From owner-freebsd-questions Tue Jan 26 06:40:28 1999 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id GAA11726 for freebsd-questions-outgoing; Tue, 26 Jan 1999 06:40:28 -0800 (PST) (envelope-from owner-freebsd-questions@FreeBSD.ORG) Received: from cs.columbia.edu (cs.columbia.edu [128.59.16.20]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id GAA11549; Tue, 26 Jan 1999 06:39:56 -0800 (PST) (envelope-from ezk@shekel.mcl.cs.columbia.edu) Received: from shekel.mcl.cs.columbia.edu (shekel.mcl.cs.columbia.edu [128.59.18.15]) by cs.columbia.edu (8.9.1/8.9.1) with ESMTP id JAA11806; Tue, 26 Jan 1999 09:39:37 -0500 (EST) Received: (from ezk@localhost) by shekel.mcl.cs.columbia.edu (8.9.1/8.9.1) id JAA04364; Tue, 26 Jan 1999 09:39:36 -0500 (EST) Date: Tue, 26 Jan 1999 09:39:36 -0500 (EST) Message-Id: <199901261439.JAA04364@shekel.mcl.cs.columbia.edu> X-Authentication-Warning: shekel.mcl.cs.columbia.edu: ezk set sender to ezk@shekel.mcl.cs.columbia.edu using -f From: Erez Zadok To: Eivind Eklund Cc: Jan Pechanec , Wolfram Schneider , lists@gal.netlab.sk, questions@FreeBSD.ORG, freebsd-isp@FreeBSD.ORG, freebsd-fs@FreeBSD.ORG Subject: Re: Need non-case sensitive fs In-reply-to: Your message of "Tue, 26 Jan 1999 10:55:31 +0100." <19990126105531.J382@bitbox.follo.net> Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In message <19990126105531.J382@bitbox.follo.net>, Eivind Eklund writes: > On Mon, Jan 25, 1999 at 05:01:25PM +0100, Jan Pechanec wrote: > > To solve the problem, I think the best solution would be to > > use stackable layering. This is a problem that somebody could already > > solved (search for heidemann and UCLA), if not and you have somebody > > that can program in C, let him add some code to the null layer > > template (see mount_null). One hundred lines of code, I estimate. > > nullfs does not work as of present. You can possibly get it to work by > using tegge's patches as a brute-force interrim solution; I'm working on > getting stacking layers to work properly again. Re: brute force, I've got a working nullfs and several f/s built on top of it. It circumvents the whole VM buffer-cache thing by using synchronous writes, and using read/write for putpage/getpage. It may be slower than what it should be, but in practice it was only a few % slower than an async implementation on linux (identical h/w of course). Until these big problems are formally resolved (yes I'm working on them too), users may wish to start implementing their favorite f/s based on my *working* implementation. Later on they can do whatever changes might be necessary to comply with a fixed stackable interface. I believe that doing a case-insensitive f/s using my template nullfs (which I call wrapfs) would be easy. You can get freebsd wrapfs software from: http://www.cs.columbia.edu/~ezk/research/software/ and a few papers that mention the freebsd port in http://www.cs.columbia.edu/~ezk/research/wip.html > Eivind. Eivind et al. I think there are already several people who are trying to do the same thing --- fix stacking support in freebsd. I would suggest that we all get together and do a mini-design that would be approved by the rest of the freebsd-fs community, and then embark on an implementation. I'm willing to help of course. Erez. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message