license question w.r.t. NFSv4.1 Layout drivers - calling all amateur lawyers

First off, I had no idea which mailing list would be appropriate
for this, so apologies in advance if I chose the wrong one.

For NFSv4.1 pNFS, there are layout drivers in Linux that I would
like to reuse for the FreeBSD client. (Re-writing these drivers
from scratch would be a lot of work and difficult to maintain. The
Linux drivers are being actively developed with the assistance of
server vendors.)

Two of these drivers carry a University of Michigan copyright notice
which looks pretty liberal to me. (Rather similar to MIT's copyright.)
I realize it would have to be approved by core_at_, but I think it could
be. (The 3rd is GPLv2'd, but that one doesn't concern me at this time.
I believe that Panasas might be able to release the code for this one
under a different license, but haven't explored this as of yet.)

However, there is a catch...
After the copyright notice on the .c files, but not the .h files,
there is also this:

MODULE_LICENSE("GPL");

and in linux/module.h, there is the following for the above:
/*
 * The following license idents are currently accepted as indicating free
 * software modules
 *
 *	"GPL"				[GNU Public License v2 or later]
 *	"GPL v2"			[GNU Public License v2]
 *	"GPL and additional rights"	[GNU Public License v2 rights and more]
 *	"Dual BSD/GPL"			[GNU Public License v2
 *					 or BSD license choice]
 *	"Dual MIT/GPL"			[GNU Public License v2
 *					 or MIT license choice]
 *	"Dual MPL/GPL"			[GNU Public License v2
 *					 or Mozilla license choice]
 *
 * The following other idents are available
 *
 *	"Proprietary"			[Non free products]
 *
 * There are dual licensed components, but when running with Linux it is the
 * GPL that is relevant so this is a non issue. Similarly LGPL linked with GPL
 * is a GPL combined work.
 *
 * This exists for several reasons
 * 1.	So modinfo can show license info for users wanting to vet their setup 
 *	is free
 * 2.	So the community can ignore bug reports including proprietary modules
 * 3.	So vendors can do likewise based on their own policies
 */
#define MODULE_LICENSE(_license) MODULE_INFO(license, _license)

Now, from what little I know, this does not imply that the .c file is GPL'd,
since it doesn't have any GPL copyright notice in the file, nor does it #include
one via MODULE_LICENSE().

Does anyone happen to know if I am correct or how to confirm this?

Thanks in advance for any help with this, rick
ps: Here's what's on the .c file, in case you're interested. The .h
    files just have what is in the comment.
/*
 *  Module for the pnfs nfs4 file layout driver.
 *  Defines all I/O and Policy interface operations, plus code
 *  to register itself with the pNFS client.
 *
 *  Copyright (c) 2002
 *  The Regents of the University of Michigan
 *  All Rights Reserved
 *
 *  Dean Hildebrand <dhildebz_at_umich.edu>
 *
 *  Permission is granted to use, copy, create derivative works, and
 *  redistribute this software and such derivative works for any purpose,
 *  so long as the name of the University of Michigan is not used in
 *  any advertising or publicity pertaining to the use or distribution
 *  of this software without specific, written prior authorization. If
 *  the above copyright notice or any other identification of the
 *  University of Michigan is included in any copy of any portion of
 *  this software, then the disclaimer below must also be included.
 *
 *  This software is provided as is, without representation or warranty
 *  of any kind either express or implied, including without limitation
 *  the implied warranties of merchantability, fitness for a particular
 *  purpose, or noninfringement.  The Regents of the University of
 *  Michigan shall not be liable for any damages, including special,
 *  indirect, incidental, or consequential damages, with respect to any
 *  claim arising out of or in connection with the use of the software,
 *  even if it has been or is hereafter advised of the possibility of
 *  such damages.
 */

#include <linux/nfs_fs.h>
#include <linux/nfs_page.h>
#include <linux/module.h>

#include "internal.h"
#include "nfs4filelayout.h"

#define NFSDBG_FACILITY         NFSDBG_PNFS_LD

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Dean Hildebrand <dhildebz_at_umich.edu>");
MODULE_DESCRIPTION("The NFSv4 file layout driver");