Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265335AbUAEDmp (ORCPT ); Sun, 4 Jan 2004 22:42:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265868AbUAEDmp (ORCPT ); Sun, 4 Jan 2004 22:42:45 -0500 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:46491 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S265335AbUAEDmn (ORCPT ); Sun, 4 Jan 2004 22:42:43 -0500 Date: Mon, 5 Jan 2004 03:42:42 +0000 From: viro@parcelfarce.linux.theplanet.co.uk To: Andries Brouwer Cc: Linus Torvalds , Rob Love , rob@landley.net, Pascal Schmidt , linux-kernel@vger.kernel.org, Greg KH Subject: Re: udev and devfs - The final word Message-ID: <20040105034242.GC4176@parcelfarce.linux.theplanet.co.uk> References: <20040104000840.A3625@pclin040.win.tue.nl> <20040104034934.A3669@pclin040.win.tue.nl> <20040104142111.A11279@pclin040.win.tue.nl> <20040104230104.A11439@pclin040.win.tue.nl> <20040104223710.GY4176@parcelfarce.linux.theplanet.co.uk> <20040105032901.A11459@pclin040.win.tue.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040105032901.A11459@pclin040.win.tue.nl> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1790 Lines: 38 On Mon, Jan 05, 2004 at 03:29:01AM +0100, Andries Brouwer wrote: > On Sun, Jan 04, 2004 at 10:37:10PM +0000, viro@parcelfarce.linux.theplanet.co.uk wrote: > > Hi Al - a happy 2004 to you too! > > > Now, care to explain how preserving aforementioned common Unix idiom > > is related to your expostulations? > > Hmm. You sound like you agree that random device numbers and NFS > are a bad combination, but don't see why my example might be > relevant. No. I don't see what the fuck does it have to POSIX compliance, ability to determine whether two files are identical by st_ino/st_dev and common UNIX idioms. > There is a great variation here in what various servers and clients do, > but roughly speaking filehandles tend to contain a fsid, and this fsid > often (no fsid= given) involves (major,minor,ino). Now, _that_ is true. And yes, I agree that setups with unstable device numbers do need explicit actions on part of admin. In particular, editing /etc/exports to add fsid= in each relevant entry. Which means that *in* *setups* *where* *numbers* *are* *currently* *stable* we should not make them random without admin's knowledge. And /etc/exports is not the only problem - RAID, journaling filesystems with device number of log stored on-disk, etc. *However*, if we are talking about new classes of devices, all bets are off and proper fix is to stop using unsuitable interfaces for those devices. For exports it means "use explicit fsid". For RAID we both agreed, IIRC, that raidtools will need to switch to saner API, etc. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/