On Tue, Oct 08, 2024 at 05:34:13PM +0530, 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'.
...
> @@ -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,
> + 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);
I think your commit message is missing the real "fix" here. The other
place that goto's this label is if blk_crypto_rq_bio_prep() fails. At
this point, the cloned 'rq' has all the bio's that get cleaned up in
blk_rq_unprep_clone(), so that failure scenario is double put'ing the
last bio.
