From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Chinner Subject: Re: [PATCH] xfstests 240: test non-aligned AIO hole-filling Date: Fri, 23 Jul 2010 13:58:11 +1000 Message-ID: <20100723035811.GE32635@dastard> References: <4C489676.2000605@redhat.com> <20100723024938.GD32635@dastard> <4C490D4D.603@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: xfs-oss , ext4 development To: Eric Sandeen Return-path: Received: from bld-mail14.adl6.internode.on.net ([150.101.137.99]:59459 "EHLO mail.internode.on.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755320Ab0GWD6Q (ORCPT ); Thu, 22 Jul 2010 23:58:16 -0400 Content-Disposition: inline In-Reply-To: <4C490D4D.603@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, Jul 22, 2010 at 10:32:29PM -0500, Eric Sandeen wrote: > Dave Chinner wrote: > > > On Thu, Jul 22, 2010 at 02:05:26PM -0500, Eric Sandeen wrote: > > > >> This replicates file corruption we've seen with qemu-kvm when > >> we use if=virtio,cache=none,aio=native for IO to a sparse > >> ext4- or xfs-hosted file, and the partitions/filesystems > >> within that file image are not block-aligned. (think sector > >> 63 here...) This results in AIO IOs not aligned to the > >> filesystem blocks. > >> > >> This test modifies aiodio_sparse2.c to add an option to start > >> the file IO at an offset. > >> > >> When we do 4k writes to a 16k file in 2 threads, starting > >> at offset 512, we get 0s interspersed in the file where they > >> should not be: > >> > >> 00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| > >> * > >> 00000200 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 |................| > >> * > >> 00001000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| > >> * > >> 00001200 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 |................| > >> .... > >> > >> Signed-off-by: Eric Sandeen > >> > > > > looks good - it needs to remove the $TEST_DIR/aiodio_sparse file > > before the test starts, though, so that repeated tests fail > > correctly. Otherwise: > > > > > hm, but: > > +rm -f "$TEST_DIR/aiodio_sparse*" > + > +# 2 threads, 4k writes, 16k filesize, stride throug file by 4k, start at 512 offset > +$here/src/aio-dio-regress/aiodio_sparse2 -i 2 -w 4k -s 16k -n 4k -o 512 "$TEST_DIR/aiodio_sparse" > > It does remove it ... no? Sorry, my bad - that went in one eye and out the other when I read through the whole patch. When i was testing I was getting a repeatable fail - pass - fail - pass ... pattern occurring without any kernel patches applied, and the test warns about removing the file after failure, so I just connected the dots up in the obvious manner and got it completely wrong.... Cheers, Dave. -- Dave Chinner david@fromorbit.com