From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ming Lei Subject: Re: [PATCH] SCSI: delay run queue if device is blocked in scsi_dev_queue_ready() Date: Mon, 4 Dec 2017 16:34:46 +0800 Message-ID: <20171204083440.GA10261@ming.t460p> References: <20171202163150.1273-1-ming.lei@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Johannes Thumshirn Cc: Jens Axboe , linux-block@vger.kernel.org, Christoph Hellwig , linux-scsi@vger.kernel.org, "Martin K . Petersen" , "James E . J . Bottomley" , Bart Van Assche , linux-kernel@vger.kernel.org, Hannes Reinecke List-Id: linux-scsi@vger.kernel.org On Mon, Dec 04, 2017 at 09:19:33AM +0100, Johannes Thumshirn wrote: > > Hi Ming, > > Ming Lei 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? Hi Johannes, I am happy to do that, but recently I am very busy, so it may be done a bit late by me. But anyone should reproduce the issue 100% with V4.15-rc kernel by just running the above script, not any specific hardware is required at all, so that means anyone can make a patch for blktest to test block/SCSI timeout if he/she is interested in doing that. Thanks, Ming