[PATCH V6 2/9] blk-mq: move cancel of requeue_work into blk_mq_release

[hare@suse.de (Hannes Reinecke)]

On 4/17/19 5:44 AM, Ming Lei wrote:
> With holding queue's kobject refcount, it is safe for driver
> to schedule requeue. However, blk_mq_kick_requeue_list() may
> be called after blk_sync_queue() is done because of concurrent
> requeue activities, then requeue work may not be completed when
> freeing queue, and kernel oops is triggered.
> 
> So moving the cancel of requeue_work into blk_mq_release() for
> avoiding race between requeue and freeing queue.
> 
> Cc: Dongli Zhang <dongli.zhang at oracle.com>
> Cc: James Smart <james.smart at broadcom.com>
> Cc: Bart Van Assche <bart.vanassche at wdc.com>
> Cc: linux-scsi at vger.kernel.org,
> Cc: Martin K . Petersen <martin.petersen at oracle.com>,
> Cc: Christoph Hellwig <hch at lst.de>,
> Cc: James E . J . Bottomley <jejb at linux.vnet.ibm.com>,
> Cc: jianchao wang <jianchao.w.wang at oracle.com>
> Reviewed-by: Bart Van Assche <bvanassche at acm.org>
> Reviewed-by: Johannes Thumshirn <jthumshirn at suse.de>
> Signed-off-by: Ming Lei <ming.lei at redhat.com>
> ---
>   block/blk-core.c | 1 -
>   block/blk-mq.c   | 2 ++
>   2 files changed, 2 insertions(+), 1 deletion(-)
> 
Reviewed-by: Hannes Reinecke <hare at suse.com>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke            Teamlead Storage & Networking
hare at suse.de                              +49 911 74053 688
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