From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:47078 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934483AbdADN3r (ORCPT ); Wed, 4 Jan 2017 08:29:47 -0500 Subject: Patch "dm rq: fix a race condition in rq_completed()" has been added to the 4.9-stable tree To: bart.vanassche@sandisk.com, gregkh@linuxfoundation.org, snitzer@redhat.com Cc: , From: Date: Wed, 04 Jan 2017 14:29:45 +0100 Message-ID: <148353658559151@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled dm rq: fix a race condition in rq_completed() to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: dm-rq-fix-a-race-condition-in-rq_completed.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From d15bb3a6467e102e60d954aadda5fb19ce6fd8ec Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Fri, 11 Nov 2016 17:05:27 -0800 Subject: dm rq: fix a race condition in rq_completed() From: Bart Van Assche commit d15bb3a6467e102e60d954aadda5fb19ce6fd8ec upstream. It is required to hold the queue lock when calling blk_run_queue_async() to avoid that a race between blk_run_queue_async() and blk_cleanup_queue() is triggered. Signed-off-by: Bart Van Assche Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-rq.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/drivers/md/dm-rq.c +++ b/drivers/md/dm-rq.c @@ -226,6 +226,9 @@ static void rq_end_stats(struct mapped_d */ static void rq_completed(struct mapped_device *md, int rw, bool run_queue) { + struct request_queue *q = md->queue; + unsigned long flags; + atomic_dec(&md->pending[rw]); /* nudge anyone waiting on suspend queue */ @@ -238,8 +241,11 @@ static void rq_completed(struct mapped_d * back into ->request_fn() could deadlock attempting to grab the * queue lock again. */ - if (!md->queue->mq_ops && run_queue) - blk_run_queue_async(md->queue); + if (!q->mq_ops && run_queue) { + spin_lock_irqsave(q->queue_lock, flags); + blk_run_queue_async(q); + spin_unlock_irqrestore(q->queue_lock, flags); + } /* * dm_put() must be at the end of this function. See the comment above Patches currently in stable-queue which might be from bart.vanassche@sandisk.com are queue-4.9/dm-rq-fix-a-race-condition-in-rq_completed.patch queue-4.9/blk-mq-do-not-invoke-.queue_rq-for-a-stopped-queue.patch queue-4.9/dm-table-fix-all_blk_mq-inconsistency-when-an-empty-table-is-loaded.patch queue-4.9/dm-table-an-all_blk_mq-table-must-be-loaded-for-a-blk-mq-dm-device.patch