CephFS works on OKD 3.11 -- and probably earlier.
Kubernetes docs are pretty much accurate dealing with CephFS on OpenShift.
You'ld need a specific provisioner, with admin privileges over your Ceph cluster (creating CephFS volumes would create a Ceph keyring with limited privileges, such as your Pods may not access shares they're not meant to use)
One small detail though: I couldn't manage to make it work using the cephfs kernel driver.
Other alternatives, glusterfs obviously. Viable: I wouldn't go there.
Stuff like CIFS shares. Though can break some applications (eg: jenkins, low posix compliance)
Haven't had much time to extensively test cephfs. I seem to remember the MDS leak (13.x)
All in all, there's no perfect solution.
Depending on your application, if you're lucky, another take on it could be to look into s3 (radosgw) integration.