block: Add bio_clone_bioset(), bio_clone_kmalloc()

Previously, there was bio_clone() but it only allocated from the fs bio
set; as a result various users were open coding it and using
__bio_clone().

This changes bio_clone() to become bio_clone_bioset(), and then we add
bio_clone() and bio_clone_kmalloc() as wrappers around it, making use of
the functionality the last patch adedd.

This will also help in a later patch changing how bio cloning works.

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
CC: NeilBrown <neilb@suse.de>
CC: Alasdair Kergon <agk@redhat.com>
CC: Boaz Harrosh <bharrosh@panasas.com>
CC: Jeff Garzik <jeff@garzik.org>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/blk-core.c b/block/blk-core.c
index b776cc9..82aab28 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2781,16 +2781,10 @@
 	blk_rq_init(NULL, rq);
 
 	__rq_for_each_bio(bio_src, rq_src) {
-		bio = bio_alloc_bioset(gfp_mask, bio_src->bi_max_vecs, bs);
+		bio = bio_clone_bioset(bio_src, gfp_mask, bs);
 		if (!bio)
 			goto free_and_out;
 
-		__bio_clone(bio, bio_src);
-
-		if (bio_integrity(bio_src) &&
-		    bio_integrity_clone(bio, bio_src, gfp_mask))
-			goto free_and_out;
-
 		if (bio_ctr && bio_ctr(bio, bio_src, data))
 			goto free_and_out;