code: func getVolumeInfo(spec *volume.Spec) (string, bool, error) {
  	if spec.Volume != nil && spec.Volume.Glusterfs != nil {
  		return spec.Volume.Glusterfs.Path, spec.Volume.Glusterfs.ReadOnly, nil
  
  	} else if spec.PersistentVolume != nil &&
  		spec.PersistentVolume.Spec.Glusterfs != nil {
  		return spec.PersistentVolume.Spec.Glusterfs.Path, spec.ReadOnly, nil
  	}
  	return "", false, fmt.Errorf("Spec does not reference a Glusterfs volume type")
  }
docs: //getVolumeInfo returns 'path' and 'readonly' field values from the provided glusterfs spec.