Comment 19 for bug 1545675

Reviewed: https://review.openstack.org/337107
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=2703a3d80bcbd49eaafaae624289d00c521b5192
Submitter: Jenkins
Branch: stable/mitaka

commit 2703a3d80bcbd49eaafaae624289d00c521b5192
Author: Stephen Finucane <email address hidden>
Date: Mon May 30 16:03:35 2016 +0100

    Evaluate 'task_state' in resource (de)allocation

    There are two types of VM states associated with shelving. The first,
    'shelved' indicates that the VM has been powered off but the resources
    remain allocated on the hypervisor. The second, 'shelved_offloaded',
    indicates that the VM has been powered off and the resources freed.
    When "unshelving" VMs in the latter state, the VM state does not change
    from 'shelved_offloaded' until some time after the VM has been
    "unshelved".

    Change I83a5f06 introduced a change that allowed for deallocation of
    resources when they were set to the 'shelved_offloaded' state. However,
    the resource (de)allocation code path assumes any VM with a state of
    'shelved_offloaded' should have resources deallocated from it, rather
    than allocated to it. As the VM state has not changed when this code
    path is executed, resources are incorrectly deallocated from the
    instance twice.

    Enhance the aformentioned check to account for task state in addition to
    VM state. This ensures a VM that's still in 'shelved_offloaded' state,
    but is in fact being unshelved, does not trigger deallocation.

    Change-Id: Ie2e7b91937fc3d61bb1197fffc3549bebc65e8aa
    Signed-off-by: Stephen Finucane <email address hidden>
    Resolves-bug: #1587386
    Related-bug: #1545675
    (cherry picked from commit f1320a7c2debf127a93773046adffb80563fd20b)