[PATCH 7/8] virtio_blk: quiesce/unquiesce live IO when entering PM states

[Michael S. Tsirkin]

On Tue, Jul 04, 2017 at 10:55:11AM +0300, Sagi Grimberg wrote:
> We must make sure that no requests are being queued before we iterate
> delete vqs. quiesce/unquiesce the request queue istead of start/stop
> hw queues.
> 
> Cc: Michael S. Tsirkin <mst at redhat.com>
> Cc: Jason Wang <jasowang at redhat.com>
> Signed-off-by: Sagi Grimberg <sagi at grimberg.me>


Acked-by: Michael S. Tsirkin <mst at redhat.com>

But please remember to Cc virtio mailing list on virtio patches.


> ---
>  drivers/block/virtio_blk.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index 0297ad7c1452..4e02aa5fdac0 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -840,7 +840,7 @@ static int virtblk_freeze(struct virtio_device *vdev)
>  	/* Make sure no work handler is accessing the device. */
>  	flush_work(&vblk->config_work);
>  
> -	blk_mq_stop_hw_queues(vblk->disk->queue);
> +	blk_mq_quiesce_queue(vblk->disk->queue);
>  
>  	vdev->config->del_vqs(vdev);
>  	return 0;
> @@ -857,7 +857,7 @@ static int virtblk_restore(struct virtio_device *vdev)
>  
>  	virtio_device_ready(vdev);
>  
> -	blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
> +	blk_mq_unquiesce_queue(vblk->disk->queue);
>  	return 0;
>  }
>  #endif
> -- 
> 2.7.4