From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754839AbZCLJAy (ORCPT ); Thu, 12 Mar 2009 05:00:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750845AbZCLJAn (ORCPT ); Thu, 12 Mar 2009 05:00:43 -0400 Received: from mail-fx0-f176.google.com ([209.85.220.176]:63671 "EHLO mail-fx0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751835AbZCLJAm (ORCPT ); Thu, 12 Mar 2009 05:00:42 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=LKhlpBM0Ymp4ePKaaa4n3/0G5Qdtjt6XGOpbwbW+J/r+jzQRrjNPb4rVlLu+EUR+H2 DilNWOi1SJBadmOQHGih7Eyq5XATWU6RwQoK69+QpNa3VlDdz7agLQNjfsCbD9k7Sty3 /ArhQsjNzkmHiFQtppWfZP1fm5KTATs/+v7SI= MIME-Version: 1.0 In-Reply-To: <200903121922.53529.nickpiggin@yahoo.com.au> References: <200903031452.43086.nickpiggin@yahoo.com.au> <38b2ab8a0903120105s59f21e0dv1dd67df41dcb2f9d@mail.gmail.com> <200903121922.53529.nickpiggin@yahoo.com.au> Date: Thu, 12 Mar 2009 10:00:38 +0100 Message-ID: <38b2ab8a0903120200h2f586c41s58d6a1520cba5ea8@mail.gmail.com> Subject: Re: Question regarding concurrent accesses through block device and fs From: Francis Moreau To: Nick Piggin Cc: Linux Kernel Mailing List , Andrew Morton Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 12, 2009 at 9:22 AM, Nick Piggin wrote: > > Ignore details like crashes, direct IO and coherency between data mappings > and buffercache where things get a bit hairy, and it's just a writeback > cache. The last thing you write to some location will be what you get back > if you read from that location -- regardless of whether it is dirty or clean > or not present when you ask for it (and has to be read from disk). > Well yes but I was wondering in the special where the kernel crash or the power supply is down how the kernel is minimizing the risk of file system inconsistency. Hence my questions about metadata handling. Thanks -- Francis