Comment 3 for bug 1719966

Reviewed: https://review.openstack.org/507948
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=b1591d1080e4dbfbaf5351e009efa3abd11d88d4
Submitter: Jenkins
Branch: master

commit b1591d1080e4dbfbaf5351e009efa3abd11d88d4
Author: Dan Smith <email address hidden>
Date: Wed Sep 27 11:46:34 2017 -0700

    Fix policy check performance in 2.47+

    In 2.47 we introduced inlined flavors, which include extra_specs if so
    authorized. The code was doing a policy check deep in the per-instance
    handler that generated this blob. For queries with a lot of instances,
    this policy check is a lot of overhead, especially as it introduces a
    check of the policy file on disk, in case it has changed.

    This patch makes us calculate the permission flag once per list operation
    and pass it down to the lower layers to honor.

    Closes-Bug: #1719966
    Change-Id: I036623ae7409c2e6c6a754b4c8d5c9120f777774