Comment 9 for bug 1535928

Reviewed: https://review.openstack.org/270532
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=530c1d30875c0ca2936303ed6e396d83018aaed6
Submitter: Jenkins
Branch: master

commit 530c1d30875c0ca2936303ed6e396d83018aaed6
Author: Swaminathan Vasudevan <email address hidden>
Date: Wed Jan 20 13:35:52 2016 -0800

    DVR: Fix Duplicate IPtables rule detected warning message in l3agent

    Duplicate IPtables rule detected warning message is seen in the
    l3 agent logs for sometime.

    This will be seen when multiple floatingips are created on
    the same node for different routers or when a floatingip
    is disassociated and re-associated to a fixed-ip on the same node.

    The fip namespace is retained in the compute node even though
    the floatingip is disassociated, but when we try to re-associate
    or create a new floatingip the code in l3agent is trying to check,
    if this is the 'first' floatingip and if so tries to re-create the
    floatingip namespace and the rules within it.

    This happens because we are unsubscribing the fip namespace count
    for every associated routers that we are deleting.

    This duplicate call to create the fip namespace should be restricted
    if there is already a fip namespace in the compute node and the fip
    namespace should be unsubscribed only when the external network is
    removed before the actual fip namespace is deleted.

    The change proposed in this fix, will only unsubscribe the fip
    namespace before it is deleted.

    Closes-Bug: #1535928

    Change-Id: I24016382091cad485f65e7753972f4b71702ff9f