Subject: RE: JFS
To: Brian Chase <>
From: Bill Studenmund <>
List: tech-kern
Date: 02/24/2003 10:14:55
On Thu, 20 Feb 2003, Brian Chase wrote:

> On Thu, 20 Feb 2003 wrote:
> Having said that, I do think the alternatives require jumping through
> some hoops in the cases where non-volatile data, or configurations, must
> be retained.  I'm sure there are some subset of embedded systems needs
> where a journalled filesystem would be a more elegant, or more
> appropriate, way to implement non-volatile data storage requirements.
> Still, it's doubtful that embedded systems will be the driving force
> behind whether a journalled filesystem should be included in NetBSD.

For configuration info, probably. However I think than an embedded system
with internal disks would certainly benefit from a journalized file
system, as it would reduce reboot latency.

> Getting back to filesystems, if someone were to "adapt" the existing
> Linux JFS and XFS implementations to NetBSD, would it be necessary to
> have them under BSD licensing, or are there technical workarounds to
> bypass contaminating the kernel with the GPL (i.e. support the
> filesystems with loadable modules)?  And maybe more importantly, would
> such an alternative be desirable even if it were feasible?

GPLd kernel modules that load into the NetBSD kernel are fine, and might
be the best way to get XFS in the kernel. Note though that XFS also places
requirements on the bottem-half of the file system, the buffer/vm system
interface. It does this so that it can maintain commitments of
isosynchronous (is that the right word?) transfers. So main-tree code
would likely need adaptation.

Take care,