Re: [RFC PATCH v2 2/3] xfs: basic functionality test for shrinking free space in the last AG

[Zorro Lang <zlang@redhat.com>]

On Fri, Mar 12, 2021 at 09:22:59PM +0800, Gao Xiang wrote:
> Add basic test to make sure the functionality works as expected.
> 
> Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
> ---
>  tests/xfs/990     | 59 +++++++++++++++++++++++++++++++++++++++++++++++
>  tests/xfs/990.out | 12 ++++++++++
>  tests/xfs/group   |  1 +
>  3 files changed, 72 insertions(+)
>  create mode 100755 tests/xfs/990
>  create mode 100644 tests/xfs/990.out
> 
> diff --git a/tests/xfs/990 b/tests/xfs/990
> new file mode 100755
> index 00000000..551c4784
> --- /dev/null
> +++ b/tests/xfs/990
> @@ -0,0 +1,59 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2021 Red Hat, Inc.  All Rights Reserved.
> +#
> +# FS QA Test 990
> +#
> +# XFS shrinkfs basic functionality test
> +#
> +# This test attempts to shrink with a small size (512K), half AG size and
> +# an out-of-bound size (agsize + 1) to observe if it works as expected.
> +#
> +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
> +
> +# real QA test starts here
> +_supported_fs xfs

_require_scratch

> +_require_xfs_shrink
> +
> +rm -f $seqres.full
> +echo "Format and mount"
> +size="$((512 * 1024 * 1024))"

Is the fixed size necessary? Is that better to let testers run this test with
their different device/XFS geometry.

> +_scratch_mkfs -dsize=$size -dagcount=3 2>&1 | \
> +	tee -a $seqres.full | _filter_mkfs 2>$tmp.mkfs
> +. $tmp.mkfs
> +_scratch_mount >> $seqres.full 2>&1
> +
> +echo "Shrink fs (small size)"
> +$XFS_GROWFS_PROG -D $((dblocks-512*1024/dbsize)) $SCRATCH_MNT \
> +	>> $seqres.full 2>&1 || echo failure
> +_scratch_cycle_mount

I don't understand the XFS Shrink new feature that much, is the "cycle_mount"
necessary? If it's not, can we get more chances to find bugs without
"cycle_mount", or with a fsck?

Another question is, should we verify the new size after shrink?

> +
> +echo "Shrink fs (half AG)"
> +$XFS_GROWFS_PROG -D $((dblocks-agsize/2)) $SCRATCH_MNT \
> +	>> $seqres.full 2>&1 || echo failure
> +_scratch_cycle_mount
> +
> +echo "Shrink fs (out-of-bound)"
> +$XFS_GROWFS_PROG -D $((dblocks-agsize-1)) $SCRATCH_MNT \
> +	>> $seqres.full 2>&1 && echo failure
> +_scratch_cycle_mount
> +
> +$XFS_INFO_PROG $SCRATCH_MNT >> $seqres.full
> +
> +_scratch_unmount
   ^^^
   It's not necessary.

> +echo "*** done"
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/xfs/990.out b/tests/xfs/990.out
> new file mode 100644
> index 00000000..812f89ef
> --- /dev/null
> +++ b/tests/xfs/990.out
> @@ -0,0 +1,12 @@
> +QA output created by 990
> +Format and mount
> +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
> +Shrink fs (small size)
> +Shrink fs (half AG)
> +Shrink fs (out-of-bound)
> +*** done
> diff --git a/tests/xfs/group b/tests/xfs/group
> index e861cec9..a7981b67 100644
> --- a/tests/xfs/group
> +++ b/tests/xfs/group
> @@ -525,3 +525,4 @@
>  525 auto quick mkfs
>  526 auto quick mkfs
>  527 auto quick quota
> +990 auto quick growfs
> -- 
> 2.27.0
>