+static ssize_t pid_show(struct gendisk *disk, char *page)
+{
+ return sprintf(page, "%ld\n",
+ (long) ((struct nbd_device *)disk->private_data)->pid);
+}
+
+static struct disk_attribute pid_attr = {
+ .attr = { .name = "pid", .mode = S_IRUGO },
+ .show = pid_show,
+};
+