From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751078AbWLRB3t (ORCPT ); Sun, 17 Dec 2006 20:29:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751222AbWLRB3t (ORCPT ); Sun, 17 Dec 2006 20:29:49 -0500 Received: from smtp.osdl.org ([65.172.181.25]:47137 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751207AbWLRB3s (ORCPT ); Sun, 17 Dec 2006 20:29:48 -0500 Date: Sun, 17 Dec 2006 17:29:30 -0800 (PST) From: Linus Torvalds To: Andrew Morton cc: andrei.popa@i-neo.ro, Linux Kernel Mailing List , Peter Zijlstra , Hugh Dickins , Florian Weimer , Marc Haber , Martin Michlmayr Subject: Re: 2.6.19 file content corruption on ext3 In-Reply-To: Message-ID: References: <1166314399.7018.6.camel@localhost> <20061217040620.91dac272.akpm@osdl.org> <1166362772.8593.2.camel@localhost> <20061217154026.219b294f.akpm@osdl.org> 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 Sun, 17 Dec 2006, Linus Torvalds wrote: > > So we should probably do a "wait_for_page()" in do_no_page()? > > Or maybe only do it for write accesses (since we don't really care about > getting mapped readably)? If so, we need to do it in the write case of > do_no_page() _and_ in the do_wp_page() case. Hmm? I think we discussed doing exactly this at some earlier time, actually, just to try to throttle people who do lots of page dirtying. Maybe we even do it somewhere, but I tried to see it, and in the normal "nopage()" routine we very much try to _avoid_ locking the page (ie if it's marked PageUptodate() we'll return it whether locked or not). Which is fine - especially for readers, there really isn't any reason to ever delay them getting access to a page just because it's locked for write-out or something (once it's mapped, they'll have access to it regardless of any locked state in the kernel anyway). So I don't actually see any serialization at all that would keep a random page from being paged back in. Linus