diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 3a27d31fcda6..44c7e567aa25 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5745,7 +5745,6 @@ static struct elevator_type iosched_bfq_mq = {
 		.exit_sched		= bfq_exit_queue,
 	},
 
-	.uses_mq =		true,
 	.icq_size =		sizeof(struct bfq_io_cq),
 	.icq_align =		__alignof__(struct bfq_io_cq),
 	.elevator_attrs =	bfq_attrs,
diff --git a/block/blk-core.c b/block/blk-core.c
index daaed4dfa719..18538a41a532 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -144,46 +144,6 @@ bool blk_queue_flag_test_and_clear(unsigned int flag, struct request_queue *q)
 }
 EXPORT_SYMBOL_GPL(blk_queue_flag_test_and_clear);
 
-static void blk_clear_congested(struct request_list *rl, int sync)
-{
-#ifdef CONFIG_CGROUP_WRITEBACK
-	clear_wb_congested(rl->blkg->wb_congested, sync);
-#else
-	/*
-	 * If !CGROUP_WRITEBACK, all blkg's map to bdi->wb and we shouldn't
-	 * flip its congestion state for events on other blkcgs.
-	 */
-	if (rl == &rl->q->root_rl)
-		clear_wb_congested(rl->q->backing_dev_info->wb.congested, sync);
-#endif
-}
-
-static void blk_set_congested(struct request_list *rl, int sync)
-{
-#ifdef CONFIG_CGROUP_WRITEBACK
-	set_wb_congested(rl->blkg->wb_congested, sync);
-#else
-	/* see blk_clear_congested() */
-	if (rl == &rl->q->root_rl)
-		set_wb_congested(rl->q->backing_dev_info->wb.congested, sync);
-#endif
-}
-
-void blk_queue_congestion_threshold(struct request_queue *q)
-{
-	int nr;
-
-	nr = q->nr_requests - (q->nr_requests / 8) + 1;
-	if (nr > q->nr_requests)
-		nr = q->nr_requests;
-	q->nr_congestion_on = nr;
-
-	nr = q->nr_requests - (q->nr_requests / 8) - (q->nr_requests / 16) - 1;
-	if (nr < 1)
-		nr = 1;
-	q->nr_congestion_off = nr;
-}
-
 void blk_rq_init(struct request_queue *q, struct request *rq)
 {
 	memset(rq, 0, sizeof(*rq));
@@ -292,99 +252,6 @@ void blk_dump_rq_flags(struct request *rq, char *msg)
 }
 EXPORT_SYMBOL(blk_dump_rq_flags);
 
-static void blk_delay_work(struct work_struct *work)
-{
-	struct request_queue *q;
-
-	q = container_of(work, struct request_queue, delay_work.work);
-	spin_lock_irq(q->queue_lock);
-	__blk_run_queue(q);
-	spin_unlock_irq(q->queue_lock);
-}
-
-/**
- * blk_delay_queue - restart queueing after defined interval
- * @q:		The &struct request_queue in question
- * @msecs:	Delay in msecs
- *
- * Description:
- *   Sometimes queueing needs to be postponed for a little while, to allow
- *   resources to come back. This function will make sure that queueing is
- *   restarted around the specified time.
- */
-void blk_delay_queue(struct request_queue *q, unsigned long msecs)
-{
-	lockdep_assert_held(q->queue_lock);
-	WARN_ON_ONCE(q->mq_ops);
-
-	if (likely(!blk_queue_dead(q)))
-		queue_delayed_work(kblockd_workqueue, &q->delay_work,
-				   msecs_to_jiffies(msecs));
-}
-EXPORT_SYMBOL(blk_delay_queue);
-
-/**
- * blk_start_queue_async - asynchronously restart a previously stopped queue
- * @q:    The &struct request_queue in question
- *
- * Description:
- *   blk_start_queue_async() will clear the stop flag on the queue, and
- *   ensure that the request_fn for the queue is run from an async
- *   context.
- **/
-void blk_start_queue_async(struct request_queue *q)
-{
-	lockdep_assert_held(q->queue_lock);
-	WARN_ON_ONCE(q->mq_ops);
-
-	queue_flag_clear(QUEUE_FLAG_STOPPED, q);
-	blk_run_queue_async(q);
-}
-EXPORT_SYMBOL(blk_start_queue_async);
-
-/**
- * blk_start_queue - restart a previously stopped queue
- * @q:    The &struct request_queue in question
- *
- * Description:
- *   blk_start_queue() will clear the stop flag on the queue, and call
- *   the request_fn for the queue if it was in a stopped state when
- *   entered. Also see blk_stop_queue().
- **/
-void blk_start_queue(struct request_queue *q)
-{
-	lockdep_assert_held(q->queue_lock);
-	WARN_ON_ONCE(q->mq_ops);
-
-	queue_flag_clear(QUEUE_FLAG_STOPPED, q);
-	__blk_run_queue(q);
-}
-EXPORT_SYMBOL(blk_start_queue);
-
-/**
- * blk_stop_queue - stop a queue
- * @q:    The &struct request_queue in question
- *
- * Description:
- *   The Linux block layer assumes that a block driver will consume all
- *   entries on the request queue when the request_fn strategy is called.
- *   Often this will not happen, because of hardware limitations (queue
- *   depth settings). If a device driver gets a 'queue full' response,
- *   or if it simply chooses not to queue more I/O at one point, it can
- *   call this function to prevent the request_fn from being called until
- *   the driver has signalled it's ready to go again. This happens by calling
- *   blk_start_queue() to restart queue operations.
- **/
-void blk_stop_queue(struct request_queue *q)
-{
-	lockdep_assert_held(q->queue_lock);
-	WARN_ON_ONCE(q->mq_ops);
-
-	cancel_delayed_work(&q->delay_work);
-	queue_flag_set(QUEUE_FLAG_STOPPED, q);
-}
-EXPORT_SYMBOL(blk_stop_queue);
-
 /**
  * blk_sync_queue - cancel any pending callbacks on a queue
  * @q: the queue
@@ -415,8 +282,6 @@ void blk_sync_queue(struct request_queue *q)
 		cancel_delayed_work_sync(&q->requeue_work);
 		queue_for_each_hw_ctx(q, hctx, i)
 			cancel_delayed_work_sync(&hctx->run_work);
-	} else {
-		cancel_delayed_work_sync(&q->delay_work);
 	}
 }
 EXPORT_SYMBOL(blk_sync_queue);
@@ -442,250 +307,12 @@ void blk_clear_pm_only(struct request_queue *q)
 }
 EXPORT_SYMBOL_GPL(blk_clear_pm_only);
 
-/**
- * __blk_run_queue_uncond - run a queue whether or not it has been stopped
- * @q:	The queue to run
- *
- * Description:
- *    Invoke request handling on a queue if there are any pending requests.
- *    May be used to restart request handling after a request has completed.
- *    This variant runs the queue whether or not the queue has been
- *    stopped. Must be called with the queue lock held and interrupts
- *    disabled. See also @blk_run_queue.
- */
-inline void __blk_run_queue_uncond(struct request_queue *q)
-{
-	lockdep_assert_held(q->queue_lock);
-	WARN_ON_ONCE(q->mq_ops);
-
-	if (unlikely(blk_queue_dead(q)))
-		return;
-
-	/*
-	 * Some request_fn implementations, e.g. scsi_request_fn(), unlock
-	 * the queue lock internally. As a result multiple threads may be
-	 * running such a request function concurrently. Keep track of the
-	 * number of active request_fn invocations such that blk_drain_queue()
-	 * can wait until all these request_fn calls have finished.
-	 */
-	q->request_fn_active++;
-	q->request_fn(q);
-	q->request_fn_active--;
-}
-EXPORT_SYMBOL_GPL(__blk_run_queue_uncond);
-
-/**
- * __blk_run_queue - run a single device queue
- * @q:	The queue to run
- *
- * Description:
- *    See @blk_run_queue.
- */
-void __blk_run_queue(struct request_queue *q)
-{
-	lockdep_assert_held(q->queue_lock);
-	WARN_ON_ONCE(q->mq_ops);
-
-	if (unlikely(blk_queue_stopped(q)))
-		return;
-
-	__blk_run_queue_uncond(q);
-}
-EXPORT_SYMBOL(__blk_run_queue);
-
-/**
- * blk_run_queue_async - run a single device queue in workqueue context
- * @q:	The queue to run
- *
- * Description:
- *    Tells kblockd to perform the equivalent of @blk_run_queue on behalf
- *    of us.
- *
- * Note:
- *    Since it is not allowed to run q->delay_work after blk_cleanup_queue()
- *    has canceled q->delay_work, callers must hold the queue lock to avoid
- *    race conditions between blk_cleanup_queue() and blk_run_queue_async().
- */
-void blk_run_queue_async(struct request_queue *q)
-{
-	lockdep_assert_held(q->queue_lock);
-	WARN_ON_ONCE(q->mq_ops);
-
-	if (likely(!blk_queue_stopped(q) && !blk_queue_dead(q)))
-		mod_delayed_work(kblockd_workqueue, &q->delay_work, 0);
-}
-EXPORT_SYMBOL(blk_run_queue_async);
-
-/**
- * blk_run_queue - run a single device queue
- * @q: The queue to run
- *
- * Description:
- *    Invoke request handling on this queue, if it has pending work to do.
- *    May be used to restart queueing when a request has completed.
- */
-void blk_run_queue(struct request_queue *q)
-{
-	unsigned long flags;
-
-	WARN_ON_ONCE(q->mq_ops);
-
-	spin_lock_irqsave(q->queue_lock, flags);
-	__blk_run_queue(q);
-	spin_unlock_irqrestore(q->queue_lock, flags);
-}
-EXPORT_SYMBOL(blk_run_queue);
-
 void blk_put_queue(struct request_queue *q)
 {
 	kobject_put(&q->kobj);
 }
 EXPORT_SYMBOL(blk_put_queue);
 
-/**
- * __blk_drain_queue - drain requests from request_queue
- * @q: queue to drain
- * @drain_all: whether to drain all requests or only the ones w/ ELVPRIV
- *
- * Drain requests from @q.  If @drain_all is set, all requests are drained.
- * If not, only ELVPRIV requests are drained.  The caller is responsible
- * for ensuring that no new requests which need to be drained are queued.
- */
-static void __blk_drain_queue(struct request_queue *q, bool drain_all)
-	__releases(q->queue_lock)
-	__acquires(q->queue_lock)
-{
-	int i;
-
-	lockdep_assert_held(q->queue_lock);
-	WARN_ON_ONCE(q->mq_ops);
-
-	while (true) {
-		bool drain = false;
-
-		/*
-		 * The caller might be trying to drain @q before its
-		 * elevator is initialized.
-		 */
-		if (q->elevator)
-			elv_drain_elevator(q);
-
-		blkcg_drain_queue(q);
-
-		/*
-		 * This function might be called on a queue which failed
-		 * driver init after queue creation or is not yet fully
-		 * active yet.  Some drivers (e.g. fd and loop) get unhappy
-		 * in such cases.  Kick queue iff dispatch queue has
-		 * something on it and @q has request_fn set.
-		 */
-		if (!list_empty(&q->queue_head) && q->request_fn)
-			__blk_run_queue(q);
-
-		drain |= q->nr_rqs_elvpriv;
-		drain |= q->request_fn_active;
-
-		/*
-		 * Unfortunately, requests are queued at and tracked from
-		 * multiple places and there's no single counter which can
-		 * be drained.  Check all the queues and counters.
-		 */
-		if (drain_all) {
-			struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL);
-			drain |= !list_empty(&q->queue_head);
-			for (i = 0; i < 2; i++) {
-				drain |= q->nr_rqs[i];
-				drain |= q->in_flight[i];
-				if (fq)
-				    drain |= !list_empty(&fq->flush_queue[i]);
-			}
-		}
-
-		if (!drain)
-			break;
-
-		spin_unlock_irq(q->queue_lock);
-
-		msleep(10);
-
-		spin_lock_irq(q->queue_lock);
-	}
-
-	/*
-	 * With queue marked dead, any woken up waiter will fail the
-	 * allocation path, so the wakeup chaining is lost and we're
-	 * left with hung waiters. We need to wake up those waiters.
-	 */
-	if (q->request_fn) {
-		struct request_list *rl;
-
-		blk_queue_for_each_rl(rl, q)
-			for (i = 0; i < ARRAY_SIZE(rl->wait); i++)
-				wake_up_all(&rl->wait[i]);
-	}
-}
-
-void blk_drain_queue(struct request_queue *q)
-{
-	spin_lock_irq(q->queue_lock);
-	__blk_drain_queue(q, true);
-	spin_unlock_irq(q->queue_lock);
-}
-
-/**
- * blk_queue_bypass_start - enter queue bypass mode
- * @q: queue of interest
- *
- * In bypass mode, only the dispatch FIFO queue of @q is used.  This
- * function makes @q enter bypass mode and drains all requests which were
- * throttled or issued before.  On return, it's guaranteed that no request
- * is being throttled or has ELVPRIV set and blk_queue_bypass() %true
- * inside queue or RCU read lock.
- */
-void blk_queue_bypass_start(struct request_queue *q)
-{
-	WARN_ON_ONCE(q->mq_ops);
-
-	spin_lock_irq(q->queue_lock);
-	q->bypass_depth++;
-	queue_flag_set(QUEUE_FLAG_BYPASS, q);
-	spin_unlock_irq(q->queue_lock);
-
-	/*
-	 * Queues start drained.  Skip actual draining till init is
-	 * complete.  This avoids lenghty delays during queue init which
-	 * can happen many times during boot.
-	 */
-	if (blk_queue_init_done(q)) {
-		spin_lock_irq(q->queue_lock);
-		__blk_drain_queue(q, false);
-		spin_unlock_irq(q->queue_lock);
-
-		/* ensure blk_queue_bypass() is %true inside RCU read lock */
-		synchronize_rcu();
-	}
-}
-EXPORT_SYMBOL_GPL(blk_queue_bypass_start);
-
-/**
- * blk_queue_bypass_end - leave queue bypass mode
- * @q: queue of interest
- *
- * Leave bypass mode and restore the normal queueing behavior.
- *
- * Note: although blk_queue_bypass_start() is only called for blk-sq queues,
- * this function is called for both blk-sq and blk-mq queues.
- */
-void blk_queue_bypass_end(struct request_queue *q)
-{
-	spin_lock_irq(q->queue_lock);
-	if (!--q->bypass_depth)
-		queue_flag_clear(QUEUE_FLAG_BYPASS, q);
-	WARN_ON_ONCE(q->bypass_depth < 0);
-	spin_unlock_irq(q->queue_lock);
-}
-EXPORT_SYMBOL_GPL(blk_queue_bypass_end);
-
 void blk_set_queue_dying(struct request_queue *q)
 {
 	blk_queue_flag_set(QUEUE_FLAG_DYING, q);
@@ -699,18 +326,6 @@ void blk_set_queue_dying(struct request_queue *q)
 
 	if (q->mq_ops)
 		blk_mq_wake_waiters(q);
-	else {
-		struct request_list *rl;
-
-		spin_lock_irq(q->queue_lock);
-		blk_queue_for_each_rl(rl, q) {
-			if (rl->rq_pool) {
-				wake_up_all(&rl->wait[BLK_RW_SYNC]);
-				wake_up_all(&rl->wait[BLK_RW_ASYNC]);
-			}
-		}
-		spin_unlock_irq(q->queue_lock);
-	}
 
 	/* Make blk_queue_enter() reexamine the DYING flag. */
 	wake_up_all(&q->mq_freeze_wq);
@@ -822,6 +437,7 @@ void blk_cleanup_queue(struct request_queue *q)
 
 	if (q->mq_ops)
 		blk_mq_free_queue(q);
+
 	percpu_ref_exit(&q->q_usage_counter);
 
 	spin_lock_irq(lock);
@@ -1013,8 +629,6 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id,
 
 	INIT_LIST_HEAD(&q->queue_head);
 	q->last_merge = NULL;
-	q->end_sector = 0;
-	q->boundary_rq = NULL;
 
 	q->id = ida_simple_get(&blk_queue_ida, 0, 0, gfp_mask);
 	if (q->id < 0)
@@ -1047,7 +661,6 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id,
 #ifdef CONFIG_BLK_CGROUP
 	INIT_LIST_HEAD(&q->blkg_list);
 #endif
-	INIT_DELAYED_WORK(&q->delay_work, blk_delay_work);
 
 	kobject_init(&q->kobj, &blk_queue_ktype);
 
@@ -1100,105 +713,6 @@ fail_q:
 }
 EXPORT_SYMBOL(blk_alloc_queue_node);
 
-/**
- * blk_init_queue  - prepare a request queue for use with a block device
- * @rfn:  The function to be called to process requests that have been
- *        placed on the queue.
- * @lock: Request queue spin lock
- *
- * Description:
- *    If a block device wishes to use the standard request handling procedures,
- *    which sorts requests and coalesces adjacent requests, then it must
- *    call blk_init_queue().  The function @rfn will be called when there
- *    are requests on the queue that need to be processed.  If the device
- *    supports plugging, then @rfn may not be called immediately when requests
- *    are available on the queue, but may be called at some time later instead.
- *    Plugged queues are generally unplugged when a buffer belonging to one
- *    of the requests on the queue is needed, or due to memory pressure.
- *
- *    @rfn is not required, or even expected, to remove all requests off the
- *    queue, but only as many as it can handle at a time.  If it does leave
- *    requests on the queue, it is responsible for arranging that the requests
- *    get dealt with eventually.
- *
- *    The queue spin lock must be held while manipulating the requests on the
- *    request queue; this lock will be taken also from interrupt context, so irq
- *    disabling is needed for it.
- *
- *    Function returns a pointer to the initialized request queue, or %NULL if
- *    it didn't succeed.
- *
- * Note:
- *    blk_init_queue() must be paired with a blk_cleanup_queue() call
- *    when the block device is deactivated (such as at module unload).
- **/
-
-struct request_queue *blk_init_queue(request_fn_proc *rfn, spinlock_t *lock)
-{
-	return blk_init_queue_node(rfn, lock, NUMA_NO_NODE);
-}
-EXPORT_SYMBOL(blk_init_queue);
-
-struct request_queue *
-blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id)
-{
-	struct request_queue *q;
-
-	q = blk_alloc_queue_node(GFP_KERNEL, node_id, lock);
-	if (!q)
-		return NULL;
-
-	q->request_fn = rfn;
-	if (blk_init_allocated_queue(q) < 0) {
-		blk_cleanup_queue(q);
-		return NULL;
-	}
-
-	return q;
-}
-EXPORT_SYMBOL(blk_init_queue_node);
-
-static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio);
-
-
-int blk_init_allocated_queue(struct request_queue *q)
-{
-	WARN_ON_ONCE(q->mq_ops);
-
-	q->fq = blk_alloc_flush_queue(q, NUMA_NO_NODE, q->cmd_size, GFP_KERNEL);
-	if (!q->fq)
-		return -ENOMEM;
-
-	if (q->init_rq_fn && q->init_rq_fn(q, q->fq->flush_rq, GFP_KERNEL))
-		goto out_free_flush_queue;
-
-	if (blk_init_rl(&q->root_rl, q, GFP_KERNEL))
-		goto out_exit_flush_rq;
-
-	INIT_WORK(&q->timeout_work, blk_timeout_work);
-	q->queue_flags		|= QUEUE_FLAG_DEFAULT;
-
-	/*
-	 * This also sets hw/phys segments, boundary and size
-	 */
-	blk_queue_make_request(q, blk_queue_bio);
-
-	q->sg_reserved_size = INT_MAX;
-
-	if (elevator_init(q))
-		goto out_exit_flush_rq;
-	return 0;
-
-out_exit_flush_rq:
-	if (q->exit_rq_fn)
-		q->exit_rq_fn(q, q->fq->flush_rq);
-out_free_flush_queue:
-	blk_free_flush_queue(q->fq);
-	q->fq = NULL;
-	return -ENOMEM;
-}
-EXPORT_SYMBOL(blk_init_allocated_queue);
-
 bool blk_get_queue(struct request_queue *q)
 {
 	if (likely(!blk_queue_dying(q))) {
@@ -1210,406 +724,6 @@ bool blk_get_queue(struct request_queue *q)
 }
 EXPORT_SYMBOL(blk_get_queue);
 
-static inline void blk_free_request(struct request_list *rl, struct request *rq)
-{
-	if (rq->rq_flags & RQF_ELVPRIV) {
-		elv_put_request(rl->q, rq);
-		if (rq->elv.icq)
-			put_io_context(rq->elv.icq->ioc);
-	}
-
-	mempool_free(rq, rl->rq_pool);
-}
-
-/*
- * ioc_batching returns true if the ioc is a valid batching request and
- * should be given priority access to a request.
- */
-static inline int ioc_batching(struct request_queue *q, struct io_context *ioc)
-{
-	if (!ioc)
-		return 0;
-
-	/*
-	 * Make sure the process is able to allocate at least 1 request
-	 * even if the batch times out, otherwise we could theoretically
-	 * lose wakeups.
-	 */
-	return ioc->nr_batch_requests == q->nr_batching ||
-		(ioc->nr_batch_requests > 0
-		&& time_before(jiffies, ioc->last_waited + BLK_BATCH_TIME));
-}
-
-/*
- * ioc_set_batching sets ioc to be a new "batcher" if it is not one. This
- * will cause the process to be a "batcher" on all queues in the system. This
- * is the behaviour we want though - once it gets a wakeup it should be given
- * a nice run.
- */
-static void ioc_set_batching(struct request_queue *q, struct io_context *ioc)
-{
-	if (!ioc || ioc_batching(q, ioc))
-		return;
-
-	ioc->nr_batch_requests = q->nr_batching;
-	ioc->last_waited = jiffies;
-}
-
-static void __freed_request(struct request_list *rl, int sync)
-{
-	struct request_queue *q = rl->q;
-
-	if (rl->count[sync] < queue_congestion_off_threshold(q))
-		blk_clear_congested(rl, sync);
-
-	if (rl->count[sync] + 1 <= q->nr_requests) {
-		if (waitqueue_active(&rl->wait[sync]))
-			wake_up(&rl->wait[sync]);
-
-		blk_clear_rl_full(rl, sync);
-	}
-}
-
-/*
- * A request has just been released.  Account for it, update the full and
- * congestion status, wake up any waiters.   Called under q->queue_lock.
- */
-static void freed_request(struct request_list *rl, bool sync,
-		req_flags_t rq_flags)
-{
-	struct request_queue *q = rl->q;
-
-	q->nr_rqs[sync]--;
-	rl->count[sync]--;
-	if (rq_flags & RQF_ELVPRIV)
-		q->nr_rqs_elvpriv--;
-
-	__freed_request(rl, sync);
-
-	if (unlikely(rl->starved[sync ^ 1]))
-		__freed_request(rl, sync ^ 1);
-}
-
-int blk_update_nr_requests(struct request_queue *q, unsigned int nr)
-{
-	struct request_list *rl;
-	int on_thresh, off_thresh;
-
-	WARN_ON_ONCE(q->mq_ops);
-
-	spin_lock_irq(q->queue_lock);
-	q->nr_requests = nr;
-	blk_queue_congestion_threshold(q);
-	on_thresh = queue_congestion_on_threshold(q);
-	off_thresh = queue_congestion_off_threshold(q);
-
-	blk_queue_for_each_rl(rl, q) {
-		if (rl->count[BLK_RW_SYNC] >= on_thresh)
-			blk_set_congested(rl, BLK_RW_SYNC);
-		else if (rl->count[BLK_RW_SYNC] < off_thresh)
-			blk_clear_congested(rl, BLK_RW_SYNC);
-
-		if (rl->count[BLK_RW_ASYNC] >= on_thresh)
-			blk_set_congested(rl, BLK_RW_ASYNC);
-		else if (rl->count[BLK_RW_ASYNC] < off_thresh)
-			blk_clear_congested(rl, BLK_RW_ASYNC);
-
-		if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
-			blk_set_rl_full(rl, BLK_RW_SYNC);
-		} else {
-			blk_clear_rl_full(rl, BLK_RW_SYNC);
-			wake_up(&rl->wait[BLK_RW_SYNC]);
-		}
-
-		if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) {
-			blk_set_rl_full(rl, BLK_RW_ASYNC);
-		} else {
-			blk_clear_rl_full(rl, BLK_RW_ASYNC);
-			wake_up(&rl->wait[BLK_RW_ASYNC]);
-		}
-	}
-
-	spin_unlock_irq(q->queue_lock);
-	return 0;
-}
-
-/**
- * __get_request - get a free request
- * @rl: request list to allocate from
- * @op: operation and flags
- * @bio: bio to allocate request for (can be %NULL)
- * @flags: BLQ_MQ_REQ_* flags
- * @gfp_mask: allocator flags
- *
- * Get a free request from @q.  This function may fail under memory
- * pressure or if @q is dead.
- *
- * Must be called with @q->queue_lock held and,
- * Returns ERR_PTR on failure, with @q->queue_lock held.
- * Returns request pointer on success, with @q->queue_lock *not held*.
- */
-static struct request *__get_request(struct request_list *rl, unsigned int op,
-		struct bio *bio, blk_mq_req_flags_t flags, gfp_t gfp_mask)
-{
-	struct request_queue *q = rl->q;
-	struct request *rq;
-	struct elevator_type *et = q->elevator->type;
-	struct io_context *ioc = rq_ioc(bio);
-	struct io_cq *icq = NULL;
-	const bool is_sync = op_is_sync(op);
-	int may_queue;
-	req_flags_t rq_flags = RQF_ALLOCED;
-
-	lockdep_assert_held(q->queue_lock);
-
-	if (unlikely(blk_queue_dying(q)))
-		return ERR_PTR(-ENODEV);
-
-	may_queue = elv_may_queue(q, op);
-	if (may_queue == ELV_MQUEUE_NO)
-		goto rq_starved;
-
-	if (rl->count[is_sync]+1 >= queue_congestion_on_threshold(q)) {
-		if (rl->count[is_sync]+1 >= q->nr_requests) {
-			/*
-			 * The queue will fill after this allocation, so set
-			 * it as full, and mark this process as "batching".
-			 * This process will be allowed to complete a batch of
-			 * requests, others will be blocked.
-			 */
-			if (!blk_rl_full(rl, is_sync)) {
-				ioc_set_batching(q, ioc);
-				blk_set_rl_full(rl, is_sync);
-			} else {
-				if (may_queue != ELV_MQUEUE_MUST
-						&& !ioc_batching(q, ioc)) {
-					/*
-					 * The queue is full and the allocating
-					 * process is not a "batcher", and not
-					 * exempted by the IO scheduler
-					 */
-					return ERR_PTR(-ENOMEM);
-				}
-			}
-		}
-		blk_set_congested(rl, is_sync);
-	}
-
-	/*
-	 * Only allow batching queuers to allocate up to 50% over the defined
-	 * limit of requests, otherwise we could have thousands of requests
-	 * allocated with any setting of ->nr_requests
-	 */
-	if (rl->count[is_sync] >= (3 * q->nr_requests / 2))
-		return ERR_PTR(-ENOMEM);
-
-	q->nr_rqs[is_sync]++;
-	rl->count[is_sync]++;
-	rl->starved[is_sync] = 0;
-
-	/*
-	 * Decide whether the new request will be managed by elevator.  If
-	 * so, mark @rq_flags and increment elvpriv.  Non-zero elvpriv will
-	 * prevent the current elevator from being destroyed until the new
-	 * request is freed.  This guarantees icq's won't be destroyed and
-	 * makes creating new ones safe.
-	 *
-	 * Flush requests do not use the elevator so skip initialization.
-	 * This allows a request to share the flush and elevator data.
-	 *
-	 * Also, lookup icq while holding queue_lock.  If it doesn't exist,
-	 * it will be created after releasing queue_lock.
-	 */
-	if (!op_is_flush(op) && !blk_queue_bypass(q)) {
-		rq_flags |= RQF_ELVPRIV;
-		q->nr_rqs_elvpriv++;
-		if (et->icq_cache && ioc)
-			icq = ioc_lookup_icq(ioc, q);
-	}
-
-	if (blk_queue_io_stat(q))
-		rq_flags |= RQF_IO_STAT;
-	spin_unlock_irq(q->queue_lock);
-
-	/* allocate and init request */
-	rq = mempool_alloc(rl->rq_pool, gfp_mask);
-	if (!rq)
-		goto fail_alloc;
-
-	blk_rq_init(q, rq);
-	blk_rq_set_rl(rq, rl);
-	rq->cmd_flags = op;
-	rq->rq_flags = rq_flags;
-	if (flags & BLK_MQ_REQ_PREEMPT)
-		rq->rq_flags |= RQF_PREEMPT;
-
-	/* init elvpriv */
-	if (rq_flags & RQF_ELVPRIV) {
-		if (unlikely(et->icq_cache && !icq)) {
-			if (ioc)
-				icq = ioc_create_icq(ioc, q, gfp_mask);
-			if (!icq)
-				goto fail_elvpriv;
-		}
-
-		rq->elv.icq = icq;
-		if (unlikely(elv_set_request(q, rq, bio, gfp_mask)))
-			goto fail_elvpriv;
-
-		/* @rq->elv.icq holds io_context until @rq is freed */
-		if (icq)
-			get_io_context(icq->ioc);
-	}
-out:
-	/*
-	 * ioc may be NULL here, and ioc_batching will be false. That's
-	 * OK, if the queue is under the request limit then requests need
-	 * not count toward the nr_batch_requests limit. There will always
-	 * be some limit enforced by BLK_BATCH_TIME.
-	 */
-	if (ioc_batching(q, ioc))
-		ioc->nr_batch_requests--;
-
-	trace_block_getrq(q, bio, op);
-	return rq;
-
-fail_elvpriv:
-	/*
-	 * elvpriv init failed.  ioc, icq and elvpriv aren't mempool backed
-	 * and may fail indefinitely under memory pressure and thus
-	 * shouldn't stall IO.  Treat this request as !elvpriv.  This will
-	 * disturb iosched and blkcg but weird is bettern than dead.
-	 */
-	printk_ratelimited(KERN_WARNING "%s: dev %s: request aux data allocation failed, iosched may be disturbed\n",
-			   __func__, dev_name(q->backing_dev_info->dev));
-
-	rq->rq_flags &= ~RQF_ELVPRIV;
-	rq->elv.icq = NULL;
-
-	spin_lock_irq(q->queue_lock);
-	q->nr_rqs_elvpriv--;
-	spin_unlock_irq(q->queue_lock);
-	goto out;
-
-fail_alloc:
-	/*
-	 * Allocation failed presumably due to memory. Undo anything we
-	 * might have messed up.
-	 *
-	 * Allocating task should really be put onto the front of the wait
-	 * queue, but this is pretty rare.
-	 */
-	spin_lock_irq(q->queue_lock);
-	freed_request(rl, is_sync, rq_flags);
-
-	/*
-	 * in the very unlikely event that allocation failed and no
-	 * requests for this direction was pending, mark us starved so that
-	 * freeing of a request in the other direction will notice
-	 * us. another possible fix would be to split the rq mempool into
-	 * READ and WRITE
-	 */
-rq_starved:
-	if (unlikely(rl->count[is_sync] == 0))
-		rl->starved[is_sync] = 1;
-	return ERR_PTR(-ENOMEM);
-}
-
-/**
- * get_request - get a free request
- * @q: request_queue to allocate request from
- * @op: operation and flags
- * @bio: bio to allocate request for (can be %NULL)
- * @flags: BLK_MQ_REQ_* flags.
- * @gfp: allocator flags
- *
- * Get a free request from @q.  If %BLK_MQ_REQ_NOWAIT is set in @flags,
- * this function keeps retrying under memory pressure and fails iff @q is dead.
- *
- * Must be called with @q->queue_lock held and,
- * Returns ERR_PTR on failure, with @q->queue_lock held.
- * Returns request pointer on success, with @q->queue_lock *not held*.
- */
-static struct request *get_request(struct request_queue *q, unsigned int op,
-		struct bio *bio, blk_mq_req_flags_t flags, gfp_t gfp)
-{
-	const bool is_sync = op_is_sync(op);
-	DEFINE_WAIT(wait);
-	struct request_list *rl;
-	struct request *rq;
-
-	lockdep_assert_held(q->queue_lock);
-	WARN_ON_ONCE(q->mq_ops);
-
-	rl = blk_get_rl(q, bio);	/* transferred to @rq on success */
-retry:
-	rq = __get_request(rl, op, bio, flags, gfp);
-	if (!IS_ERR(rq))
-		return rq;
-
-	if (op & REQ_NOWAIT) {
-		blk_put_rl(rl);
-		return ERR_PTR(-EAGAIN);
-	}
-
-	if ((flags & BLK_MQ_REQ_NOWAIT) || unlikely(blk_queue_dying(q))) {
-		blk_put_rl(rl);
-		return rq;
-	}
-
-	/* wait on @rl and retry */
-	prepare_to_wait_exclusive(&rl->wait[is_sync], &wait,
-				  TASK_UNINTERRUPTIBLE);
-
-	trace_block_sleeprq(q, bio, op);
-
-	spin_unlock_irq(q->queue_lock);
-	io_schedule();
-
-	/*
-	 * After sleeping, we become a "batching" process and will be able
-	 * to allocate at least one request, and up to a big batch of them
-	 * for a small period time.  See ioc_batching, ioc_set_batching
-	 */
-	ioc_set_batching(q, current->io_context);
-
-	spin_lock_irq(q->queue_lock);
-	finish_wait(&rl->wait[is_sync], &wait);
-
-	goto retry;
-}
-
-/* flags: BLK_MQ_REQ_PREEMPT and/or BLK_MQ_REQ_NOWAIT. */
-static struct request *blk_old_get_request(struct request_queue *q,
-				unsigned int op, blk_mq_req_flags_t flags)
-{
-	struct request *rq;
-	gfp_t gfp_mask = flags & BLK_MQ_REQ_NOWAIT ? GFP_ATOMIC : GFP_NOIO;
-	int ret = 0;
-
-	WARN_ON_ONCE(q->mq_ops);
-
-	/* create ioc upfront */
-	create_io_context(gfp_mask, q->node);
-
-	ret = blk_queue_enter(q, flags);
-	if (ret)
-		return ERR_PTR(ret);
-	spin_lock_irq(q->queue_lock);
-	rq = get_request(q, op, NULL, flags, gfp_mask);
-	if (IS_ERR(rq)) {
-		spin_unlock_irq(q->queue_lock);
-		blk_queue_exit(q);
-		return rq;
-	}
-
-	/* q->queue_lock is unlocked at this point */
-	rq->__data_len = 0;
-	rq->__sector = (sector_t) -1;
-	rq->bio = rq->biotail = NULL;
-	return rq;
-}
-
 /**
  * blk_get_request - allocate a request
  * @q: request queue to allocate a request for
@@ -1624,53 +738,14 @@ struct request *blk_get_request(struct request_queue *q, unsigned int op,
 	WARN_ON_ONCE(op & REQ_NOWAIT);
 	WARN_ON_ONCE(flags & ~(BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_PREEMPT));
 
-	if (q->mq_ops) {
-		req = blk_mq_alloc_request(q, op, flags);
-		if (!IS_ERR(req) && q->mq_ops->initialize_rq_fn)
-			q->mq_ops->initialize_rq_fn(req);
-	} else {
-		req = blk_old_get_request(q, op, flags);
-		if (!IS_ERR(req) && q->initialize_rq_fn)
-			q->initialize_rq_fn(req);
-	}
+	req = blk_mq_alloc_request(q, op, flags);
+	if (!IS_ERR(req) && q->mq_ops->initialize_rq_fn)
+		q->mq_ops->initialize_rq_fn(req);
 
 	return req;
 }
 EXPORT_SYMBOL(blk_get_request);
 
-/**
- * blk_requeue_request - put a request back on queue
- * @q:		request queue where request should be inserted
- * @rq:		request to be inserted
- *
- * Description:
- *    Drivers often keep queueing requests until the hardware cannot accept
- *    more, when that condition happens we need to put the request back
- *    on the queue. Must be called with queue lock held.
- */
-void blk_requeue_request(struct request_queue *q, struct request *rq)
-{
-	lockdep_assert_held(q->queue_lock);
-	WARN_ON_ONCE(q->mq_ops);
-
-	blk_delete_timer(rq);
-	blk_clear_rq_complete(rq);
-	trace_block_rq_requeue(q, rq);
-	rq_qos_requeue(q, rq);
-
-	BUG_ON(blk_queued_rq(rq));
-
-	elv_requeue_request(q, rq);
-}
-EXPORT_SYMBOL(blk_requeue_request);
-
-static void add_acct_request(struct request_queue *q, struct request *rq,
-			     int where)
-{
-	blk_account_io_start(rq, true);
-	__elv_add_request(q, rq, where);
-}
-
 static void part_round_stats_single(struct request_queue *q, int cpu,
 				    struct hd_struct *part, unsigned long now,
 				    unsigned int inflight)
@@ -1730,61 +805,16 @@ EXPORT_SYMBOL_GPL(part_round_stats);
 
 void __blk_put_request(struct request_queue *q, struct request *req)
 {
-	req_flags_t rq_flags = req->rq_flags;
-
 	if (unlikely(!q))
 		return;
 
-	if (q->mq_ops) {
-		blk_mq_free_request(req);
-		return;
-	}
-
-	lockdep_assert_held(q->queue_lock);
-
-	blk_req_zone_write_unlock(req);
-	blk_pm_put_request(req);
-	blk_pm_mark_last_busy(req);
-
-	elv_completed_request(q, req);
-
-	/* this is a bio leak */
-	WARN_ON(req->bio != NULL);
-
-	rq_qos_done(q, req);
-
-	/*
-	 * Request may not have originated from ll_rw_blk. if not,
-	 * it didn't come out of our reserved rq pools
-	 */
-	if (rq_flags & RQF_ALLOCED) {
-		struct request_list *rl = blk_rq_rl(req);
-		bool sync = op_is_sync(req->cmd_flags);
-
-		BUG_ON(!list_empty(&req->queuelist));
-		BUG_ON(ELV_ON_HASH(req));
-
-		blk_free_request(rl, req);
-		freed_request(rl, sync, rq_flags);
-		blk_put_rl(rl);
-		blk_queue_exit(q);
-	}
+	blk_mq_free_request(req);
 }
 EXPORT_SYMBOL_GPL(__blk_put_request);
 
 void blk_put_request(struct request *req)
 {
-	struct request_queue *q = req->q;
-
-	if (q->mq_ops)
-		blk_mq_free_request(req);
-	else {
-		unsigned long flags;
-
-		spin_lock_irqsave(q->queue_lock, flags);
-		__blk_put_request(q, req);
-		spin_unlock_irqrestore(q->queue_lock, flags);
-	}
+	blk_mq_free_request(req);
 }
 EXPORT_SYMBOL(blk_put_request);
 
@@ -1893,10 +923,7 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
 		return false;
 	*request_count = 0;
 
-	if (q->mq_ops)
-		plug_list = &plug->mq_list;
-	else
-		plug_list = &plug->list;
+	plug_list = &plug->mq_list;
 
 	list_for_each_entry_reverse(rq, plug_list, queuelist) {
 		bool merged = false;
@@ -1947,11 +974,7 @@ unsigned int blk_plug_queued_count(struct request_queue *q)
 	if (!plug)
 		goto out;
 
-	if (q->mq_ops)
-		plug_list = &plug->mq_list;
-	else
-		plug_list = &plug->list;
-
+	plug_list = &plug->mq_list;
 	list_for_each_entry(rq, plug_list, queuelist) {
 		if (rq->q == q)
 			ret++;
@@ -1979,133 +1002,6 @@ void blk_init_request_from_bio(struct request *req, struct bio *bio)
 }
 EXPORT_SYMBOL_GPL(blk_init_request_from_bio);
 
-static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio)
-{
-	struct blk_plug *plug;
-	int where = ELEVATOR_INSERT_SORT;
-	struct request *req, *free;
-	unsigned int request_count = 0;
-
-	/*
-	 * low level driver can indicate that it wants pages above a
-	 * certain limit bounced to low memory (ie for highmem, or even
-	 * ISA dma in theory)
-	 */
-	blk_queue_bounce(q, &bio);
-
-	blk_queue_split(q, &bio);
-
-	if (!bio_integrity_prep(bio))
-		return BLK_QC_T_NONE;
-
-	if (op_is_flush(bio->bi_opf)) {
-		spin_lock_irq(q->queue_lock);
-		where = ELEVATOR_INSERT_FLUSH;
-		goto get_rq;
-	}
-
-	/*
-	 * Check if we can merge with the plugged list before grabbing
-	 * any locks.
-	 */
-	if (!blk_queue_nomerges(q)) {
-		if (blk_attempt_plug_merge(q, bio, &request_count, NULL))
-			return BLK_QC_T_NONE;
-	} else
-		request_count = blk_plug_queued_count(q);
-
-	spin_lock_irq(q->queue_lock);
-
-	switch (elv_merge(q, &req, bio)) {
-	case ELEVATOR_BACK_MERGE:
-		if (!bio_attempt_back_merge(q, req, bio))
-			break;
-		elv_bio_merged(q, req, bio);
-		free = attempt_back_merge(q, req);
-		if (free)
-			__blk_put_request(q, free);
-		else
-			elv_merged_request(q, req, ELEVATOR_BACK_MERGE);
-		goto out_unlock;
-	case ELEVATOR_FRONT_MERGE:
-		if (!bio_attempt_front_merge(q, req, bio))
-			break;
-		elv_bio_merged(q, req, bio);
-		free = attempt_front_merge(q, req);
-		if (free)
-			__blk_put_request(q, free);
-		else
-			elv_merged_request(q, req, ELEVATOR_FRONT_MERGE);
-		goto out_unlock;
-	default:
-		break;
-	}
-
-get_rq:
-	rq_qos_throttle(q, bio, q->queue_lock);
-
-	/*
-	 * Grab a free request. This is might sleep but can not fail.
-	 * Returns with the queue unlocked.
-	 */
-	blk_queue_enter_live(q);
-	req = get_request(q, bio->bi_opf, bio, 0, GFP_NOIO);
-	if (IS_ERR(req)) {
-		blk_queue_exit(q);
-		rq_qos_cleanup(q, bio);
-		if (PTR_ERR(req) == -ENOMEM)
-			bio->bi_status = BLK_STS_RESOURCE;
-		else
-			bio->bi_status = BLK_STS_IOERR;
-		bio_endio(bio);
-		goto out_unlock;
-	}
-
-	rq_qos_track(q, req, bio);
-
-	/*
-	 * After dropping the lock and possibly sleeping here, our request
-	 * may now be mergeable after it had proven unmergeable (above).
-	 * We don't worry about that case for efficiency. It won't happen
-	 * often, and the elevators are able to handle it.
-	 */
-	blk_init_request_from_bio(req, bio);
-
-	if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags))
-		req->cpu = raw_smp_processor_id();
-
-	plug = current->plug;
-	if (plug) {
-		/*
-		 * If this is the first request added after a plug, fire
-		 * of a plug trace.
-		 *
-		 * @request_count may become stale because of schedule
-		 * out, so check plug list again.
-		 */
-		if (!request_count || list_empty(&plug->list))
-			trace_block_plug(q);
-		else {
-			struct request *last = list_entry_rq(plug->list.prev);
-			if (request_count >= BLK_MAX_REQUEST_COUNT ||
-			    blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE) {
-				blk_flush_plug_list(plug, false);
-				trace_block_plug(q);
-			}
-		}
-		list_add_tail(&req->queuelist, &plug->list);
-		blk_account_io_start(req, true);
-	} else {
-		spin_lock_irq(q->queue_lock);
-		add_acct_request(q, req, where);
-		__blk_run_queue(q);
-out_unlock:
-		spin_unlock_irq(q->queue_lock);
-	}
-
-	return BLK_QC_T_NONE;
-}
-
 static void handle_bad_sector(struct bio *bio, sector_t maxsector)
 {
 	char b[BDEVNAME_SIZE];
@@ -2617,9 +1513,6 @@ static int blk_cloned_rq_check_limits(struct request_queue *q,
  */
 blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request *rq)
 {
-	unsigned long flags;
-	int where = ELEVATOR_INSERT_BACK;
-
 	if (blk_cloned_rq_check_limits(q, rq))
 		return BLK_STS_IOERR;
 
@@ -2627,38 +1520,15 @@ blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request *
 	    should_fail_request(&rq->rq_disk->part0, blk_rq_bytes(rq)))
 		return BLK_STS_IOERR;
 
-	if (q->mq_ops) {
-		if (blk_queue_io_stat(q))
-			blk_account_io_start(rq, true);
-		/*
-		 * Since we have a scheduler attached on the top device,
-		 * bypass a potential scheduler on the bottom device for
-		 * insert.
-		 */
-		return blk_mq_request_issue_directly(rq);
-	}
-
-	spin_lock_irqsave(q->queue_lock, flags);
-	if (unlikely(blk_queue_dying(q))) {
-		spin_unlock_irqrestore(q->queue_lock, flags);
-		return BLK_STS_IOERR;
-	}
+	if (blk_queue_io_stat(q))
+		blk_account_io_start(rq, true);
 
 	/*
-	 * Submitting request must be dequeued before calling this function
-	 * because it will be linked to another request_queue
+	 * Since we have a scheduler attached on the top device,
+	 * bypass a potential scheduler on the bottom device for
+	 * insert.
 	 */
-	BUG_ON(blk_queued_rq(rq));
-
-	if (op_is_flush(rq->cmd_flags))
-		where = ELEVATOR_INSERT_FLUSH;
-
-	add_acct_request(q, rq, where);
-	if (where == ELEVATOR_INSERT_FLUSH)
-		__blk_run_queue(q);
-	spin_unlock_irqrestore(q->queue_lock, flags);
-
-	return BLK_STS_OK;
+	return blk_mq_request_issue_directly(rq);
 }
 EXPORT_SYMBOL_GPL(blk_insert_cloned_request);
 
@@ -2778,225 +1648,6 @@ void blk_account_io_start(struct request *rq, bool new_io)
 	part_stat_unlock();
 }
 
-static struct request *elv_next_request(struct request_queue *q)
-{
-	struct request *rq;
-	struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL);
-
-	WARN_ON_ONCE(q->mq_ops);
-
-	while (1) {
-		list_for_each_entry(rq, &q->queue_head, queuelist) {
-#ifdef CONFIG_PM
-			/*
-			 * If a request gets queued in state RPM_SUSPENDED
-			 * then that's a kernel bug.
-			 */
-			WARN_ON_ONCE(q->rpm_status == RPM_SUSPENDED);
-#endif
-			return rq;
-		}
-
-		/*
-		 * Flush request is running and flush request isn't queueable
-		 * in the drive, we can hold the queue till flush request is
-		 * finished. Even we don't do this, driver can't dispatch next
-		 * requests and will requeue them. And this can improve
-		 * throughput too. For example, we have request flush1, write1,
-		 * flush 2. flush1 is dispatched, then queue is hold, write1
-		 * isn't inserted to queue. After flush1 is finished, flush2
-		 * will be dispatched. Since disk cache is already clean,
-		 * flush2 will be finished very soon, so looks like flush2 is
-		 * folded to flush1.
-		 * Since the queue is hold, a flag is set to indicate the queue
-		 * should be restarted later. Please see flush_end_io() for
-		 * details.
-		 */
-		if (fq->flush_pending_idx != fq->flush_running_idx &&
-				!queue_flush_queueable(q)) {
-			fq->flush_queue_delayed = 1;
-			return NULL;
-		}
-		if (unlikely(blk_queue_bypass(q)) ||
-		    !q->elevator->type->ops.sq.elevator_dispatch_fn(q, 0))
-			return NULL;
-	}
-}
-
-/**
- * blk_peek_request - peek at the top of a request queue
- * @q: request queue to peek at
- *
- * Description:
- *     Return the request at the top of @q.  The returned request
- *     should be started using blk_start_request() before LLD starts
- *     processing it.
- *
- * Return:
- *     Pointer to the request at the top of @q if available.  Null
- *     otherwise.
- */
-struct request *blk_peek_request(struct request_queue *q)
-{
-	struct request *rq;
-	int ret;
-
-	lockdep_assert_held(q->queue_lock);
-	WARN_ON_ONCE(q->mq_ops);
-
-	while ((rq = elv_next_request(q)) != NULL) {
-		if (!(rq->rq_flags & RQF_STARTED)) {
-			/*
-			 * This is the first time the device driver
-			 * sees this request (possibly after
-			 * requeueing).  Notify IO scheduler.
-			 */
-			if (rq->rq_flags & RQF_SORTED)
-				elv_activate_rq(q, rq);
-
-			/*
-			 * just mark as started even if we don't start
-			 * it, a request that has been delayed should
-			 * not be passed by new incoming requests
-			 */
-			rq->rq_flags |= RQF_STARTED;
-			trace_block_rq_issue(q, rq);
-		}
-
-		if (!q->boundary_rq || q->boundary_rq == rq) {
-			q->end_sector = rq_end_sector(rq);
-			q->boundary_rq = NULL;
-		}
-
-		if (rq->rq_flags & RQF_DONTPREP)
-			break;
-
-		if (q->dma_drain_size && blk_rq_bytes(rq)) {
-			/*
-			 * make sure space for the drain appears we
-			 * know we can do this because max_hw_segments
-			 * has been adjusted to be one fewer than the
-			 * device can handle
-			 */
-			rq->nr_phys_segments++;
-		}
-
-		if (!q->prep_rq_fn)
-			break;
-
-		ret = q->prep_rq_fn(q, rq);
-		if (ret == BLKPREP_OK) {
-			break;
-		} else if (ret == BLKPREP_DEFER) {
-			/*
-			 * the request may have been (partially) prepped.
-			 * we need to keep this request in the front to
-			 * avoid resource deadlock.  RQF_STARTED will
-			 * prevent other fs requests from passing this one.
-			 */
-			if (q->dma_drain_size && blk_rq_bytes(rq) &&
-			    !(rq->rq_flags & RQF_DONTPREP)) {
-				/*
-				 * remove the space for the drain we added
-				 * so that we don't add it again
-				 */
-				--rq->nr_phys_segments;
-			}
-
-			rq = NULL;
-			break;
-		} else if (ret == BLKPREP_KILL || ret == BLKPREP_INVALID) {
-			rq->rq_flags |= RQF_QUIET;
-			/*
-			 * Mark this request as started so we don't trigger
-			 * any debug logic in the end I/O path.
-			 */
-			blk_start_request(rq);
-			__blk_end_request_all(rq, ret == BLKPREP_INVALID ?
-					BLK_STS_TARGET : BLK_STS_IOERR);
-		} else {
-			printk(KERN_ERR "%s: bad return=%d\n", __func__, ret);
-			break;
-		}
-	}
-
-	return rq;
-}
-EXPORT_SYMBOL(blk_peek_request);
-
-static void blk_dequeue_request(struct request *rq)
-{
-	struct request_queue *q = rq->q;
-
-	BUG_ON(list_empty(&rq->queuelist));
-	BUG_ON(ELV_ON_HASH(rq));
-
-	list_del_init(&rq->queuelist);
-
-	/*
-	 * the time frame between a request being removed from the lists
-	 * and to it is freed is accounted as io that is in progress at
-	 * the driver side.
-	 */
-	if (blk_account_rq(rq))
-		q->in_flight[rq_is_sync(rq)]++;
-}
-
-/**
- * blk_start_request - start request processing on the driver
- * @req: request to dequeue
- *
- * Description:
- *     Dequeue @req and start timeout timer on it.  This hands off the
- *     request to the driver.
- */
-void blk_start_request(struct request *req)
-{
-	lockdep_assert_held(req->q->queue_lock);
-	WARN_ON_ONCE(req->q->mq_ops);
-
-	blk_dequeue_request(req);
-
-	if (test_bit(QUEUE_FLAG_STATS, &req->q->queue_flags)) {
-		req->io_start_time_ns = ktime_get_ns();
-#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
-		req->throtl_size = blk_rq_sectors(req);
-#endif
-		req->rq_flags |= RQF_STATS;
-		rq_qos_issue(req->q, req);
-	}
-
-	BUG_ON(blk_rq_is_complete(req));
-	blk_add_timer(req);
-}
-EXPORT_SYMBOL(blk_start_request);
-
-/**
- * blk_fetch_request - fetch a request from a request queue
- * @q: request queue to fetch a request from
- *
- * Description:
- *     Return the request at the top of @q.  The request is started on
- *     return and LLD can start processing it immediately.
- *
- * Return:
- *     Pointer to the request at the top of @q if available.  Null
- *     otherwise.
- */
-struct request *blk_fetch_request(struct request_queue *q)
-{
-	struct request *rq;
-
-	lockdep_assert_held(q->queue_lock);
-	WARN_ON_ONCE(q->mq_ops);
-
-	rq = blk_peek_request(q);
-	if (rq)
-		blk_start_request(rq);
-	return rq;
-}
-EXPORT_SYMBOL(blk_fetch_request);
-
 /*
  * Steal bios from a request and add them to a bio list.
  * The request must not have been partially completed before.
@@ -3122,252 +1773,6 @@ bool blk_update_request(struct request *req, blk_status_t error,
 }
 EXPORT_SYMBOL_GPL(blk_update_request);
 
-static bool blk_update_bidi_request(struct request *rq, blk_status_t error,
-				    unsigned int nr_bytes,
-				    unsigned int bidi_bytes)
-{
-	if (blk_update_request(rq, error, nr_bytes))
-		return true;
-
-	/* Bidi request must be completed as a whole */
-	if (unlikely(blk_bidi_rq(rq)) &&
-	    blk_update_request(rq->next_rq, error, bidi_bytes))
-		return true;
-
-	if (blk_queue_add_random(rq->q))
-		add_disk_randomness(rq->rq_disk);
-
-	return false;
-}
-
-/**
- * blk_unprep_request - unprepare a request
- * @req:	the request
- *
- * This function makes a request ready for complete resubmission (or
- * completion).  It happens only after all error handling is complete,
- * so represents the appropriate moment to deallocate any resources
- * that were allocated to the request in the prep_rq_fn.  The queue
- * lock is held when calling this.
- */
-void blk_unprep_request(struct request *req)
-{
-	struct request_queue *q = req->q;
-
-	req->rq_flags &= ~RQF_DONTPREP;
-	if (q->unprep_rq_fn)
-		q->unprep_rq_fn(q, req);
-}
-EXPORT_SYMBOL_GPL(blk_unprep_request);
-
-void blk_finish_request(struct request *req, blk_status_t error)
-{
-	struct request_queue *q = req->q;
-	u64 now = ktime_get_ns();
-
-	lockdep_assert_held(req->q->queue_lock);
-	WARN_ON_ONCE(q->mq_ops);
-
-	if (req->rq_flags & RQF_STATS)
-		blk_stat_add(req, now);
-
-	BUG_ON(blk_queued_rq(req));
-
-	if (unlikely(laptop_mode) && !blk_rq_is_passthrough(req))
-		laptop_io_completion(req->q->backing_dev_info);
-
-	blk_delete_timer(req);
-
-	if (req->rq_flags & RQF_DONTPREP)
-		blk_unprep_request(req);
-
-	blk_account_io_done(req, now);
-
-	if (req->end_io) {
-		rq_qos_done(q, req);
-		req->end_io(req, error);
-	} else {
-		if (blk_bidi_rq(req))
-			__blk_put_request(req->next_rq->q, req->next_rq);
-
-		__blk_put_request(q, req);
-	}
-}
-EXPORT_SYMBOL(blk_finish_request);
-
-/**
- * blk_end_bidi_request - Complete a bidi request
- * @rq:         the request to complete
- * @error:      block status code
- * @nr_bytes:   number of bytes to complete @rq
- * @bidi_bytes: number of bytes to complete @rq->next_rq
- *
- * Description:
- *     Ends I/O on a number of bytes attached to @rq and @rq->next_rq.
- *     Drivers that supports bidi can safely call this member for any
- *     type of request, bidi or uni.  In the later case @bidi_bytes is
- *     just ignored.
- *
- * Return:
- *     %false - we are done with this request
- *     %true  - still buffers pending for this request
- **/
-static bool blk_end_bidi_request(struct request *rq, blk_status_t error,
-				 unsigned int nr_bytes, unsigned int bidi_bytes)
-{
-	struct request_queue *q = rq->q;
-	unsigned long flags;
-
-	WARN_ON_ONCE(q->mq_ops);
-
-	if (blk_update_bidi_request(rq, error, nr_bytes, bidi_bytes))
-		return true;
-
-	spin_lock_irqsave(q->queue_lock, flags);
-	blk_finish_request(rq, error);
-	spin_unlock_irqrestore(q->queue_lock, flags);
-
-	return false;
-}
-
-/**
- * __blk_end_bidi_request - Complete a bidi request with queue lock held
- * @rq:         the request to complete
- * @error:      block status code
- * @nr_bytes:   number of bytes to complete @rq
- * @bidi_bytes: number of bytes to complete @rq->next_rq
- *
- * Description:
- *     Identical to blk_end_bidi_request() except that queue lock is
- *     assumed to be locked on entry and remains so on return.
- *
- * Return:
- *     %false - we are done with this request
- *     %true  - still buffers pending for this request
- **/
-static bool __blk_end_bidi_request(struct request *rq, blk_status_t error,
-				   unsigned int nr_bytes, unsigned int bidi_bytes)
-{
-	lockdep_assert_held(rq->q->queue_lock);
-	WARN_ON_ONCE(rq->q->mq_ops);
-
-	if (blk_update_bidi_request(rq, error, nr_bytes, bidi_bytes))
-		return true;
-
-	blk_finish_request(rq, error);
-
-	return false;
-}
-
-/**
- * blk_end_request - Helper function for drivers to complete the request.
- * @rq:       the request being processed
- * @error:    block status code
- * @nr_bytes: number of bytes to complete
- *
- * Description:
- *     Ends I/O on a number of bytes attached to @rq.
- *     If @rq has leftover, sets it up for the next range of segments.
- *
- * Return:
- *     %false - we are done with this request
- *     %true  - still buffers pending for this request
- **/
-bool blk_end_request(struct request *rq, blk_status_t error,
-		unsigned int nr_bytes)
-{
-	WARN_ON_ONCE(rq->q->mq_ops);
-	return blk_end_bidi_request(rq, error, nr_bytes, 0);
-}
-EXPORT_SYMBOL(blk_end_request);
-
-/**
- * blk_end_request_all - Helper function for drives to finish the request.
- * @rq: the request to finish
- * @error: block status code
- *
- * Description:
- *     Completely finish @rq.
- */
-void blk_end_request_all(struct request *rq, blk_status_t error)
-{
-	bool pending;
-	unsigned int bidi_bytes = 0;
-
-	if (unlikely(blk_bidi_rq(rq)))
-		bidi_bytes = blk_rq_bytes(rq->next_rq);
-
-	pending = blk_end_bidi_request(rq, error, blk_rq_bytes(rq), bidi_bytes);
-	BUG_ON(pending);
-}
-EXPORT_SYMBOL(blk_end_request_all);
-
-/**
- * __blk_end_request - Helper function for drivers to complete the request.
- * @rq:       the request being processed
- * @error:    block status code
- * @nr_bytes: number of bytes to complete
- *
- * Description:
- *     Must be called with queue lock held unlike blk_end_request().
- *
- * Return:
- *     %false - we are done with this request
- *     %true  - still buffers pending for this request
- **/
-bool __blk_end_request(struct request *rq, blk_status_t error,
-		unsigned int nr_bytes)
-{
-	lockdep_assert_held(rq->q->queue_lock);
-	WARN_ON_ONCE(rq->q->mq_ops);
-
-	return __blk_end_bidi_request(rq, error, nr_bytes, 0);
-}
-EXPORT_SYMBOL(__blk_end_request);
-
-/**
- * __blk_end_request_all - Helper function for drives to finish the request.
- * @rq: the request to finish
- * @error:    block status code
- *
- * Description:
- *     Completely finish @rq.  Must be called with queue lock held.
- */
-void __blk_end_request_all(struct request *rq, blk_status_t error)
-{
-	bool pending;
-	unsigned int bidi_bytes = 0;
-
-	lockdep_assert_held(rq->q->queue_lock);
-	WARN_ON_ONCE(rq->q->mq_ops);
-
-	if (unlikely(blk_bidi_rq(rq)))
-		bidi_bytes = blk_rq_bytes(rq->next_rq);
-
-	pending = __blk_end_bidi_request(rq, error, blk_rq_bytes(rq), bidi_bytes);
-	BUG_ON(pending);
-}
-EXPORT_SYMBOL(__blk_end_request_all);
-
-/**
- * __blk_end_request_cur - Helper function to finish the current request chunk.
- * @rq: the request to finish the current chunk for
- * @error:    block status code
- *
- * Description:
- *     Complete the current consecutively mapped chunk from @rq.  Must
- *     be called with queue lock held.
- *
- * Return:
- *     %false - we are done with this request
- *     %true  - still buffers pending for this request
- */
-bool __blk_end_request_cur(struct request *rq, blk_status_t error)
-{
-	return __blk_end_request(rq, error, blk_rq_cur_bytes(rq));
-}
-EXPORT_SYMBOL(__blk_end_request_cur);
-
 void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
 		     struct bio *bio)
 {
@@ -3567,7 +1972,6 @@ void blk_start_plug(struct blk_plug *plug)
 	if (tsk->plug)
 		return;
 
-	INIT_LIST_HEAD(&plug->list);
 	INIT_LIST_HEAD(&plug->mq_list);
 	INIT_LIST_HEAD(&plug->cb_list);
 	/*
@@ -3578,36 +1982,6 @@ void blk_start_plug(struct blk_plug *plug)
 }
 EXPORT_SYMBOL(blk_start_plug);
 
-static int plug_rq_cmp(void *priv, struct list_head *a, struct list_head *b)
-{
-	struct request *rqa = container_of(a, struct request, queuelist);
-	struct request *rqb = container_of(b, struct request, queuelist);
-
-	return !(rqa->q < rqb->q ||
-		(rqa->q == rqb->q && blk_rq_pos(rqa) < blk_rq_pos(rqb)));
-}
-
-/*
- * If 'from_schedule' is true, then postpone the dispatch of requests
- * until a safe kblockd context. We due this to avoid accidental big
- * additional stack usage in driver dispatch, in places where the originally
- * plugger did not intend it.
- */
-static void queue_unplugged(struct request_queue *q, unsigned int depth,
-			    bool from_schedule)
-	__releases(q->queue_lock)
-{
-	lockdep_assert_held(q->queue_lock);
-
-	trace_block_unplug(q, depth, !from_schedule);
-
-	if (from_schedule)
-		blk_run_queue_async(q);
-	else
-		__blk_run_queue(q);
-	spin_unlock_irq(q->queue_lock);
-}
-
 static void flush_plug_callbacks(struct blk_plug *plug, bool from_schedule)
 {
 	LIST_HEAD(callbacks);
@@ -3652,65 +2026,10 @@ EXPORT_SYMBOL(blk_check_plugged);
 
 void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
 {
-	struct request_queue *q;
-	struct request *rq;
-	LIST_HEAD(list);
-	unsigned int depth;
-
 	flush_plug_callbacks(plug, from_schedule);
 
 	if (!list_empty(&plug->mq_list))
 		blk_mq_flush_plug_list(plug, from_schedule);
-
-	if (list_empty(&plug->list))
-		return;
-
-	list_splice_init(&plug->list, &list);
-
-	list_sort(NULL, &list, plug_rq_cmp);
-
-	q = NULL;
-	depth = 0;
-
-	while (!list_empty(&list)) {
-		rq = list_entry_rq(list.next);
-		list_del_init(&rq->queuelist);
-		BUG_ON(!rq->q);
-		if (rq->q != q) {
-			/*
-			 * This drops the queue lock
-			 */
-			if (q)
-				queue_unplugged(q, depth, from_schedule);
-			q = rq->q;
-			depth = 0;
-			spin_lock_irq(q->queue_lock);
-		}
-
-		/*
-		 * Short-circuit if @q is dead
-		 */
-		if (unlikely(blk_queue_dying(q))) {
-			__blk_end_request_all(rq, BLK_STS_IOERR);
-			continue;
-		}
-
-		/*
-		 * rq is already accounted, so use raw insert
-		 */
-		if (op_is_flush(rq->cmd_flags))
-			__elv_add_request(q, rq, ELEVATOR_INSERT_FLUSH);
-		else
-			__elv_add_request(q, rq, ELEVATOR_INSERT_SORT_MERGE);
-
-		depth++;
-	}
-
-	/*
-	 * This drops the queue lock
-	 */
-	if (q)
-		queue_unplugged(q, depth, from_schedule);
 }
 
 void blk_finish_plug(struct blk_plug *plug)
diff --git a/block/blk-exec.c b/block/blk-exec.c
index f7b292f12449..a34b7d918742 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -48,8 +48,6 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
 			   struct request *rq, int at_head,
 			   rq_end_io_fn *done)
 {
-	int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
-
 	WARN_ON(irqs_disabled());
 	WARN_ON(!blk_rq_is_passthrough(rq));
 
@@ -60,23 +58,7 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
 	 * don't check dying flag for MQ because the request won't
 	 * be reused after dying flag is set
 	 */
-	if (q->mq_ops) {
-		blk_mq_sched_insert_request(rq, at_head, true, false);
-		return;
-	}
-
-	spin_lock_irq(q->queue_lock);
-
-	if (unlikely(blk_queue_dying(q))) {
-		rq->rq_flags |= RQF_QUIET;
-		__blk_end_request_all(rq, BLK_STS_IOERR);
-		spin_unlock_irq(q->queue_lock);
-		return;
-	}
-
-	__elv_add_request(q, rq, where);
-	__blk_run_queue(q);
-	spin_unlock_irq(q->queue_lock);
+	blk_mq_sched_insert_request(rq, at_head, true, false);
 }
 EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
 
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 01580f88fcb3..391128456aec 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -48,10 +48,8 @@ static void ioc_exit_icq(struct io_cq *icq)
 	if (icq->flags & ICQ_EXITED)
 		return;
 
-	if (et->uses_mq && et->ops.mq.exit_icq)
+	if (et->ops.mq.exit_icq)
 		et->ops.mq.exit_icq(icq);
-	else if (!et->uses_mq && et->ops.sq.elevator_exit_icq_fn)
-		et->ops.sq.elevator_exit_icq_fn(icq);
 
 	icq->flags |= ICQ_EXITED;
 }
@@ -187,25 +185,13 @@ void put_io_context_active(struct io_context *ioc)
 	 * reverse double locking.  Read comment in ioc_release_fn() for
 	 * explanation on the nested locking annotation.
 	 */
-retry:
 	spin_lock_irqsave_nested(&ioc->lock, flags, 1);
 	hlist_for_each_entry(icq, &ioc->icq_list, ioc_node) {
 		if (icq->flags & ICQ_EXITED)
 			continue;
 
 		et = icq->q->elevator->type;
-		if (et->uses_mq) {
-			ioc_exit_icq(icq);
-		} else {
-			if (spin_trylock(icq->q->queue_lock)) {
-				ioc_exit_icq(icq);
-				spin_unlock(icq->q->queue_lock);
-			} else {
-				spin_unlock_irqrestore(&ioc->lock, flags);
-				cpu_relax();
-				goto retry;
-			}
-		}
+		ioc_exit_icq(icq);
 	}
 	spin_unlock_irqrestore(&ioc->lock, flags);
 
@@ -232,7 +218,7 @@ static void __ioc_clear_queue(struct list_head *icq_list)
 
 	while (!list_empty(icq_list)) {
 		struct io_cq *icq = list_entry(icq_list->next,
-					       struct io_cq, q_node);
+						struct io_cq, q_node);
 		struct io_context *ioc = icq->ioc;
 
 		spin_lock_irqsave(&ioc->lock, flags);
@@ -253,14 +239,9 @@ void ioc_clear_queue(struct request_queue *q)
 
 	spin_lock_irq(q->queue_lock);
 	list_splice_init(&q->icq_list, &icq_list);
+	spin_unlock_irq(q->queue_lock);
 
-	if (q->mq_ops) {
-		spin_unlock_irq(q->queue_lock);
-		__ioc_clear_queue(&icq_list);
-	} else {
-		__ioc_clear_queue(&icq_list);
-		spin_unlock_irq(q->queue_lock);
-	}
+	__ioc_clear_queue(&icq_list);
 }
 
 int create_task_io_context(struct task_struct *task, gfp_t gfp_flags, int node)
@@ -415,10 +396,8 @@ struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
 	if (likely(!radix_tree_insert(&ioc->icq_tree, q->id, icq))) {
 		hlist_add_head(&icq->ioc_node, &ioc->icq_list);
 		list_add(&icq->q_node, &q->icq_list);
-		if (et->uses_mq && et->ops.mq.init_icq)
+		if (et->ops.mq.init_icq)
 			et->ops.mq.init_icq(icq);
-		else if (!et->uses_mq && et->ops.sq.elevator_init_icq_fn)
-			et->ops.sq.elevator_init_icq_fn(icq);
 	} else {
 		kmem_cache_free(et->icq_cache, icq);
 		icq = ioc_lookup_icq(ioc, q);
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 6b5ad275ed56..c068c30b0c35 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -862,13 +862,8 @@ struct request *attempt_front_merge(struct request_queue *q, struct request *rq)
 int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
 			  struct request *next)
 {
-	struct elevator_queue *e = q->elevator;
 	struct request *free;
 
-	if (!e->uses_mq && e->type->ops.sq.elevator_allow_rq_merge_fn)
-		if (!e->type->ops.sq.elevator_allow_rq_merge_fn(q, rq, next))
-			return 0;
-
 	free = attempt_merge(q, rq, next);
 	if (free) {
 		__blk_put_request(q, free);
diff --git a/block/blk-settings.c b/block/blk-settings.c
index ac8b8ba4b126..39c3c301a687 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -20,40 +20,6 @@ EXPORT_SYMBOL(blk_max_low_pfn);
 
 unsigned long blk_max_pfn;
 
-/**
- * blk_queue_prep_rq - set a prepare_request function for queue
- * @q:		queue
- * @pfn:	prepare_request function
- *
- * It's possible for a queue to register a prepare_request callback which
- * is invoked before the request is handed to the request_fn. The goal of
- * the function is to prepare a request for I/O, it can be used to build a
- * cdb from the request data for instance.
- *
- */
-void blk_queue_prep_rq(struct request_queue *q, prep_rq_fn *pfn)
-{
-	q->prep_rq_fn = pfn;
-}
-EXPORT_SYMBOL(blk_queue_prep_rq);
-
-/**
- * blk_queue_unprep_rq - set an unprepare_request function for queue
- * @q:		queue
- * @ufn:	unprepare_request function
- *
- * It's possible for a queue to register an unprepare_request callback
- * which is invoked before the request is finally completed. The goal
- * of the function is to deallocate any data that was allocated in the
- * prepare_request callback.
- *
- */
-void blk_queue_unprep_rq(struct request_queue *q, unprep_rq_fn *ufn)
-{
-	q->unprep_rq_fn = ufn;
-}
-EXPORT_SYMBOL(blk_queue_unprep_rq);
-
 void blk_queue_softirq_done(struct request_queue *q, softirq_done_fn *fn)
 {
 	q->softirq_done_fn = fn;
@@ -163,8 +129,6 @@ void blk_queue_make_request(struct request_queue *q, make_request_fn *mfn)
 
 	q->make_request_fn = mfn;
 	blk_queue_dma_alignment(q, 511);
-	blk_queue_congestion_threshold(q);
-	q->nr_batching = BLK_BATCH_REQ;
 
 	blk_set_default_limits(&q->limits);
 }
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 1b82ccfde3fe..d4b1b84ba8ca 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -68,7 +68,7 @@ queue_requests_store(struct request_queue *q, const char *page, size_t count)
 	unsigned long nr;
 	int ret, err;
 
-	if (!q->request_fn && !q->mq_ops)
+	if (!q->mq_ops)
 		return -EINVAL;
 
 	ret = queue_var_store(&nr, page, count);
@@ -78,11 +78,7 @@ queue_requests_store(struct request_queue *q, const char *page, size_t count)
 	if (nr < BLKDEV_MIN_RQ)
 		nr = BLKDEV_MIN_RQ;
 
-	if (q->request_fn)
-		err = blk_update_nr_requests(q, nr);
-	else
-		err = blk_mq_update_nr_requests(q, nr);
-
+	err = blk_mq_update_nr_requests(q, nr);
 	if (err)
 		return err;
 
@@ -463,20 +459,14 @@ static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
 	 * ends up either enabling or disabling wbt completely. We can't
 	 * have IO inflight if that happens.
 	 */
-	if (q->mq_ops) {
-		blk_mq_freeze_queue(q);
-		blk_mq_quiesce_queue(q);
-	} else
-		blk_queue_bypass_start(q);
+	blk_mq_freeze_queue(q);
+	blk_mq_quiesce_queue(q);
 
 	wbt_set_min_lat(q, val);
 	wbt_update_limits(q);
 
-	if (q->mq_ops) {
-		blk_mq_unquiesce_queue(q);
-		blk_mq_unfreeze_queue(q);
-	} else
-		blk_queue_bypass_end(q);
+	blk_mq_unquiesce_queue(q);
+	blk_mq_unfreeze_queue(q);
 
 	return count;
 }
@@ -847,17 +837,10 @@ static void __blk_release_queue(struct work_struct *work)
 
 	blk_free_queue_stats(q->stats);
 
-	blk_exit_rl(q, &q->root_rl);
-
 	blk_queue_free_zone_bitmaps(q);
 
-	if (!q->mq_ops) {
-		if (q->exit_rq_fn)
-			q->exit_rq_fn(q, q->fq->flush_rq);
-		blk_free_flush_queue(q->fq);
-	} else {
+	if (q->mq_ops)
 		blk_mq_release(q);
-	}
 
 	blk_trace_shutdown(q);
 
@@ -920,7 +903,6 @@ int blk_register_queue(struct gendisk *disk)
 	if (!blk_queue_init_done(q)) {
 		queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q);
 		percpu_ref_switch_to_percpu(&q->q_usage_counter);
-		blk_queue_bypass_end(q);
 	}
 
 	ret = blk_trace_init_sysfs(dev);
@@ -947,7 +929,7 @@ int blk_register_queue(struct gendisk *disk)
 
 	blk_throtl_register_queue(q);
 
-	if (q->request_fn || (q->mq_ops && q->elevator)) {
+	if ((q->mq_ops && q->elevator)) {
 		ret = elv_register_queue(q);
 		if (ret) {
 			mutex_unlock(&q->sysfs_lock);
@@ -1005,7 +987,7 @@ void blk_unregister_queue(struct gendisk *disk)
 	blk_trace_remove_sysfs(disk_to_dev(disk));
 
 	mutex_lock(&q->sysfs_lock);
-	if (q->request_fn || (q->mq_ops && q->elevator))
+	if (q->mq_ops && q->elevator)
 		elv_unregister_queue(q);
 	mutex_unlock(&q->sysfs_lock);
 
diff --git a/block/blk.h b/block/blk.h
index 57a302bf5a70..e2604ae7ddfa 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -7,12 +7,6 @@
 #include <xen/xen.h>
 #include "blk-mq.h"
 
-/* Amount of time in which a process may batch requests */
-#define BLK_BATCH_TIME	(HZ/50UL)
-
-/* Number of requests a "batching" process may submit */
-#define BLK_BATCH_REQ	32
-
 /* Max future timer expiry for timeouts */
 #define BLK_MAX_TIMEOUT		(5 * HZ)
 
@@ -132,9 +126,6 @@ void blk_exit_rl(struct request_queue *q, struct request_list *rl);
 void blk_exit_queue(struct request_queue *q);
 void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
 			struct bio *bio);
-void blk_queue_bypass_start(struct request_queue *q);
-void blk_queue_bypass_end(struct request_queue *q);
-void __blk_queue_free_tags(struct request_queue *q);
 void blk_freeze_queue(struct request_queue *q);
 
 static inline void blk_queue_enter_live(struct request_queue *q)
@@ -281,23 +272,6 @@ static inline bool blk_rq_is_complete(struct request *rq)
 
 void blk_insert_flush(struct request *rq);
 
-static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
-{
-	struct elevator_queue *e = q->elevator;
-
-	if (e->type->ops.sq.elevator_activate_req_fn)
-		e->type->ops.sq.elevator_activate_req_fn(q, rq);
-}
-
-static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
-{
-	struct elevator_queue *e = q->elevator;
-
-	if (e->type->ops.sq.elevator_deactivate_req_fn)
-		e->type->ops.sq.elevator_deactivate_req_fn(q, rq);
-}
-
-int elevator_init(struct request_queue *);
 int elevator_init_mq(struct request_queue *q);
 int elevator_switch_mq(struct request_queue *q,
 			      struct elevator_type *new_e);
@@ -332,31 +306,8 @@ void blk_rq_set_mixed_merge(struct request *rq);
 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
 
-void blk_queue_congestion_threshold(struct request_queue *q);
-
 int blk_dev_init(void);
 
-
-/*
- * Return the threshold (number of used requests) at which the queue is
- * considered to be congested.  It include a little hysteresis to keep the
- * context switch rate down.
- */
-static inline int queue_congestion_on_threshold(struct request_queue *q)
-{
-	return q->nr_congestion_on;
-}
-
-/*
- * The threshold at which a queue is considered to be uncongested
- */
-static inline int queue_congestion_off_threshold(struct request_queue *q)
-{
-	return q->nr_congestion_off;
-}
-
-extern int blk_update_nr_requests(struct request_queue *, unsigned int);
-
 /*
  * Contribute to IO statistics IFF:
  *
@@ -478,8 +429,6 @@ static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
 }
 #endif /* CONFIG_BOUNCE */
 
-extern void blk_drain_queue(struct request_queue *q);
-
 #ifdef CONFIG_BLK_CGROUP_IOLATENCY
 extern int blk_iolatency_init(struct request_queue *q);
 #else
diff --git a/block/elevator.c b/block/elevator.c
index 54e1adac26c5..334097c54b08 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -61,10 +61,8 @@ static int elv_iosched_allow_bio_merge(struct request *rq, struct bio *bio)
 	struct request_queue *q = rq->q;
 	struct elevator_queue *e = q->elevator;
 
-	if (e->uses_mq && e->type->ops.mq.allow_merge)
+	if (e->type->ops.mq.allow_merge)
 		return e->type->ops.mq.allow_merge(q, rq, bio);
-	else if (!e->uses_mq && e->type->ops.sq.elevator_allow_bio_merge_fn)
-		return e->type->ops.sq.elevator_allow_bio_merge_fn(q, rq, bio);
 
 	return 1;
 }
@@ -95,14 +93,14 @@ static bool elevator_match(const struct elevator_type *e, const char *name)
 }
 
 /*
- * Return scheduler with name 'name' and with matching 'mq capability
+ * Return scheduler with name 'name'
  */
-static struct elevator_type *elevator_find(const char *name, bool mq)
+static struct elevator_type *elevator_find(const char *name)
 {
 	struct elevator_type *e;
 
 	list_for_each_entry(e, &elv_list, list) {
-		if (elevator_match(e, name) && (mq == e->uses_mq))
+		if (elevator_match(e, name))
 			return e;
 	}
 
@@ -121,12 +119,12 @@ static struct elevator_type *elevator_get(struct request_queue *q,
 
 	spin_lock(&elv_list_lock);
 
-	e = elevator_find(name, q->mq_ops != NULL);
+	e = elevator_find(name);
 	if (!e && try_loading) {
 		spin_unlock(&elv_list_lock);
 		request_module("%s-iosched", name);
 		spin_lock(&elv_list_lock);
-		e = elevator_find(name, q->mq_ops != NULL);
+		e = elevator_find(name);
 	}
 
 	if (e && !try_module_get(e->elevator_owner))
@@ -150,26 +148,6 @@ static int __init elevator_setup(char *str)
 
 __setup("elevator=", elevator_setup);
 
-/* called during boot to load the elevator chosen by the elevator param */
-void __init load_default_elevator_module(void)
-{
-	struct elevator_type *e;
-
-	if (!chosen_elevator[0])
-		return;
-
-	/*
-	 * Boot parameter is deprecated, we haven't supported that for MQ.
-	 * Only look for non-mq schedulers from here.
-	 */
-	spin_lock(&elv_list_lock);
-	e = elevator_find(chosen_elevator, false);
-	spin_unlock(&elv_list_lock);
-
-	if (!e)
-		request_module("%s-iosched", chosen_elevator);
-}
-
 static struct kobj_type elv_ktype;
 
 struct elevator_queue *elevator_alloc(struct request_queue *q,
@@ -185,7 +163,6 @@ struct elevator_queue *elevator_alloc(struct request_queue *q,
 	kobject_init(&eq->kobj, &elv_ktype);
 	mutex_init(&eq->sysfs_lock);
 	hash_init(eq->hash);
-	eq->uses_mq = e->uses_mq;
 
 	return eq;
 }
@@ -200,52 +177,11 @@ static void elevator_release(struct kobject *kobj)
 	kfree(e);
 }
 
-/*
- * Use the default elevator specified by config boot param for non-mq devices,
- * or by config option.  Don't try to load modules as we could be running off
- * async and request_module() isn't allowed from async.
- */
-int elevator_init(struct request_queue *q)
-{
-	struct elevator_type *e = NULL;
-	int err = 0;
-
-	/*
-	 * q->sysfs_lock must be held to provide mutual exclusion between
-	 * elevator_switch() and here.
-	 */
-	mutex_lock(&q->sysfs_lock);
-	if (unlikely(q->elevator))
-		goto out_unlock;
-
-	if (*chosen_elevator) {
-		e = elevator_get(q, chosen_elevator, false);
-		if (!e)
-			printk(KERN_ERR "I/O scheduler %s not found\n",
-							chosen_elevator);
-	}
-
-	if (!e) {
-		printk(KERN_ERR
-			"Default I/O scheduler not found. Using noop.\n");
-		e = elevator_get(q, "noop", false);
-	}
-
-	err = e->ops.sq.elevator_init_fn(q, e);
-	if (err)
-		elevator_put(e);
-out_unlock:
-	mutex_unlock(&q->sysfs_lock);
-	return err;
-}
-
 void elevator_exit(struct request_queue *q, struct elevator_queue *e)
 {
 	mutex_lock(&e->sysfs_lock);
-	if (e->uses_mq && e->type->ops.mq.exit_sched)
+	if (e->type->ops.mq.exit_sched)
 		blk_mq_exit_sched(q, e);
-	else if (!e->uses_mq && e->type->ops.sq.elevator_exit_fn)
-		e->type->ops.sq.elevator_exit_fn(e);
 	mutex_unlock(&e->sysfs_lock);
 
 	kobject_put(&e->kobj);
@@ -393,10 +329,8 @@ enum elv_merge elv_merge(struct request_queue *q, struct request **req,
 		return ELEVATOR_BACK_MERGE;
 	}
 
-	if (e->uses_mq && e->type->ops.mq.request_merge)
+	if (e->type->ops.mq.request_merge)
 		return e->type->ops.mq.request_merge(q, req, bio);
-	else if (!e->uses_mq && e->type->ops.sq.elevator_merge_fn)
-		return e->type->ops.sq.elevator_merge_fn(q, req, bio);
 
 	return ELEVATOR_NO_MERGE;
 }
@@ -447,10 +381,8 @@ void elv_merged_request(struct request_queue *q, struct request *rq,
 {
 	struct elevator_queue *e = q->elevator;
 
-	if (e->uses_mq && e->type->ops.mq.request_merged)
+	if (e->type->ops.mq.request_merged)
 		e->type->ops.mq.request_merged(q, rq, type);
-	else if (!e->uses_mq && e->type->ops.sq.elevator_merged_fn)
-		e->type->ops.sq.elevator_merged_fn(q, rq, type);
 
 	if (type == ELEVATOR_BACK_MERGE)
 		elv_rqhash_reposition(q, rq);
@@ -464,13 +396,8 @@ void elv_merge_requests(struct request_queue *q, struct request *rq,
 	struct elevator_queue *e = q->elevator;
 	bool next_sorted = false;
 
-	if (e->uses_mq && e->type->ops.mq.requests_merged)
+	if (e->type->ops.mq.requests_merged)
 		e->type->ops.mq.requests_merged(q, rq, next);
-	else if (e->type->ops.sq.elevator_merge_req_fn) {
-		next_sorted = (__force bool)(next->rq_flags & RQF_SORTED);
-		if (next_sorted)
-			e->type->ops.sq.elevator_merge_req_fn(q, rq, next);
-	}
 
 	elv_rqhash_reposition(q, rq);
 
@@ -482,156 +409,12 @@ void elv_merge_requests(struct request_queue *q, struct request *rq,
 	q->last_merge = rq;
 }
 
-void elv_bio_merged(struct request_queue *q, struct request *rq,
-			struct bio *bio)
-{
-	struct elevator_queue *e = q->elevator;
-
-	if (WARN_ON_ONCE(e->uses_mq))
-		return;
-
-	if (e->type->ops.sq.elevator_bio_merged_fn)
-		e->type->ops.sq.elevator_bio_merged_fn(q, rq, bio);
-}
-
-void elv_requeue_request(struct request_queue *q, struct request *rq)
-{
-	/*
-	 * it already went through dequeue, we need to decrement the
-	 * in_flight count again
-	 */
-	if (blk_account_rq(rq)) {
-		q->in_flight[rq_is_sync(rq)]--;
-		if (rq->rq_flags & RQF_SORTED)
-			elv_deactivate_rq(q, rq);
-	}
-
-	rq->rq_flags &= ~RQF_STARTED;
-
-	blk_pm_requeue_request(rq);
-
-	__elv_add_request(q, rq, ELEVATOR_INSERT_REQUEUE);
-}
-
-void elv_drain_elevator(struct request_queue *q)
-{
-	struct elevator_queue *e = q->elevator;
-	static int printed;
-
-	if (WARN_ON_ONCE(e->uses_mq))
-		return;
-
-	lockdep_assert_held(q->queue_lock);
-
-	while (e->type->ops.sq.elevator_dispatch_fn(q, 1))
-		;
-	if (q->nr_sorted && !blk_queue_is_zoned(q) && printed++ < 10 ) {
-		printk(KERN_ERR "%s: forced dispatching is broken "
-		       "(nr_sorted=%u), please report this\n",
-		       q->elevator->type->elevator_name, q->nr_sorted);
-	}
-}
-
-void __elv_add_request(struct request_queue *q, struct request *rq, int where)
-{
-	trace_block_rq_insert(q, rq);
-
-	blk_pm_add_request(q, rq);
-
-	rq->q = q;
-
-	if (rq->rq_flags & RQF_SOFTBARRIER) {
-		/* barriers are scheduling boundary, update end_sector */
-		if (!blk_rq_is_passthrough(rq)) {
-			q->end_sector = rq_end_sector(rq);
-			q->boundary_rq = rq;
-		}
-	} else if (!(rq->rq_flags & RQF_ELVPRIV) &&
-		    (where == ELEVATOR_INSERT_SORT ||
-		     where == ELEVATOR_INSERT_SORT_MERGE))
-		where = ELEVATOR_INSERT_BACK;
-
-	switch (where) {
-	case ELEVATOR_INSERT_REQUEUE:
-	case ELEVATOR_INSERT_FRONT:
-		rq->rq_flags |= RQF_SOFTBARRIER;
-		list_add(&rq->queuelist, &q->queue_head);
-		break;
-
-	case ELEVATOR_INSERT_BACK:
-		rq->rq_flags |= RQF_SOFTBARRIER;
-		elv_drain_elevator(q);
-		list_add_tail(&rq->queuelist, &q->queue_head);
-		/*
-		 * We kick the queue here for the following reasons.
-		 * - The elevator might have returned NULL previously
-		 *   to delay requests and returned them now.  As the
-		 *   queue wasn't empty before this request, ll_rw_blk
-		 *   won't run the queue on return, resulting in hang.
-		 * - Usually, back inserted requests won't be merged
-		 *   with anything.  There's no point in delaying queue
-		 *   processing.
-		 */
-		__blk_run_queue(q);
-		break;
-
-	case ELEVATOR_INSERT_SORT_MERGE:
-		/*
-		 * If we succeed in merging this request with one in the
-		 * queue already, we are done - rq has now been freed,
-		 * so no need to do anything further.
-		 */
-		if (elv_attempt_insert_merge(q, rq))
-			break;
-		/* fall through */
-	case ELEVATOR_INSERT_SORT:
-		BUG_ON(blk_rq_is_passthrough(rq));
-		rq->rq_flags |= RQF_SORTED;
-		q->nr_sorted++;
-		if (rq_mergeable(rq)) {
-			elv_rqhash_add(q, rq);
-			if (!q->last_merge)
-				q->last_merge = rq;
-		}
-
-		/*
-		 * Some ioscheds (cfq) run q->request_fn directly, so
-		 * rq cannot be accessed after calling
-		 * elevator_add_req_fn.
-		 */
-		q->elevator->type->ops.sq.elevator_add_req_fn(q, rq);
-		break;
-
-	case ELEVATOR_INSERT_FLUSH:
-		rq->rq_flags |= RQF_SOFTBARRIER;
-		blk_insert_flush(rq);
-		break;
-	default:
-		printk(KERN_ERR "%s: bad insertion point %d\n",
-		       __func__, where);
-		BUG();
-	}
-}
-EXPORT_SYMBOL(__elv_add_request);
-
-void elv_add_request(struct request_queue *q, struct request *rq, int where)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(q->queue_lock, flags);
-	__elv_add_request(q, rq, where);
-	spin_unlock_irqrestore(q->queue_lock, flags);
-}
-EXPORT_SYMBOL(elv_add_request);
-
 struct request *elv_latter_request(struct request_queue *q, struct request *rq)
 {
 	struct elevator_queue *e = q->elevator;
 
-	if (e->uses_mq && e->type->ops.mq.next_request)
+	if (e->type->ops.mq.next_request)
 		return e->type->ops.mq.next_request(q, rq);
-	else if (!e->uses_mq && e->type->ops.sq.elevator_latter_req_fn)
-		return e->type->ops.sq.elevator_latter_req_fn(q, rq);
 
 	return NULL;
 }
@@ -640,68 +423,12 @@ struct request *elv_former_request(struct request_queue *q, struct request *rq)
 {
 	struct elevator_queue *e = q->elevator;
 
-	if (e->uses_mq && e->type->ops.mq.former_request)
+	if (e->type->ops.mq.former_request)
 		return e->type->ops.mq.former_request(q, rq);
-	if (!e->uses_mq && e->type->ops.sq.elevator_former_req_fn)
-		return e->type->ops.sq.elevator_former_req_fn(q, rq);
+
 	return NULL;
 }
 
-int elv_set_request(struct request_queue *q, struct request *rq,
-		    struct bio *bio, gfp_t gfp_mask)
-{
-	struct elevator_queue *e = q->elevator;
-
-	if (WARN_ON_ONCE(e->uses_mq))
-		return 0;
-
-	if (e->type->ops.sq.elevator_set_req_fn)
-		return e->type->ops.sq.elevator_set_req_fn(q, rq, bio, gfp_mask);
-	return 0;
-}
-
-void elv_put_request(struct request_queue *q, struct request *rq)
-{
-	struct elevator_queue *e = q->elevator;
-
-	if (WARN_ON_ONCE(e->uses_mq))
-		return;
-
-	if (e->type->ops.sq.elevator_put_req_fn)
-		e->type->ops.sq.elevator_put_req_fn(rq);
-}
-
-int elv_may_queue(struct request_queue *q, unsigned int op)
-{
-	struct elevator_queue *e = q->elevator;
-
-	if (WARN_ON_ONCE(e->uses_mq))
-		return 0;
-
-	if (e->type->ops.sq.elevator_may_queue_fn)
-		return e->type->ops.sq.elevator_may_queue_fn(q, op);
-
-	return ELV_MQUEUE_MAY;
-}
-
-void elv_completed_request(struct request_queue *q, struct request *rq)
-{
-	struct elevator_queue *e = q->elevator;
-
-	if (WARN_ON_ONCE(e->uses_mq))
-		return;
-
-	/*
-	 * request is released from the driver, io must be done
-	 */
-	if (blk_account_rq(rq)) {
-		q->in_flight[rq_is_sync(rq)]--;
-		if ((rq->rq_flags & RQF_SORTED) &&
-		    e->type->ops.sq.elevator_completed_req_fn)
-			e->type->ops.sq.elevator_completed_req_fn(q, rq);
-	}
-}
-
 #define to_elv(atr) container_of((atr), struct elv_fs_entry, attr)
 
 static ssize_t
@@ -768,8 +495,6 @@ int elv_register_queue(struct request_queue *q)
 		}
 		kobject_uevent(&e->kobj, KOBJ_ADD);
 		e->registered = 1;
-		if (!e->uses_mq && e->type->ops.sq.elevator_registered_fn)
-			e->type->ops.sq.elevator_registered_fn(q);
 	}
 	return error;
 }
@@ -809,7 +534,7 @@ int elv_register(struct elevator_type *e)
 
 	/* register, don't allow duplicate names */
 	spin_lock(&elv_list_lock);
-	if (elevator_find(e->elevator_name, e->uses_mq)) {
+	if (elevator_find(e->elevator_name)) {
 		spin_unlock(&elv_list_lock);
 		kmem_cache_destroy(e->icq_cache);
 		return -EBUSY;
@@ -919,71 +644,17 @@ out_unlock:
  */
 static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
 {
-	struct elevator_queue *old = q->elevator;
-	bool old_registered = false;
 	int err;
 
 	lockdep_assert_held(&q->sysfs_lock);
 
-	if (q->mq_ops) {
-		blk_mq_freeze_queue(q);
-		blk_mq_quiesce_queue(q);
+	blk_mq_freeze_queue(q);
+	blk_mq_quiesce_queue(q);
 
-		err = elevator_switch_mq(q, new_e);
+	err = elevator_switch_mq(q, new_e);
 
-		blk_mq_unquiesce_queue(q);
-		blk_mq_unfreeze_queue(q);
-
-		return err;
-	}
-
-	/*
-	 * Turn on BYPASS and drain all requests w/ elevator private data.
-	 * Block layer doesn't call into a quiesced elevator - all requests
-	 * are directly put on the dispatch list without elevator data
-	 * using INSERT_BACK.  All requests have SOFTBARRIER set and no
-	 * merge happens either.
-	 */
-	if (old) {
-		old_registered = old->registered;
-
-		blk_queue_bypass_start(q);
-
-		/* unregister and clear all auxiliary data of the old elevator */
-		if (old_registered)
-			elv_unregister_queue(q);
-
-		ioc_clear_queue(q);
-	}
-
-	/* allocate, init and register new elevator */
-	err = new_e->ops.sq.elevator_init_fn(q, new_e);
-	if (err)
-		goto fail_init;
-
-	err = elv_register_queue(q);
-	if (err)
-		goto fail_register;
-
-	/* done, kill the old one and finish */
-	if (old) {
-		elevator_exit(q, old);
-		blk_queue_bypass_end(q);
-	}
-
-	blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name);
-
-	return 0;
-
-fail_register:
-	elevator_exit(q, q->elevator);
-fail_init:
-	/* switch failed, restore and re-register old elevator */
-	if (old) {
-		q->elevator = old;
-		elv_register_queue(q);
-		blk_queue_bypass_end(q);
-	}
+	blk_mq_unquiesce_queue(q);
+	blk_mq_unfreeze_queue(q);
 
 	return err;
 }
@@ -1032,7 +703,7 @@ ssize_t elv_iosched_store(struct request_queue *q, const char *name,
 {
 	int ret;
 
-	if (!(q->mq_ops || q->request_fn) || !elv_support_iosched(q))
+	if (!q->mq_ops || !elv_support_iosched(q))
 		return count;
 
 	ret = __elevator_change(q, name);
@@ -1047,7 +718,6 @@ ssize_t elv_iosched_show(struct request_queue *q, char *name)
 	struct elevator_queue *e = q->elevator;
 	struct elevator_type *elv = NULL;
 	struct elevator_type *__e;
-	bool uses_mq = q->mq_ops != NULL;
 	int len = 0;
 
 	if (!queue_is_rq_based(q))
@@ -1060,14 +730,11 @@ ssize_t elv_iosched_show(struct request_queue *q, char *name)
 
 	spin_lock(&elv_list_lock);
 	list_for_each_entry(__e, &elv_list, list) {
-		if (elv && elevator_match(elv, __e->elevator_name) &&
-		    (__e->uses_mq == uses_mq)) {
+		if (elv && elevator_match(elv, __e->elevator_name)) {
 			len += sprintf(name+len, "[%s] ", elv->elevator_name);
 			continue;
 		}
-		if (__e->uses_mq && q->mq_ops && elv_support_iosched(q))
-			len += sprintf(name+len, "%s ", __e->elevator_name);
-		else if (!__e->uses_mq && !q->mq_ops)
+		if (elv_support_iosched(q))
 			len += sprintf(name+len, "%s ", __e->elevator_name);
 	}
 	spin_unlock(&elv_list_lock);
diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c
index eccac01a10b6..728757a34fa0 100644
--- a/block/kyber-iosched.c
+++ b/block/kyber-iosched.c
@@ -1032,7 +1032,6 @@ static struct elevator_type kyber_sched = {
 		.dispatch_request = kyber_dispatch_request,
 		.has_work = kyber_has_work,
 	},
-	.uses_mq = true,
 #ifdef CONFIG_BLK_DEBUG_FS
 	.queue_debugfs_attrs = kyber_queue_debugfs_attrs,
 	.hctx_debugfs_attrs = kyber_hctx_debugfs_attrs,
diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index 099a9e05854c..513edefd10fd 100644
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -777,7 +777,6 @@ static struct elevator_type mq_deadline = {
 		.exit_sched		= dd_exit_queue,
 	},
 
-	.uses_mq	= true,
 #ifdef CONFIG_BLK_DEBUG_FS
 	.queue_debugfs_attrs = deadline_queue_debugfs_attrs,
 #endif
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 8afe3331777e..a9f6db8abcda 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -58,9 +58,6 @@ struct blk_stat_callback;
 
 typedef void (rq_end_io_fn)(struct request *, blk_status_t);
 
-#define BLK_RL_SYNCFULL		(1U << 0)
-#define BLK_RL_ASYNCFULL	(1U << 1)
-
 struct request_list {
 	struct request_queue	*q;	/* the queue this rl belongs to */
 #ifdef CONFIG_BLK_CGROUP
@@ -309,11 +306,8 @@ static inline unsigned short req_get_ioprio(struct request *req)
 
 struct blk_queue_ctx;
 
-typedef void (request_fn_proc) (struct request_queue *q);
 typedef blk_qc_t (make_request_fn) (struct request_queue *q, struct bio *bio);
 typedef bool (poll_q_fn) (struct request_queue *q, blk_qc_t);
-typedef int (prep_rq_fn) (struct request_queue *, struct request *);
-typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
 
 struct bio_vec;
 typedef void (softirq_done_fn)(struct request *);
@@ -432,8 +426,6 @@ struct request_queue {
 	struct list_head	queue_head;
 	struct request		*last_merge;
 	struct elevator_queue	*elevator;
-	int			nr_rqs[2];	/* # allocated [a]sync rqs */
-	int			nr_rqs_elvpriv;	/* # allocated rqs w/ elvpriv */
 
 	struct blk_queue_stats	*stats;
 	struct rq_qos		*rq_qos;
@@ -446,11 +438,8 @@ struct request_queue {
 	 */
 	struct request_list	root_rl;
 
-	request_fn_proc		*request_fn;
 	make_request_fn		*make_request_fn;
 	poll_q_fn		*poll_fn;
-	prep_rq_fn		*prep_rq_fn;
-	unprep_rq_fn		*unprep_rq_fn;
 	softirq_done_fn		*softirq_done_fn;
 	rq_timed_out_fn		*rq_timed_out_fn;
 	dma_drain_needed_fn	*dma_drain_needed;
@@ -458,8 +447,6 @@ struct request_queue {
 	init_rq_fn		*init_rq_fn;
 	/* Called just before a request is freed */
 	exit_rq_fn		*exit_rq_fn;
-	/* Called from inside blk_get_request() */
-	void (*initialize_rq_fn)(struct request *rq);
 
 	const struct blk_mq_ops	*mq_ops;
 
@@ -475,17 +462,6 @@ struct request_queue {
 	struct blk_mq_hw_ctx	**queue_hw_ctx;
 	unsigned int		nr_hw_queues;
 
-	/*
-	 * Dispatch queue sorting
-	 */
-	sector_t		end_sector;
-	struct request		*boundary_rq;
-
-	/*
-	 * Delayed queue handling
-	 */
-	struct delayed_work	delay_work;
-
 	struct backing_dev_info	*backing_dev_info;
 
 	/*
@@ -548,9 +524,6 @@ struct request_queue {
 	 * queue settings
 	 */
 	unsigned long		nr_requests;	/* Max # of requests */
-	unsigned int		nr_congestion_on;
-	unsigned int		nr_congestion_off;
-	unsigned int		nr_batching;
 
 	unsigned int		dma_drain_size;
 	void			*dma_drain_buffer;
@@ -560,13 +533,6 @@ struct request_queue {
 	unsigned int		nr_sorted;
 	unsigned int		in_flight[2];
 
-	/*
-	 * Number of active block driver functions for which blk_drain_queue()
-	 * must wait. Must be incremented around functions that unlock the
-	 * queue_lock internally, e.g. scsi_request_fn().
-	 */
-	unsigned int		request_fn_active;
-
 	unsigned int		rq_timeout;
 	int			poll_nsec;
 
@@ -740,11 +706,6 @@ bool blk_queue_flag_test_and_clear(unsigned int flag, struct request_queue *q);
 extern void blk_set_pm_only(struct request_queue *q);
 extern void blk_clear_pm_only(struct request_queue *q);
 
-static inline int queue_in_flight(struct request_queue *q)
-{
-	return q->in_flight[0] + q->in_flight[1];
-}
-
 static inline bool blk_account_rq(struct request *rq)
 {
 	return (rq->rq_flags & RQF_STARTED) && !blk_rq_is_passthrough(rq);
@@ -765,7 +726,7 @@ static inline bool blk_account_rq(struct request *rq)
  */
 static inline bool queue_is_rq_based(struct request_queue *q)
 {
-	return q->request_fn || q->mq_ops;
+	return q->mq_ops;
 }
 
 static inline unsigned int blk_queue_cluster(struct request_queue *q)
@@ -828,27 +789,6 @@ static inline bool rq_is_sync(struct request *rq)
 	return op_is_sync(rq->cmd_flags);
 }
 
-static inline bool blk_rl_full(struct request_list *rl, bool sync)
-{
-	unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
-
-	return rl->flags & flag;
-}
-
-static inline void blk_set_rl_full(struct request_list *rl, bool sync)
-{
-	unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
-
-	rl->flags |= flag;
-}
-
-static inline void blk_clear_rl_full(struct request_list *rl, bool sync)
-{
-	unsigned int flag = sync ? BLK_RL_SYNCFULL : BLK_RL_ASYNCFULL;
-
-	rl->flags &= ~flag;
-}
-
 static inline bool rq_mergeable(struct request *rq)
 {
 	if (blk_rq_is_passthrough(rq))
@@ -969,7 +909,6 @@ extern void blk_put_request(struct request *);
 extern void __blk_put_request(struct request_queue *, struct request *);
 extern struct request *blk_get_request(struct request_queue *, unsigned int op,
 				       blk_mq_req_flags_t flags);
-extern void blk_requeue_request(struct request_queue *, struct request *);
 extern int blk_lld_busy(struct request_queue *q);
 extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
 			     struct bio_set *bs, gfp_t gfp_mask,
@@ -979,7 +918,6 @@ extern void blk_rq_unprep_clone(struct request *rq);
 extern blk_status_t blk_insert_cloned_request(struct request_queue *q,
 				     struct request *rq);
 extern int blk_rq_append_bio(struct request *rq, struct bio **bio);
-extern void blk_delay_queue(struct request_queue *, unsigned long);
 extern void blk_queue_split(struct request_queue *, struct bio **);
 extern void blk_recount_segments(struct request_queue *, struct bio *);
 extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int);
@@ -992,15 +930,7 @@ extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
 
 extern int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags);
 extern void blk_queue_exit(struct request_queue *q);
-extern void blk_start_queue(struct request_queue *q);
-extern void blk_start_queue_async(struct request_queue *q);
-extern void blk_stop_queue(struct request_queue *q);
 extern void blk_sync_queue(struct request_queue *q);
-extern void __blk_stop_queue(struct request_queue *q);
-extern void __blk_run_queue(struct request_queue *q);
-extern void __blk_run_queue_uncond(struct request_queue *q);
-extern void blk_run_queue(struct request_queue *);
-extern void blk_run_queue_async(struct request_queue *q);
 extern int blk_rq_map_user(struct request_queue *, struct request *,
 			   struct rq_map_data *, void __user *, unsigned long,
 			   gfp_t);
@@ -1155,13 +1085,6 @@ static inline unsigned int blk_rq_count_bios(struct request *rq)
 	return nr_bios;
 }
 
-/*
- * Request issue related functions.
- */
-extern struct request *blk_peek_request(struct request_queue *q);
-extern void blk_start_request(struct request *rq);
-extern struct request *blk_fetch_request(struct request_queue *q);
-
 void blk_steal_bios(struct bio_list *list, struct request *rq);
 
 /*
@@ -1179,9 +1102,6 @@ void blk_steal_bios(struct bio_list *list, struct request *rq);
  */
 extern bool blk_update_request(struct request *rq, blk_status_t error,
 			       unsigned int nr_bytes);
-extern void blk_finish_request(struct request *rq, blk_status_t error);
-extern bool blk_end_request(struct request *rq, blk_status_t error,
-			    unsigned int nr_bytes);
 extern void blk_end_request_all(struct request *rq, blk_status_t error);
 extern bool __blk_end_request(struct request *rq, blk_status_t error,
 			      unsigned int nr_bytes);
@@ -1190,15 +1110,10 @@ extern bool __blk_end_request_cur(struct request *rq, blk_status_t error);
 
 extern void __blk_complete_request(struct request *);
 extern void blk_abort_request(struct request *);
-extern void blk_unprep_request(struct request *);
 
 /*
  * Access functions for manipulating queue properties
  */
-extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
-					spinlock_t *lock, int node_id);
-extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
-extern int blk_init_allocated_queue(struct request_queue *);
 extern void blk_cleanup_queue(struct request_queue *);
 extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
 extern void blk_queue_bounce_limit(struct request_queue *, u64);
@@ -1239,8 +1154,6 @@ extern int blk_queue_dma_drain(struct request_queue *q,
 			       void *buf, unsigned int size);
 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
 extern void blk_queue_virt_boundary(struct request_queue *, unsigned long);
-extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
-extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
 extern void blk_queue_dma_alignment(struct request_queue *, int);
 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
@@ -1298,7 +1211,6 @@ extern void blk_set_queue_dying(struct request_queue *);
  * schedule() where blk_schedule_flush_plug() is called.
  */
 struct blk_plug {
-	struct list_head list; /* requests */
 	struct list_head mq_list; /* blk-mq requests */
 	struct list_head cb_list; /* md requires an unplug callback */
 };
@@ -1339,8 +1251,7 @@ static inline bool blk_needs_flush_plug(struct task_struct *tsk)
 	struct blk_plug *plug = tsk->plug;
 
 	return plug &&
-		(!list_empty(&plug->list) ||
-		 !list_empty(&plug->mq_list) ||
+		 (!list_empty(&plug->mq_list) ||
 		 !list_empty(&plug->cb_list));
 }
 
diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index 015bb59c0331..158004f1754d 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -23,74 +23,6 @@ enum elv_merge {
 	ELEVATOR_DISCARD_MERGE	= 3,
 };
 
-typedef enum elv_merge (elevator_merge_fn) (struct request_queue *, struct request **,
-				 struct bio *);
-
-typedef void (elevator_merge_req_fn) (struct request_queue *, struct request *, struct request *);
-
-typedef void (elevator_merged_fn) (struct request_queue *, struct request *, enum elv_merge);
-
-typedef int (elevator_allow_bio_merge_fn) (struct request_queue *,
-					   struct request *, struct bio *);
-
-typedef int (elevator_allow_rq_merge_fn) (struct request_queue *,
-					  struct request *, struct request *);
-
-typedef void (elevator_bio_merged_fn) (struct request_queue *,
-						struct request *, struct bio *);
-
-typedef int (elevator_dispatch_fn) (struct request_queue *, int);
-
-typedef void (elevator_add_req_fn) (struct request_queue *, struct request *);
-typedef struct request *(elevator_request_list_fn) (struct request_queue *, struct request *);
-typedef void (elevator_completed_req_fn) (struct request_queue *, struct request *);
-typedef int (elevator_may_queue_fn) (struct request_queue *, unsigned int);
-
-typedef void (elevator_init_icq_fn) (struct io_cq *);
-typedef void (elevator_exit_icq_fn) (struct io_cq *);
-typedef int (elevator_set_req_fn) (struct request_queue *, struct request *,
-				   struct bio *, gfp_t);
-typedef void (elevator_put_req_fn) (struct request *);
-typedef void (elevator_activate_req_fn) (struct request_queue *, struct request *);
-typedef void (elevator_deactivate_req_fn) (struct request_queue *, struct request *);
-
-typedef int (elevator_init_fn) (struct request_queue *,
-				struct elevator_type *e);
-typedef void (elevator_exit_fn) (struct elevator_queue *);
-typedef void (elevator_registered_fn) (struct request_queue *);
-
-struct elevator_ops
-{
-	elevator_merge_fn *elevator_merge_fn;
-	elevator_merged_fn *elevator_merged_fn;
-	elevator_merge_req_fn *elevator_merge_req_fn;
-	elevator_allow_bio_merge_fn *elevator_allow_bio_merge_fn;
-	elevator_allow_rq_merge_fn *elevator_allow_rq_merge_fn;
-	elevator_bio_merged_fn *elevator_bio_merged_fn;
-
-	elevator_dispatch_fn *elevator_dispatch_fn;
-	elevator_add_req_fn *elevator_add_req_fn;
-	elevator_activate_req_fn *elevator_activate_req_fn;
-	elevator_deactivate_req_fn *elevator_deactivate_req_fn;
-
-	elevator_completed_req_fn *elevator_completed_req_fn;
-
-	elevator_request_list_fn *elevator_former_req_fn;
-	elevator_request_list_fn *elevator_latter_req_fn;
-
-	elevator_init_icq_fn *elevator_init_icq_fn;	/* see iocontext.h */
-	elevator_exit_icq_fn *elevator_exit_icq_fn;	/* ditto */
-
-	elevator_set_req_fn *elevator_set_req_fn;
-	elevator_put_req_fn *elevator_put_req_fn;
-
-	elevator_may_queue_fn *elevator_may_queue_fn;
-
-	elevator_init_fn *elevator_init_fn;
-	elevator_exit_fn *elevator_exit_fn;
-	elevator_registered_fn *elevator_registered_fn;
-};
-
 struct blk_mq_alloc_data;
 struct blk_mq_hw_ctx;
 
@@ -138,16 +70,15 @@ struct elevator_type
 
 	/* fields provided by elevator implementation */
 	union {
-		struct elevator_ops sq;
 		struct elevator_mq_ops mq;
 	} ops;
+
 	size_t icq_size;	/* see iocontext.h */
 	size_t icq_align;	/* ditto */
 	struct elv_fs_entry *elevator_attrs;
 	char elevator_name[ELV_NAME_MAX];
 	const char *elevator_alias;
 	struct module *elevator_owner;
-	bool uses_mq;
 #ifdef CONFIG_BLK_DEBUG_FS
 	const struct blk_mq_debugfs_attr *queue_debugfs_attrs;
 	const struct blk_mq_debugfs_attr *hctx_debugfs_attrs;
@@ -175,40 +106,25 @@ struct elevator_queue
 	struct kobject kobj;
 	struct mutex sysfs_lock;
 	unsigned int registered:1;
-	unsigned int uses_mq:1;
 	DECLARE_HASHTABLE(hash, ELV_HASH_BITS);
 };
 
 /*
  * block elevator interface
  */
-extern void elv_dispatch_sort(struct request_queue *, struct request *);
-extern void elv_dispatch_add_tail(struct request_queue *, struct request *);
-extern void elv_add_request(struct request_queue *, struct request *, int);
-extern void __elv_add_request(struct request_queue *, struct request *, int);
 extern enum elv_merge elv_merge(struct request_queue *, struct request **,
 		struct bio *);
 extern void elv_merge_requests(struct request_queue *, struct request *,
 			       struct request *);
 extern void elv_merged_request(struct request_queue *, struct request *,
 		enum elv_merge);
-extern void elv_bio_merged(struct request_queue *q, struct request *,
-				struct bio *);
 extern bool elv_attempt_insert_merge(struct request_queue *, struct request *);
-extern void elv_requeue_request(struct request_queue *, struct request *);
 extern struct request *elv_former_request(struct request_queue *, struct request *);
 extern struct request *elv_latter_request(struct request_queue *, struct request *);
-extern int elv_may_queue(struct request_queue *, unsigned int);
-extern void elv_completed_request(struct request_queue *, struct request *);
-extern int elv_set_request(struct request_queue *q, struct request *rq,
-			   struct bio *bio, gfp_t gfp_mask);
-extern void elv_put_request(struct request_queue *, struct request *);
-extern void elv_drain_elevator(struct request_queue *);
 
 /*
  * io scheduler registration
  */
-extern void __init load_default_elevator_module(void);
 extern int elv_register(struct elevator_type *);
 extern void elv_unregister(struct elevator_type *);
 
@@ -260,9 +176,5 @@ enum {
 #define rq_entry_fifo(ptr)	list_entry((ptr), struct request, queuelist)
 #define rq_fifo_clear(rq)	list_del_init(&(rq)->queuelist)
 
-#else /* CONFIG_BLOCK */
-
-static inline void load_default_elevator_module(void) { }
-
 #endif /* CONFIG_BLOCK */
 #endif
diff --git a/include/linux/init.h b/include/linux/init.h
index 9c2aba1dbabf..5255069f5a9f 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -146,7 +146,6 @@ extern unsigned int reset_devices;
 /* used by init/main.c */
 void setup_arch(char **);
 void prepare_namespace(void);
-void __init load_default_modules(void);
 int __init init_rootfs(void);
 
 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_STRICT_MODULE_RWX)
diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c
index d1a5d885ce13..73e02ea5d5d1 100644
--- a/init/do_mounts_initrd.c
+++ b/init/do_mounts_initrd.c
@@ -53,9 +53,6 @@ static void __init handle_initrd(void)
 	ksys_mkdir("/old", 0700);
 	ksys_chdir("/old");
 
-	/* try loading default modules from initrd */
-	load_default_modules();
-
 	/*
 	 * In case that a resume from disk is carried out by linuxrc or one of
 	 * its children, we need to tell the freezer not to wait for us.
diff --git a/init/initramfs.c b/init/initramfs.c
index 640557788026..96af18fec4d0 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -644,12 +644,6 @@ static int __init populate_rootfs(void)
 #endif
 	}
 	flush_delayed_fput();
-	/*
-	 * Try loading default modules from initramfs.  This gives
-	 * us a chance to load before device_initcalls.
-	 */
-	load_default_modules();
-
 	return 0;
 }
 rootfs_initcall(populate_rootfs);
diff --git a/init/main.c b/init/main.c
index ee147103ba1b..ca0cdb0c388b 100644
--- a/init/main.c
+++ b/init/main.c
@@ -996,17 +996,6 @@ static void __init do_pre_smp_initcalls(void)
 		do_one_initcall(initcall_from_entry(fn));
 }
 
-/*
- * This function requests modules which should be loaded by default and is
- * called twice right after initrd is mounted and right before init is
- * exec'd.  If such modules are on either initrd or rootfs, they will be
- * loaded before control is passed to userland.
- */
-void __init load_default_modules(void)
-{
-	load_default_elevator_module();
-}
-
 static int run_init_process(const char *init_filename)
 {
 	argv_init[0] = init_filename;
@@ -1180,5 +1169,4 @@ static noinline void __init kernel_init_freeable(void)
 	 */
 
 	integrity_load_keys();
-	load_default_modules();
 }