blk-mq: Refactor and rename blk_mq_free_map_and_{requests->rqs}()

mainline inclusion
from mainline-v5.16-rc1
commit 645db34e
category: performance
bugzilla: 186917, https://gitee.com/openeuler/kernel/issues/I5N1S5
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=645db34e50501aac141713fb47a315e5202ff890

--------------------------------

Refactor blk_mq_free_map_and_requests() such that it can be used at many
sites at which the tag map and rqs are freed.

Also rename to blk_mq_free_map_and_rqs(), which is shorter and matches the
alloc equivalent.
Suggested-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/1633429419-228500-12-git-send-email-john.garry@huawei.comSigned-off-by: NJens Axboe <axboe@kernel.dk>

Conflict: commit a846a8e6 ("blk-mq: don't free tags if the tag_set is
used by other device in queue initialztion") is already backported,
blk_mq_free_map_and_rqs() is moved to __blk_mq_update_nr_hw_queues()
instead of blk_mq_realloc_hw_ctxs().
Signed-off-by: NYu Kuai <yukuai3@huawei.com>
Reviewed-by: NYu Kuai <yukuai3@huawei.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

block/blk-mq-tag.c

@@ -674,8 +674,7 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx,
 		if (!new)
 			return -ENOMEM;
 
-		blk_mq_free_rqs(set, *tagsptr, hctx->queue_num);
-		blk_mq_free_rq_map(*tagsptr, set->flags);
+		blk_mq_free_map_and_rqs(set, *tagsptr, hctx->queue_num);
 		*tagsptr = new;
 	} else {
 		/*

block/blk-mq.c

@@ -3016,15 +3016,15 @@ static bool __blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set,
 	return set->tags[hctx_idx];
 }
 
-static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set,
-					 unsigned int hctx_idx)
+void blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set,
+			     struct blk_mq_tags *tags,
+			     unsigned int hctx_idx)
 {
 	unsigned int flags = set->flags;
 
-	if (set->tags && set->tags[hctx_idx]) {
-		blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx);
-		blk_mq_free_rq_map(set->tags[hctx_idx], flags);
-		set->tags[hctx_idx] = NULL;
+	if (tags) {
+		blk_mq_free_rqs(set, tags, hctx_idx);
+		blk_mq_free_rq_map(tags, flags);
 	}
 }
 
@@ -3105,8 +3105,10 @@ static void blk_mq_map_swqueue(struct request_queue *q)
 			 * fallback in case of a new remap fails
 			 * allocation
 			 */
-			if (i && set->tags[i])
-				blk_mq_free_map_and_requests(set, i);
+			if (i && set->tags[i]) {
+				blk_mq_free_map_and_rqs(set, set->tags[i], i);
+				set->tags[i] = NULL;
+			}
 
 			hctx->tags = NULL;
 			continue;
@@ -3533,8 +3535,10 @@ static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
 	return 0;
 
 out_unwind:
-	while (--i >= 0)
-		blk_mq_free_map_and_requests(set, i);
+	while (--i >= 0) {
+		blk_mq_free_map_and_rqs(set, set->tags[i], i);
+		set->tags[i] = NULL;
+	}
 
 	return -ENOMEM;
 }
@@ -3724,8 +3728,10 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
 	return 0;
 
 out_free_mq_rq_maps:
-	for (i = 0; i < set->nr_hw_queues; i++)
-		blk_mq_free_map_and_requests(set, i);
+	for (i = 0; i < set->nr_hw_queues; i++) {
+		blk_mq_free_map_and_rqs(set, set->tags[i], i);
+		set->tags[i] = NULL;
+	}
 out_free_mq_map:
 	for (i = 0; i < set->nr_maps; i++) {
 		kfree(set->map[i].mq_map);
@@ -3741,8 +3747,10 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
 {
 	int i, j;
 
-	for (i = 0; i < set->nr_hw_queues; i++)
-		blk_mq_free_map_and_requests(set, i);
+	for (i = 0; i < set->nr_hw_queues; i++) {
+		blk_mq_free_map_and_rqs(set, set->tags[i], i);
+		set->tags[i] = NULL;
+	}
 
 	if (blk_mq_is_sbitmap_shared(set->flags))
 		blk_mq_exit_shared_sbitmap(set);
@@ -3932,7 +3940,7 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set,
 			pr_warn("Increasing nr_hw_queues to %d fails, fallback to %d\n",
 					nr_hw_queues, prev_nr_hw_queues);
 			for (; i < set->nr_hw_queues; i++)
-				blk_mq_free_map_and_requests(set, i);
+				blk_mq_free_map_and_rqs(set, set->tags[i], i);
 
 			set->nr_hw_queues = prev_nr_hw_queues;
 			blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]);

block/blk-mq.h

@@ -57,7 +57,9 @@ void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
 void blk_mq_free_rq_map(struct blk_mq_tags *tags, unsigned int flags);
 struct blk_mq_tags *blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set,
 				unsigned int hctx_idx, unsigned int depth);
-
+void blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set,
+			     struct blk_mq_tags *tags,
+			     unsigned int hctx_idx);
 /*
  * Internal helpers for request insertion into sw queues
  */