From: Dave Chinner <david@fromorbit.com>
Subject: Re: [PATCH] ext4: test partial blocksize defrag integrity issue
Date: Thu, 11 Feb 2016 10:16:14 +1100
Message-ID: <20160210231614.GC19486@dastard>
References: <1455117464-15565-1-git-send-email-eguan@redhat.com>
Mime-Version: 1.0
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Cc: fstests@vger.kernel.org, linux-ext4@vger.kernel.org
To: Eryu Guan <eguan@redhat.com>
Content-Disposition: inline
In-Reply-To: <1455117464-15565-1-git-send-email-eguan@redhat.com>
Sender: linux-ext4-owner@vger.kernel.org

On Wed, Feb 10, 2016 at 11:17:44PM +0800, Eryu Guan wrote:
> Calling EXT4_IOC_MOVE_EXTENT on file not aligned with block size and
> block size is smaller than page size would cause integrity issue on the
> partial-blocksize part when copying data between orign file and donor
> file.
> 
> This ext4 kernel patch would fix it, titled
> "ext4: don't read blocks from disk after extents being swapped in
> move_extent_per_page())"
> 
> Though this bug only happens in the blocksize smaller than pagesize
> case, there's no harm to test on various block size fs, so no block size
> is specified in the test, it depends on the test configurations.
> 
> Signed-off-by: Eryu Guan <eguan@redhat.com>
> ---
>  tests/ext4/020     | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  tests/ext4/020.out |  6 ++++
>  tests/ext4/group   |  1 +
>  3 files changed, 96 insertions(+)
>  create mode 100755 tests/ext4/020
>  create mode 100644 tests/ext4/020.out
> 
> diff --git a/tests/ext4/020 b/tests/ext4/020
> new file mode 100755
> index 0000000..6740c7e
> --- /dev/null
> +++ b/tests/ext4/020
> @@ -0,0 +1,89 @@
> +#! /bin/bash
> +# FS QA Test 020
> +#
> +# Test partial blocksize defrag integrity issue.
> +#
> +# Calling EXT4_IOC_MOVE_EXTENT on file not aligned with block size and block
> +# size is smaller than page size would cause integrity issue on the
> +# partial-blocksize part when copying data between orign file and donor file.
> +#
> +#-----------------------------------------------------------------------
> +# Copyright (c) 2016 Red Hat Inc. All Rights Reserved.
> +#
> +# This program is free software; you can redistribute it and/or
> +# modify it under the terms of the GNU General Public License as
> +# published by the Free Software Foundation.
> +#
> +# This program is distributed in the hope that it would be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program; if not, write the Free Software Foundation,
> +# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
> +#-----------------------------------------------------------------------
> +#
> +
> +seq=`basename $0`
> +seqres=$RESULT_DIR/$seq
> +echo "QA output created by $seq"
> +
> +here=`pwd`
> +tmp=/tmp/$$
> +status=1	# failure is the default!
> +trap "_cleanup; exit \$status" 0 1 2 3 15
> +
> +_cleanup()
> +{
> +	cd /
> +	rm -f $tmp.*
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/filter
> +. ./common/defrag
> +
> +# remove previous $seqres.full before test
> +rm -f $seqres.full
> +
> +# real QA test starts here
> +_supported_fs ext4
> +_supported_os Linux
> +_require_scratch
> +_require_defrag
> +
> +e4compact=$here/src/e4compact
> +if [ ! -x $d4compact ]; then
              ^^^^^^^^^
> +	_notrun "$e4compact executable not found"
> +fi

And, yes, we really need that _requires_test_command function that
Darrick was adding to his patchset...

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com