Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 31 Jul 2002 17:04:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 31 Jul 2002 17:04:16 -0400 Received: from RAVEL.CODA.CS.CMU.EDU ([128.2.222.215]:13505 "EHLO ravel.coda.cs.cmu.edu") by vger.kernel.org with ESMTP id ; Wed, 31 Jul 2002 17:04:15 -0400 Date: Wed, 31 Jul 2002 17:07:40 -0400 To: "Peter J. Braam" Cc: linux-kernel@vger.kernel.org Subject: Re: BIG files & file systems Message-ID: <20020731210739.GA15492@ravel.coda.cs.cmu.edu> Mail-Followup-To: "Peter J. Braam" , linux-kernel@vger.kernel.org References: <20020731131620.M15238@lustre.cfs> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20020731131620.M15238@lustre.cfs> User-Agent: Mutt/1.4i From: Jan Harkes Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1018 Lines: 25 On Wed, Jul 31, 2002 at 01:16:20PM -0600, Peter J. Braam wrote: > Hi, > > I've just been told that some "limitations" of the following kind will > remain: > page index = unsigned long > ino_t = unsigned long The number of files is not limited by ino_t, just look at the iget5_locked operation in fs/inode.c. It is possible to have your own n-bit file identifier, and simply provide your own comparison function. The ino_t then becomes the 'hash-bucket' in which the actual inode is looked up. For the page_index, maybe at some point someone manages to cleanly mix large pages (2MB?) with the current 4KB pages. Very large files could then use the page_index as an index into these large pages which should allow for 9PB files (or something close to that). 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/