Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757686AbZAVTbV (ORCPT ); Thu, 22 Jan 2009 14:31:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755993AbZAVTbD (ORCPT ); Thu, 22 Jan 2009 14:31:03 -0500 Received: from cantor.suse.de ([195.135.220.2]:37745 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755154AbZAVTbB (ORCPT ); Thu, 22 Jan 2009 14:31:01 -0500 Message-ID: <4978CAD4.9090607@suse.de> Date: Fri, 23 Jan 2009 03:36:52 +0800 From: Coly Li Reply-To: coly.li@suse.de Organization: SuSE Labs User-Agent: Thunderbird 2.0.0.19 (X11/20090106) MIME-Version: 1.0 To: Jamie Lokier Cc: Andreas Dilger , Dave Kleikamp , linux-kernel@vger.kernel.org, Andrew Morton , Roman Zippel , "Sergey S. Kostyliov" , OGAWA Hirofumi , Mikulas Patocka , Bob Copeland , Anders Larsen , reiserfs-devel@vger.kernel.org, Phillip Lougher , Christoph Hellwig , Evgeniy Dushistov , Jan Kara , linux-fsdevel Subject: Re: [PATCH 0/20] return f_fsid for statfs(2) References: <4974B8C4.3070703@suse.de> <1232393334.5893.42.camel@norville.austin.ibm.com> <20090119233651.GK3286@webber.adilger.int> <1232419149.19468.3.camel@norville.austin.ibm.com> <20090120041349.GL3286@webber.adilger.int> <49755376.3000100@suse.de> <20090120044447.GM3286@webber.adilger.int> <20090120184822.GF27464@shareable.org> In-Reply-To: <20090120184822.GF27464@shareable.org> X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1205 Lines: 29 Jamie Lokier Wrote: > Andreas Dilger wrote: >> On Jan 20, 2009 12:30 +0800, Coly Li wrote: >>> Ext[234] is sophisticated to have on-disk uuid record. Most file systems >>> in the patches (except jfs and reiser3) do not have a persistent uuid, >>> a reasonable/feasible solution without media format modification is fsid >>> in boot/mount life cycle. That's why huge_encode_dev(sb->s_bdev->bd_dev) >>> is used here. For jfs and reiserfs3, is there any use case for >>> persistent fsid cross boots ? >> I would say yes, this is worthwhile to do, or the fsid can change between >> boots unnecessarily. > > Even FAT has a volume id which should probably be used. > I'm guessing NTFS does too. > vfat volume id is assigned manually in mkfs.vfat, vfat volumes in one machine can be assigned to same volume id value, even worse the volume id can be modified when volume is mounted. Therefore, IMHO it's not suitable to be used as a fsid. -- Coly Li SuSE Labs -- 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/