Storage Mode Converter

if ( ! function_exists( 'msd_convert_storage' ) ) :
	function msd_convert_storage($key,$prefix,$posttype) {
		$args = array(
		    'numberposts'     => -1,
		    'post_type'       => $posttype,
		);
		$items = get_posts($args);
		foreach($items AS $item){
			$the_meta = get_post_meta($item->ID,$key);
			$fields = array();
			foreach($the_meta[0] AS $meta_key => $meta_value){
				$meta_key = $prefix.$meta_key;
				update_post_meta($item->ID, $meta_key, $meta_value);
				$fields[] = $meta_key;
			}
			update_post_meta($item->ID,$key.'_fields',$fields);
			delete_post_meta($item->ID,$key);
		}
	}
endif;