Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964961AbVKVP1u (ORCPT ); Tue, 22 Nov 2005 10:27:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964963AbVKVP1u (ORCPT ); Tue, 22 Nov 2005 10:27:50 -0500 Received: from DELFT.AURA.CS.CMU.EDU ([128.2.206.88]:26023 "EHLO delft.aura.cs.cmu.edu") by vger.kernel.org with ESMTP id S964961AbVKVP1t (ORCPT ); Tue, 22 Nov 2005 10:27:49 -0500 Date: Tue, 22 Nov 2005 10:25:31 -0500 To: "Theodore Ts'o" , Christoph Hellwig , J?rn Engel , Alfred Brons , pocm@sat.inesc-id.pt, linux-kernel@vger.kernel.org Subject: Re: what is our answer to ZFS? Message-ID: <20051122152531.GU12760@delft.aura.cs.cmu.edu> Mail-Followup-To: Theodore Ts'o , Christoph Hellwig , J?rn Engel , Alfred Brons , pocm@sat.inesc-id.pt, linux-kernel@vger.kernel.org References: <11b141710511210144h666d2edfi@mail.gmail.com> <20051121095915.83230.qmail@web36406.mail.mud.yahoo.com> <20051121101959.GB13927@wohnheim.fh-wedel.de> <20051122075148.GB20476@infradead.org> <20051122145047.GB29179@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20051122145047.GB29179@thunk.org> User-Agent: Mutt/1.5.9i From: Jan Harkes Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1177 Lines: 24 On Tue, Nov 22, 2005 at 09:50:47AM -0500, Theodore Ts'o wrote: > I will note though that there are people who are asking for 64-bit > inode numbers on 32-bit platforms, since 2**32 inodes are not enough > for certain distributed/clustered filesystems. And this is something > we don't yet support today, and probably will need to think about much > sooner than 128-bit filesystems.... As far as the kernel is concerned this hasn't been a problem in a while (2.4.early). The iget4 operation that was introduced by reiserfs (now iget5) pretty much makes it possible for a filesystem to use anything to identify it's inodes. The 32-bit inode numbers are simply used as a hash index. The only thing that tends to break are userspace archiving tools like tar, which assume that 2 objects with the same 32-bit st_ino value are identical. I think that by now several actually double check that the inode linkcount is larger than 1. Jan - 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/