From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 4 Aug 2001 14:18:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 4 Aug 2001 14:18:14 -0400 Received: from weta.f00f.org ([203.167.249.89]:20112 "EHLO weta.f00f.org") by vger.kernel.org with ESMTP id ; Sat, 4 Aug 2001 14:18:09 -0400 Date: Sun, 5 Aug 2001 06:18:59 +1200 From: Chris Wedgwood To: Jan Harkes , linux-kernel@vger.kernel.org Subject: Re: [PATCH] 2.4.8-pre3 fsync entire path (+reiserfs fsync semantic change patch) Message-ID: <20010805061859.A20111@weta.f00f.org> In-Reply-To: <01080315090600.01827@starship> <9keqr6$egl$1@penguin.transmeta.com> <20010804100143.A17774@weta.f00f.org> <20010804133500.F22090@cs.cmu.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20010804133500.F22090@cs.cmu.edu> User-Agent: Mutt/1.3.20i X-No-Archive: Yes Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org (cc' list trimmed) On Sat, Aug 04, 2001 at 01:35:00PM -0400, Jan Harkes wrote: Deadly for Coda, every fsync triggers an upcall to userspace, which costs at least 2 context switches and a whole bunch of network traffic as updates are sent back to the server, i.e. the fact that some parent has a new child or timestamp is not related to or interesting for this delivery. would limiting it to just the parent dentry be acceptable? - fsync(dir) is an _explicit_ indication by an application that actually cares what precisely needs to be written to disk. i though nothing used it (maybe qmail?) - fsync(dir) doesn't negatively affect applications that don't care. fsync(dir) or fsync(file)? - The proposed patch doesn't solve the 'oops I relinked the file, or I renamed a parent' problems where the path leading to a file is lost anyways. And the relinking is exactly what is done by both qmail and cyrus imap, i.e. this patch wouldn't even solve the problem that is being discussed. cryrus/qmail do link("tmp_place", "store/where_i_want_it") ? do they also do fsync(open("store")) ? --cw