[PATCH 2/9] dm: Fix a race condition related to stopping and starting queues

[Hannes Reinecke]

On 09/26/2016 08:26 PM, Bart Van Assche wrote:
> Ensure that all ongoing dm_mq_queue_rq() and dm_mq_requeue_request()
> calls have stopped before setting the "queue stopped" flag. This
> allows to remove the "queue stopped" test from dm_mq_queue_rq() and
> dm_mq_requeue_request(). This patch fixes a race condition because
> dm_mq_queue_rq() is called without holding the queue lock and hence
> BLK_MQ_S_STOPPED can be set at any time while dm_mq_queue_rq() is
> in progress.
> 
> Signed-off-by: Bart Van Assche <bart.vanassche at sandisk.com>
> Cc: Mike Snitzer <snitzer at redhat.com>
> ---
>  drivers/md/dm-rq.c | 14 +++-----------
>  1 file changed, 3 insertions(+), 11 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare at suse.com>

Cheers,

Hannes
-- 
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