Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266408AbUAIBRh (ORCPT ); Thu, 8 Jan 2004 20:17:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266413AbUAIBRh (ORCPT ); Thu, 8 Jan 2004 20:17:37 -0500 Received: from waste.org ([209.173.204.2]:41109 "EHLO waste.org") by vger.kernel.org with ESMTP id S266408AbUAIBQw (ORCPT ); Thu, 8 Jan 2004 20:16:52 -0500 Date: Thu, 8 Jan 2004 19:16:35 -0600 From: Matt Mackall To: Robert Love Cc: Linus Torvalds , Andries Brouwer , Greg KH , Andrey Borzenkov , linux-hotplug-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: removable media revalidation - udev vs. devfs or static /dev Message-ID: <20040109011635.GM18208@waste.org> 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> <1073608126.1228.16.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1073608126.1228.16.camel@localhost> User-Agent: Mutt/1.3.28i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1935 Lines: 44 On Thu, Jan 08, 2004 at 07:28:47PM -0500, Robert Love wrote: > On Wed, 2004-01-07 at 22:43, Linus Torvalds wrote: > > > 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 > > I like the idea of a hotplug event on media change (basically, a hotplug > event for partitions). And, in fact, I am loath not to do it. > > The current direction with the kernel and udev is letting us move _away_ > from polling. Projects such as HAL are helping to finally integrate > hardware management throughout the system. But HAL is going to be very > confused by some of the alternative solutions for partitions: requiring > that all of the partition device nodes preexist is going to really > complicate things, and I really do not want to have to poll on all of > them in order for HAL to have an idea of what partitions are valid. > > But I hear you loud and clear about dumb devices that cannot detect > media change. They pose a problem. If we have a hotplug media change event we can do: if new device x appears: x->device_nodes = all possible partition nodes start_media_change_timer() if media change on x: x->device_nodes = current media partitions clear_media_change_timer() create_nodes(x) if timeout: /* we didn't get media change so create all nodes */ create_nodes(x) Then the dumb devices (which should be a small minority) just show up with a harmless excess of partitions. -- Matt Mackall : http://www.selenic.com : Linux development and consulting - 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/