code: func (disk *dataDisk) GetGlobalMapPath(spec *volume.Spec) (string, error) {
  	volumeSource, _, err := getVolumeSource(spec)
  	if err != nil {
  		return "", err
  	}
  	return filepath.Join(disk.plugin.host.GetVolumeDevicePluginDir(azureDataDiskPluginName), string(volumeSource.DiskName)), nil
  }
docs: // GetGlobalMapPath returns global map path and error
  // path: plugins/kubernetes.io/{PluginName}/volumeDevices/volumeID
  //       plugins/kubernetes.io/azure-disk/volumeDevices/vol-XXXXXX