ModPorter - problems accessing the hash

I'm trying to set up an upload interface to use mod_porter, however I
can't seem to read the hash that it hands off to the rails method.

It seems like I should be able to access the hash content using params
[:file][:data][:filename] and params[:file][:data][:path] etc..

But it throws an error saying:

undefined method `[]' for #<ModPorter::UploadedFile: .... >

What am I doing wrong?

Nobody?

Ok maybe I'm asking the wrong question:

Has Rack come up with a way to handle uploads in a way that scales
well without emptying the rails thread pool so that nobody is even
using mod_porter?