block: allow passing a NULL bdev to bio_alloc_clone/bio_init_clone

Device mapper wants to allocate a bio before knowing the device it
gets send to, so add explicit support for that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Link: https://lore.kernel.org/r/20220504142950.567582-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2022-05-04 07:29:50 -07:00 committed by Jens Axboe
parent 513616843d
commit 7ecc56c62b

View File

@ -761,13 +761,15 @@ static int __bio_clone(struct bio *bio, struct bio *bio_src, gfp_t gfp)
bio_set_flag(bio, BIO_CLONED);
if (bio_flagged(bio_src, BIO_THROTTLED))
bio_set_flag(bio, BIO_THROTTLED);
if (bio->bi_bdev == bio_src->bi_bdev &&
bio_flagged(bio_src, BIO_REMAPPED))
bio_set_flag(bio, BIO_REMAPPED);
bio->bi_ioprio = bio_src->bi_ioprio;
bio->bi_iter = bio_src->bi_iter;
bio_clone_blkg_association(bio, bio_src);
if (bio->bi_bdev) {
if (bio->bi_bdev == bio_src->bi_bdev &&
bio_flagged(bio_src, BIO_REMAPPED))
bio_set_flag(bio, BIO_REMAPPED);
bio_clone_blkg_association(bio, bio_src);
}
if (bio_crypt_clone(bio, bio_src, gfp) < 0)
return -ENOMEM;