> To: tech-kern@NetBSD.ORG
> Subject: Quick Q's about 4.4 vs 4.3, fs code
> Date: Tue, 14 May 1996 09:57:59 -0500
> From: VaX#n8 <vax@linkdead.paranoia.com>
> 
> Reading the Leffler book chapter on filesystems, it appears there were
> substantial modifications to the filesystem code.  For example, I can't
> seem to find bio(), and bmap() appears as ufs_bmap/ufs_bmaparray
> instead of the form he describes.  Additionally, I'm not clear how
> ffs and ufs differ; they have distinct subdirectories under sys/ufs
> but the mount_[uf]fs manpage makes them sound like the same thing.
> 
> I assume it has to do with the stackable vfs/vnode/whatever thing.
> Does anyone have any references where I can read about how the filesystem
> works now?
> 
The new (4.4) version of the Devil book is supposed to be in stores now.
(see http://heg-school.aw.com/cseng/authors/mckusick/4.4bsd/4.4bsd.html)
It talks about the new FS structure.

> Also, if I ported ext2fs filesystem driver (that's a big if) from FreeBSD,
> it would not go in the development tree because it is GPLed, right?
> 
Most of the code should have the Berkeley copyright.  We (Utah, origin of
the ext2fs port) would be perfectly happy if the GPLed code were rewritten.
Godmar just didn't have time to do that.