Re: [Qemu-devel] [PATCH v2] iotests: Filter 175's allocation information

[Nir Soffer <nsoffer@redhat.com>]

On Mon, May 13, 2019, 18:52 Max Reitz <mreitz@redhat.com> wrote:

> It is possible for an empty file to take up blocks on a filesystem.
> Make iotest 175 take this into account.
>
> Reported-by: Thomas Huth <thuth@redhat.com>
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
> v2: [Nir]
> - Use a function for filtering
> - s/empty_blocks/extra_blocks/
> ---
>  tests/qemu-iotests/175     | 26 ++++++++++++++++++++++----
>  tests/qemu-iotests/175.out |  8 ++++----
>  2 files changed, 26 insertions(+), 8 deletions(-)
>
> diff --git a/tests/qemu-iotests/175 b/tests/qemu-iotests/175
> index d0ffc495c2..b5eb0aa856 100755
> --- a/tests/qemu-iotests/175
> +++ b/tests/qemu-iotests/175
> @@ -28,10 +28,25 @@ status=1    # failure is the default!
>
>  _cleanup()
>  {
> -       _cleanup_test_img
> +    _cleanup_test_img
> +    rm -f "$TEST_DIR/empty"
>  }
>  trap "_cleanup; exit \$status" 0 1 2 3 15
>
> +# Some file systems sometimes allocate extra blocks independently of
> +# the file size.  This function hides the resulting difference in the
> +# stat -c '%b' output.
> +# Parameter 1: Number of blocks an empty file occupies
> +# Parameter 2: Image size in bytes
> +_filter_blocks()
> +{
> +    extra_blocks=$1
> +    img_size=$2
> +
> +    sed -e "s/blocks=$extra_blocks/nothing allocated/" \
> +        -e "s/blocks=$((extra_blocks + img_size / 512))/everything
> allocated/"
> +}
> +
>  # get standard environment, filters and checks
>  . ./common.rc
>  . ./common.filter
> @@ -40,18 +55,21 @@ _supported_fmt raw
>  _supported_proto file
>  _supported_os Linux
>
> -size=1m
> +size=$((1 * 1024 * 1024))
> +
> +touch "$TEST_DIR/empty"
> +extra_blocks=$(stat -c '%b' "$TEST_DIR/empty")
>
>  echo
>  echo "== creating image with default preallocation =="
>  _make_test_img $size | _filter_imgfmt
> -stat -c "size=%s, blocks=%b" $TEST_IMG
> +stat -c "size=%s, blocks=%b" $TEST_IMG | _filter_blocks $extra_blocks
> $size
>
>  for mode in off full falloc; do
>      echo
>      echo "== creating image with preallocation $mode =="
>      IMGOPTS=preallocation=$mode _make_test_img $size | _filter_imgfmt
> -    stat -c "size=%s, blocks=%b" $TEST_IMG
> +    stat -c "size=%s, blocks=%b" $TEST_IMG | _filter_blocks $extra_blocks
> $size
>  done
>
>  # success, all done
> diff --git a/tests/qemu-iotests/175.out b/tests/qemu-iotests/175.out
> index 76c02c6a57..6d9a5ed84e 100644
> --- a/tests/qemu-iotests/175.out
> +++ b/tests/qemu-iotests/175.out
> @@ -2,17 +2,17 @@ QA output created by 175
>
>  == creating image with default preallocation ==
>  Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576
> -size=1048576, blocks=0
> +size=1048576, nothing allocated
>
>  == creating image with preallocation off ==
>  Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576 preallocation=off
> -size=1048576, blocks=0
> +size=1048576, nothing allocated
>
>  == creating image with preallocation full ==
>  Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576 preallocation=full
> -size=1048576, blocks=2048
> +size=1048576, everything allocated
>
>  == creating image with preallocation falloc ==
>  Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576
> preallocation=falloc
> -size=1048576, blocks=2048
> +size=1048576, everything allocated
>   *** done
> --
> 2.21.0


Reviewed-by: Nir Soffer <nsoffer@redhat.com>

>