WIP Allow the usage of Clone v2 API

This will allow for handling the deletion of cinder snapshots
which have clones.

Change-Id: Id8e581893ee4b373b268acc7c59b670985cedc2f

devstack/lib/ceph

@@ -484,6 +484,16 @@ function configure_ceph {
         sudo systemctl enable ceph-osd@${OSD_ID}
     done
 
+    if is_ceph_enabled_for_service cinder; then
+        # enables new features like Clone v2 API, which allows
+        # for proper handling of the deletion of snapshots
+        # with child clone images
+        if vercmp "$ceph_version" ">=" "13.0"; then
+            sudo ceph -c ${CEPH_CONF_FILE} \
+                osd set-require-min-compat-client mimic
+        fi
+    fi
+
     if is_ceph_enabled_for_service manila; then
         # create a MDS
         sudo mkdir -p ${CEPH_DATA_DIR}/mds/ceph-${MDS_ID}