WP MS Nginx

map $uri $blogname{
	~^(?P<blogpath>/[^/]+/)files/(.*)	$blogpath ;
}
 
map $blogname $blogid{
	default -999;
 
	#Ref: http://wordpress.org/extend/plugins/nginx-helper/
	#include /var/www/wordpress/wp-content/plugins/nginx-helper/map.conf ;
}

[...]

location ~ ^(/[^/]+/)?files/(.+) {
		try_files /wp-content/blogs.dir/$blogid/files/$2 /wp-includes/ms-files.php?file=$2 ;
		access_log off;	
		log_not_found off; 
		expires max;
}
 
#avoid php readfile()
location ^~ /blogs.dir {
	internal;
	alias /var/www/example.com/htdocs/wp-content/blogs.dir ;
	access_log off;	
	log_not_found off; 
	expires max;
}