Cinder resize procedure should not require lock/unlock

[Maria Yousaf]

Brief Description
-----------------
The cinder resize procedure does not match what is documented. The current procedure requires a lock/unlock for some labs/disk types. The lock/unlock should not be required.

Severity
--------
Major

Steps to Reproduce
------------------
Currently to resize cinder successfully, the user must do the following:

1. On standby controller, lock controller, enlarge cinder partition and unlock
2. Swact
3. On new standby controller, lock controller, enlarge cinder partition and unlock
4. Swact
5. Now both cinder-volume sizes should be increased

In the documentation, cinder resize is described as an in-service procedure. No lock/unlock requirement is listed.

Expected Behavior
------------------
No lock/unlock required

Actual Behavior
----------------
Lock/unlock required with certain disks

Reproducibility
---------------
Reproducible

System Configuration
--------------------
Any LVM system with slower disks

Branch/Pull Time/Commit
-----------------------
N/A

Timestamp/Logs
--------------
N/A

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/619051

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/619051
Committed: https://git.openstack.org/cgit/openstack/stx-config/commit/?id=e052d9c86073afb669d6388521b3961e945ea555
Submitter: Zuul
Branch: master

commit e052d9c86073afb669d6388521b3961e945ea555
Author: Wei Zhou <email address hidden>
Date: Tue Nov 20 12:46:08 2018 -0500

    Cinder-volumes Volume Group Resize Procedure Failed

    When the disk partition for the cinder-volumes VG is increased
    on the newly standby controller after controller swact, drbd sync
    starts before cinder-volumes VG is extended. When drbd sync starts,
    the drbd is in "SyncSource" state. But the code waits for drbd to
    be in "Connected" state. If that doesn't happen within 5 seconds,
    it will fail and won't continue to extend cinder-volumes VG.

    The solution is to allow cinder-volumes VG extension while drbd is
    in either "Connected" or "SyncSource" state.

    Change-Id: Ib164ce5fb433789d0806ac8d4faae9d675695b65
    Closes-bug: 1803772
    Signed-off-by: Wei Zhou <email address hidden>