From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nikolay Aleksandrov Subject: Re: [PATCH] bonding: correct the MAC address for "follow" fail_over_mac policy Date: Thu, 16 Jul 2015 13:50:18 +0200 Message-ID: <55A79A7A.3000204@cumulusnetworks.com> References: <55A76B8A.5040804@huawei.com> <55A77840.5010506@cumulusnetworks.com> <55A799F7.8080904@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit To: Ding Tianhong , "j.vosburgh@gmail.com >> Jay Vosburgh" , "vfalico@gmail.com >> Veaceslav Falico" , Andy Gospodarek , Netdev , "David S. Miller" , fengtiantian@huawei.com, "hahaer.guo@huawei.com >> Guozhibin (Hahaer)" Return-path: Received: from mail-wi0-f181.google.com ([209.85.212.181]:34251 "EHLO mail-wi0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753742AbbGPLuV (ORCPT ); Thu, 16 Jul 2015 07:50:21 -0400 Received: by wibud3 with SMTP id ud3so13019350wib.1 for ; Thu, 16 Jul 2015 04:50:19 -0700 (PDT) In-Reply-To: <55A799F7.8080904@huawei.com> Sender: netdev-owner@vger.kernel.org List-ID: On 07/16/2015 01:48 PM, Ding Tianhong wrote: > On 2015/7/16 17:24, Nikolay Aleksandrov wrote: >> On 07/16/2015 10:30 AM, Ding Tianhong wrote: >>> The "follow" fail_over_mac policy is useful for multiport devices that >>> either become confused or incur a performance penalty when multiple >>> ports are programmed with the same MAC address, but the same MAC >>> address still may happened by this steps for this policy: >>> >>> 1) echo +eth0 > /sys/class/net/bond0/bonding/slaves >>> bond0 has the same mac address with eth0, it is MAC1. >>> >>> 2) echo +eth1 > /sys/class/net/bond0/bonding/slaves >>> eth1 is backup, eth1 has MAC2. >>> >>> 3) ifconfig eth0 down >>> eth1 became active slave, bond will swap MAC for eth0 and eth1, >>> so eth1 has MAC1, and eth0 has MAC2. >>> >>> 4) ifconfig eth1 down >>> there is no active slave, and eth1 still has MAC1, eth2 has MAC2. >>> >>> 5) ifconfig eth0 up >>> the eth0 became active slave again, the bond set eth0 to MAC1. >>> >>> Something wrong here, then if you set eth1 up, the eth0 and eth1 will have the same >>> MAC address, it will break this policy for ACTIVE_BACKUP mode. >>> >>> This patch will fix this problem by finding the old active slave and >>> swap them MAC address before change active slave. >>> >>> Signed-off-by: Ding Tianhong >>> --- >>> drivers/net/bonding/bond_main.c | 20 ++++++++++++++++++++ >>> 1 file changed, 20 insertions(+) >>> >> >> This doesn't seem to be true: >> ~# cat /sys/class/net/bond0/bonding/fail_over_mac >> follow 2 >> root@debian:~# ip l sh eth1 >> 3: eth1: mtu 1500 qdisc pfifo_fast master bond0 state UP mode DEFAULT group default qlen 1000 >> link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff >> root@debian:~# ip l sh eth2 >> 4: eth2: mtu 1500 qdisc pfifo_fast master bond0 state UP mode DEFAULT group default qlen 1000 >> link/ether 52:54:00:4f:a5:99 brd ff:ff:ff:ff:ff:ff >> root@debian:~# ip l sh bond0 >> 26: bond0: mtu 1500 qdisc noqueue state UP mode DEFAULT group default >> link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff >> >> *eth1 is the first and active slave and bond0 has taken its mac. >> Now trying your steps: >> Step 3) (bringing down the active eth1) >> root@debian:~# ip l set eth1 down >> root@debian:~# ip l sh bond0 >> 26: bond0: mtu 1500 qdisc noqueue state UP mode DEFAULT group default >> link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff >> root@debian:~# ip l sh eth1 >> 3: eth1: mtu 1500 qdisc pfifo_fast master bond0 state DOWN mode DEFAULT group default qlen 1000 >> link/ether 52:54:00:4f:a5:99 brd ff:ff:ff:ff:ff:ff >> root@debian:~# ip l sh eth2 >> 4: eth2: mtu 1500 qdisc pfifo_fast master bond0 state UP mode DEFAULT group default qlen 1000 >> link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff >> >> *The mac addresses of eth1 and eth2 are correctly swapped, so far so good. >> >> Step 4) (bringing down the active eth2) >> root@debian:~# ip l set eth2 down >> 3: eth1: mtu 1500 qdisc pfifo_fast master bond0 state DOWN mode DEFAULT group default qlen 1000 >> link/ether 52:54:00:4f:a5:99 brd ff:ff:ff:ff:ff:ff >> 4: eth2: mtu 1500 qdisc pfifo_fast master bond0 state DOWN mode DEFAULT group default qlen 1000 >> link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff >> 26: bond0: mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default >> link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff >> >> *eth2 has kept the mac address of the bond and they're both down now >> >> Step 5) (bring eth1 up again and observe the macs) >> ~# ip l set eth1 up >> 3: eth1: mtu 1500 qdisc pfifo_fast master bond0 state UP mode DEFAULT group default qlen 1000 >> link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff >> 4: eth2: mtu 1500 qdisc pfifo_fast master bond0 state DOWN mode DEFAULT group default qlen 1000 >> link/ether 52:54:00:4f:a5:99 brd ff:ff:ff:ff:ff:ff >> 26: bond0: mtu 1500 qdisc noqueue state UP mode DEFAULT group default >> link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff >> >> *The macs are correctly swapped and there's no such bug. >> >> Step 6(?) bring eth2 up >> ~# ip l set eth2 up >> 3: eth1: mtu 1500 qdisc pfifo_fast master bond0 state UP mode DEFAULT group default qlen 1000 >> link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff >> 4: eth2: mtu 1500 qdisc pfifo_fast master bond0 state UP mode DEFAULT group default qlen 1000 >> link/ether 52:54:00:4f:a5:99 brd ff:ff:ff:ff:ff:ff >> 26: bond0: mtu 1500 qdisc noqueue state UP mode DEFAULT group default >> link/ether 52:54:00:3f:47:69 brd ff:ff:ff:ff:ff:ff >> >> *Still correct. >> >> Also the mac address that gets set is dev_addr which is changed when >> the swapping is done, if you'd like to get the original mac address >> you should be using slave->perm_hwaddr. >> > > Hi Nik: > > Which kernel version do you use, I test this on kernel 3.19.8 and 4.2-rc2, this problem exist on both version, > maybe I miss something? > > Ding > > It's current net-next. ~# uname -a Linux debian 4.2.0-rc2+ #8 SMP Wed Jul 15 21:22:14 CEST 2015 x86_64 GNU/Linux >> Cheers, >> Nik >> >> . >> > >