DB migration 91 fails on precise with mysql

[Brian Waldon]

I see this traceback from migration 91 while running Nova on MySQL on Ubuntu Precise:

IntegrityError: (IntegrityError) (1451, 'Cannot delete or update a parent row: a foreign key constraint fails (`test_migrations`.`iscsi_targets`, CONSTRAINT `iscsi_targets_ibfk_1` FOREIGN KEY (`volume_id`) REFERENCES `volumes` (`id`))') 'UPDATE volumes SET id=%s WHERE volumes.id = %s' ('9db3c2e5-8cac-4e94-9e6c-b5f750736727', '10')

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/13203

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/13203
Committed: http://github.com/openstack/nova/commit/82d33f51f0fa2258f2a8d4003520af560d8bef11
Submitter: Jenkins
Branch: master

commit 82d33f51f0fa2258f2a8d4003520af560d8bef11
Author: Brian Waldon <email address hidden>
Date: Mon Sep 17 13:25:31 2012 -0700

    Correct db migration 91

    * Snapshot.id gets the new snapshot uuid rather than snapshot.volume_id
    * Foreign keys are dropped before and recreated after updating id fields
    * Snapshot id <-> uuid queries use snapshot_id_mappings.c.id rather
      than volume_id_mappings.id
    * Snapshot id <-> uuid queries are executed before passing the new id
      values into subsequent UPDATE queries
    * Thoroughly inspect the expected modifications in a new functional test
    * Fixes bug 1052244
    * Fixes bug 1052220

    Change-Id: I22c820e5747562251c6447ac678c80dd9e0e2e20