From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268268AbUHFTuY (ORCPT ); Fri, 6 Aug 2004 15:50:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268267AbUHFTsc (ORCPT ); Fri, 6 Aug 2004 15:48:32 -0400 Received: from fw.osdl.org ([65.172.181.6]:15844 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S268265AbUHFTrw (ORCPT ); Fri, 6 Aug 2004 15:47:52 -0400 Date: Fri, 6 Aug 2004 12:46:09 -0700 From: Andrew Morton To: Phillip Lougher Cc: nickpiggin@yahoo.com.au, linux-kernel@vger.kernel.org, viro@parcelfarce.linux.theplanet.co.uk Subject: Re: [PATCH] VFS readahead bug in 2.6.8-rc[1-3] Message-Id: <20040806124609.3d489a0d.akpm@osdl.org> In-Reply-To: <4113D977.9040105@lougher.demon.co.uk> References: <41127371.1000603@lougher.demon.co.uk> <4112D6FD.4030707@yahoo.com.au> <4112EAAB.8040005@yahoo.com.au> <4113B8A2.4050609@lougher.demon.co.uk> <4113D4CD.5080109@yahoo.com.au> <4113D977.9040105@lougher.demon.co.uk> X-Mailer: Sylpheed version 0.9.7 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Phillip Lougher wrote: > > Nick Piggin wrote: > > > No, I suggest you start to code assuming this interface does > > what it does. I didn't say there is no bug here, but nobody > > else's filesystem breaks. > > > > To stop this silly argument from escalating, I will patch my code. > Well I don't think it's silly. We are deterministically asking the fs to read a page which lies outside EOF, and we shouldn't. If for no other reason than that the ever-popular "read a million 4k files" workload will consume extra CPU and twice the pagecache.