code: func makePDNameInternal(host volume.VolumeHost, pool string, image string) string {
  	// Backward compatibility for the deprecated format: /var/lib/kubelet/plugins/kubernetes.io/rbd/rbd/pool-image-image.
  	deprecatedDir := filepath.Join(host.GetPluginDir(rbdPluginName), "rbd", pool+"-image-"+image)
  	info, err := os.Stat(deprecatedDir)
  	if err == nil && info.IsDir() {
  		// The device mount path has already been created with the deprecated format, return it.
  		klog.V(5).Infof("Deprecated format path %s found", deprecatedDir)
  		return deprecatedDir
  	}
  	// Return the canonical format path.
  	return filepath.Join(host.GetPluginDir(rbdPluginName), volutil.MountsInGlobalPDPath, pool+"-image-"+image)
  }
docs: // Make a directory like /var/lib/kubelet/plugins/kubernetes.io/rbd/mounts/pool-image-image.