From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964801AbWFSQzW (ORCPT ); Mon, 19 Jun 2006 12:55:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964802AbWFSQzW (ORCPT ); Mon, 19 Jun 2006 12:55:22 -0400 Received: from thunk.org ([69.25.196.29]:5054 "EHLO thunker.thunk.org") by vger.kernel.org with ESMTP id S964801AbWFSQzU (ORCPT ); Mon, 19 Jun 2006 12:55:20 -0400 Date: Mon, 19 Jun 2006 12:55:22 -0400 From: Theodore Tso To: Avi Kivity Cc: linux-kernel@vger.kernel.org Subject: Re: [RFC] [PATCH 5/8] inode-diet: Eliminate i_blksize and use a per-superblock default Message-ID: <20060619165522.GA15216@thunk.org> Mail-Followup-To: Theodore Tso , Avi Kivity , linux-kernel@vger.kernel.org References: <20060619153109.817554000@candygram.thunk.org> <4496C782.8090605@argo.co.il> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4496C782.8090605@argo.co.il> User-Agent: Mutt/1.5.11 X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@thunk.org X-SA-Exim-Scanned: No (on thunker.thunk.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 19, 2006 at 06:49:22PM +0300, Avi Kivity wrote: > > Isn't this a behavioral change? If a filesystem chooses to provide > i_blksize via a getattr method, it will not show on nfs mounts. There's actually a philosophical question hiding here over what's the right thing to do with how st_blksize should be handled over NFS --- st_blksize is supposed to be the "optimum I/O size"; the question is what is the right answer that we report in both directions. For example, it doesn't matter if we're exporting a Ultra Fast whiz-bang cluster filesystem with a stripsize of 100 gigabytes. If wsize is 1024, it might be that we shouldn't be sending back an st_blksize that's really big. So I'm not pretending that what we have in the patch is the right thing, only that I'm not entirely sure we were ever doing the right thing here. - Ted