1 files changed, 22 insertions, 355 deletions

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;
 }
@@ -640,66 +423,10 @@ 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);
-	}
+	return NULL;
 }
 
 #define to_elv(atr) container_of((atr), struct elv_fs_entry, attr)
@@ -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);
-
-		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);
+	blk_mq_freeze_queue(q);
+	blk_mq_quiesce_queue(q);
 
-	return 0;
+	err = elevator_switch_mq(q, new_e);
 
-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);