Re: [PATCH v2 3/3] generic/470: add syncfs test

[Eryu Guan <eguan@redhat.com>]

On Thu, Dec 07, 2017 at 10:22:07AM +0800, Chengguang Xu wrote:
> Inspired by syncfs bug of overlayfs which does not sync dirtyinodes in
> underlying filesystem.
> Run syncfs and shutdown filesystem(or underlying filesystem of overlayfs)
> to check syncfs result.
> 
> Signed-off-by: Chengguang Xu <cgxu519@icloud.com>
> ---
> 
> Changes since v1:
> Use fs shutdown and fssum to check syncfs result instead of
> checking delalloc state of extents.
> 
>  tests/generic/470     | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  tests/generic/470.out |  2 ++
>  tests/generic/group   |  1 +
>  3 files changed, 91 insertions(+)
>  create mode 100755 tests/generic/470
>  create mode 100644 tests/generic/470.out
> 
> diff --git a/tests/generic/470 b/tests/generic/470
> new file mode 100755
> index 0000000..b488747
> --- /dev/null
> +++ b/tests/generic/470
> @@ -0,0 +1,88 @@
> +#! /bin/bash
> +# FS QA Test 470
> +#
> +# Inspired by syncfs bug of overlayfs which does not sync dirty inodes in
> +# underlying filesystem. 

Trailing whitespace in above line.

> +#
> +# Run syncfs and shutdown filesystem(or underlying filesystem of overlayfs)
> +# to check syncfs result.
> +#
> +# Test will be skipped if filesystem(or underlying filesystem of overlayfs)
> +# does not support shutdown.
> +#
> +#-----------------------------------------------------------------------
> +# Copyright (c) 2017 Chengguang Xu <cgxu519@icloud.com>
> +# 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
> +trap "_cleanup; exit \$status" 0 1 2 3 15
> +
> +_cleanup()
> +{
> +	cd /
> +	rm -f $tmp.*
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/filter
> +
> +# remove previous $seqres.full before test
> +rm -f $seqres.full
> +
> +# real QA test starts here
> +
> +_supported_fs generic
> +_supported_os Linux
> +_require_test
> +_require_fssum
> +_require_scratch
> +_require_scratch_shutdown
> +_require_xfs_io_command "syncfs"
> +
> +
> +FCNT=1000
> +
> +_scratch_mkfs >/dev/null 2>&1
> +_scratch_mount
> +
> +# In order to mitigate interference of write-back,
> +# create many files for test.

Sorry, I still don't understand how writeback could interfere this test
from this comment, what happens if we don't create such files? Why
writing files starting from offset 1k?

> +for i in `seq 1 $FCNT`; do
> +	$XFS_IO_PROG -f -c "pwrite 1K 1M" \
> +		$SCRATCH_MNT/$i >/dev/null 2>&1
> +done
> +
> +$FSSUM_PROG -ugomAcdES -f -w $TEST_DIR/before_test $SCRATCH_MNT

$tmp.fssum looks a better choice of the fssum record file, then you
don't need _require_test anymore.

> +$XFS_IO_PROG -c "syncfs" $SCRATCH_MNT/${FCNT} >/dev/null 2>&1
> +_scratch_shutdown
> +_scratch_cycle_mount
> +$FSSUM_PROG -ugomAcdES -f -w $TEST_DIR/after_test $SCRATCH_MNT
> +diff $TEST_DIR/before_test $TEST_DIR/after_test
> +if [ $? -eq 0 ]; then
> +	status=0
> +fi

No need to check return value of diff here, just set status=0
unconditionally, test will break the golden image matching anyway if
diff finds something different.

But why not use "-r" option of fssum to read and compare the checksums?
e.g.

$FSSUM_PROG -r $tmp.fssum $SCRATCH_MNT

Thanks,
Eryu

> +
> +echo "Silence is golden"
> +exit
> diff --git a/tests/generic/470.out b/tests/generic/470.out
> new file mode 100644
> index 0000000..79fb532
> --- /dev/null
> +++ b/tests/generic/470.out
> @@ -0,0 +1,2 @@
> +QA output created by 470
> +Silence is golden
> diff --git a/tests/generic/group b/tests/generic/group
> index 6c3bb03..493a44c 100644
> --- a/tests/generic/group
> +++ b/tests/generic/group
> @@ -472,3 +472,4 @@
>  467 auto quick exportfs
>  468 shutdown auto quick metadata
>  469 auto quick
> +470 auto quick shutdown sync
> -- 
> 1.8.3.1
>