Re: [RFC PATCH v2 3/3] xfs: stress test for shrinking free space in the last AG

Zorro Lang
2021-03-12T16:00:37Z

On Fri, Mar 12, 2021 at 09:23:00PM +0800, Gao Xiang wrote:
> This adds a stress testcase to shrink free space as much as
> possible in the last AG with background fsstress workload.
>
> The expectation is that no crash happens with expected output.
>
> Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
> ---
> Note that I don't use _fill_fs instead, since fill_scratch here mainly to
> eat 125M to make fsstress more effectively, rather than fill data as
> much as possible.

As Darrick had given lots of review points to this case, I just have
2 picky questions as below:)

>
> tests/xfs/991 | 121 ++++++++++++++++++++++++++++++++++++++++++++++
> tests/xfs/991.out | 8 +++
> tests/xfs/group | 1 +
> 3 files changed, 130 insertions(+)
> create mode 100755 tests/xfs/991
> create mode 100644 tests/xfs/991.out
>
> diff --git a/tests/xfs/991 b/tests/xfs/991
> new file mode 100755
> index 00000000..22a5ac81
> --- /dev/null
> +++ b/tests/xfs/991
> @@ -0,0 +1,121 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2020-2021 Red Hat, Inc. All Rights Reserved.
> +#
> +# FS QA Test 991
> +#
> +# XFS online shrinkfs stress test
> +#
> +# This test attempts to shrink unused space as much as possible with
> +# background fsstress workload. It will decrease the shrink size if
> +# larger size fails. And totally repeat 2 * TIME_FACTOR times.
> +#
> +seq=`basename $0`
> +seqres=$RESULT_DIR/$seq
> +echo "QA output created by $seq"
> +
> +here=`pwd`
> +tmp=/tmp/$$
> +status=1 # failure is the default!
> +trap "rm -f $tmp.*; exit \$status" 0 1 2 3 15
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/filter
> +
> +create_scratch()
> +{
> + _scratch_mkfs_xfs $@ | tee -a $seqres.full | \
> + _filter_mkfs 2>$tmp.mkfs >/dev/null
> + . $tmp.mkfs
> +
> + if ! _try_scratch_mount 2>/dev/null; then
> + echo "failed to mount $SCRATCH_DEV"
> + exit 1
> + fi
> +
> + # fix the reserve block pool to a known size so that the enospc
> + # calculations work out correctly.
> + _scratch_resvblks 1024 > /dev/null 2>&1
> +}
> +
> +fill_scratch()
> +{
> + $XFS_IO_PROG -f -c "resvsp 0 ${1}" $SCRATCH_MNT/resvfile
> +}
> +
> +stress_scratch()
> +{
> + procs=3
> + nops=$((1000 * LOAD_FACTOR))
> + # -w ensures that the only ops are ones which cause write I/O
> + FSSTRESS_ARGS=`_scale_fsstress_args -d $SCRATCH_MNT -w -p $procs \
> + -n $nops $FSSTRESS_AVOID`
> + $FSSTRESS_PROG $FSSTRESS_ARGS >> $seqres.full 2>&1 &
> +}
> +
> +# real QA test starts here
> +_supported_fs xfs
> +_require_scratch
> +_require_xfs_shrink
> +_require_xfs_io_command "falloc"

Do I miss something? I only found you use xfs_io "resvsp", why you need "falloc" cmd?

> +
> +rm -f $seqres.full
> +_scratch_mkfs_xfs | tee -a $seqres.full | _filter_mkfs 2>$tmp.mkfs
> +. $tmp.mkfs # extract blocksize and data size for scratch device
> +
> +decsize=`expr 42 \* 1048576` # shrink in chunks of this size at most
> +endsize=`expr 125 \* 1048576` # stop after shrinking this big
> +[ `expr $endsize / $dbsize` -lt $dblocks ] || _notrun "Scratch device too small"
> +
> +nags=2
> +totalcount=$((2 * TIME_FACTOR))
> +
> +while [ $totalcount -gt 0 ]; do
> + size=`expr 1010 \* 1048576` # 1010 megabytes initially
> + logblks=$(_scratch_find_xfs_min_logblocks -dsize=${size} -dagcount=${nags})
> +
> + create_scratch -lsize=${logblks}b -dsize=${size} -dagcount=${nags}
> +
> + for i in `seq 125 -1 90`; do
> + fillsize=`expr $i \* 1048576`
> + out="$(fill_scratch $fillsize 2>&1)"
> + echo "$out" | grep -q 'No space left on device' && continue
> + test -n "${out}" && echo "$out"
> + break
> + done
> +
> + while [ $size -gt $endsize ]; do
> + stress_scratch
> + sleep 1
> +
> + decb=`expr $decsize / $dbsize` # in data blocks
> + while [ $decb -gt 0 ]; do
> + sizeb=`expr $size / $dbsize - $decb`
> +
> + $XFS_GROWFS_PROG -D ${sizeb} $SCRATCH_MNT \
> + >> $seqres.full 2>&1 && break
> +
> + [ $decb -gt 100 ] && decb=`expr $decb + $RANDOM % 10`
> + decb=`expr $decb / 2`
> + done
> +
> + wait
> + [ $decb -eq 0 ] && break
> +
> + # get latest dblocks
> + $XFS_INFO_PROG $SCRATCH_MNT 2>&1 | _filter_mkfs 2>$tmp.growfs >/dev/null
> + . $tmp.growfs
> +
> + size=`expr $dblocks \* $dbsize`
> + _scratch_cycle_mount
> + done
> +
> + _scratch_unmount
> + _repair_scratch_fs >> $seqres.full
> + totalcount=`expr $totalcount - 1`
> +done
> +
> +echo "*** done"
> +status=0
> +exit
> diff --git a/tests/xfs/991.out b/tests/xfs/991.out
> new file mode 100644
> index 00000000..e8209672
> --- /dev/null
> +++ b/tests/xfs/991.out
> @@ -0,0 +1,8 @@
> +QA output created by 991
> +meta-data=DDEV isize=XXX agcount=N, agsize=XXX blks
> +data = bsize=XXX blocks=XXX, imaxpct=PCT
> + = sunit=XXX swidth=XXX, unwritten=X
> +naming =VERN bsize=XXX
> +log =LDEV bsize=XXX blocks=XXX
> +realtime =RDEV extsz=XXX blocks=XXX, rtextents=XXX
> +*** done
> diff --git a/tests/xfs/group b/tests/xfs/group
> index a7981b67..b479ed3a 100644
> --- a/tests/xfs/group
> +++ b/tests/xfs/group
> @@ -526,3 +526,4 @@
> 526 auto quick mkfs
> 527 auto quick quota
> 990 auto quick growfs
> +991 auto quick growfs

Is this "stress" test case really "quick" :)

> --
> 2.27.0
>