max file size for proxy_cache_path

[Andrey Feldman]

Hi.
Is there any way to limit size of file, that can be cached into 
proxy_cache_path?

For example, we have:
proxy_cache_path  /var/nginx/cache/html         levels=1:2 
keys_zone=html-cache:18m max_size=5g inactive=60m;

So, if someone on backend will place a 2G file, and it will be cached, 
the big part of useful cached data will be destroyed by cache manager.
And second problem - we can't be sure, that proxy_temp_path and 
proxy_cache_path will not be overflowed.