blk-mq: remove blk_mq_delay_queue()

No driver uses this interface any more, so remove it.

Cc: Stefan Haberland <sth@linux.vnet.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-mq-debugfs.c

@@ -235,7 +235,6 @@ static const char *const hctx_state_name[] = {
 	HCTX_STATE_NAME(STOPPED),
 	HCTX_STATE_NAME(TAG_ACTIVE),
 	HCTX_STATE_NAME(SCHED_RESTART),
-	HCTX_STATE_NAME(START_ON_RUN),
 };
 #undef HCTX_STATE_NAME
 

block/blk-mq.c

@@ -1562,40 +1562,14 @@ static void blk_mq_run_work_fn(struct work_struct *work)
 	hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work);
 
 	/*
-	 * If we are stopped, don't run the queue. The exception is if
-	 * BLK_MQ_S_START_ON_RUN is set. For that case, we auto-clear
-	 * the STOPPED bit and run it.
+	 * If we are stopped, don't run the queue.
 	 */
-	if (test_bit(BLK_MQ_S_STOPPED, &hctx->state)) {
-		if (!test_bit(BLK_MQ_S_START_ON_RUN, &hctx->state))
-			return;
-
-		clear_bit(BLK_MQ_S_START_ON_RUN, &hctx->state);
+	if (test_bit(BLK_MQ_S_STOPPED, &hctx->state))
 		clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
-	}
 
 	__blk_mq_run_hw_queue(hctx);
 }
 
-
-void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs)
-{
-	if (WARN_ON_ONCE(!blk_mq_hw_queue_mapped(hctx)))
-		return;
-
-	/*
-	 * Stop the hw queue, then modify currently delayed work.
-	 * This should prevent us from running the queue prematurely.
-	 * Mark the queue as auto-clearing STOPPED when it runs.
-	 */
-	blk_mq_stop_hw_queue(hctx);
-	set_bit(BLK_MQ_S_START_ON_RUN, &hctx->state);
-	kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx),
-					&hctx->run_work,
-					msecs_to_jiffies(msecs));
-}
-EXPORT_SYMBOL(blk_mq_delay_queue);
-
 static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx,
 					    struct request *rq,
 					    bool at_head)

include/linux/blk-mq.h

@@ -183,7 +183,6 @@ enum {
 	BLK_MQ_S_STOPPED	= 0,
 	BLK_MQ_S_TAG_ACTIVE	= 1,
 	BLK_MQ_S_SCHED_RESTART	= 2,
-	BLK_MQ_S_START_ON_RUN	= 3,
 
 	BLK_MQ_MAX_DEPTH	= 10240,
 
@@ -270,7 +269,6 @@ void blk_mq_unquiesce_queue(struct request_queue *q);
 void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
 bool blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
 void blk_mq_run_hw_queues(struct request_queue *q, bool async);
-void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
 void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
 		busy_tag_iter_fn *fn, void *priv);
 void blk_mq_freeze_queue(struct request_queue *q);