A WordPress loop to display post/page attachments

loop_through_post_attachments.php

<?php /*
  * This is just a simple loop to display 7 attachments attached to a post or page in WordPress
  * You can change 'medium' and 'thumbnail' to add sizes you have definied in your theme by the add_image_size function
  * in WordPress
  */
?>
<div id="thumbs" class="pic_list">
<ul class="thumbs">
    <?php /* Time to create a new loop that pulls out  the first 7 image attachments for this post */
    $args = array( 'post_type' => 'attachment', 'numberposts' => 7, 'post_status' => null, 'post_parent' => $post->ID );
    $attachments = get_posts( $args );
    if ( $attachments ) {
        foreach ( $attachments as $attachment ) {
            $image_attributes = wp_get_attachment_image_src( $attachment->ID, 'medium' );
            echo '<li><a class="thumb" href="';
            echo $image_attributes[0];
            echo '">';
            echo wp_get_attachment_image( $attachment->ID, 'thumbnail' );
            echo '</a></li>'; ?>
        <?php } ?>
        </ul>
    <?php } ?>
</div>

Thanks

What if I would like the images to link back to the post how do I go about this

get_permalink($post->post_parent);