+/* return id (s/n) string for *disk to *id_str
+ */
+static int virtblk_get_id(struct gendisk *disk, char *id_str)
+{
+ struct virtio_blk *vblk = disk->private_data;
+ struct request *req;
+ struct bio *bio;
+
+ bio = bio_map_kern(vblk->disk->queue, id_str, VIRTIO_BLK_ID_BYTES,
+ GFP_KERNEL);
+ if (IS_ERR(bio))
+ return PTR_ERR(bio);
+
+ req = blk_make_request(vblk->disk->queue, bio, GFP_KERNEL);
+ if (IS_ERR(req)) {
+ bio_put(bio);
+ return PTR_ERR(req);
+ }
+
+ req->cmd_type = REQ_TYPE_SPECIAL;
+ return blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
+}
+