Re: [WIP] [RFC PATCH] xfs: add test on shrinking unused space in the last AG

[Zorro Lang <zlang@redhat.com>]

On Thu, Oct 29, 2020 at 07:09:09AM +0800, Gao Xiang wrote:
> This adds a testcase to test shrinking unused 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>
> ---
>  tests/xfs/522     | 125 ++++++++++++++++++++++++++++++++++++++++++++++
>  tests/xfs/522.out |  73 +++++++++++++++++++++++++++
>  tests/xfs/group   |   1 +
>  3 files changed, 199 insertions(+)
>  create mode 100755 tests/xfs/522
>  create mode 100644 tests/xfs/522.out
> 
> diff --git a/tests/xfs/522 b/tests/xfs/522
> new file mode 100755
> index 00000000..e427a33a
> --- /dev/null
> +++ b/tests/xfs/522
> @@ -0,0 +1,125 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2020 Red Hat, Inc.  All Rights Reserved.
> +#
> +# FS QA Test 522
> +#
> +# XFS online shrinkfs-while-allocating tests
> +#
> +# 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 6 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()
> +{
> +	echo "*** mkfs"
> +	_scratch_mkfs_xfs $@ | tee -a $seqres.full | _filter_mkfs 2>$tmp.mkfs
> +	. $tmp.mkfs
> +
> +	echo "*** mount"
> +	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
> +	# -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_io_command "falloc"
> +
> +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
> +
> +endsize=`expr 125 \* 1048576`	# stop after shrinking this big
> +[ `expr $endsize / $dbsize` -lt $dblocks ] || _notrun "Scratch device too small"
> +
> +nags=2
> +totalcount=6
> +
> +while [ $totalcount -gt 0 ]; do
> +	size=`expr 1010 \* 1048576`	# 1010 megabytes initially
> +	echo "*** creating scratch filesystem"
> +	logblks=$(_scratch_find_xfs_min_logblocks -dsize=${size} -dagcount=${nags})
> +
> +	_create_scratch -lsize=${logblks}b -dsize=${size} -dagcount=${nags}
> +
> +	echo "*** using some initial space on scratch filesystem"
> +	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
> +
> +	decsize=`expr  42 \* 1048576`	# shrink in chunks of this size at most
> +
> +	echo "*** stressing filesystem"
> +	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 -D ${sizeb} $SCRATCH_MNT 2>&1 \
> +				| tee -a $seqres.full | _filter_mkfs 2>$tmp.growfs > /dev/null

As Darrick has reviewed, I have one more question. Looks like we can shrink a
mounted xfs via giving a smaller size to xfs_growfs.

If xfs_growfs or kernel doesn't support 'shrink', I think the whole test will
be failed. So maybe we need a _require_* function to check if current xfs
support shrinking feature at first?

Thanks,
Zorro

> +
> +			ret="${PIPESTATUS[0]}"
> +			. $tmp.growfs
> +
> +			[ $ret -eq 0 ] && break
> +
> +			[ $decb -gt 100 ] && decb=`expr $decb + $RANDOM % 10`
> +			decb=`expr $decb / 2`
> +		done
> +
> +		wait
> +		[ $decb -eq 0 ] && break
> +
> +		size=`expr $size - $decb \* $dbsize`
> +	done
> +
> +	_scratch_unmount
> +	_repair_scratch_fs >> $seqres.full
> +	totalcount=`expr $totalcount - 1`
> +done
> +
> +status=0
> +exit
> diff --git a/tests/xfs/522.out b/tests/xfs/522.out
> new file mode 100644
> index 00000000..03d512f5
> --- /dev/null
> +++ b/tests/xfs/522.out
> @@ -0,0 +1,73 @@
> +QA output created by 522
> +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
> +*** creating scratch filesystem
> +*** mkfs
> +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
> +*** mount
> +*** using some initial space on scratch filesystem
> +*** stressing filesystem
> +*** creating scratch filesystem
> +*** mkfs
> +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
> +*** mount
> +*** using some initial space on scratch filesystem
> +*** stressing filesystem
> +*** creating scratch filesystem
> +*** mkfs
> +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
> +*** mount
> +*** using some initial space on scratch filesystem
> +*** stressing filesystem
> +*** creating scratch filesystem
> +*** mkfs
> +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
> +*** mount
> +*** using some initial space on scratch filesystem
> +*** stressing filesystem
> +*** creating scratch filesystem
> +*** mkfs
> +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
> +*** mount
> +*** using some initial space on scratch filesystem
> +*** stressing filesystem
> +*** creating scratch filesystem
> +*** mkfs
> +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
> +*** mount
> +*** using some initial space on scratch filesystem
> +*** stressing filesystem
> diff --git a/tests/xfs/group b/tests/xfs/group
> index b89c0a4e..ab762ed6 100644
> --- a/tests/xfs/group
> +++ b/tests/xfs/group
> @@ -519,3 +519,4 @@
>  519 auto quick reflink
>  520 auto quick reflink
>  521 auto quick realtime growfs
> +522 auto quick growfs
> -- 
> 2.18.1
>