Comment 5 for bug 1551958

Reviewed: https://review.openstack.org/286843
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=afe1a834000d33900b8646d308fa26fa807a2ca0
Submitter: Jenkins
Branch: master

commit afe1a834000d33900b8646d308fa26fa807a2ca0
Author: Kevin Benton <email address hidden>
Date: Tue Mar 1 10:47:00 2016 -0800

    Block delete_(network|subnet) transactioned calls

    These functions assume that they won't be called inside of a
    transaction for two reasons. The first is an infinite loop that
    will only terminate if it can actually retrieve the latest
    information from the database. The second is that ML2's post-commit
    operations are expected to occur after data was actually committed
    so mechanism drivers that do DB lookups using a different session
    may break.

    This adds an explicit guard that prevents these two functions from
    being called within an active DB session. The rest of the ML2
    functions should eventually be converted to this style as well
    (see the partial bug).

    Related-Bug: #1551958
    Partial-Bug: #1540844
    Change-Id: I5c00b186585369ef6c8e2b9cb5a43b8bba0e5a7c