Race condition in db floating_ip_create and floating_ip_bulk_create

[Boris Pavlovic]

floating_ip rows should have a unique value in address column.

At this moment we are checking that it doesn't exists in DB and then if it doesn't then we save it in DB.

Select then Insert and this will cause race conditions.

We should add unique constraint on (address, deleted) columns and then just try to insert.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/23466

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/23466
Committed: http://github.com/openstack/nova/commit/6dc7dedaf08de70264a00824dfd35e8e03ffb610
Submitter: Jenkins
Branch: master

commit 6dc7dedaf08de70264a00824dfd35e8e03ffb610
Author: Boris Pavlovic <email address hidden>
Date: Tue Mar 5 00:58:14 2013 +0400

    Remove race condition (in FloatingIps)

    Soft delete all duplicate rows with the same address except one with
    the biggest value in `id` column.

    Create UC on columns (address, deleted)

    Fix floating_ip_create
      Replace Select then Insert -> Try to Insert.

    Fix floating_ip_bulk_create
      Replace get all and locally compare -> Try to Insert

    Fix floating_ip_update
      If we update floating_ip with existing address, raise
      rollback and raise FloatingIpExists

    Add missing test for floating_ip_update to duplicate

    Fixes bug 1145216

    blueprint db-enforce-unique-keys

    Change-Id: Idd0c8305ca348700235f757a29fc7998edca576b