From f9cd4bfe96955e7a1d3ec54b393dee87b815ba3b Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Thu, 1 Nov 2018 16:41:41 -0600
Subject: [PATCH] block: get rid of MQ scheduler ops union

This is a remnant of when we had ops for both SQ and MQ
schedulers. Now it's just MQ, so get rid of the union.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 block/bfq-iosched.c      |  2 +-
 block/blk-ioc.c          |  8 ++++----
 block/blk-mq-sched.c     | 33 ++++++++++++++++-----------------
 block/blk-mq-sched.h     | 20 ++++++++++----------
 block/blk-mq.c           | 12 ++++++------
 block/elevator.c         | 26 +++++++++++++-------------
 block/kyber-iosched.c    |  2 +-
 block/mq-deadline.c      |  2 +-
 include/linux/elevator.h |  4 +---
 9 files changed, 53 insertions(+), 56 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 44c7e567aa25..c7636cbefc85 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5724,7 +5724,7 @@ static struct elv_fs_entry bfq_attrs[] = {
 };
 
 static struct elevator_type iosched_bfq_mq = {
-	.ops.mq = {
+	.ops = {
 		.limit_depth		= bfq_limit_depth,
 		.prepare_request	= bfq_prepare_request,
 		.requeue_request        = bfq_finish_requeue_request,
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 391128456aec..007aac6e6a4b 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -48,8 +48,8 @@ static void ioc_exit_icq(struct io_cq *icq)
 	if (icq->flags & ICQ_EXITED)
 		return;
 
-	if (et->ops.mq.exit_icq)
-		et->ops.mq.exit_icq(icq);
+	if (et->ops.exit_icq)
+		et->ops.exit_icq(icq);
 
 	icq->flags |= ICQ_EXITED;
 }
@@ -396,8 +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->ops.mq.init_icq)
-			et->ops.mq.init_icq(icq);
+		if (et->ops.init_icq)
+			et->ops.init_icq(icq);
 	} else {
 		kmem_cache_free(et->icq_cache, icq);
 		icq = ioc_lookup_icq(ioc, q);
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index 29bfe8017a2d..0feefd6c6aaa 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -85,14 +85,13 @@ static void blk_mq_do_dispatch_sched(struct blk_mq_hw_ctx *hctx)
 	do {
 		struct request *rq;
 
-		if (e->type->ops.mq.has_work &&
-				!e->type->ops.mq.has_work(hctx))
+		if (e->type->ops.has_work && !e->type->ops.has_work(hctx))
 			break;
 
 		if (!blk_mq_get_dispatch_budget(hctx))
 			break;
 
-		rq = e->type->ops.mq.dispatch_request(hctx);
+		rq = e->type->ops.dispatch_request(hctx);
 		if (!rq) {
 			blk_mq_put_dispatch_budget(hctx);
 			break;
@@ -163,7 +162,7 @@ void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx)
 {
 	struct request_queue *q = hctx->queue;
 	struct elevator_queue *e = q->elevator;
-	const bool has_sched_dispatch = e && e->type->ops.mq.dispatch_request;
+	const bool has_sched_dispatch = e && e->type->ops.dispatch_request;
 	LIST_HEAD(rq_list);
 
 	/* RCU or SRCU read lock is needed before checking quiesced flag */
@@ -314,9 +313,9 @@ bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio)
 	struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu);
 	bool ret = false;
 
-	if (e && e->type->ops.mq.bio_merge) {
+	if (e && e->type->ops.bio_merge) {
 		blk_mq_put_ctx(ctx);
-		return e->type->ops.mq.bio_merge(hctx, bio);
+		return e->type->ops.bio_merge(hctx, bio);
 	}
 
 	if ((hctx->flags & BLK_MQ_F_SHOULD_MERGE) &&
@@ -380,11 +379,11 @@ void blk_mq_sched_insert_request(struct request *rq, bool at_head,
 	if (blk_mq_sched_bypass_insert(hctx, !!e, rq))
 		goto run;
 
-	if (e && e->type->ops.mq.insert_requests) {
+	if (e && e->type->ops.insert_requests) {
 		LIST_HEAD(list);
 
 		list_add(&rq->queuelist, &list);
-		e->type->ops.mq.insert_requests(hctx, &list, at_head);
+		e->type->ops.insert_requests(hctx, &list, at_head);
 	} else {
 		spin_lock(&ctx->lock);
 		__blk_mq_insert_request(hctx, rq, at_head);
@@ -403,8 +402,8 @@ void blk_mq_sched_insert_requests(struct request_queue *q,
 	struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu);
 	struct elevator_queue *e = hctx->queue->elevator;
 
-	if (e && e->type->ops.mq.insert_requests)
-		e->type->ops.mq.insert_requests(hctx, list, false);
+	if (e && e->type->ops.insert_requests)
+		e->type->ops.insert_requests(hctx, list, false);
 	else {
 		/*
 		 * try to issue requests directly if the hw queue isn't
@@ -489,15 +488,15 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
 			goto err;
 	}
 
-	ret = e->ops.mq.init_sched(q, e);
+	ret = e->ops.init_sched(q, e);
 	if (ret)
 		goto err;
 
 	blk_mq_debugfs_register_sched(q);
 
 	queue_for_each_hw_ctx(q, hctx, i) {
-		if (e->ops.mq.init_hctx) {
-			ret = e->ops.mq.init_hctx(hctx, i);
+		if (e->ops.init_hctx) {
+			ret = e->ops.init_hctx(hctx, i);
 			if (ret) {
 				eq = q->elevator;
 				blk_mq_exit_sched(q, eq);
@@ -523,14 +522,14 @@ void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e)
 
 	queue_for_each_hw_ctx(q, hctx, i) {
 		blk_mq_debugfs_unregister_sched_hctx(hctx);
-		if (e->type->ops.mq.exit_hctx && hctx->sched_data) {
-			e->type->ops.mq.exit_hctx(hctx, i);
+		if (e->type->ops.exit_hctx && hctx->sched_data) {
+			e->type->ops.exit_hctx(hctx, i);
 			hctx->sched_data = NULL;
 		}
 	}
 	blk_mq_debugfs_unregister_sched(q);
-	if (e->type->ops.mq.exit_sched)
-		e->type->ops.mq.exit_sched(e);
+	if (e->type->ops.exit_sched)
+		e->type->ops.exit_sched(e);
 	blk_mq_sched_tags_teardown(q);
 	q->elevator = NULL;
 }
diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h
index 8a9544203173..947f236b273d 100644
--- a/block/blk-mq-sched.h
+++ b/block/blk-mq-sched.h
@@ -43,8 +43,8 @@ blk_mq_sched_allow_merge(struct request_queue *q, struct request *rq,
 {
 	struct elevator_queue *e = q->elevator;
 
-	if (e && e->type->ops.mq.allow_merge)
-		return e->type->ops.mq.allow_merge(q, rq, bio);
+	if (e && e->type->ops.allow_merge)
+		return e->type->ops.allow_merge(q, rq, bio);
 
 	return true;
 }
@@ -53,8 +53,8 @@ static inline void blk_mq_sched_completed_request(struct request *rq, u64 now)
 {
 	struct elevator_queue *e = rq->q->elevator;
 
-	if (e && e->type->ops.mq.completed_request)
-		e->type->ops.mq.completed_request(rq, now);
+	if (e && e->type->ops.completed_request)
+		e->type->ops.completed_request(rq, now);
 }
 
 static inline void blk_mq_sched_started_request(struct request *rq)
@@ -62,8 +62,8 @@ static inline void blk_mq_sched_started_request(struct request *rq)
 	struct request_queue *q = rq->q;
 	struct elevator_queue *e = q->elevator;
 
-	if (e && e->type->ops.mq.started_request)
-		e->type->ops.mq.started_request(rq);
+	if (e && e->type->ops.started_request)
+		e->type->ops.started_request(rq);
 }
 
 static inline void blk_mq_sched_requeue_request(struct request *rq)
@@ -71,16 +71,16 @@ static inline void blk_mq_sched_requeue_request(struct request *rq)
 	struct request_queue *q = rq->q;
 	struct elevator_queue *e = q->elevator;
 
-	if (e && e->type->ops.mq.requeue_request)
-		e->type->ops.mq.requeue_request(rq);
+	if (e && e->type->ops.requeue_request)
+		e->type->ops.requeue_request(rq);
 }
 
 static inline bool blk_mq_sched_has_work(struct blk_mq_hw_ctx *hctx)
 {
 	struct elevator_queue *e = hctx->queue->elevator;
 
-	if (e && e->type->ops.mq.has_work)
-		return e->type->ops.mq.has_work(hctx);
+	if (e && e->type->ops.has_work)
+		return e->type->ops.has_work(hctx);
 
 	return false;
 }
diff --git a/block/blk-mq.c b/block/blk-mq.c
index a58d2d953876..d106d7a970cc 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -363,9 +363,9 @@ static struct request *blk_mq_get_request(struct request_queue *q,
 		 * dispatch list. Don't include reserved tags in the
 		 * limiting, as it isn't useful.
 		 */
-		if (!op_is_flush(op) && e->type->ops.mq.limit_depth &&
+		if (!op_is_flush(op) && e->type->ops.limit_depth &&
 		    !(data->flags & BLK_MQ_REQ_RESERVED))
-			e->type->ops.mq.limit_depth(op, data);
+			e->type->ops.limit_depth(op, data);
 	} else {
 		blk_mq_tag_busy(data->hctx);
 	}
@@ -383,11 +383,11 @@ static struct request *blk_mq_get_request(struct request_queue *q,
 	rq = blk_mq_rq_ctx_init(data, tag, op);
 	if (!op_is_flush(op)) {
 		rq->elv.icq = NULL;
-		if (e && e->type->ops.mq.prepare_request) {
+		if (e && e->type->ops.prepare_request) {
 			if (e->type->icq_cache && rq_ioc(bio))
 				blk_mq_sched_assign_ioc(rq, bio);
 
-			e->type->ops.mq.prepare_request(rq, bio);
+			e->type->ops.prepare_request(rq, bio);
 			rq->rq_flags |= RQF_ELVPRIV;
 		}
 	}
@@ -491,8 +491,8 @@ void blk_mq_free_request(struct request *rq)
 	struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu);
 
 	if (rq->rq_flags & RQF_ELVPRIV) {
-		if (e && e->type->ops.mq.finish_request)
-			e->type->ops.mq.finish_request(rq);
+		if (e && e->type->ops.finish_request)
+			e->type->ops.finish_request(rq);
 		if (rq->elv.icq) {
 			put_io_context(rq->elv.icq->ioc);
 			rq->elv.icq = NULL;
diff --git a/block/elevator.c b/block/elevator.c
index 334097c54b08..19351ffa56b1 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -61,8 +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->type->ops.mq.allow_merge)
-		return e->type->ops.mq.allow_merge(q, rq, bio);
+	if (e->type->ops.allow_merge)
+		return e->type->ops.allow_merge(q, rq, bio);
 
 	return 1;
 }
@@ -180,7 +180,7 @@ static void elevator_release(struct kobject *kobj)
 void elevator_exit(struct request_queue *q, struct elevator_queue *e)
 {
 	mutex_lock(&e->sysfs_lock);
-	if (e->type->ops.mq.exit_sched)
+	if (e->type->ops.exit_sched)
 		blk_mq_exit_sched(q, e);
 	mutex_unlock(&e->sysfs_lock);
 
@@ -329,8 +329,8 @@ enum elv_merge elv_merge(struct request_queue *q, struct request **req,
 		return ELEVATOR_BACK_MERGE;
 	}
 
-	if (e->type->ops.mq.request_merge)
-		return e->type->ops.mq.request_merge(q, req, bio);
+	if (e->type->ops.request_merge)
+		return e->type->ops.request_merge(q, req, bio);
 
 	return ELEVATOR_NO_MERGE;
 }
@@ -381,8 +381,8 @@ void elv_merged_request(struct request_queue *q, struct request *rq,
 {
 	struct elevator_queue *e = q->elevator;
 
-	if (e->type->ops.mq.request_merged)
-		e->type->ops.mq.request_merged(q, rq, type);
+	if (e->type->ops.request_merged)
+		e->type->ops.request_merged(q, rq, type);
 
 	if (type == ELEVATOR_BACK_MERGE)
 		elv_rqhash_reposition(q, rq);
@@ -396,8 +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->type->ops.mq.requests_merged)
-		e->type->ops.mq.requests_merged(q, rq, next);
+	if (e->type->ops.requests_merged)
+		e->type->ops.requests_merged(q, rq, next);
 
 	elv_rqhash_reposition(q, rq);
 
@@ -413,8 +413,8 @@ struct request *elv_latter_request(struct request_queue *q, struct request *rq)
 {
 	struct elevator_queue *e = q->elevator;
 
-	if (e->type->ops.mq.next_request)
-		return e->type->ops.mq.next_request(q, rq);
+	if (e->type->ops.next_request)
+		return e->type->ops.next_request(q, rq);
 
 	return NULL;
 }
@@ -423,8 +423,8 @@ struct request *elv_former_request(struct request_queue *q, struct request *rq)
 {
 	struct elevator_queue *e = q->elevator;
 
-	if (e->type->ops.mq.former_request)
-		return e->type->ops.mq.former_request(q, rq);
+	if (e->type->ops.former_request)
+		return e->type->ops.former_request(q, rq);
 
 	return NULL;
 }
diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c
index 728757a34fa0..1fd83a91e749 100644
--- a/block/kyber-iosched.c
+++ b/block/kyber-iosched.c
@@ -1017,7 +1017,7 @@ static const struct blk_mq_debugfs_attr kyber_hctx_debugfs_attrs[] = {
 #endif
 
 static struct elevator_type kyber_sched = {
-	.ops.mq = {
+	.ops = {
 		.init_sched = kyber_init_sched,
 		.exit_sched = kyber_exit_sched,
 		.init_hctx = kyber_init_hctx,
diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index 513edefd10fd..1bd06cefce57 100644
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -761,7 +761,7 @@ static const struct blk_mq_debugfs_attr deadline_queue_debugfs_attrs[] = {
 #endif
 
 static struct elevator_type mq_deadline = {
-	.ops.mq = {
+	.ops = {
 		.insert_requests	= dd_insert_requests,
 		.dispatch_request	= dd_dispatch_request,
 		.prepare_request	= dd_prepare_request,
diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index 158004f1754d..2e9e2763bf47 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -69,9 +69,7 @@ struct elevator_type
 	struct kmem_cache *icq_cache;
 
 	/* fields provided by elevator implementation */
-	union {
-		struct elevator_mq_ops mq;
-	} ops;
+	struct elevator_mq_ops ops;
 
 	size_t icq_size;	/* see iocontext.h */
 	size_t icq_align;	/* ditto */