blk_rq_map_bio_alloc
bio = blk_rq_map_bio_alloc(rq, nr_pages, gfp_mask);
bio = blk_rq_map_bio_alloc(rq, nr_vecs, gfp_mask);
bio = blk_rq_map_bio_alloc(rq, nr_vecs, gfp_mask);
bio = blk_rq_map_bio_alloc(rq, nr_pages, gfp_mask);
bio = blk_rq_map_bio_alloc(rq, 0, GFP_KERNEL);