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

[Gao Xiang <hsiangkao@redhat.com>]

On Fri, Mar 12, 2021 at 11:56:13PM +0800, Zorro Lang wrote:
> 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

Will fix.

> 
> > +_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.

I'm fine with either way since it's a simple functionality test, yet for most
common cases, stratch devices are somewhat large. I tend to use a relative
controllable small value.

Actually, this case was from xfs/127 with some modification.

> 
> > +_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?

maybe it's useful to test unmount here. Yeah, I think it's better to try fsck
here. Good idea.

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

Yeah, will add xfs_info.

> 
> > +
> > +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.

ok. It seems that ./check will fsck scratch device as well.
Will update it.

Thanks,
Gao Xiang