From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266400AbUAIBUW (ORCPT ); Thu, 8 Jan 2004 20:20:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266414AbUAIBUW (ORCPT ); Thu, 8 Jan 2004 20:20:22 -0500 Received: from fw.osdl.org ([65.172.181.6]:38024 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S266400AbUAIBUE (ORCPT ); Thu, 8 Jan 2004 20:20:04 -0500 Date: Thu, 8 Jan 2004 16:52:26 -0800 (PST) From: Linus Torvalds To: Robert Love cc: 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 In-Reply-To: <1073608126.1228.16.camel@localhost> Message-ID: 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 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 8 Jan 2004, Robert Love wrote: > > 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 thing is, you won't actually get a "media changed" event with almost any normal hardware. What you will get is "somebody tried to open the media, and we realized that it has changed since the last open". > The current direction with the kernel and udev is letting us move _away_ > from polling. .. but this isn't actually the case for media change. You'd still not get the media change when the change _occurs_. You'd only get it much later. > But I hear you loud and clear about dumb devices that cannot detect > media change. They pose a problem. No, even the smart devices pose a problem - but at least for those the test whether the media has changed is pretty simple. The really _dumb_ devices just assume the media has changed every time the device is opened. Linus