I'm developing a cross platform application that needs to be able to monitor file system access in real time. By real time I mean, I have to know when a user tried to open a file in the moment he clicked it, because I might have to do several operations before he is allowed to open the file. This is just a simple example, but it shows me that I cannot relly for instance in Inotify.

What I'm trying to do for both platforms is a File System Filter, I've already found it for Windows (check this link: Filter Manager Concepts, or this webcast Neal Christiansen - Inside File System Filter, part I), but I'm having a hard time finding something similar for Linux.
Does anyone know if such thing is possible under Linux? Can you please point me in the right track?