Comment 1 for bug 1870289

Reviewed: https://review.opendev.org/716874
Committed: https://git.openstack.org/cgit/openstack/glance_store/commit/?id=f5d46996139593f6249138bcc9f09b6120f0034a
Submitter: Zuul
Branch: master

commit f5d46996139593f6249138bcc9f09b6120f0034a
Author: whoami-rajat <email address hidden>
Date: Wed Apr 1 14:18:44 2020 +0000

    Add lock per share for cinder nfs mount/umount

    With cinder configured as glance store and nfs as cinder backend,
    if we create multiple images concurrently into the same share,
    there might be race conditions.
    This patch ensures a lock per export to avoid the race conditions.

    This patch also introduces a reference counting mechamism for unmounting
    which will unmount the share if no active thread/process is using it.

    Closes-Bug: #1870289

    Change-Id: I9197f64e29a0ae2e0a58186f1a70aa134f7f1db6