def rename_lvol_bdev(client, old_name, new_name):
    """Rename a logical volume.

    Args:
        old_name: existing logical volume name
        new_name: new logical volume name
    """
    params = {
        'old_name': old_name,
        'new_name': new_name
    }
    return client.call('rename_lvol_bdev', params)