403 nginx 错误 - 权限被拒绝

当我尝试使用 nginx 访问域时，我收到 403 禁止错误。我得到的nginx日志是：

[error] 13656#0: *4 "/var/www/example.com/www/index.php" is forbidden (13: Permission denied), client: 31.179.107.194, server: example.com, request: "GET / HTTP/1.1", host: "example.com"

/var/www/具有递归 777 权限。站点可用配置为：

#HTTP serve
#
server {
        listen   80;
        root /var/www/example.com/www/;
        index index.php index.html index.htm;
        server_name example.com;
        access_log /var/log/nginx/example.com.access.log combined buffer=1024k;
        error_log /var/log/nginx/example.com.error.log;
        client_max_body_size 128M;
        if (!-e $request_filename) {
                rewrite ^/([a-zA-Z0-9]+)/([a-zA-Z0-9]+)/$ /index.php?controller=$1&action=$2 last;
        }
        location ~ '.php$ {
                if (!-f $document_root/$fastcgi_script_name){
                        return 404;
                }
                fastcgi_split_path_info ^(.+'.php)(/.+)$;
                fastcgi_pass unix:/var/run/php5-fpm.sock;
                fastcgi_index index.php;
                proxy_connect_timeout 600s;
                proxy_read_timeout 600s;
                include fastcgi_params;
        }
        location ~ /'.ht {
                deny all;
        }
}

nginx.conf包含user root;指令。

怎么了？