Facebook分享按钮数据-href Wordpress永久链接显示：“facebook.com/v2.0 ...”

This is how I render my button:

function fb_share() {
    $permalink = get_permalink();
    echo '<div class="fb-share-button" data-href="'.$permalink.'" data-layout="button_count"></div>';
}

I include the scripts right after tag opens. However, what it does when you click share is:

Any thoughts?