drbd: use bio_{start,end}_io_acct

Switch drbd to use the nicer bio accounting helpers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/drbd/drbd_req.c

@@ -21,24 +21,6 @@
 
 static bool drbd_may_do_local_read(struct drbd_device *device, sector_t sector, int size);
 
-/* Update disk stats at start of I/O request */
-static void _drbd_start_io_acct(struct drbd_device *device, struct drbd_request *req)
-{
-	struct request_queue *q = device->rq_queue;
-
-	generic_start_io_acct(q, bio_op(req->master_bio),
-				req->i.size >> 9, &device->vdisk->part0);
-}
-
-/* Update disk stats when completing request upwards */
-static void _drbd_end_io_acct(struct drbd_device *device, struct drbd_request *req)
-{
-	struct request_queue *q = device->rq_queue;
-
-	generic_end_io_acct(q, bio_op(req->master_bio),
-			    &device->vdisk->part0, req->start_jif);
-}
-
 static struct drbd_request *drbd_req_new(struct drbd_device *device, struct bio *bio_src)
 {
 	struct drbd_request *req;
@@ -263,7 +245,7 @@ void drbd_req_complete(struct drbd_request *req, struct bio_and_error *m)
 		start_new_tl_epoch(first_peer_device(device)->connection);
 
 	/* Update disk stats */
-	_drbd_end_io_acct(device, req);
+	bio_end_io_acct(req->master_bio, req->start_jif);
 
 	/* If READ failed,
 	 * have it be pushed back to the retry work queue,
@@ -1222,16 +1204,15 @@ drbd_request_prepare(struct drbd_device *device, struct bio *bio, unsigned long
 		bio_endio(bio);
 		return ERR_PTR(-ENOMEM);
 	}
-	req->start_jif = start_jif;
+
+	/* Update disk stats */
+	req->start_jif = bio_start_io_acct(req->master_bio);
 
 	if (!get_ldev(device)) {
 		bio_put(req->private_bio);
 		req->private_bio = NULL;
 	}
 
-	/* Update disk stats */
-	_drbd_start_io_acct(device, req);
-
 	/* process discards always from our submitter thread */
 	if (bio_op(bio) == REQ_OP_WRITE_ZEROES ||
 	    bio_op(bio) == REQ_OP_DISCARD)