Quota error after deleting snapshot group

[Nolwenn Cauchois]

Uses are out of sync when we delete snapshot groups.

Impacted version : pike.

Steps :
----

1. Create a volume group
2. Create a volume of 2 gigabytes in this volume group
3. Create a snapshot group
4. cinder quota-usage

+----------------------+--------+----------+------------+
| Type | In_use | Reserved | Limit |
+----------------------+--------+----------+------------+
| backup_gigabytes | 0 | 0 | 1000 |
| backups | 0 | 0 | 40 |
| gigabytes | 4 | 0 | 1000000000 |
| gigabytes_performant | 0 | 0 | -1 |
| gigabytes_standard | 4 | 0 | -1 |
| groups | 1 | 0 | 10 |
| per_volume_gigabytes | 0 | 0 | -1 |
| snapshots | 1 | 0 | 50 |
| snapshots_performant | 0 | 0 | -1 |
| snapshots_standard | 1 | 0 | -1 |
| volumes | 1 | 0 | 50 |
| volumes_performant | 0 | 0 | -1 |
| volumes_standard | 1 | 0 | -1 |
+----------------------+--------+----------+------------+

5. Delete the snapshot group
6. cinder quota-usage

Actual result
+----------------------+--------+----------+------------+
| Type | In_use | Reserved | Limit |
+----------------------+--------+----------+------------+
| backup_gigabytes | 0 | 0 | 1000 |
| backups | 0 | 0 | 40 |
| gigabytes | 4 | 0 | 1000000000 |
| gigabytes_performant | 0 | 0 | -1 |
| gigabytes_standard | 4 | 0 | -1 |
| groups | 1 | 0 | 10 |
| per_volume_gigabytes | 0 | 0 | -1 |
| snapshots | 0 | 0 | 50 |
| snapshots_performant | 0 | 0 | -1 |
| snapshots_standard | 0 | 0 | -1 |
| volumes | 1 | 0 | 50 |
| volumes_performant | 0 | 0 | -1 |
| volumes_standard | 1 | 0 | -1 |
+----------------------+--------+----------+------------+

Expected result
+----------------------+--------+----------+------------+
| Type | In_use | Reserved | Limit |
+----------------------+--------+----------+------------+
| backup_gigabytes | 0 | 0 | 1000 |
| backups | 0 | 0 | 40 |
| gigabytes | 2 | 0 | 1000000000 |
| gigabytes_performant | 0 | 0 | -1 |
| gigabytes_standard | 2 | 0 | -1 |
| groups | 1 | 0 | 10 |
| per_volume_gigabytes | 0 | 0 | -1 |
| snapshots | 0 | 0 | 50 |
| snapshots_performant | 0 | 0 | -1 |
| snapshots_standard | 0 | 0 | -1 |
| volumes | 1 | 0 | 50 |
| volumes_performant | 0 | 0 | -1 |
| volumes_standard | 1 | 0 | -1 |
+----------------------+--------+----------+------------+

Gigabytes and gigabytes_standard are not decremented

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/626863

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/626863
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=e0048d4c99e8e6110ebd349c2065bf215653f880
Submitter: Zuul
Branch: master

commit e0048d4c99e8e6110ebd349c2065bf215653f880
Author: Nolwenn Cauchois <email address hidden>
Date: Fri Dec 21 11:19:51 2018 +0100

    Fix gigabytes usage error when deleting snapshot group

    When deleting snapshot group, the number of snapshots
    is well decremented with the number of snapshots present
    in the group. But not the number of gigabytes.

    Change-Id: I0fe6d4682a16cbe30e563079964a5275bac728bb
    Closes-Bug: #1809434

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/cinder 14.0.0.0rc1 release candidate.