Running periodic task during live migration results in incorrect usage

[Stephen Finucane]

With the introduction of NUMA-aware live migration in Train, we now do proper claiming and, if necessary, unclaiming of resources at the destination host. However, the latter uses the same mechanism as resize/cold migrate confirm/revert, which means its subject to the same races as those highlighted in bug 1879878. This bug tracks the live migration side of the work to fix that.

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.opendev.org/749713

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/749713
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=99850a04812fe1530b5555f08bd9afba41cbddce
Submitter: Zuul
Branch: master

commit 99850a04812fe1530b5555f08bd9afba41cbddce
Author: Stephen Finucane <email address hidden>
Date: Thu Sep 3 12:56:41 2020 +0100

    Add reproducer for bug #1894095

    As with the resize/cold migration confirm/resize flow, the rolling back
    of live migrations can be racy due to us doing various things without
    the benefit of locks. Add a reproducer demonstrating this.

    Change-Id: I276d2bbce4a0390a6cfd597bb51481cc53eca918
    Signed-off-by: Stephen Finucane <email address hidden>
    Related-Bug: #1894095
    Related-Bug: #1879878

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/nova/+/851832