custom excerpt read-more link

// add a 'Custom Excerpt Link URL' field below post/page editor
add_action('admin_menu', 'custom_excerpt_link');
add_action('save_post', 'save_custom_excerpt_link');
function custom_excerpt_link() {
add_meta_box('custom_excerpt_link', 'Custom Excerpt Link URL <small>example: http://website.com - if left empty, the link will go to the full post</small>', 'custom_excerpt_link_input_function', 'post', 'normal', 'high');
}
function custom_excerpt_link_input_function() {
global $post;
echo '<input type="hidden" name="custom_excerpt_link_input_hidden" id="custom_excerpt_link_input_hidden" value="'.wp_create_nonce('custom_excerpt_link-nonce').'" />';
echo '<input type="text" name="custom_excerpt_link_input" id="custom_excerpt_link_input" style="width:100%;" value="'.get_post_meta($post->ID,'excerpt_link',true).'" />';
}
function save_custom_excerpt_link($post_id) {
if (!wp_verify_nonce($_POST['custom_excerpt_link_input_hidden'], 'custom_excerpt_link-nonce')) return $post_id;
if (defined('DOING_AUTOSAVE') && DOING_AUTOSAVE) return $post_id;
$customMetaDesc = $_POST['custom_excerpt_link_input'];
update_post_meta($post_id, 'excerpt_link', $customMetaDesc);
}

//to use custom read-more link on excerpts//
function excerpt_read_more_custom_link($output) {
       global $post;
       if( !($link = get_post_meta($post->ID,'excerpt_link',true)) ) $link = get_permalink($post->ID);

    return '<a href="'. esc_url($link) . '">' . ' [&hellip;&nbsp;Read&nbsp;All]' . '</a>';
}
add_filter('excerpt_more', 'excerpt_read_more_custom_link');