'Revert an LV to snapshot.
:param snapshot_name: Name of snapshot to revert'

def revert(self, snapshot_name):

    cmd = ['lvconvert', '--merge', ('%s/%s' % (self.vg_name, snapshot_name))]
    try:
        self._execute(root_helper=self._root_helper, run_as_root=True, *cmd)
    except putils.ProcessExecutionError as err:
        LOG.exception('Error    Revert    Volume')
        LOG.error('Cmd                    :%s', err.cmd)
        LOG.error('StdOut        :%s', err.stdout)
        LOG.error('StdErr        :%s', err.stderr)
        raise
