From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752959AbZDGKji (ORCPT ); Tue, 7 Apr 2009 06:39:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751821AbZDGKj2 (ORCPT ); Tue, 7 Apr 2009 06:39:28 -0400 Received: from mx2.redhat.com ([66.187.237.31]:53096 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751800AbZDGKj2 (ORCPT ); Tue, 7 Apr 2009 06:39:28 -0400 Message-ID: <49DB2D14.5010603@redhat.com> Date: Tue, 07 Apr 2009 13:38:12 +0300 From: Avi Kivity User-Agent: Thunderbird 2.0.0.21 (X11/20090320) MIME-Version: 1.0 To: Andrew Morton CC: Apollon Oikonomopoulos , linux-kernel@vger.kernel.org Subject: Re: Block device cache issue References: <20090402145205.GG30077@apollon.noc.grnet.gr> <20090407003153.41fb9c78.akpm@linux-foundation.org> In-Reply-To: <20090407003153.41fb9c78.akpm@linux-foundation.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton wrote: > >> should it perhaps be the case that the partition's buffers somehow be >> linked with those of the containing device, or even be part of them? I >> don't even know if this is possible without significant overhead in the >> page cache (of which my understanding is very shallow), but keep in mind >> that this behaviour almost led to filesystem corruption (luckily we only >> changed a single file and hit a single inode). >> > > It would incur overhead. We could perhaps fix it by having a single > cache for /dev/sda and then just making /dev/sda1 access that cache > with an offset. The offset can be non PAGE_SIZE aligned (and usually isn't, 63 sectors difference with normal partitioning). -- error compiling committee.c: too many arguments to function