如何禁用搜索引擎收录WordPress 媒体图片页面

//禁用 WordPress
    function wpb_redirect_attachment_to_post() {
    if ( is_attachment() ) {
    global $post;
    if( empty( $post ) ) $post = get_queried_object();
    if ($post->post_parent) {
    $link = get_permalink( $post->post_parent );
    wp_redirect( $link, '301' );
    exit();
    }
    else {
    // What to do if parent post is not available
    wp_redirect( home_url(), '301' );
    exit();
    }
  }
}