2022-11-01 15:40:56

by Jinlong Chen

Subject: [PATCH 2/4] blk-mq: improve error handling in blk_mq_alloc_rq_map()

Use goto-style error handling like we do elsewhere in the kernel.

Signed-off-by: Jinlong Chen <[email protected]>
---
block/blk-mq.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 7ceceea91b3b..408a929be90e 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3272,26 +3272,28 @@ static struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
tags = blk_mq_init_tags(nr_tags, reserved_tags, node,
BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags));
if (!tags)
- return NULL;
+ goto err_out;

tags->rqs = kcalloc_node(nr_tags, sizeof(struct request *),
GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY,
node);
- if (!tags->rqs) {
- blk_mq_free_tags(tags);
- return NULL;
- }
+ if (!tags->rqs)
+ goto err_free_tags;

tags->static_rqs = kcalloc_node(nr_tags, sizeof(struct request *),
GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY,
node);
- if (!tags->static_rqs) {
- kfree(tags->rqs);
- blk_mq_free_tags(tags);
- return NULL;
- }
+ if (!tags->static_rqs)
+ goto err_free_rqs;

return tags;
+
+err_free_rqs:
+ kfree(tags->rqs);
+err_free_tags:
+ blk_mq_free_tags(tags);
+err_out:
+ return NULL;
}

static int blk_mq_init_request(struct blk_mq_tag_set *set, struct request *rq,
--
2.31.1

2022-11-01 18:11:26

by Christoph Hellwig

Subject: Re: [PATCH 2/4] blk-mq: improve error handling in blk_mq_alloc_rq_map()

> if (!tags)
> - return NULL;
> + goto err_out;

Using a label just for the direct error return here is a bit silly.

The rest looks fine.

2022-11-01 18:40:48

by Jens Axboe

Subject: Re: [PATCH 2/4] blk-mq: improve error handling in blk_mq_alloc_rq_map()

On 11/1/22 11:34 AM, Christoph Hellwig wrote:
>> if (!tags)
>> - return NULL;
>> + goto err_out;
>
> Using a label just for the direct error return here is a bit silly.

Plus that's not idiomatic code for cleanup, just keep the NULL
return if there's no cleanup to be done.

--
Jens Axboe