GPL and proprietary driver code

Please let me know if this should be asked elsewhere - I wasn't sure what the most appropriate forum would be for licensing questions...

I have plans to write a proprietary file system that can be mounted on top of XFS, in order to track and process certain file system requests. My question here is, assuming that all source code for my file system driver is original work and not based on existing GPLed code, is my driver required to be open source? I know that it would have to be if I was modifying the Linux kernel or the XFS file system code, but I'm not planning to do any of that. However, I've heard some conservative opinions of the belief that this new driver would still need to be open source.

Can anyone give me a definitive answer, or perhaps point me to an authoritative source? I've read up on the GPL license, and it is my opinion that my source could be kept proprietary, but I'd like to get expert opinions before continuing on.

Thanks!
James

[snip]

So talk to a lawyer...

Eli
--------------------. "If it ain't broke now,
Eli Carter \ it will be soon." -- crypto-gram
eli.carter(a)inet.com `-------------------------------------------------

Regarding "mounted on top of," if you're planning to use stackable file systems from my FiST work for Linux, that work has a unique copyright scheme that follows the Bison license.

Caveat: IANAL.

Erez.

In a related question, it seems to me that any work done using the FUSE toolkit could likewise be kept proprietary, yes?

--pj