From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S271140AbTHLVkc (ORCPT ); Tue, 12 Aug 2003 17:40:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S271177AbTHLVkb (ORCPT ); Tue, 12 Aug 2003 17:40:31 -0400 Received: from fw.osdl.org ([65.172.181.6]:3299 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S271140AbTHLVjG (ORCPT ); Tue, 12 Aug 2003 17:39:06 -0400 Date: Tue, 12 Aug 2003 14:25:19 -0700 From: Andrew Morton To: Valdis.Kletnieks@vt.edu Cc: linux-kernel@vger.kernel.org Subject: Re: 2.6.0-test3-mm1 and rootflags Message-Id: <20030812142519.69a04b7c.akpm@osdl.org> In-Reply-To: <200308121855.h7CIt6St002437@turing-police.cc.vt.edu> References: <200308121855.h7CIt6St002437@turing-police.cc.vt.edu> X-Mailer: Sylpheed version 0.9.4 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Valdis.Kletnieks@vt.edu wrote: > > OK.. I'm stumped.. > > While testing something, I tried to boot with 'rootflags=noatime', and > found the system wouldn't boot, as ext3, ext2, and reiserfs all failed to > recognize the option. Looking at the code in fs/ext3/super.c:parse_options() > and init/do_mounts.c:root_data_setup(), it appears to be impossible > to set any of the filesystem-independent flags via rootflags, which explains > the special-case code for the 'ro' and 'rw' flags. However, there doesn't > seem to be any way to pass nodev, noatime, nodiratime, or any of the other > flags. (And yes, all 3 of those make sense in my environment - it's a laptop > and I don't need atime, and I use devfs so nodev on the root makes sense too). > The fs-independent options are parsed in user space by mount(8), and are passed into the kernel as individual bits in a `flags' argument. So we'd need a new `rootopts=0x0040' thingy to support this. But given that most things can be set after boot with `mount / -o remount,noatime', it may not be necessary.