Comment 10 for bug 1807239

Reviewed: https://review.openstack.org/625578
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=e459b20fb50c5791fb30de0b35b5b5099b04cf2a
Submitter: Zuul
Branch: stable/queens

commit e459b20fb50c5791fb30de0b35b5b5099b04cf2a
Author: Nate Johnston <email address hidden>
Date: Thu Dec 6 12:39:49 2018 -0500

    Do not delete trunk bridges if service port attached

    When a deployment has instance ports that are neutron trunk ports with
    DPDK vhu in vhostuserclient mode, when the instance reboots nova will
    delete the ovs port and then recreate when the host comes back from
    reboot. This quick transition change can trigger a race condition that
    causes the tbr trunk bridge to be deleted after the port has been
    recreated. See the bug for more details.

    This change mitigates the race condition by adding a check for active
    service ports within the trunk port deletion function.

    Change-Id: I70b9c26990e6902f8888449bfd7483c25e5bff46
    Closes-Bug: #1807239
    (cherry picked from commit bd2a1bc6c3d68ddd27fc0b77ec767b11ec0fcb54)