From owner-freebsd-fs@FreeBSD.ORG Wed Mar 28 12:54:46 2007 Return-Path: X-Original-To: freebsd-fs@freebsd.org Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 2CDE816A404 for ; Wed, 28 Mar 2007 12:54:46 +0000 (UTC) (envelope-from ivoras@fer.hr) Received: from pinus.cc.fer.hr (pinus.cc.fer.hr [161.53.73.18]) by mx1.freebsd.org (Postfix) with ESMTP id AF6BF13C48A for ; Wed, 28 Mar 2007 12:54:45 +0000 (UTC) (envelope-from ivoras@fer.hr) Received: from [161.53.72.113] (lara.cc.fer.hr [161.53.72.113]) by pinus.cc.fer.hr (8.12.2/8.12.2) with ESMTP id l2SD2bLT020013; Wed, 28 Mar 2007 15:02:37 +0200 (MEST) Message-ID: <460A6592.3040308@fer.hr> Date: Wed, 28 Mar 2007 14:54:42 +0200 From: Ivan Voras User-Agent: Thunderbird 1.5.0.10 (X11/20060911) MIME-Version: 1.0 To: Greg Troxel References: <4746DA006C148BC0FF1241C6@ganymede.hub.org> <45CCECCB7ECB612F504211F3@ganymede.hub.org> In-Reply-To: X-Enigmail-Version: 0.94.2.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig2C3E0AB31D9E8E614263480B" Cc: freebsd-fs@freebsd.org Subject: Re: TDFS ... or other distributed file system technologies for FreeBSD? X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 Mar 2007 12:54:46 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig2C3E0AB31D9E8E614263480B Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable Greg Troxel wrote: > I've been playing with Coda for a long time, originally in FreeBSD > 2.2, 3 and 4, and more recently in NetBSD. My problems have been all > correctness issues, both in coda's handling of conflicts and in the > kernel vfs locking code. Coda has not yet worked reliably enough that > I've been worried about performance. Once you put a network and > another system in the path, the round trip to user space is not that > big a deal. Yes, I suspected that locking will one of the big problems. > It is truly hard to get the vfs locking issues right (lock one vnode, > release another, do it in the right order, reference counts, follow > the rules exactly). FUSE should (and probably is) taking care of this > for you. Yes, but it doesn't support file locking (flock()), which is kind of=20 required for serious work. > The other thing people could do is import puffs and librefuse from > NetBSD (also originally an SoC project). puffs is like FUSE, but aims > to be a richer interface. librefuse uses puffs to provide a > FUSE-compatible interface, so you can run FUSE filesystems linked > against librefuse, and there's no GPL/LGPL code in the base system. Interesting. I'll look into that. It's too late for SoC but it's nice=20 having something like it. > Porting it to FreeBSD should mostly be straightforward, but I think > the VFS locking rules have diverged, particularly in how .. locking is > handled in vfs_lookup. So making puffs work in FreeBSD will require > cycles from someone who groks the vfs layer. Thanks for the information. --------------enig2C3E0AB31D9E8E614263480B Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iD8DBQFGCmWSldnAQVacBcgRAtBwAKDic50nucGAt+rZ5Y7gc1NMheoXsQCgkWwW lMxis2EnwDZ3ds4hWtBfxjY= =gw6L -----END PGP SIGNATURE----- --------------enig2C3E0AB31D9E8E614263480B--