From 4d063237b92a4e8d99350ad05492a45009a3c78c Mon Sep 17 00:00:00 2001
From: Hannes Reinecke <hare@suse.de>
Date: Wed, 19 Aug 2020 23:20:21 +0800
Subject: [PATCH] blk-mq: Free tags in blk_mq_init_tags() upon error

References: jsc#SLE-15442 bsc#1180814 ltc#187461
Patch-mainline: v5.10-rc1
Git-commit: 4d063237b92a4e8d99350ad05492a45009a3c78c

Since the tags are allocated in blk_mq_init_tags(), it's better practice
to free in that same function upon error, rather than a callee which is to
init the bitmap tags (blk_mq_init_tags()).

[jpg: Split from an earlier patch with a new commit message]

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: John Garry <john.garry@huawei.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 block/blk-mq-tag.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 32d82e23b095..c2c9f369d777 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -429,24 +429,22 @@ static int bt_alloc(struct sbitmap_queue *bt, unsigned int depth,
 				       node);
 }
 
-static struct blk_mq_tags *blk_mq_init_bitmap_tags(struct blk_mq_tags *tags,
-						   int node, int alloc_policy)
+static int blk_mq_init_bitmap_tags(struct blk_mq_tags *tags,
+				   int node, int alloc_policy)
 {
 	unsigned int depth = tags->nr_tags - tags->nr_reserved_tags;
 	bool round_robin = alloc_policy == BLK_TAG_ALLOC_RR;
 
 	if (bt_alloc(&tags->bitmap_tags, depth, round_robin, node))
-		goto free_tags;
+		return -ENOMEM;
 	if (bt_alloc(&tags->breserved_tags, tags->nr_reserved_tags, round_robin,
 		     node))
 		goto free_bitmap_tags;
 
-	return tags;
+	return 0;
 free_bitmap_tags:
 	sbitmap_queue_free(&tags->bitmap_tags);
-free_tags:
-	kfree(tags);
-	return NULL;
+	return -ENOMEM;
 }
 
 struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags,
@@ -467,7 +465,11 @@ struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags,
 	tags->nr_tags = total_tags;
 	tags->nr_reserved_tags = reserved_tags;
 
-	return blk_mq_init_bitmap_tags(tags, node, alloc_policy);
+	if (blk_mq_init_bitmap_tags(tags, node, alloc_policy) < 0) {
+		kfree(tags);
+		return NULL;
+	}
+	return tags;
 }
 
 void blk_mq_free_tags(struct blk_mq_tags *tags)
-- 
2.26.2