def snapshot_lvol_bdev(client, lvol_name, snapshot_name):
    """Capture a snapshot of the current state of a logical volume.

    Args:
        lvol_name: logical volume to create a snapshot from
        snapshot_name: name for the newly created snapshot

    Returns:
        Name of created logical volume snapshot.
    """
    params = {
        'lvol_name': lvol_name,
        'snapshot_name': snapshot_name
    }
    return client.call('snapshot_lvol_bdev', params)