func validateAdminReq(ctx context.Context, w http.ResponseWriter, r *http.Request, actions ...policy.AdminAction) (ObjectLayer, auth.Credentials) {
	// Get current object layer instance.
	objectAPI := newObjectLayerFn()
	if objectAPI == nil || globalNotificationSys == nil {
		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrServerNotInitialized), r.URL)
		return nil, auth.Credentials{}
	}