okay with this version then you can submit it as a patch, I'll re-base my third one later and resubmit.