block: cleanup for _blk/blk_rq_prep_clone

Both cmd and sense had been moved to scsi_request, so remove
the related comments to avoid confusion.

And as Bart suggested, move _blk_rq_prep_clone into the only
caller (blk_rq_prep_clone).

Signed-off-by: Guoqing Jiang <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

block/blk-core.c

···
 }
 EXPORT_SYMBOL_GPL(blk_rq_unprep_clone);
 
-/*
- * Copy attributes of the original request to the clone request.
- * The actual data parts (e.g. ->cmd, ->sense) are not copied.
- */
-static void __blk_rq_prep_clone(struct request *dst, struct request *src)
-{
-	dst->__sector = blk_rq_pos(src);
-	dst->__data_len = blk_rq_bytes(src);
-	if (src->rq_flags & RQF_SPECIAL_PAYLOAD) {
-		dst->rq_flags |= RQF_SPECIAL_PAYLOAD;
-		dst->special_vec = src->special_vec;
-	}
-	dst->nr_phys_segments = src->nr_phys_segments;
-	dst->ioprio = src->ioprio;
-	dst->extra_len = src->extra_len;
-}
-
 /**
  * blk_rq_prep_clone - Helper function to setup clone request
  * @rq: the request to be setup
···
  *
  * Description:
  *     Clones bios in @rq_src to @rq, and copies attributes of @rq_src to @rq.
- *     The actual data parts of @rq_src (e.g. ->cmd, ->sense)
- *     are not copied, and copying such parts is the caller's responsibility.
  *     Also, pages which the original bios are pointing to are not copied
  *     and the cloned bios just point same pages.
  *     So cloned bios must be completed before original bios, which means
···
 			rq->bio = rq->biotail = bio;
 	}
 
-	__blk_rq_prep_clone(rq, rq_src);
+	/* Copy attributes of the original request to the clone request. */
+	rq->__sector = blk_rq_pos(rq_src);
+	rq->__data_len = blk_rq_bytes(rq_src);
+	if (rq_src->rq_flags & RQF_SPECIAL_PAYLOAD) {
+		rq->rq_flags |= RQF_SPECIAL_PAYLOAD;
+		rq->special_vec = rq_src->special_vec;
+	}
+	rq->nr_phys_segments = rq_src->nr_phys_segments;
+	rq->ioprio = rq_src->ioprio;
+	rq->extra_len = rq_src->extra_len;
 
 	return 0;