From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263537AbUAHIBd (ORCPT ); Thu, 8 Jan 2004 03:01:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263793AbUAHIBd (ORCPT ); Thu, 8 Jan 2004 03:01:33 -0500 Received: from AGrenoble-101-1-4-93.w217-128.abo.wanadoo.fr ([217.128.202.93]:27559 "EHLO awak.dyndns.org") by vger.kernel.org with ESMTP id S263537AbUAHIBa convert rfc822-to-8bit (ORCPT ); Thu, 8 Jan 2004 03:01:30 -0500 Subject: Re: removable media revalidation - udev vs. devfs or static /dev From: Xavier Bestel To: Linus Torvalds Cc: Andries Brouwer , Greg KH , Andrey Borzenkov , linux-hotplug-devel@lists.sourceforge.net, Linux Kernel Mailing List In-Reply-To: References: <200401012333.04930.arvidjaar@mail.ru> <20040103055847.GC5306@kroah.com> <20040108031357.A1396@pclin040.win.tue.nl> <20040108034906.A1409@pclin040.win.tue.nl> <20040108043506.A1555@pclin040.win.tue.nl> Content-Type: text/plain; charset=iso-8859-15 Message-Id: <1073548840.6189.144.camel@nomade> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.5 Date: Thu, 08 Jan 2004 09:00:41 +0100 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Le jeu 08/01/2004 à 04:43, Linus Torvalds a écrit : > On Thu, 8 Jan 2004, Andries Brouwer wrote: > > > > I am even happy in a somewhat more general situation that you are. > > If the kernel autopartitions (and make recognition of new partitions > > hotplug events so that udev can create the device nodes), all is well. > > Yes. We _could_ do that, by just making a "we noticed the disk change" be > a hotplug event. However, I'm loath to do that, because some devices > literally don't even have an easily read disk change signal, so what they > do is > > - assume the disk _always_ changed on open > - do a quick IO to verify it > > and I'd be nervous about that kind of thing resulting in hotplug being > called constantly if somebody rude just has an endless loop of > "open()/close()". Theses devices are kind of broken anyway, aren't they ? I see no safe way of handling disk changes on them, except having a "I changed disk in this drive" button on the desktop and rely on the user's good behavior. Currently the kernel will may have a wrong idea of what's in the drive if it doesn't poll, and that may wreak havoc. Xav