From: Bart Van Assche <bvanassche@acm.org>
To: Mike Christie <michaelc@cs.wisc.edu>
Cc: linux-scsi <linux-scsi@vger.kernel.org>,
James Bottomley <jbottomley@parallels.com>,
Jun'ichi Nomura <j-nomura@ce.jp.nec.com>,
Stefan Richter <stefanr@s5r6.in-berlin.de>,
Jens Axboe <axboe@kernel.dk>, Joe Lawrence <jdl1291@gmail.com>
Subject: Re: [PATCH 4/4] scsi: Stop accepting SCSI requests before removing a device
Date: Wed, 06 Jun 2012 16:18:06 +0000 [thread overview]
Message-ID: <4FCF82BE.1090505@acm.org> (raw)
In-Reply-To: <4FCF7720.6030306@cs.wisc.edu>
On 06/06/12 15:28, Mike Christie wrote:
> On 06/06/2012 10:04 AM, Bart Van Assche wrote:
>> I'm not sure. If a requeued request times out before blk_cleanup_queue()
>> is invoked then it's possible that the requeue_work is started after the
>> struct scsi_device has already been deleted.
>
> Won't the cancel_work_sync call you are adding prevent that? After
> blk_cleanup_queue has returned we know that no IO is running or in the
> eh, and we know no new IO will be started. And then, after the
> cancel_work_sync call you are adding has returned we know that there
> will not be any workstruct queued or running.
We've probably each made different assumptions about whether or not the
requeue work scheduling happens under the queue lock, so we're probably
both right. I'll prepare, test and post a new patch set, that will make
the discussion easier.
Bart.
next prev parent reply other threads:[~2012-06-06 16:18 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-05 17:08 [PATCH 0/4 v7] Fixes for SCSI device removal Bart Van Assche
2012-06-05 17:10 ` [PATCH 1/4] block: Fix race on request_queue.end_io invocations Bart Van Assche
2012-06-05 21:32 ` Tejun Heo
2012-06-06 12:44 ` Bart Van Assche
2012-06-06 12:45 ` Jens Axboe
2012-06-06 13:10 ` Bart Van Assche
2012-06-05 17:11 ` [PATCH 2/4] scsi: Fix device removal NULL pointer dereference Bart Van Assche
2012-06-05 17:12 ` [PATCH 3/4] scsi: Change return type of scsi_queue_insert() into void Bart Van Assche
2012-06-05 17:14 ` [PATCH 4/4] scsi: Stop accepting SCSI requests before removing a device Bart Van Assche
2012-06-05 21:36 ` Mike Christie
2012-06-06 12:17 ` Bart Van Assche
2012-06-06 13:29 ` Mike Christie
2012-06-06 14:53 ` Bart Van Assche
2012-06-06 15:21 ` Mike Christie
2012-06-05 22:08 ` Mike Christie
2012-06-06 12:25 ` Bart Van Assche
2012-06-06 13:43 ` Mike Christie
2012-06-06 14:01 ` Mike Christie
2012-06-06 14:12 ` Mike Christie
2012-06-06 15:04 ` Bart Van Assche
2012-06-06 15:28 ` Mike Christie
2012-06-06 16:18 ` Bart Van Assche [this message]
2012-06-06 15:07 ` Bart Van Assche
-- strict thread matches above, loose matches on Subject: below --
2012-06-07 18:39 [PATCH 0/4 v8] Fixes for SCSI device removal Bart Van Assche
2012-06-07 18:46 ` [PATCH 4/4] scsi: Stop accepting SCSI requests before removing a device Bart Van Assche
2012-06-25 18:12 [PATCH 0/4 v9] SCSI device removal fixes Bart Van Assche
2012-06-25 18:17 ` [PATCH 4/4] scsi: Stop accepting SCSI requests before removing a device Bart Van Assche
2012-06-25 20:42 ` Tejun Heo
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