From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932098AbZE0Oa1 (ORCPT ); Wed, 27 May 2009 10:30:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760817AbZE0OaQ (ORCPT ); Wed, 27 May 2009 10:30:16 -0400 Received: from THUNK.ORG ([69.25.196.29]:36784 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758598AbZE0OaP (ORCPT ); Wed, 27 May 2009 10:30:15 -0400 Date: Wed, 27 May 2009 10:30:06 -0400 From: Theodore Tso To: Jan Kara Cc: LKML , npiggin@suse.de, linux-ext4@vger.kernel.org, "Aneesh Kumar K.V" Subject: Re: [PATCH 05/11] ext4: Make sure blocks are properly allocated under mmaped page even when blocksize < pagesize Message-ID: <20090527143006.GC10842@mit.edu> Mail-Followup-To: Theodore Tso , Jan Kara , LKML , npiggin@suse.de, linux-ext4@vger.kernel.org, "Aneesh Kumar K.V" References: <1243429268-3028-1-git-send-email-jack@suse.cz> <1243429268-3028-6-git-send-email-jack@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1243429268-3028-6-git-send-email-jack@suse.cz> User-Agent: Mutt/1.5.18 (2008-05-17) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@mit.edu X-SA-Exim-Scanned: No (on thunker.thunk.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 27, 2009 at 03:01:02PM +0200, Jan Kara wrote: > In a situation like: > truncate(f, 1024); > a = mmap(f, 0, 4096); > a[0] = 'a'; > truncate(f, 4096); > > we end up with a dirty page which does not have all blocks allocated / > reserved. Fix the problem by using new VFS infrastructure. > > Signed-off-by: Jan Kara Hi Jan, Have you tested with -o nodelalloc? There is apparently a problem with ext4 when blocksize < pagesize which Aneesh has been working on. He has been able to reproduce the problem, and theorized that an earlier version your patch set would address the problem, but it apparently did not. See: http://bugzilla.kernel.org/show_bug.cgi?id=13369 ... and Aneesh can provide more details. Aneesh, you might want to try testing with this latest set and see if you can reproduce the problem with this set. - Ted