Re: [PATCH v2 7/8] mtip32xx: quiesce request queues to make sure no submissions are inflight

[Ming Lei <ming.lei@redhat.com>]

On Wed, Jul 05, 2017 at 09:53:10AM +0300, Sagi Grimberg wrote:
> Unlike blk_mq_stop_hw_queues, blk_mq_quiesce_queue respects the
> submission path rcu grace. quiesce the queue before iterating
> on live tags, or performing device io quiescing.
> 
> While were at it, verify that the request started in mtip_abort_cmd
> amd mtip_queue_cmd tag iteration calls.
> 
> Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
> ---
>  drivers/block/mtip32xx/mtip32xx.c | 19 +++++++++++++++----
>  1 file changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
> index 61b046f256ca..87717a1a5c89 100644
> --- a/drivers/block/mtip32xx/mtip32xx.c
> +++ b/drivers/block/mtip32xx/mtip32xx.c
> @@ -950,7 +950,7 @@ static int mtip_quiesce_io(struct mtip_port *port, unsigned long timeout)
>  	unsigned long to;
>  	bool active = true;
>  
> -	blk_mq_stop_hw_queues(port->dd->queue);
> +	blk_mq_quiesce_queue(port->dd->queue);
>  
>  	to = jiffies + msecs_to_jiffies(timeout);
>  	do {
> @@ -970,10 +970,10 @@ static int mtip_quiesce_io(struct mtip_port *port, unsigned long timeout)
>  			break;
>  	} while (time_before(jiffies, to));
>  
> -	blk_mq_start_stopped_hw_queues(port->dd->queue, true);
> +	blk_mq_unquiesce_queue(port->dd->queue);
>  	return active ? -EBUSY : 0;
>  err_fault:
> -	blk_mq_start_stopped_hw_queues(port->dd->queue, true);
> +	blk_mq_unquiesce_queue(port->dd->queue);
>  	return -EFAULT;
>  }
>  
> @@ -2737,6 +2737,9 @@ static void mtip_abort_cmd(struct request *req, void *data,
>  	struct mtip_cmd *cmd = blk_mq_rq_to_pdu(req);
>  	struct driver_data *dd = data;
>  
> +	if (!blk_mq_request_started(req))
> +		return;
> +
>  	dbg_printk(MTIP_DRV_NAME " Aborting request, tag = %d\n", req->tag);
>  
>  	clear_bit(req->tag, dd->port->cmds_to_issue);
> @@ -2749,6 +2752,9 @@ static void mtip_queue_cmd(struct request *req, void *data,
>  {
>  	struct driver_data *dd = data;
>  
> +	if (!blk_mq_request_started(req))
> +		return;
> +
>  	set_bit(req->tag, dd->port->cmds_to_issue);
>  	blk_abort_request(req);
>  }
> @@ -2814,6 +2820,8 @@ static int mtip_service_thread(void *data)
>  				dev_warn(&dd->pdev->dev,
>  					"Completion workers still active!");
>  
> +			blk_mq_quiesce_queue(dd->queue);
> +
>  			spin_lock(dd->queue->queue_lock);
>  			blk_mq_tagset_busy_iter(&dd->tags,
>  							mtip_queue_cmd, dd);
> @@ -2826,6 +2834,8 @@ static int mtip_service_thread(void *data)
>  							mtip_abort_cmd, dd);
>  
>  			clear_bit(MTIP_PF_TO_ACTIVE_BIT, &dd->port->flags);
> +
> +			blk_mq_unquiesce_queue(dd->queue);
>  		}
>  
>  		if (test_bit(MTIP_PF_ISSUE_CMDS_BIT, &port->flags)) {
> @@ -3995,8 +4005,9 @@ static int mtip_block_remove(struct driver_data *dd)
>  						dd->disk->disk_name);
>  
>  	blk_freeze_queue_start(dd->queue);
> -	blk_mq_stop_hw_queues(dd->queue);
> +	blk_mq_quiesce_queue(dd->queue);
>  	blk_mq_tagset_busy_iter(&dd->tags, mtip_no_dev_cleanup, dd);
> +	blk_mq_unquiesce_queue(dd->queue);
>  
>  	/*
>  	 * Delete our gendisk structure. This also removes the device
> -- 
> 2.7.4

Looks fine:

	Reviewed-by: Ming Lei <ming.lei@redhat.com>

-- 
Ming