Linux USB Mass Storage Emulation

My purpose is to emulate an USB device locally in a Linux environment. I mean that I want to “mount” a local backing storage file (made with dd) as an USB device inside the root user workspace.

After a Google search, I found the Linux USB Gadget API and the Mass Storage Function : http://www.linux-usb.org/gadget/file_storage.html. But it's not crystal clear : it seems that it can act only as client/server with USB coection between a Linux host and another computer (Linux, Windows or Mac).

I started to set a POC on a Debian Jessie with customized 3.16.7 keel, but I’m facing the following error "insmod: can't insert 'g_mass_storage.ko': No such device" when I try to load the g_mass_storage module.

Has anyone experienced this kind of stuff ? Thanks.

Mathieu