fail if annotation not present

pkg/controller/controller.go

@@ -1135,7 +1135,7 @@ func (p *csiProvisioner) getSnapshotSource(ctx context.Context, claim *v1.Persis
 			// Verify if this volume is allowed to alter its mode.
 			allowVolumeModeChange, ok := snapContentObj.Annotations[annAllowVolumeModeChange]
 			if !ok {
-				klog.Infof("%s annotation not present on VolumeSnapshotContent %s. Allowing volume mode change ...", annAllowVolumeModeChange, snapContentObj.Name)
+				return nil, fmt.Errorf("requested volume %s/%s modifies the mode of the source volume but does not have permission to do so.", claim.Namespace, claim.Name)
 			}
 			allowVolumeModeChangeBool, err := strconv.ParseBool(allowVolumeModeChange)
 			if err != nil {