Re: [bug report] Don't enter SCSI error handler on kernel 4.16-rc1

Re: [bug report] Don't enter SCSI error handler on kernel 4.16-rc1

[Bart Van Assche]

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Re: [bug report] Don't enter SCSI error handler on kernel 4.16-rc1

[chenxiang (M)]

在 2018/2/27 22:57, Bart Van Assche 写道:
> On Tue, 2018-02-27 at 15:09 +0800, chenxiang (M) wrote:
>> 在 2018/2/26 23:25, Bart Van Assche 写道:
>>> On Mon, 2018-02-26 at 17:37 +0800, chenxiang (M) wrote:
>>>> When i have a test on kernel 4.16-rc1, find a issue: running IO on SATA disk, then disable the disk through
>>>> sysfs interface(echo 0 > /sys/class/sas_phy/phy-1:0:0/enable), IO will hang and never enter SCSI EH. The issue
>>>> appears every time.
>>>>
>>>> I add some prints on code and find that  those IOs will be timeout after 30s, and they all enter
>>>> function scsi_eh_scmd_add, but only some of them can enter function scsi_eh_inc_host_failed. So it will never
>>>> enter SCSI EH.  I suspect it is related to the patch ("commit 3bd6f43f5cb371" scsi: core: Ensure that the
>>>> SCSI error handler gets woken up ). Please have a check.
>>> Hello chenxiang,
>>>
>>> Had you already noticed patch "[PATCH v2] Avoid that ATA error handling can
>>> trigger a kernel hang or oops"? If not, can you apply that patch to your
>>> kernel and verify whether it fixes this behavior? See also
>>> https://www.mail-archive.com/linux-scsi@vger.kernel.org/msg71189.html or
>>> https://patchwork.kernel.org/patch/10236213/.
>> After applied your patch, the issue i reported seems be solved.
> Thanks for having testing that patch!
>
>> But when i have long time test(disable/enable disk when running IO) on
>> the testcase, Null pointer occurs.
>> It seems not related to current issue but i am not sure.
>> I ran the testcase for long time before in kernel 4.15-rc5, and it was okay.
>>
>> Part of log is as follows, and i add attachment of log in the email :
>>
>> [  485.716578] pc : blk_abort_request+0x14/0x68
> (+Tejun)
>
> Hello chenxiang,
>
> Please check whether the following patch fixes the kernel crash you ran into:
>
> https://marc.info/?l=linux-block&m=151895951207014

It seems the patch is for block mq, but the issue i encount is under 
block legacy as CONFIG_SCSI_MQ_DEFAULT is not enabled.

>
> Thanks,
>
> Bart.

Re: [bug report] Don't enter SCSI error handler on kernel 4.16-rc1

[Bart Van Assche]

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