From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753333AbYJTMrh (ORCPT ); Mon, 20 Oct 2008 08:47:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751830AbYJTMr2 (ORCPT ); Mon, 20 Oct 2008 08:47:28 -0400 Received: from mx2.redhat.com ([66.187.237.31]:37638 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751587AbYJTMr1 (ORCPT ); Mon, 20 Oct 2008 08:47:27 -0400 From: Jeff Moyer To: Dmitri Monakhov Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 1/2] fs: truncate blocks outside i_size after generic_file_direct_write error References: <1224424981-5144-1-git-send-email-dmonakhov@openvz.org> X-PGP-KeyID: 1F78E1B4 X-PGP-CertKey: F6FE 280D 8293 F72C 65FD 5A58 1FF8 A7CA 1F78 E1B4 X-PCLoadLetter: What the f**k does that mean? Date: Mon, 20 Oct 2008 08:47:22 -0400 In-Reply-To: <1224424981-5144-1-git-send-email-dmonakhov@openvz.org> (Dmitri Monakhov's message of "Sun, 19 Oct 2008 18:03:00 +0400") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.0.60 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dmitri Monakhov writes: > We need to remove block that was allocated in generic_file_direct_write() > if we fail. We have to do it *regardless* to blocksize. At least ext2, > ext3 and reiserfs interpret (i_size < biggest block) condition as error. > Fsck will complain about wrong i_size. Then fsck will fix the error > by changing i_size according to the biggest block. This is bad because > this blocks contain gurbage from previous write attempt. And result in > data corruption. > > In order to call vmtruncate() we have to hold host->i_mutex. This is true > for generic_file_aio_write(). In fact occasionally it is also true for all > generic_file_aio_write_nolock() callers except blockdev. But this situation > may change someday. This patch fix only generic_write_aio_write() case. > BTW: update generic_file_direct_write's comment with currently outdated. Do you have a test case for this, by any chance? Cheers, Jeff