Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263166AbUAHCDo (ORCPT ); Wed, 7 Jan 2004 21:03:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263185AbUAHCDo (ORCPT ); Wed, 7 Jan 2004 21:03:44 -0500 Received: from fw.osdl.org ([65.172.181.6]:16279 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S263166AbUAHCDm (ORCPT ); Wed, 7 Jan 2004 21:03:42 -0500 Date: Wed, 7 Jan 2004 18:03:35 -0800 (PST) From: Linus Torvalds To: Olaf Hering cc: 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: <20040107205237.GB16832@suse.de> Message-ID: References: <200401012333.04930.arvidjaar@mail.ru> <20040103055847.GC5306@kroah.com> <20040107205237.GB16832@suse.de> 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 Content-Length: 1301 Lines: 33 On Wed, 7 Jan 2004, Olaf Hering wrote: > > > > Then, user space can just access "/dev/sda1" or whatever, and the act of > > accessing it will force the re-scan. > > How would that work? I mean, what will a tool that cares about a block > event do? It will run a fdisk/parted -l /udev/sda to figure out what partitions > are there (just to skip an extended partition sda5, as example) and > finds no media. That tool will never run again on sda, unless a new > block add event comes in. So some sort of polling is required for that > class of devices. What is your problem? I'll use a very common and simple case that I do myself: use any USB media reader to read a camera card. It will be a FAT filesystem on the first partition, so your fstab might look like this: /dev/sda1 /mnt/smartmedia vfat noauto,user,ro 0 0 and then you just do "mount /mnt/smartmedia", and you're done. This works. I do it all the time. You just stick in your card, and mount it, and off it foes. No "fdisk" or "parted" _anywhere_. Linus - 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/