Comment 9 for bug 1730933

Reviewed: https://review.openstack.org/522245
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=05a73c0f3a9f8edf9024f9870279bc6fb7bba2e7
Submitter: Zuul
Branch: master

commit 05a73c0f3a9f8edf9024f9870279bc6fb7bba2e7
Author: Silvan Kaiser <email address hidden>
Date: Wed Nov 22 14:35:11 2017 +0100

    Added mount fstype based validation of Quobyte mounts

    The validation of Quobyte mounts is extended to validate based
    on a mounts file system type being set to "fuse.quobyte".
    This includes adding a new StaleVolumeMount exception type to
    the Nova exceptions.
    This also closes a bug concerning multi-registry configurations
    for Quobyte volumes due to no longer using the is_mounted()
    method that failed in that case.
    Finally this adds exception handling for the unmount call that
    is issued on trying to mount an already mounted volume.

    Closes-Bug: #1730933
    Closes-Bug: #1737131

    Change-Id: Ia5a23ce1123a68608ee2ec6f2ac5dca02da67c59