1 files changed, 15 insertions, 3 deletions

diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index 65cd61a41..3177b245d 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -99,7 +99,7 @@ static int null_set_queue_mode(const char *str, const struct kernel_param *kp)
 	return null_param_store_val(str, &queue_mode, NULL_Q_BIO, NULL_Q_MQ);
 }
 
-static struct kernel_param_ops null_queue_mode_param_ops = {
+static const struct kernel_param_ops null_queue_mode_param_ops = {
 	.set	= null_set_queue_mode,
 	.get	= param_get_int,
 };
@@ -127,7 +127,7 @@ static int null_set_irqmode(const char *str, const struct kernel_param *kp)
 					NULL_IRQ_TIMER);
 }
 
-static struct kernel_param_ops null_irqmode_param_ops = {
+static const struct kernel_param_ops null_irqmode_param_ops = {
 	.set	= null_set_irqmode,
 	.get	= param_get_int,
 };
@@ -240,9 +240,20 @@ static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer)
 	while ((entry = llist_del_all(&cq->list)) != NULL) {
 		entry = llist_reverse_order(entry);
 		do {
+			struct request_queue *q = NULL;
+
 			cmd = container_of(entry, struct nullb_cmd, ll_list);
 			entry = entry->next;
+			if (cmd->rq)
+				q = cmd->rq->q;
 			end_cmd(cmd);
+
+			if (q && !q->mq_ops && blk_queue_stopped(q)) {
+				spin_lock(q->queue_lock);
+				if (blk_queue_stopped(q))
+					blk_start_queue(q);
+				spin_unlock(q->queue_lock);
+			}
 		} while (entry);
 	}
 
@@ -257,7 +268,7 @@ static void null_cmd_end_timer(struct nullb_cmd *cmd)
 	if (llist_add(&cmd->ll_list, &cq->list)) {
 		ktime_t kt = ktime_set(0, completion_nsec);
 
-		hrtimer_start(&cq->timer, kt, HRTIMER_MODE_REL);
+		hrtimer_start(&cq->timer, kt, HRTIMER_MODE_REL_PINNED);
 	}
 
 	put_cpu();
@@ -334,6 +345,7 @@ static int null_rq_prep_fn(struct request_queue *q, struct request *req)
 		req->special = cmd;
 		return BLKPREP_OK;
 	}
+	blk_stop_queue(q);
 
 	return BLKPREP_DEFER;
 }