From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262320AbTE2QRb (ORCPT ); Thu, 29 May 2003 12:17:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262323AbTE2QRb (ORCPT ); Thu, 29 May 2003 12:17:31 -0400 Received: from bay-bridge.veritas.com ([143.127.3.10]:46714 "EHLO mtvmime02.veritas.com") by vger.kernel.org with ESMTP id S262320AbTE2QRa (ORCPT ); Thu, 29 May 2003 12:17:30 -0400 Date: Thu, 29 May 2003 17:33:04 +0100 (BST) From: Hugh Dickins X-X-Sender: hugh@localhost.localdomain To: "Paul E. McKenney" cc: phillips@arcor.de, , , , Subject: Re: [RFC][PATCH] Avoid vmtruncate/mmap-page-fault race In-Reply-To: <20030529151424.GA1397@us.ibm.com> Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 29 May 2003, Paul E. McKenney wrote: > On Fri, May 23, 2003 at 11:42:02AM -0700, Paul E. McKenney wrote: > > > > Exactly -- allows a ->nopage() to drop some lock to avoid races > > between pagefault and either vmtruncate() or invalidate_mmap_range(). > > This race (from the cross-host mmap viewpoint) is described in: > > > > http://marc.theaimsgroup.com/?l=linux-kernel&m=105286345316249&w=2 > > Rediffed for 2.5.70-mm1. Me? I much preferred your original, much sparer, nopagedone patch (labelled "uglyh as hell" by hch). I dislike passing lots of args down a level so they can be passed up again to the library function. In particular, I feel queasy (fear loss of control) about passing a pmd_t* down to a filesystem, which I'd prefer to have no access to such. But I may be in a minority, and the decision won't be mine. Hugh