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Date: Thu, 28 Jul 2016 17:08:55 +0800
From: Fam Zheng <famz@redhat.com>
Message-ID: <20160728090855.GC9625@ad.usersys.redhat.com>
References: <20160727145146.8864-1-fullmanet@gmail.com>
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Subject: Re: [Qemu-devel] [PATCH v3] qemu-img: add skip option to dd
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To: Reda Sallahi <fullmanet@gmail.com>
Cc: qemu-devel@nongnu.org, Kevin Wolf <kwolf@redhat.com>, qemu-block@nongnu.org, Max Reitz <mreitz@redhat.com>

On Wed, 07/27 16:51, Reda Sallahi wrote:
> +for skip in $TEST_SKIP_BLOCKS; do
> +    echo
> +    echo "== Creating image =="
> +
> +    size=1M
> +    _make_test_img $size
> +    _check_test_img
> +    $QEMU_IO -c "write -P 0xa 0 $size" "$TEST_IMG" | _filter_qemu_io

I think the data pattern could to be made less plain (i.e. add some variantion
based on the offset), to catch any misplacement bug in qemu-img dd (for example
off by one errors).

Fam

> +
> +    echo
> +    echo "== Converting the image with dd with skip=$skip =="
> +
> +    $QEMU_IMG dd if="$TEST_IMG" of="$TEST_IMG.out" skip="$skip" -O "$IMGFMT" \
> +        2> /dev/null
> +    $QEMU_IMG check "$TEST_IMG.out" -f "$IMGFMT" 2>&1  | _filter_testdir | \
> +        _filter_qemu_img_check
> +    dd if="$TEST_IMG" of="$TEST_IMG.out.dd" skip="$skip" status=none
> +    echo
> +    echo "== Compare the images with qemu-img compare =="
> +
> +    $QEMU_IMG compare "$TEST_IMG.out.dd" "$TEST_IMG.out"
> +done