Comment 25 for bug 1696125

Reviewed: https://review.openstack.org/472309
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=55e2c851f15d68e7891f867cc5f32eece9a95034
Submitter: Jenkins
Branch: stable/ocata

commit 55e2c851f15d68e7891f867cc5f32eece9a95034
Author: Lee Yarwood <email address hidden>
Date: Tue Jun 6 14:08:37 2017 -0400

    libvirt: Check if domain is persistent before detaching devices

    Previously the libvirt driver would always assume that it was only
    detaching devices (volumes or virtual interfaces) from a persistent
    domain however that is not always the case.

    For example when rolling back from a live migration an attempt is made
    to detach volumes from the transient destination domain that is being
    cleaned up. This attempt would fail with the previous assumption of the
    domain being persistent in place.

    This change introduces a simple call to has_persistent_configuration
    within detach_device_with_retry to confirm the state of the domain
    before attempting to detach.

    Closes-Bug: #1669857
    Closes-Bug: #1696125
    Change-Id: I95948721a0119f5f54dbe50d4455fd47d422164b
    (cherry picked from commit 563c0927d14d052e3f1fad80df95fe4a7c48d38b)