From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751730AbWAKVFz (ORCPT ); Wed, 11 Jan 2006 16:05:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751737AbWAKVFz (ORCPT ); Wed, 11 Jan 2006 16:05:55 -0500 Received: from smtp.osdl.org ([65.172.181.4]:35794 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1751729AbWAKVFz (ORCPT ); Wed, 11 Jan 2006 16:05:55 -0500 Date: Wed, 11 Jan 2006 13:05:33 -0800 From: Andrew Morton To: Hugh Dickins Cc: andrea@suse.de, nickpiggin@yahoo.com.au, linux-kernel@vger.kernel.org Subject: Re: smp race fix between invalidate_inode_pages* and do_no_page Message-Id: <20060111130533.6f23685b.akpm@osdl.org> In-Reply-To: References: <20051213193735.GE3092@opteron.random> <20051213130227.2efac51e.akpm@osdl.org> <20051213211441.GH3092@opteron.random> <20051216135147.GV5270@opteron.random> <20060110062425.GA15897@opteron.random> <43C484BF.2030602@yahoo.com.au> <20060111082359.GV15897@opteron.random> <20060111005134.3306b69a.akpm@osdl.org> <20060111090225.GY15897@opteron.random> <20060111010638.0eb0f783.akpm@osdl.org> <20060111091327.GZ15897@opteron.random> X-Mailer: Sylpheed version 1.0.4 (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 Hugh Dickins wrote: > > But I do not know what guarantees invalidate_inode_pages2 is supposed > to give. As soon as you emerge from iipages2, its work could be undone: yup. It cannot become a hard guarantee unless we add some new really big locks. So it can be fooled by silly or poorly-designed apps. What we're aiming for here is predictable behaviour for sanely-implemented applications and refusal to oops or to expose insecure data for poorly-designed ones or exploits.