From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265305AbUAAAPx (ORCPT ); Wed, 31 Dec 2003 19:15:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265309AbUAAAPx (ORCPT ); Wed, 31 Dec 2003 19:15:53 -0500 Received: from mailhost.tue.nl ([131.155.2.7]:31504 "EHLO mailhost.tue.nl") by vger.kernel.org with ESMTP id S265305AbUAAAPw (ORCPT ); Wed, 31 Dec 2003 19:15:52 -0500 Date: Thu, 1 Jan 2004 01:15:49 +0100 From: Andries Brouwer To: Rob Love Cc: Pascal Schmidt , linux-kernel@vger.kernel.org, Greg KH Subject: Re: udev and devfs - The final word Message-ID: <20040101001549.GA17401@win.tue.nl> References: <18Cz7-7Ep-7@gated-at.bofh.it> <20031231192306.GG25389@kroah.com> <1072901961.11003.14.camel@fur> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1072901961.11003.14.camel@fur> User-Agent: Mutt/1.3.25i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 31, 2003 at 03:19:22PM -0500, Rob Love wrote: > We can get to the point where we don't even need the explicit concept of > device numbers, but just "any old unique value" to use as a cookie. The > kernel can pull that number from anywhere, and notify user-space via > udev ala hotplug. My plan has been to essentially use a hashed disk serial number for this "any old unique value". The problem is that "any old" is easy enough, but "unique" is more difficult. Naming devices is very difficult, but in some important cases, like SCSI or IDE disks, that would work and give a stable name. The kernel must not invent consecutive numbers - that does not lead to stable names. Setting this up correctly is nontrivial.