From mboxrd@z Thu Jan 1 00:00:00 1970 From: Veaceslav Falico Subject: Re: [PATCH v2 net-next 1/6] bonding: add rcu to vlan_uses_dev() and make bond_vlan_used() use it Date: Fri, 9 Aug 2013 13:11:21 +0200 Message-ID: <20130809111121.GB17510@redhat.com> References: <1375981079-2936-1-git-send-email-vfalico@redhat.com> <1375981079-2936-2-git-send-email-vfalico@redhat.com> <5204CD4B.5080401@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Cc: netdev@vger.kernel.org, Jay Vosburgh , Andy Gospodarek , Patrick McHardy , "David S. Miller" To: Nikolay Aleksandrov Return-path: Received: from mx1.redhat.com ([209.132.183.28]:33661 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967570Ab3HILMy (ORCPT ); Fri, 9 Aug 2013 07:12:54 -0400 Content-Disposition: inline In-Reply-To: <5204CD4B.5080401@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On Fri, Aug 09, 2013 at 01:06:51PM +0200, Nikolay Aleksandrov wrote: >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: Good catch, leftover from previous version. > >Signed-off-by: Nikolay Aleksandrov Thank you. >