Comment 10 for bug 971621

Reviewed: https://review.openstack.org/10962
Committed: http://github.com/openstack/nova/commit/272b98d718a68f5f714543ed2948d49ffe052ca5
Submitter: Jenkins
Branch: stable/essex

commit 272b98d718a68f5f714543ed2948d49ffe052ca5
Author: Pádraig Brady <email address hidden>
Date: Tue Aug 7 15:17:08 2012 +0100

    fix unmounting of LXC containers

    There were two issues here.

    1. There was a global object stored for all instances,
    thus the last mounted instance was always unmounted.

    2. Even if there was only a single LXC instance in use,
    the global object would be lost on restart of Nova.

    Therefore we reset the internal state for the mount object,
    by passing in the mount point to destroy_container(),
    and querying the device in use for that mount point.

    Fixes bug: 971621
    Change-Id: I5442442f00d93f5e8b82f492d62918419db5cd3b
    Cherry-picked: a5184d5dbf67630dac3abb69b1678b60807cfce7