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@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
---
 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