[PATCH v8 03/18] blk-mq: Free tags in blk_mq_init_tags() upon error

John Garry
2020-08-19T15:26:54Z

From: Hannes Reinecke <hare@suse.de>

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()).

Signed-off-by: Hannes Reinecke <hare@suse.de>
[jpg: Split from an earlier patch with a new commit message]
Signed-off-by: John Garry <john.garry@huawei.com>
---
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