From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753184AbZHFAOJ (ORCPT ); Wed, 5 Aug 2009 20:14:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751806AbZHFAOI (ORCPT ); Wed, 5 Aug 2009 20:14:08 -0400 Received: from kroah.org ([198.145.64.141]:41366 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751338AbZHFAOH (ORCPT ); Wed, 5 Aug 2009 20:14:07 -0400 Date: Wed, 5 Aug 2009 17:06:59 -0700 From: Greg KH To: Alan Jenkins Cc: linux-kernel@vger.kernel.org, Kay Sievers , Jan Blunck , gregkh@suse.de, Harald Hoyer , Scott James Remnant Subject: Re: [PATCH] Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev Message-ID: <20090806000659.GA22754@kroah.com> References: <20090805171513.GA10443@kroah.com> <9b2b86520908051355o79699e99ke045b635c6b443ad@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9b2b86520908051355o79699e99ke045b635c6b443ad@mail.gmail.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 05, 2009 at 09:55:49PM +0100, Alan Jenkins wrote: > On 8/5/09, Greg KH wrote: > > Here's the devtmpfs patch again. For .32 it's a simple and clean patch. > > It's been tested and agreed by three major distros that this is a good > > idea. SuSE has been shipping this in their kernels for a while now with > > no problems, and actual speedups measured on their boot times. Gentoo > > also has been testing it, but we haven't gotten a tested-by: line from > > them yet, hopefully that will happen soon. > > > > A number of embedded distros have also privately said they would be > > using this patch, I really don't understand why they don't publically > > want to state this, but oh well... > > > > It's been in linux-next for many months now, with no reported > > regressions at all as well. > > > > thanks, > > > > greg k-h > > > > -------------- > > > > > > From: Kay Sievers > > > > Devtmpfs lets the kernel create a tmpfs instance called devtmpfs > > very early at kernel initialization, before any driver-core device > > is registered. Every device with a major/minor will provide a > > device node in devtmpfs. > > > > Devtmpfs can be changed and altered by userspace at any time, > > and in any way needed - just like today's udev-mounted tmpfs. > > Unmodified udev versions will run just fine on top of it, and will > > recognize an already existing kernel-created device node and use it. > > The default node permissions are root:root 0600. Proper permissions > > and user/group ownership, meaningful symlinks, all other policy still > > needs to be applied by userspace. > > > + err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt, > > + path, LOOKUP_PARENT, &nd); > > + if (err == 0) { > > + struct dentry *dentry; > > + > > + /* create directory right away */ > > + dentry = lookup_create(&nd, 1); > > + if (!IS_ERR(dentry)) { > > + err = vfs_mkdir(nd.path.dentry->d_inode, > > + dentry, 0775); > > Is there a typo here? I think the mode should be 0755. 0755 is used > below, and that does fit better with the 0600 mode for device nodes. Yeah, I think you are correct. Kay, any objection to me making this change? thanks, greg k-h