Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932178AbXAAW60 (ORCPT ); Mon, 1 Jan 2007 17:58:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932215AbXAAW60 (ORCPT ); Mon, 1 Jan 2007 17:58:26 -0500 Received: from artax.karlin.mff.cuni.cz ([195.113.31.125]:55103 "EHLO artax.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932178AbXAAW6Y (ORCPT ); Mon, 1 Jan 2007 17:58:24 -0500 Date: Mon, 1 Jan 2007 23:58:23 +0100 (CET) From: Mikulas Patocka To: Nikita Danilov Cc: Arjan van de Ven , Benny Halevy , Jan Harkes , Miklos Szeredi , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, nfsv4@ietf.org Subject: Re: Finding hardlinks In-Reply-To: <17816.29254.497543.329777@gargle.gargle.HOWL> Message-ID: References: <20061221185850.GA16807@delft.aura.cs.cmu.edu> <1166869106.3281.587.camel@laptopd505.fenrus.org> <4593890C.8030207@panasas.com> <1167300352.3281.4183.camel@laptopd505.fenrus.org> <1167388475.6106.51.camel@lade.trondhjem.org> <17816.29254.497543.329777@gargle.gargle.HOWL> X-Personality-Disorder: Schizoid MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1363 Lines: 30 > > The question is: why does the kernel contain iget5 function that looks up > > according to callback, if the filesystem cannot have more than 64-bit > > inode identifier? > > Generally speaking, file system might have two different identifiers for > files: > > - one that makes it easy to tell whether two files are the same one; > > - one that makes it easy to locate file on the storage. > > According to POSIX, inode number should always work as identifier of the > first class, but not necessary as one of the second. For example, in > reiserfs something called "a key" is used to locate on-disk inode, which > in turn, contains inode number. Identifiers of the second class tend to BTW. How does ReiserFS find that a given inode number (or object ID in ReiserFS terminology) is free before assigning it to new file/directory? Mikulas > live in directory entries, and during lookup we want to consult inode > cache _before_ reading inode from the disk (otherwise cache is mostly > useless), right? This means that some file systems want to index inodes > in a cache by something different than inode number. - 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/