Re: [PATCH 6/6] fstests: regression test for nocsum buffered read's repair

[Eryu Guan <eguan@redhat.com>]

On Tue, May 09, 2017 at 11:56:11AM -0600, Liu Bo wrote:
> This is to test whether buffered read retry-repair code is able to work in
> raid1 case as expected.
> 
> Please note that without checksum, btrfs doesn't know if the data used to
> repair is correct, so repair is more of resync which makes sure that both
> of the copy has the same content.
> 
> Commit 20a7db8ab3f2 ("btrfs: add dummy callback for readpage_io_failed and drop
> checks") introduced the regression.
> 
> The upstream fix is
> 	Btrfs: bring back repair during read

btrfs/14[1-3] all could refer to the upstream patch along with its
commit id.

> 
> Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
> ---
>  tests/btrfs/143     | 155 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  tests/btrfs/143.out |  39 +++++++++++++
>  tests/btrfs/group   |   1 +
>  3 files changed, 195 insertions(+)
>  create mode 100755 tests/btrfs/143
>  create mode 100644 tests/btrfs/143.out
> 
> diff --git a/tests/btrfs/143 b/tests/btrfs/143
> new file mode 100755
> index 0000000..5263e78
> --- /dev/null
> +++ b/tests/btrfs/143
> @@ -0,0 +1,155 @@
> +#! /bin/bash
> +# FS QA Test 143
> +#
> +# Regression test for btrfs buffered read's repair during read without checksum.
> +#
> +# This is to test whether buffered read retry-repair code is able to work in
> +# raid1 case as expected.
> +#
> +# Please note that without checksum, btrfs doesn't know if the data used to
> +# repair is correct, so repair is more of resync which makes sure that both
> +# of the copy has the same content.
> +#
> +# Commit 20a7db8ab3f2 ("btrfs: add dummy callback for readpage_io_failed and drop
> +# checks") introduced the regression.
> +#
> +# The upstream fix is
> +#        Btrfs: bring back repair during read
> +#
> +#-----------------------------------------------------------------------
> +# Copyright (c) 2017 Liu Bo.  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
> +
> +# remove previous $seqres.full before test
> +rm -f $seqres.full
> +
> +# real QA test starts here
> +
> +# Modify as appropriate.
> +_supported_fs btrfs
> +_supported_os Linux
> +_require_scratch_dev_pool 2

btrfs/142 and btrfs/143 need a "_require_fail_make_request"

> +
> +_require_btrfs_command inspect-internal dump-tree
> +_require_command "$FILEFRAG_PROG" filefrag
> +
> +_check_repair()
> +{
> +	filter=${1:-cat}
> +	dmesg | tac | sed -ne "0,\#run fstests $seqnum at $date_time#p" | tac | $filter | grep -q -e "read error corrected"
> +	if [ $? -eq 0 ]; then
> +		echo 1
> +	else
> +		echo 0
> +	fi
> +}

This function can be removed.

Thanks,
Eryu

> +
> +get_physical()
> +{
> +        # $1 is logical address
> +        # print chunk tree and find devid 2 which is $SCRATCH_DEV
> +        $BTRFS_UTIL_PROG inspect-internal dump-tree -t 3 $SCRATCH_DEV | \
> +	grep $1 -A 6 | awk '($1 ~ /stripe/ && $3 ~ /devid/ && $4 ~ /1/) { print $6 }'
> +}
> +
> +SYSFS_BDEV=`_sysfs_dev $SCRATCH_DEV`
> +
> +start_fail()
> +{
> +	echo 100 > $DEBUGFS_MNT/fail_make_request/probability
> +	echo 4 > $DEBUGFS_MNT/fail_make_request/times
> +	echo 0 > $DEBUGFS_MNT/fail_make_request/verbose
> +	echo 1 > $SYSFS_BDEV/make-it-fail
> +}
> +
> +stop_fail()
> +{
> +	echo 0 > $DEBUGFS_MNT/fail_make_request/probability
> +	echo 0 > $DEBUGFS_MNT/fail_make_request/times
> +	echo 0 > $SYSFS_BDEV/make-it-fail
> +}
> +
> +_scratch_dev_pool_get 2
> +# step 1, create a raid1 btrfs which contains one 128k file.
> +echo "step 1......mkfs.btrfs" >>$seqres.full
> +
> +mkfs_opts="-d raid1 -b 1G"
> +_scratch_pool_mkfs $mkfs_opts >>$seqres.full 2>&1
> +
> +# -o nospace_cache makes sure data is written to the start position of the data
> +# chunk
> +_scratch_mount -o nospace_cache,nodatasum
> +
> +$XFS_IO_PROG -f -d -c "pwrite -S 0xaa -b 128K 0 128K" "$SCRATCH_MNT/foobar" | _filter_xfs_io
> +
> +# step 2, corrupt the first 64k of one copy (on SCRATCH_DEV which is the first
> +# one in $SCRATCH_DEV_POOL
> +echo "step 2......corrupt file extent" >>$seqres.full
> +
> +${FILEFRAG_PROG} -v $SCRATCH_MNT/foobar >> $seqres.full
> +logical_in_btrfs=`${FILEFRAG_PROG} -v $SCRATCH_MNT/foobar | _filter_filefrag | cut -d '#' -f 1`
> +physical_on_scratch=`get_physical ${logical_in_btrfs}`
> +
> +_scratch_unmount
> +$XFS_IO_PROG -d -c "pwrite -S 0xbb -b 64K $physical_on_scratch 64K" $SCRATCH_DEV | _filter_xfs_io
> +
> +_scratch_mount -o nospace_cache
> +
> +# step 3, 128k buffered read (this read can repair bad copy)
> +echo "step 3......repair the bad copy" >>$seqres.full
> +
> +# since raid1 consists of two copies, and the following read may read the good
> +# copy directly, so lets loop 10 times here and discard output that buffered
> +# reads give
> +for i in `seq 1 10`; do
> +	# start_fail only fails the following buffered read so the repair is
> +	# supposed to work.
> +	echo 3 > /proc/sys/vm/drop_caches
> +	start_fail
> +	$XFS_IO_PROG -c "pread -b 128K 0 128K" "$SCRATCH_MNT/foobar" > /dev/null
> +	stop_fail
> +	_get_current_dmesg | grep -q -e "read error corrected" && break
> +done
> +
> +_scratch_unmount
> +
> +# check if the repair works
> +$XFS_IO_PROG -c "pread -v -b 512 $physical_on_scratch 512" $SCRATCH_DEV | _filter_xfs_io
> +
> +_scratch_dev_pool_put
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/btrfs/143.out b/tests/btrfs/143.out
> new file mode 100644
> index 0000000..97bf45c
> --- /dev/null
> +++ b/tests/btrfs/143.out
> @@ -0,0 +1,39 @@
> +QA output created by 143
> +wrote 131072/131072 bytes at offset 0
> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> +wrote 65536/65536 bytes at offset 136708096
> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> +08260000:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260010:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260020:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260030:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260040:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260050:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260060:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260070:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260080:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260090:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +082600a0:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +082600b0:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +082600c0:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +082600d0:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +082600e0:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +082600f0:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260100:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260110:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260120:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260130:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260140:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260150:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260160:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260170:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260180:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +08260190:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +082601a0:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +082601b0:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +082601c0:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +082601d0:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +082601e0:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +082601f0:  aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa  ................
> +read 512/512 bytes at offset 136708096
> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> diff --git a/tests/btrfs/group b/tests/btrfs/group
> index a4f97cd..6f19619 100644
> --- a/tests/btrfs/group
> +++ b/tests/btrfs/group
> @@ -144,3 +144,4 @@
>  140 auto quick
>  141 auto quick
>  142 auto quick
> +143 auto quick
> -- 
> 2.5.0
>