From owner-freebsd-fs Wed Jun 24 11:33:22 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id LAA00818 for freebsd-fs-outgoing; Wed, 24 Jun 1998 11:33:22 -0700 (PDT) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from dash.isi.edu (root@dash.isi.edu [128.9.160.184]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id LAA00709; Wed, 24 Jun 1998 11:32:56 -0700 (PDT) (envelope-from johnh@dash.isi.edu) Received: from dash.isi.edu (johnh@localhost.isi.edu [127.0.0.1]) by dash.isi.edu (8.8.7/8.8.7) with ESMTP id LAA10210; Wed, 24 Jun 1998 11:31:02 -0700 Message-Id: <199806241831.LAA10210@dash.isi.edu> X-url: http://www.isi.edu/~johnh/ To: "Alton, Matthew" , "'Terry Lambert'" , FreeBSD-fs@FreeBSD.ORG, Hackers@FreeBSD.ORG, "Smallie, Scott" Subject: Re: Stackable filesystems and SunOS 4.1.1 In-reply-to: <31B3F0BF1C40D11192A700805FD48BF9017765F1@STLABCEXG011> Date: Wed, 24 Jun 1998 11:31:02 -0700 From: John Heidemann Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Back from a trip I can finally pick up this thread: On Wed, 17 Jun 1998 18:21:37 -0500, "Alton, Matthew" wrote: >... >It is conceivable that Sun may be persuaded to release the sources for a fee >a la SCO's "Ancient Versions" source license. If so, we FreeBeasties could >benifit from the mature SunOS 4.1.1 stackable filesystem code. Maybe we >should pester them. On Fri, 19 Jun 1998 10:48:51 -0500, "Alton, Matthew" wrote: > I apologize for being hopelessy vague and incomplete here. I was >thinking about > John Heidemann's work. His web page says that his primary development > platform was SunOS 4.1.1 and that there is "unsatisfactory" code in >Free- & > Net- BSD. I downloaded the necessarily incomplete (license issues)code >from > his site and was pining away for the rest. First, I don't think I've ever said the 4.4BSD stacking code was ``unsatisfactory''...it's just not a complete version of what was in the thesis. (This was for a variety of reasons, including time and other reasons.) For people wanting to expand BSD stacking, I can imagine some interesting projects: - adding support for user-level file-systems - replacing parallel lists of vnops in the filesystems (ex. ffs_{specop,fifoop}_opv_desc) with a generic ffs node that stacks over a spec/fifo node - building a real compression/encryption layer - structuring CD-ROM file systems as a set of layers (I don't know how hard this would be...) Of these things, none would hugely benefit from the SunOS-specific code. Only the first really requires code that's not already in BSD. Because of differences between BSD and SunOS' NFS implementations, I doubt full access to my modified SunOS-4.1.1 source code would substantally more helpful than just starting with the code on my web page, and it would raise lots of licensing issues that are best not messed with. More than more stacking infrastructure, I think BSD would benefit from more *use* of stacking (the last 3 bullets). -John Heidemann To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message