Comment 4 for bug 1616974

Reviewed: https://review.openstack.org/402923
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=2195885e7710adfc6c4be944f22e5cc01a2361e8
Submitter: Jenkins
Branch: master

commit 2195885e7710adfc6c4be944f22e5cc01a2361e8
Author: Gorka Eguileor <email address hidden>
Date: Fri Nov 25 15:56:51 2016 +0100

    Fix replication freeze mechanism

    Freeze functionality in the replication feature doesn't work as
    expected, since it is not being used on the scheduler to exclude
    backends or used on the API or volume nodes so API-to-Vol operations
    like delete and create snapshot will also work.

    This patch fixes the freeze mechanism by excluding frozen backends in
    the scheduler and checking the if the service is frozen on all other
    modifying operations.

    Since extend operation now goes through the scheduler it will be frozen
    there.

    Closes-Bug: #1616974
    Change-Id: I4561500746c95b96136878ddfde8ca88e96b28c6