From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ding Tianhong Subject: Re: [PATCH] bonding: correct the MAC address for "follow" fail_over_mac policy Date: Thu, 16 Jul 2015 20:02:00 +0800 Message-ID: <55A79D38.2000205@huawei.com> References: <55A76B8A.5040804@huawei.com> <55A77840.5010506@cumulusnetworks.com> <55A799F7.8080904@huawei.com> <55A79A7A.3000204@cumulusnetworks.com> <55A79B74.1000701@cumulusnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit To: Nikolay Aleksandrov , "j.vosburgh@gmail.com >> Jay Vosburgh" , "vfalico@gmail.com >> Veaceslav Falico" , Andy Gospodarek , Netdev , "David S. Miller" , , "hahaer.guo@huawei.com >> Guozhibin (Hahaer)" Return-path: Received: from szxga01-in.huawei.com ([58.251.152.64]:37114 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755039AbbGPMFn (ORCPT ); Thu, 16 Jul 2015 08:05:43 -0400 In-Reply-To: <55A79B74.1000701@cumulusnetworks.com> Sender: netdev-owner@vger.kernel.org List-ID: On 2015/7/16 19:54, Nikolay Aleksandrov wrote: > On 07/16/2015 01:50 PM, Nikolay Aleksandrov wrote: >> 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 >> > > Ah this is my bad, my setup was polluted from previous tests and the bonding wasn't > clean, you're right - this does reproduce. > Sorry about that > :) >>>> Cheers, >>>> Nik >>>> >>>> . >>>> >>> >>> >> > > > . >