Cinder scheduler broken with lvm mirroring enabled

[Vish Ishaya]

The status reporting in the lvm driver for cinder volume incorrectly reports free capacity. This is due to a couple of issues:

a) the number of mirrors isn't taken into account
b) there are some pathological cases where a simple division by total mirrors isn't sufficient because all mirrors must be on separate physical volumes.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/67350

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/67579
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=51099632dfc979c57133a69e4c68cdad3fe47008
Submitter: Jenkins
Branch: master

commit 51099632dfc979c57133a69e4c68cdad3fe47008
Author: Vishvananda Ishaya <email address hidden>
Date: Fri Jan 17 14:07:43 2014 -0700

    Fix up calculating space info for mirrored volumes

    The status reporting in the lvm driver for cinder volume incorrectly
    reports free capacity. This is due to a couple of issues:
      a) the number of mirrors isn't taken into account
      b) there are some pathological cases where a
         simple division by total mirrors isn't sufficient
         because all mirrors must be on separate physical volumes.

    Co-authored-by: Vishvananda Ishaya <email address hidden>
    Co-authored-by: John Griffith <email address hidden>

    Closes-Bug: 1269964
    Change-Id: I65e16b24367b4093a52c1c52d895fb58ef6a29ff