So I actually noticed this during code inspection a while ago, but I think we need to use the actual underlying device instead of NULL here to keep our block layer gurantees. See the patch in my queue below. --- >From 1e330b8e57fc0d6c6fb07c0ec2915dca5d7a585a Mon Sep 17 00:00:00 2001 From: Christoph Hellwig <hch@xxxxxx> Date: Thu, 13 Jan 2022 10:53:59 +0100 Subject: block: assign bi_bdev for cloned bios in blk_rq_prep_clone The cloned bios for the cloned request in blk_rq_prep_clone currently still point to the original bi_bdev. This is harmless because dm-mpath doesn't look at bi_bdev but violates the invariants of always having the correct bi_bdev. Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- block/blk-mq.c | 1 + 1 file changed, 1 insertion(+) diff --git a/block/blk-mq.c b/block/blk-mq.c index a6d4780580fcd..b5e35e63adad4 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2976,6 +2976,7 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src, bio = bio_clone_fast(bio_src, gfp_mask, bs); if (!bio) goto free_and_out; + bio->bi_bdev = rq->q->disk->part0; if (bio_ctr && bio_ctr(bio, bio_src, data)) goto free_and_out; -- 2.30.2 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel
