From: Johannes Thumshirn <jthumshirn@suse.de>
To: Ming Lei <ming.lei@redhat.com>
Cc: Jens Axboe <axboe@fb.com>, linux-block@vger.kernel.org,
        Christoph Hellwig <hch@infradead.org>, linux-scsi@vger.kernel.org,
        "Martin K . Petersen" <martin.petersen@oracle.com>,
        "James E . J . Bottomley" <jejb@linux.vnet.ibm.com>,
        Bart Van Assche <bart.vanassche@sandisk.com>,
        linux-kernel@vger.kernel.org, Hannes Reinecke <hare@suse.com>
Subject: Re: [PATCH] SCSI: delay run queue if device is blocked in scsi_dev_queue_ready()
References: <20171202163150.1273-1-ming.lei@redhat.com>
Date: Mon, 04 Dec 2017 09:19:33 +0100
In-Reply-To: <20171202163150.1273-1-ming.lei@redhat.com> (Ming Lei's message
        of "Sun, 3 Dec 2017 00:31:50 +0800")
Message-ID: <mqdindmoqga.fsf@linux-x5ow.site>
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Hi Ming,

Ming Lei <ming.lei@redhat.com> writes:
> This issue can be triggered by the following script:
>
> 	#!/bin/sh
> 	rmmod scsi_debug
> 	modprobe scsi_debug max_queue=1
>
> 	DEVICE=`ls -d /sys/bus/pseudo/drivers/scsi_debug/adapter*/host*/target*/*/block/* | head -1 | xargs basename`
>
> 	DISK_DIR=`ls -d /sys/block/$DEVICE/device/scsi_disk/*`
>
> 	echo "using scsi device $DEVICE"
> 	echo "-1" >/sys/bus/pseudo/drivers/scsi_debug/every_nth
> 	echo starting loop $i
> 	echo "temporary write through" >$DISK_DIR/cache_type
> 	echo "128" >/sys/bus/pseudo/drivers/scsi_debug/opts
> 	echo none > /sys/block/$DEVICE/queue/scheduler
> 	dd if=/dev/$DEVICE of=/dev/null bs=1M iflag=direct count=1 &
> 	sleep 5
> 	echo "0" >/sys/bus/pseudo/drivers/scsi_debug/opts
> 	wait
> 	echo "SUCCESS"

Can you please submit a test-case for blktest as well, given you have a
nice reproducer?

Thanks,
        Johannes
-- 
Johannes Thumshirn                                          Storage
jthumshirn@suse.de                                +49 911 74053 689
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