Revert "block: blk-mq: Use swait"

This reverts commit "block: blk-mq: Use swait". The issue remains but
will be fixed differently.

Cc: stable-rt@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
(cherry-picked from ca3fd6cf836739fd59eac2f7a9b0261365e818bb)
Signed-off-by: Julia Cartwright <julia@ni.com>

block/blk-core.c

@@ -662,9 +662,9 @@ int blk_queue_enter(struct request_queue *q, bool nowait)
 		if (nowait)
 			return -EBUSY;
 
-		swait_event(q->mq_freeze_wq,
-			    !atomic_read(&q->mq_freeze_depth) ||
-			    blk_queue_dying(q));
+		wait_event(q->mq_freeze_wq,
+			   !atomic_read(&q->mq_freeze_depth) ||
+			   blk_queue_dying(q));
 		if (blk_queue_dying(q))
 			return -ENODEV;
 	}
@@ -680,7 +680,7 @@ static void blk_queue_usage_counter_release(struct percpu_ref *ref)
 	struct request_queue *q =
 		container_of(ref, struct request_queue, q_usage_counter);
 
-	swake_up_all(&q->mq_freeze_wq);
+	wake_up_all(&q->mq_freeze_wq);
 }
 
 static void blk_rq_timed_out_timer(unsigned long data)
@@ -750,7 +750,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
 	q->bypass_depth = 1;
 	__set_bit(QUEUE_FLAG_BYPASS, &q->queue_flags);
 
-	init_swait_queue_head(&q->mq_freeze_wq);
+	init_waitqueue_head(&q->mq_freeze_wq);
 
 	/*
 	 * Init percpu_ref in atomic mode so that it's faster to shutdown.

block/blk-mq.c

@@ -72,7 +72,7 @@ EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_start);
 
 static void blk_mq_freeze_queue_wait(struct request_queue *q)
 {
-	swait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter));
+	wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter));
 }
 
 /*
@@ -110,7 +110,7 @@ void blk_mq_unfreeze_queue(struct request_queue *q)
 	WARN_ON_ONCE(freeze_depth < 0);
 	if (!freeze_depth) {
 		percpu_ref_reinit(&q->q_usage_counter);
-		swake_up_all(&q->mq_freeze_wq);
+		wake_up_all(&q->mq_freeze_wq);
 	}
 }
 EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);
@@ -129,7 +129,7 @@ void blk_mq_wake_waiters(struct request_queue *q)
 	 * dying, we need to ensure that processes currently waiting on
 	 * the queue are notified as well.
 	 */
-	swake_up_all(&q->mq_freeze_wq);
+	wake_up_all(&q->mq_freeze_wq);
 }
 
 bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx)

include/linux/blkdev.h

@@ -468,7 +468,7 @@ struct request_queue {
 	struct throtl_data *td;
 #endif
 	struct rcu_head		rcu_head;
-	struct swait_queue_head	mq_freeze_wq;
+	wait_queue_head_t	mq_freeze_wq;
 	struct percpu_ref	q_usage_counter;
 	struct list_head	all_q_node;