4.20 introduces user namespace support however some CSI drivers don't support it, specially the ones that are file based
We need to add a column in the CSI driver table to mention user namespace support
https://docs.redhat.com/en/documentation/openshift_container_platform/4.20/html/storage/using-container-storage-interface-csi#csi-drivers-supported_persistent-storage-csi

For in-tree NFS add a note to https://docs.redhat.com/en/documentation/openshift_container_platform/4.20/html/storage/configuring-persistent-storage#persistent-storage-using-nfs

    4.20

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    https://docs.redhat.com/en/documentation/openshift_container_platform/4.20/html/nodes/working-with-pods#nodes-pods-user-namespaces