Re: [PATCH v4] block: Fix uninitialized symbol 'bio' in blk_rq_prep_clone

[Suraj Sonawane <surajsonawane0215@xxxxxxxxx>]

On 08/10/24 23:22, SurajSonawane2415 wrote:
> Fix the uninitialized symbol 'bio' in the function blk_rq_prep_clone
> to resolve the following error:
> block/blk-mq.c:3199 blk_rq_prep_clone() error: uninitialized symbol 'bio'.
>
> Signed-off-by: SurajSonawane2415 <surajsonawane0215@xxxxxxxxx>
> ---
> V1 - Initialize 'bio' to NULL.
> V2 - Move bio_put(bio) into the bio_ctr error handling block,
> ensuring memory cleanup occurs only when the bio_ctr fail.
> V3 - Moved the bio declaration into the loop scope, eliminating
> the need to set it to NULL at the end of the loop.
> V4 - Adjusted position of arguments of bio_alloc_clone.
>
>   block/blk-mq.c | 13 ++++++-------
>   1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index 4b2c8e940..89c9a6c4d 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -3156,19 +3156,21 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
>   		      int (*bio_ctr)(struct bio *, struct bio *, void *),
>   		      void *data)
>   {
> -	struct bio *bio, *bio_src;
> +	struct bio *bio_src;
>   
>   	if (!bs)
>   		bs = &fs_bio_set;
>   
>   	__rq_for_each_bio(bio_src, rq_src) {
> -		bio = bio_alloc_clone(rq->q->disk->part0, bio_src, gfp_mask,
> -				      bs);
> +		struct bio *bio = bio_alloc_clone(rq->q->disk->part0, bio_src,
> +					gfp_mask, bs);
>   		if (!bio)
>   			goto free_and_out;
>   
> -		if (bio_ctr && bio_ctr(bio, bio_src, data))
> +		if (bio_ctr && bio_ctr(bio, bio_src, data)) {
> +			bio_put(bio);
>   			goto free_and_out;
> +		}
>   
>   		if (rq->bio) {
>   			rq->biotail->bi_next = bio;
> @@ -3176,7 +3178,6 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
>   		} else {
>   			rq->bio = rq->biotail = bio;
>   		}
> -		bio = NULL;
>   	}
>   
>   	/* Copy attributes of the original request to the clone request. */
> @@ -3196,8 +3197,6 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
>   	return 0;
>   
>   free_and_out:
> -	if (bio)
> -		bio_put(bio);
>   	blk_rq_unprep_clone(rq);
>   
>   	return -ENOMEM;

Hello Jens!

I wanted to follow up on this patch I submitted. I have done all the 
suggested changes till v4. I was wondering if you had a chance to review 
it and if there are any comments or feedback.

Thank you for your time and consideration. I look forward to your response.

Best regards,
Suraj Sonawane