Attaching PDF to User Notification Clarification

# add attachment feature to user notification
add_filter("gform_user_notification_attachments", "add_attachment", 10, 3);
function add_attachment($attachments, $lead, $form){

    //getting wordpress upload folder
    $upload = wp_upload_dir();
    $upload_path = $upload["/var/www/2xy/data/www/messagehouse_2012/wordpress/wp-content/uploads/temp"];

    $attachments = array();

    //add a file from the uploads folder
    $attachments[] = $upload_path . "/test.pdf";

    return $attachments;
}