[dm-devel] [PATCH] multipathd: LUN protection by checking path's wwid change status

[Chongyun Wu]

Thank you very much Ben and your pathset based on my patch looks good.

On 2021/2/9 12:50, Benjamin Marzinski wrote:
> I've actually managed to reproduce this issue with the latest code.  All
> it takes is two machines in the same FC zone, with one of them having a
> FC driver that supports target mode and LIO.
> 
> To do it:
> You can grab TGT_WWPN and INIT_WWPN from
> /sys/class/fc_host/host<n>/port_name
> 
> On the target machine (assuming you're using the ql2xxx module)
> load the FC driver in target mode
> # modprobe qla2xxx qlini_mode=disabled
> 
> start up the LIO target.service
> # service target start
> 
> configure the setup in targetcli
> # targetcli
> /> qla2xxx/ create <TGT_WWPN>
> /> backstores/fileio create file1 <FILE_1> 100M
> /> backstores/fileio create file2 <FILE_2> 100M
> /> qla2xxx/<TGT_WWPN>/luns create /backstores/fileio/file1 1
> /> qla2xxx/<TGT_WWPN>/luns create /backstores/fileio/file2 2
> /> qla2xxx/<TGT_WWPN>/acls create <INIT_WWPN>
> 
> On the host machine:
> discover the LIO devices on each FC host
> # echo 1 > /sys/class/fc_host/host<N>/issue_lip
> 
> You should have two multipath devices now
> 
> On the target machine:
> switch the LUNs
> /> qla2xxx/<TGT_WWPN>/acls/<INIT_WWPN> delete 1
> /> qla2xxx/<TGT_WWPN>/acls/<INIT_WWPN> delete 2
> /> qla2xxx/<TGT_WWPN>/acls/<INIT_WWPN> create 2 /backstores/fileio/file1
> /> qla2xxx/<TGT_WWPN>/acls/<INIT_WWPN> create 1 /backstores/fileio/file2
> 
> This will often generate a change event, but not on every path,
> leaving some paths as part of the wrong multipath device.
> 
> I'll post a patchset based on Chongyun's patch shortly to deal with
> this.
> 
> -Ben
> 
> On Fri, Jan 08, 2021 at 11:13:01AM +0800, Chongyun Wu wrote:
>> Thanks Martin, I will try to reproduce this issue with the latest version
>> when the enviroments ready, if reproduce it again I will let you know,
>> thanks again~
>>
>> On 2021/1/7 19:27, Martin Wilck wrote:
>>> On Thu, 2021-01-07 at 10:23 +0800, Chongyun Wu wrote:
>>>> Hello Martin,
>>>> Thanks for view this patch.
>>>>
>>>> On 2021/1/7 5:10, Martin Wilck wrote:
>>>>> Hello Chongyun,
>>>>>
>>>>> On Mon, 2020-12-28 at 11:34 +0800, Chongyun Wu wrote:
>>>>>>    From 37c74873acfc1587e79a6504ca3d42b8fa00d49e Mon Sep 17
>>>>>> 00:00:00
>>>>>> 2001
>>>>>>
>>>>>> From: Chongyun Wu <wucy11 at chinatelecom.cn>
>>>>>> Date: Mon, 21 Dec 2020 09:51:20 +0800
>>>>>> Subject: [PATCH] multipathd: LUN data protection by checking
>>>>>> path's
>>>>>> wwid
>>>>>>     change status
>>>>>>
>>>>>> Issue description:
>>>>>> A) Device sda and sdb correspend to LUN1 and LUN2 in storage
>>>>>> backend
>>>>>> and
>>>>>> the upper layer application uses those two devices.
>>>>>> B) Doing illegal operation: unmapping LUN1 and LUN2 in storage
>>>>>> backend,
>>>>>> and export LUN2 and LUN1 to host with exchanged assignment
>>>>>> relation
>>>>>> between sda and sdb.
>>>>>> C) The upper layer application run for a while and found that the
>>>>>> data
>>>>>> in both LUN1 and LUN2 has been corrupted.
>>>>>
>>>>> Can you please be explicit about which multipath-tools version you
>>>>> have
>>>>> tested? I thought we had the wwid change issues covered. Ben and I
>>>>> have
>>>>> been putting quite some effort into this recently. Of course we can
>>>>> be
>>>>> wrong, but I'd like to understand the issue fully.
>>>>>
>>>> The test version is 0.8.3.
>>>
>>> A test with 0.8.5 would be in necessary, then. The INIT_REMOVED logic
>>> has been added after 0.8.4.
>>>>>
>>>>> Please confirm that you've been using the latest version from
>>>>> Christophe's repo (or better even, from my upstream-queue), and
>>>>> provide
>>>>> -v3 logs showing what goes wrong.
>>>> Sorry Martin, I haven't save the logs and the enviroment is
>>>> unavailable now.
>>>
>>> Well, please report back if you can reproduce the issue with current
>>> upstream.
>>>
>>> Regards,
>>> Martin
>>>
>>>
>>
>> -- 
>> Best Regard,
>> Chongyun Wu
> 

-- 
Best Regard,
Chongyun Wu