On Sat, Jan 15, 2022 at 1:59 AM Benjamin Marzinski <bmarzins@xxxxxxxxxx> wrote: > > bio_clone_fast() sets the cloned bio to have the same ->bi_bdev as the > source bio. This means that when request-based dm called setup_clone(), > the cloned bio had its ->bi_bdev pointing to the dm device. After Commit > 0b6e522cdc4a ("blk-mq: use ->bi_bdev for I/O accounting") > __blk_account_io_start() started using the request's ->bio->bi_bdev for > I/O accounting, if it was set. This caused IO going to the underlying > devices to use the dm device for their I/O accounting. > > Request-based dm can't be used on top of partitions, so > dm_rq_bio_constructor() can just clear the cloned bio's ->bi_bdev and > have __blk_account_io_start() fall back to using rq->rq_disk->part0 for > the I/O accounting. > > Signed-off-by: Benjamin Marzinski <bmarzins@xxxxxxxxxx> > --- > drivers/md/dm-rq.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c > index 579ab6183d4d..42099dc76e3c 100644 > --- a/drivers/md/dm-rq.c > +++ b/drivers/md/dm-rq.c > @@ -328,6 +328,7 @@ static int dm_rq_bio_constructor(struct bio *bio, struct bio *bio_orig, > info->orig = bio_orig; > info->tio = tio; > bio->bi_end_io = end_clone_bio; > + bio->bi_bdev = NULL; Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx> -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel