Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759063AbZASXhv (ORCPT ); Mon, 19 Jan 2009 18:37:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752892AbZASXhi (ORCPT ); Mon, 19 Jan 2009 18:37:38 -0500 Received: from sca-es-mail-2.Sun.COM ([192.18.43.133]:62134 "EHLO sca-es-mail-2.sun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756504AbZASXhh (ORCPT ); Mon, 19 Jan 2009 18:37:37 -0500 Date: Tue, 20 Jan 2009 07:36:51 +0800 From: Andreas Dilger Subject: Re: [PATCH 0/20] return f_fsid for statfs(2) In-reply-to: <1232393334.5893.42.camel@norville.austin.ibm.com> To: Dave Kleikamp Cc: coly.li@suse.de, linux-kernel@vger.kernel.org, Andrew Morton , Roman Zippel , "Sergey S. Kostyliov" , OGAWA Hirofumi , Mikulas Patocka , Dave Kleikamp , Bob Copeland , Anders Larsen , reiserfs-devel@vger.kernel.org, Phillip Lougher , Christoph Hellwig , Evgeniy Dushistov , Jan Kara , linux-fsdevel Message-id: <20090119233651.GK3286@webber.adilger.int> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7BIT Content-disposition: inline X-GPG-Key: 1024D/0D35BED6 X-GPG-Fingerprint: 7A37 5D79 BF1B CECA D44F 8A29 A488 39F5 0D35 BED6 References: <4974B8C4.3070703@suse.de> <1232393334.5893.42.camel@norville.austin.ibm.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 988 Lines: 23 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). Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. -- 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/