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Date:   Mon, 4 Apr 2022 07:28:00 +0200
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Subject: Re: [REQUEST DISCUSS]: speed up SCSI error handle for host with
 massive devices
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To:     Mike Christie <michael.christie@oracle.com>,
        Wenchao Hao <haowenchao@huawei.com>,
        Steffen Maier <maier@linux.ibm.com>,
        linux-scsi@vger.kernel.org,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Lee Duncan <lduncan@suse.com>,
        John Garry <john.garry@huawei.com>
Cc:     Wu Bo <wubo40@huawei.com>, Feilong Lin <linfeilong@huawei.com>,
        zhangjian013@huawei.com
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From:   Hannes Reinecke <hare@suse.de>
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On 4/3/22 19:17, Mike Christie wrote:
> On 4/3/22 12:14 PM, Mike Christie wrote:
>> We could share code with scsi_ioctl_reset as well. Drivers that support
>> TMFs via that ioctl already expect queuecommand to be possibly in the
>> middle of a run and IO not yet timed out. For example, the code to
>> block a queue and reset the device could be used for the new EH and
>> SG_SCSI_RESET_DEVICE handling.
>>
> 
> Hannes or others,
> 
> How do parallel SCSI drivers support scsi_ioctl_reset? Is is not fully
> supported and more only used for controlled testing?

That's actually a problem in scsi_ioctl_reset(); it really should wait 
for all I/O to quiesce. Currently it just sets the 'tmf' flag and calls 
into the various reset functions.

But really, I'd rather get my EH rework in before we're start discussing 
modifying EH behaviour.
Let me repost it ...

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
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