---
upgrade:
  - |
    This release modifies the online database migrations to address an
    an upgrade issue (`Bug #1893107
    <https://bugs.launchpad.net/cinder/+bug/1893107>`_).  The issue does
    not manifest itself in the Train release of cinder, but under specific
    circumstances it can prevent a cinder database upgrade from Train to
    Ussuri.

    This upgrade notice applies to you only if **all** of the following
    conditions are met:

    #. You upgraded to Train from Stein
    #. Before upgrading from Stein, you did **not** purge the cinder database
    #. Your original upgrade from Stein was to cinder version 15.3.0 or
       earlier.

       .. note::
          If you are upgrading a Stein installation directly to this release
          (cinder 15.4.0) or later, this notice does *not* apply to you.

    If all the above three items apply to you, as part of your upgrade
    to cinder 15.4.0 you should re-run the online database migrations
    contained in this release.  This will prepare your cinder database
    for an eventual upgrade to the Ussuri release.

    .. note::
       The online database migrations in this release require the existence
       of a volume type named ``__DEFAULT__``.  A ``__DEFAULT__`` volume
       type was created as part of your original installation of/upgrade to
       a Train release of cinder.  If you have renamed (or renamed and deleted)
       the ``__DEFAULT__`` volume type, you must re-create it before running
       the online migrations.  (If you renamed it, you don't have to un-rename
       it; you can create a new one just for the purposes of the online
       database migration.)

       If necessary, you can create a new ``__DEFAULT__`` volume type as
       follows using the Block Storage API, or by using the
       python-cinderclient or python-openstackclient to do the equivalent:

       API request: ``POST /v3/{project_id}/types``

       Request body::

          {
              "volume_type": {
                  "name": "__DEFAULT__",
                  "description": "Default Volume Type",
                  "os-volume-type-access:is_public": true
              }
          }

       The ``__DEFAULT__`` volume type may safely be renamed (or renamed
       and deleted) after you have run the online migrations as long as
       the ``default_volume_type`` configuration option is set to a valid
       existing volume type.

fixes:
  - |
    `Bug #1893107 <https://bugs.launchpad.net/cinder/+bug/1893107>`_:
    The Ussuri release changes the cinder database schema to make the
    ``volume_type_id`` column in the ``volumes`` and ``snapshots`` tables
    non-nullable because all volumes have been required to have a volume type
    since the Train release.  The online database migration in the cinder
    Train series (release 15.3.0 or earlier), however, did not process
    soft-deleted rows, leaving the possibility that there could be a
    deleted volume or snapshot with a null ``volume_type_id``, which in
    turn will make the database upgrade fail when the non-nullability
    constraint cannot be applied when a Train installation is upgraded
    to Ussuri.

    If you are upgrading to this release from an earlier release in the
    Train series (that is, you are upgrading from cinder>=15.0.0,<=15.3.0),
    under specific circumstances you should re-run the online database
    migrations so that your database will be in the correct state when
    you eventually upgrade to a Ussuri release.  See the "Upgrade Notes"
    for more information.