don't secure delete thin provisioned volumes or snapshots

[John Griffith]

Performing the secure delete operation on volumes and snapshots writes zeros (or other patterns) across the entire surface of an LVM volume on delete calls. This is pointless with thin provisioning, and in fact results in defeating the purpose of thin provisioning as it requires actual allocation of all of the blocks.

Add a check before calling lvm.clear_volume and skip this step if thin provisioning is configured.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/51990

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/51990
Committed: http://github.com/openstack/cinder/commit/de4392314f9b0def8fab65679ec5668aec98fbee
Submitter: Jenkins
Branch: master

commit de4392314f9b0def8fab65679ec5668aec98fbee
Author: John Griffith <email address hidden>
Date: Tue Oct 15 19:39:22 2013 -0600

    Don't zero out thin provisioned LV's on delete

    Thin provisioned LV's don't need secure delete to protect
    from data leakage. Also, zeroing these out kinda defeats
    the purpose of using thing provisioning.

    This patch add a check for the lvm type and if it's thin simply
    returns from the lvm.clear_volume() method.

    Change-Id: Ie6764209018152565295291efc6fbba553698ae6
    Closes-Bug: #1240299

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/havana
Review: https://review.openstack.org/56081

[Eric Harney (eharney)]

Suggest this as a backport to Havana because outside of the original reasons for the change, LVM versions that are relevant for Havana have changed the behavior so that these devices may not exist, causing the delete operation to fail anyway.

From LVM2 2.02.99 changelog:
"Automatically flag thin snapshots to be skipped during activation. "

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/grizzly
Review: https://review.openstack.org/56083

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/56083
Committed: http://github.com/openstack/cinder/commit/c9c9eaac573b65df671aab5c0f9ab4411557b926
Submitter: Jenkins
Branch: stable/grizzly

commit c9c9eaac573b65df671aab5c0f9ab4411557b926
Author: Eric Harney <email address hidden>
Date: Tue Nov 12 14:34:44 2013 -0500

    Don't zero out thin provisioned LV's on delete

    Thin provisioned LV's don't need secure delete to protect
    from data leakage. Also, zeroing these out kinda defeats
    the purpose of using thing provisioning.

    This patch add a check for the lvm type and if it's thin simply
    returns from the lvm.clear_volume() method.

    Conflicts:
     cinder/tests/test_volume.py
     cinder/volume/drivers/lvm.py

    Change-Id: Ie6764209018152565295291efc6fbba553698ae6
    Closes-Bug: #1240299
    (cherry picked from commit de4392314f9b0def8fab65679ec5668aec98fbee)

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/56081
Committed: http://github.com/openstack/cinder/commit/709130b4777d059b9300f9f5d5614a4ed9c633b2
Submitter: Jenkins
Branch: stable/havana

commit 709130b4777d059b9300f9f5d5614a4ed9c633b2
Author: John Griffith <email address hidden>
Date: Tue Oct 15 19:39:22 2013 -0600

    Don't zero out thin provisioned LV's on delete

    Thin provisioned LV's don't need secure delete to protect
    from data leakage. Also, zeroing these out kinda defeats
    the purpose of using thing provisioning.

    This patch add a check for the lvm type and if it's thin simply
    returns from the lvm.clear_volume() method.

    Change-Id: Ie6764209018152565295291efc6fbba553698ae6
    Closes-Bug: #1240299
    (cherry picked from commit de4392314f9b0def8fab65679ec5668aec98fbee)