Comment 10 for bug 1869746

Reviewed: https://review.opendev.org/739154
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=f3cdc27563766b2f49a1d88500f32c8d86838c96
Submitter: Zuul
Branch: stable/train

commit f3cdc27563766b2f49a1d88500f32c8d86838c96
Author: Rodrigo Barbieri <email address hidden>
Date: Wed Jul 1 18:20:15 2020 -0300

    Fix cross-project incremental backups

    This patch addresses the scenario where an
    incremental backup can be created having a
    parent backup that was taken in a different
    project. This scenario ultimately leads to
    a silent error when creating/deleting the
    incremental backup and quotas going out of
    sync.

    The proposed fix is to narrow the backup search
    down to the same project. To achieve this, a
    method's signature had to be updated to achieve
    the desired optimized behavior of passing the
    volume's project_id parameter.

    Closes-bug: #1869746
    Closes-bug: #1873518

    conflicts:
        cinder/tests/unit/backup/test_backup.py

    Test test_create_backup_failed_with_empty_backup_objects
    required a mock for
    test_create_backup_failed_with_empty_backup_objects
    which had been removed in ussuri, as part of commit
    f0211b53b82cde96eb39e9914c3e5fae232db07c. That
    commit removed code and leftover the mock, which I
    had removed in the change this patch was
    cherry-picked from, as it was unnecessary.

    The removed code section of cinder/backup/api.py
    from commit f0211b53b82cde96eb39e9914c3e5fae232db07c
    does not impact the functionality of this change at all.

    Change-Id: Icb621ff5966133f59d9d43ca2dd9f8e1919b1149
    (cherry picked from commit 8ebeafcbbafb700052f3abfc1f7ba004269a92e8)
    (cherry picked from commit 5358c996b40bbb0fd749ec182ff3ef67f5d71c16)