Unable to mount NFS share on /var/lib/cinder/conversion

Issue

• In OSP10/13, we've been mounting an NFS share on the /var/lib/cinder/conversion directory for cinder-volume, in order to provide more space for doing image to volume conversions during boot-from-volume type deployments.

• We are hitting https://bugzilla.redhat.com/show_bug.cgi?id=1886762, in which an selinux option is not allowing an NFS share to be mounted. If you mount the NFS share on this directory, the cinder-volume container will

  * openstack-cinder-volume-podman-0  (ocf::heartbeat:podman):        Stopped

Failed Resource Actions:
  * openstack-cinder-volume-podman-0_start_0 on controller 'error' (1): call=258, status='comntainer', last-rc-change='2021-05-06 15:19:15Z', queued=0ms, exec=1290ms
  * openstack-cinder-volume-podman-0_start_0 on controller 'error' (1): call=103, status='comntainer', last-rc-change='2021-05-06 15:19:17Z', queued=0ms, exec=393ms
  * openstack-cinder-volume-podman-0_start_0 on controller 'error' (1): call=198, status='comntainer', last-rc-change='2021-05-06 15:19:12Z', queued=0ms, exec=2641ms