Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755144AbZATCj1 (ORCPT ); Mon, 19 Jan 2009 21:39:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753537AbZATCjP (ORCPT ); Mon, 19 Jan 2009 21:39:15 -0500 Received: from e34.co.us.ibm.com ([32.97.110.152]:34234 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753018AbZATCjN (ORCPT ); Mon, 19 Jan 2009 21:39:13 -0500 Subject: Re: [PATCH 0/20] return f_fsid for statfs(2) From: Dave Kleikamp To: Andreas Dilger Cc: coly.li@suse.de, 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 In-Reply-To: <20090119233651.GK3286@webber.adilger.int> References: <4974B8C4.3070703@suse.de> <1232393334.5893.42.camel@norville.austin.ibm.com> <20090119233651.GK3286@webber.adilger.int> Content-Type: text/plain Date: Mon, 19 Jan 2009 20:39:09 -0600 Message-Id: <1232419149.19468.3.camel@norville.austin.ibm.com> Mime-Version: 1.0 X-Mailer: Evolution 2.24.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1231 Lines: 27 On Tue, 2009-01-20 at 07:36 +0800, Andreas Dilger wrote: > On Jan 19, 2009 13:28 -0600, Dave Kleikamp wrote: > > ext[234] return a portion of the uuid in f_fsid. There is a theoretical > > chance of those values being non-unique. Since there doesn't appear to > > be any case for the fsid to be persistent between boots, I guess > > huge_encode_dev() is probably a better choice. In practice it probably > > makes no difference. > > I'm not sure what you mean about "no case for fsid to be persistent"? > The whole point of fsid (for NFS) is that this identifies the filesystem > over reboot, even if the block device ID changes, or if the filesystem > doesn't have a block device at all (e.g. cluster filesystem). I guess that just demonstrates how little I know about what the fsid is about. Would it be preferable for file systems that have a uuid to use that instead? Of course anything is an improvement over zeroes. Shaggy -- David Kleikamp IBM Linux Technology Center -- 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/