Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752757AbZIROmO (ORCPT ); Fri, 18 Sep 2009 10:42:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751138AbZIROmO (ORCPT ); Fri, 18 Sep 2009 10:42:14 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:40598 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750787AbZIROmN (ORCPT ); Fri, 18 Sep 2009 10:42:13 -0400 To: Arjan van de Ven Cc: Kay Sievers , Linus Torvalds , linux-kernel@vger.kernel.org, Greg Kroah-Hartmann References: <20090918160944.58e5c1f5@infradead.org> From: ebiederm@xmission.com (Eric W. Biederman) Date: Fri, 18 Sep 2009 07:42:08 -0700 In-Reply-To: <20090918160944.58e5c1f5@infradead.org> (Arjan van de Ven's message of "Fri\, 18 Sep 2009 16\:09\:44 +0200") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-XM-SPF: eid=;;;mid=;;;hst=in01.mta.xmission.com;;;ip=76.21.114.89;;;frm=ebiederm@xmission.com;;;spf=neutral X-SA-Exim-Connect-IP: 76.21.114.89 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-DCC: XMission; sa04 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Arjan van de Ven X-Spam-Relay-Country: X-Spam-Report: * -1.8 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -2.6 BAYES_00 BODY: Bayesian spam probability is 0 to 1% * [score: 0.0000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa04 1397; Body=1 Fuz1=1 Fuz2=1] * 0.5 XM_Body_Dirty_Words Contains a dirty word * 0.0 XM_SPF_Neutral SPF-Neutral * 0.4 UNTRUSTED_Relay Comes from a non-trusted relay Subject: Re: [PATCH] Remove broken by design and by implementation devtmpfs maintenance disaster X-SA-Exim-Version: 4.2.1 (built Thu, 25 Oct 2007 00:26:12 +0000) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1828 Lines: 47 Arjan van de Ven writes: > On Fri, 18 Sep 2009 06:54:39 -0700 > ebiederm@xmission.com (Eric W. Biederman) wrote: > >> >> > I don't understand. Udev applies the final policy including >> > permissions/ownership, just as before. There is no differrence. It's >> > just that you can bring up a box without complex userspace to >> > bootstrap /dev. And that's a big win on its own. >> >> udev is too complex to use? That sounds like a userspace bug. >> >> This I guess is where I am baffled. The argument for devtmpfs >> always seem to boil down to: udev sucks let's write some kernel >> code instead. >> >> I have been trying to ask for a long time why we can't just fix >> udev to not suck. >> >> > And things like >> > "modprobe loop; losetup /dev/loop0" will just work, which it doesn't >> > with todays async udev. Again, please make yourself familiar how >> > things work, and what the problems are. >> >> I guess I don't understand why >> modprobe loop; losetup /dev/loop0 is an interesting case. >> When you can just as easily do: >> modprobe loop; udevadm settle; losetup /dev/loop0. > > frankly, modprobe should call the settle. > And not just this one, but we can use this to settle other things as > well... and then it can get an --async command line option for the > cases where you know you don't want to synchronize. I think this would be a bit of a pain when I modprobe a network driver and the udev scripts trigger a blocking dhcp on the device. If this is a major pain point in initscripts I can see how it would make sense. Eric -- 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/