Re: [PATCH v2] generic/391: check inode metadata on f{data}sync after power-cut

Eryu Guan
2016-11-18T06:39:46Z

On Thu, Nov 17, 2016 at 11:20:51AM -0800, Jaegeuk Kim wrote:
> This patch adds tests/generic/391 to test fsync and fdatasync with power-cuts.
>
> The rule to check is:
> 1) fsync should guarantee all the inode metadata after power-cut,
> 2) fdatasync should guarantee i_size and i_blocks at least after power-cut.
>
> Suggested-by: Chao Yu <yuchao0@huawei.com>
> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> ---
> tests/generic/391 | 136 ++++++++++++++++++++++++++++++++++++++++++++++++++
> tests/generic/391.out | 11 ++++
> tests/generic/group | 1 +
> 3 files changed, 148 insertions(+)
> create mode 100644 tests/generic/391
> create mode 100644 tests/generic/391.out
>
> diff --git a/tests/generic/391 b/tests/generic/391
> new file mode 100644
> index 0000000..2b95151
> --- /dev/null
> +++ b/tests/generic/391
> @@ -0,0 +1,136 @@
> +#! /bin/bash
> +# FS QA Test 391
> +#
> +# Test inode's metadata after fsync or fdatasync calls.
> +# In the case of fsync, filesystem should recover all the inode metadata, while
> +# recovering i_blocks and i_size at least for fdatasync.
> +#
> +#-----------------------------------------------------------------------
> +# Copyright (c) 2016 Jaegeuk Kim. 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/punch
> +
> +# real QA test starts here
> +_supported_fs generic
> +_supported_os Linux
> +
> +rm -f $seqres.full
> +_require_scratch
> +_require_scratch_shutdown
> +_require_xfs_io_command "fpunch"
> +
> +_scratch_mkfs >/dev/null 2>&1
> +_scratch_mount
> +
> +testfile=$SCRATCH_MNT/testfile
> +
> +# check inode metadata after shutdown
> +check_inode_metadata()
> +{
> + $XFS_IO_PROG -r -c "stat -v" $1 >$tmp.before
> + src/godown $SCRATCH_MNT >> $seqres.full
> + _scratch_cycle_mount
> + $XFS_IO_PROG -r -c "stat -v" $1 >$tmp.after
> +
> + if [ $FSTYP = xfs ]; then
> + sed -i '/stat.blocks/d' $tmp.before
> + sed -i '/stat.blocks/d' $tmp.after
> + fi

Blacklist some fs "randomly" seems not easy to maintain, at least we
need some comments to explain why we do this.

I prefer the other way Brian suggested, i.e. truncate the file to
correct size before the real fsync/fdatasync to remove any preallocated
blocks past eof. I made the following update and test passed on XFS
without problems, what do you think?

--- a/tests/generic/391
+++ b/tests/generic/391
@@ -65,10 +65,6 @@ check_inode_metadata()
_scratch_cycle_mount
$XFS_IO_PROG -r -c "stat -v" $1 >$tmp.after

- if [ $FSTYP = xfs ]; then
- sed -i '/stat.blocks/d' $tmp.before
- sed -i '/stat.blocks/d' $tmp.after
- fi
diff $tmp.before $tmp.after >$tmp.diff

if [ "$2" = "fdatasync" ]; then
@@ -82,13 +78,19 @@ check_inode_metadata()
}

# append XX KB with f{data}sync, followed by power-cut
+# truncate file to the current size to avoid post-eof preallocated
+# blocks on XFS
test_i_size()
{
+ local len=$2
+ local base_len=$((4 * 1024 * 1024))
+ local new_len=$((base_len + len))
echo "==== i_size $2 test with $1 ====" | tee -a $seqres.full
- $XFS_IO_PROG -f -c "pwrite 0 4M" \
- -c "fsync" \
- -c "pwrite 4M $2" \
- -c "$1" \
+ $XFS_IO_PROG -f -c "pwrite 0 $base_len" \
+ -c "fsync" \
+ -c "pwrite $base_len $len" \
+ -c "truncate $new_len" \
+ -c "$1" \
$testfile >/dev/null
check_inode_metadata $testfile $1
}
@@ -108,12 +110,15 @@ test_i_time()
}

# punch XX KB with f{data}sync, followed by power-cut
+# truncate file to the current size to avoid post-eof preallocated
+# blocks on XFS
test_punch()
{
echo "==== fpunch $2 test with $1 ====" | tee -a $seqres.full
$XFS_IO_PROG -f -c "pwrite 0 4202496" \
-c "fsync" \
- -c "fpunch 4194304 $2"\
+ -c "fpunch 4194304 $2" \
+ -c "truncate 4202496" \
-c "$1" \
$testfile >/dev/null

Thanks,
Eryu