From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nikolay Aleksandrov Subject: Re: [PATCH v2 net-next 1/6] bonding: add rcu to vlan_uses_dev() and make bond_vlan_used() use it Date: Fri, 09 Aug 2013 13:06:51 +0200 Message-ID: <5204CD4B.5080401@redhat.com> References: <1375981079-2936-1-git-send-email-vfalico@redhat.com> <1375981079-2936-2-git-send-email-vfalico@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, Jay Vosburgh , Andy Gospodarek , Patrick McHardy , "David S. Miller" To: Veaceslav Falico Return-path: Received: from mx1.redhat.com ([209.132.183.28]:11144 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967444Ab3HILKn (ORCPT ); Fri, 9 Aug 2013 07:10:43 -0400 In-Reply-To: <1375981079-2936-2-git-send-email-vfalico@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On 08/08/2013 06:57 PM, Veaceslav Falico wrote: > RFC -> v1: don't add vlan_uses_dev_rcu() and change vlan_uses_dev() instead > v1 -> v2: remove the ASSERT_RTNL(), cause we can now be called under rcu. > > 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 changing vlan_uses_dev() to use rcu_dereference_rtnl() instead of > rtnl_dereference(), and thus it can already be used in bond_vlan_used() > under rcu_read_lock(). > > By the time vlan_uses_dev() returns we cannot be sure if there were no > vlans added/removed, so it's basicly an optimization function. > > Also, use the vlan_uses_dev() in __bond_release_one() cause the rtnl lock > is held there. > > For this call to be visible in bonding.h, add include , > and also remove it from any other bonding file, cause they all include > bonding.h, and thus linux/if_vlan.h. > > CC: Jay Vosburgh > CC: Andy Gospodarek > CC: Patrick McHardy > CC: "David S. Miller" > CC: Nikolay Aleksandrov > Signed-off-by: Veaceslav Falico > --- > drivers/net/bonding/bond_alb.c | 1 - > drivers/net/bonding/bond_main.c | 3 +-- > drivers/net/bonding/bonding.h | 10 +++++++++- > net/8021q/vlan_core.c | 5 ++--- > 4 files changed, 12 insertions(+), 7 deletions(-) > > diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c > index 3a5db7b..2684329 100644 > --- a/drivers/net/bonding/bond_alb.c > +++ b/drivers/net/bonding/bond_alb.c > @@ -34,7 +34,6 @@ > #include > #include > #include > -#include > #include > #include > #include > diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c > index 4264a76..9d1045d 100644 > --- a/drivers/net/bonding/bond_main.c > +++ b/drivers/net/bonding/bond_main.c > @@ -69,7 +69,6 @@ > #include > #include > #include > -#include > #include > #include > #include > @@ -1953,7 +1952,7 @@ static int __bond_release_one(struct net_device *bond_dev, > bond_set_carrier(bond); > eth_hw_addr_random(bond_dev); > > - if (bond_vlan_used(bond)) { > + if (vlan_uses_dev(bond_dev)) { > pr_warning("%s: Warning: clearing HW address of %s while it still has VLANs.\n", > bond_dev->name, bond_dev->name); > pr_warning("%s: When re-adding slaves, make sure the bond's HW address matches its VLANs'.\n", > diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h > index 4bf52d5..9c4539e 100644 > --- a/drivers/net/bonding/bonding.h > +++ b/drivers/net/bonding/bonding.h > @@ -23,6 +23,7 @@ > #include > #include > #include > +#include > #include "bond_3ad.h" > #include "bond_alb.h" > > @@ -267,9 +268,16 @@ struct bonding { > #endif /* CONFIG_DEBUG_FS */ > }; > > +/* use vlan_uses_dev() if under rtnl */ Small nitpick - I don't think this comment is necessary as both calls now reduce to vlan_uses_dev() and can be used interchangeably, maybe it's better to stick to bond_vlan_used() just for consistency everywhere. Anyway, I'm okay with this version as well: Signed-off-by: Nikolay Aleksandrov