From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anton Altaparmakov Subject: Re: i_generation = 0 special casing Date: Wed, 24 Nov 2004 12:25:04 +0000 Message-ID: <1101299105.15596.22.camel@imp.csi.cam.ac.uk> References: <20041124094320.GA10206@infradead.org> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: nfs@lists.sourceforge.net, linux-fsdevel@vger.kernel.org Return-path: Received: from ppsw-6.csi.cam.ac.uk ([131.111.8.136]:25568 "EHLO ppsw-6.csi.cam.ac.uk") by vger.kernel.org with ESMTP id S261402AbUKXMnw (ORCPT ); Wed, 24 Nov 2004 07:43:52 -0500 To: Christoph Hellwig In-Reply-To: <20041124094320.GA10206@infradead.org> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Wed, 2004-11-24 at 09:43 +0000, Christoph Hellwig wrote: > export_iget (and routines based on it such as xfs_vget) check for > i_generation beeing 0 meaning that every generation is okay. Where in > the NFS code is this wildcard needed? I didn't have anything to do with the i_generation handling in NFS but at least NTFS takes i_generation beeing 0 meaning that every generation is ok. (That is how Windows NTFS does it so we do the same. It allows to disable generation checking by setting all i_generations to 0 on a volume.) > I had to find out that XFS starts it's i_generation at zero and either > I have to fix up the i_generation or drop this wildcard if it's not > actually used. In NTFS I start i_generation at 1 and when it reaches 0xffff I wrap it to 1 again, skipping zero. (On disk it is 16 bits on NTFS.) Best regards, Anton -- Anton Altaparmakov (replace at with @) Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK Linux NTFS maintainer / IRC: #ntfs on irc.freenode.net WWW: http://linux-ntfs.sf.net/ & http://www-stu.christs.cam.ac.uk/~aia21/