Comment 6 for bug 1374458

The code doesn't do any kind of retry right now, so adding that should help:

    def _close_volume(self, **kwargs):
        """Closes the device (effectively removes the dm-crypt mapping)."""
        LOG.debug("closing encrypted volume %s", self.dev_path)
        utils.execute('cryptsetup', 'luksClose', self.dev_name,
                      run_as_root=True, check_exit_code=True)