Re: [PATCH 3/9] xfs: test mkfs.xfs sizing of internal logs that

["Darrick J. Wong" <djwong@kernel.org>]

On Thu, Jun 30, 2022 at 02:37:14PM +0800, Zorro Lang wrote:
> On Wed, Jun 29, 2022 at 03:43:36PM -0700, Darrick J. Wong wrote:
> > On Wed, Jun 29, 2022 at 02:18:07PM +1000, Dave Chinner wrote:
> > > On Tue, Jun 28, 2022 at 01:21:34PM -0700, Darrick J. Wong wrote:
> > > > From: Darrick J. Wong <djwong@kernel.org>
> > > > 
> > > > This is a regression test that exercises the mkfs.xfs code that creates
> > > > log sizes that are very close to the AG size when stripe units are in
> > > > play and/or when the log is forced to be in AG 0.
> > > > 
> > > > Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> > > > ---
> > > >  tests/xfs/843     |   51 +++++++++++++++++++++++++++++++++++++++++++++++++++
> > > >  tests/xfs/843.out |    2 ++
> > > >  2 files changed, 53 insertions(+)
> > > >  create mode 100755 tests/xfs/843
> > > >  create mode 100644 tests/xfs/843.out
> > > > 
> > > > 
> > > > diff --git a/tests/xfs/843 b/tests/xfs/843
> > > > new file mode 100755
> > > > index 00000000..5bb4bfb4
> > > > --- /dev/null
> > > > +++ b/tests/xfs/843
> > > > @@ -0,0 +1,51 @@
> > > > +#! /bin/bash
> > > > +# SPDX-License-Identifier: GPL-2.0
> > > > +# Copyright (c) 2022 Oracle.  All Rights Reserved.
> > > > +#
> > > > +# FS QA Test 843
> > > > +#
> > > > +# Now that we've increased the default log size calculation, test mkfs with
> > > > +# various stripe units and filesystem sizes to see if we can provoke mkfs into
> > > > +# breaking.
> > > > +#
> > > > +. ./common/preamble
> > > > +_begin_fstest auto mkfs
> > > > +
> > > > +# real QA test starts here
> > > > +
> > > > +# Modify as appropriate.
> > > > +_supported_fs xfs
> > > > +_require_test
> > > > +echo Silence is golden
> > > > +
> > > > +testfile=$TEST_DIR/a
> > > > +rm -f $testfile
> > > > +
> > > > +test_format() {
> > > > +	local tag="$1"
> > > > +	shift
> > > > +
> > > > +	echo "$tag" >> $seqres.full
> > > > +	$MKFS_XFS_PROG $@ -d file,name=$testfile &>> $seqres.full
> > > > +	local res=$?
> > > > +	test $res -eq 0 || echo "$tag FAIL $res" | tee -a $seqres.full
> > > > +}
> > > > +
> > > > +# First we try various small filesystems and stripe sizes.
> > > > +for M in `seq 298 302` `seq 490 520`; do
> > > > +	for S in `seq 32 4 64`; do
> > > > +		test_format "M=$M S=$S" -dsu=${S}k,sw=1,size=${M}m -N
> > > > +	done
> > > > +done
> > > > +
> > > > +# Log so large it pushes the root dir into AG 1.  We can't use -N for the mkfs
> > > > +# because this check only occurs after the root directory has been allocated,
> > > > +# which mkfs -N doesn't do.
> > > > +test_format "log pushes rootdir into AG 1" -d agcount=3200,size=6366g -lagnum=0 -N
> > > 
> > > Why are you passing "-N" to the test if it can't be used to test
> > > this?
> > 
> > I guess I went a little overboard after you asked for more -N and less
> > test runtime last time.
> 
> Is there anything different coverage if mkfs.xfs with or without "-N" (except
> really writing on disk) ? If no difference, I'm fine with that, or I think
> without "-N" might be good, especially this case only makes fs with small size,
> it's fast enough.

Yes -- with that one exception, the mkfs geometry validation examined by
this test are all performed before mkfs writes anything to disk.  The
root inode location check is performed /after/ allocating it, which
means that we actually have to let it write the new filesystem to disk.

That's why *most* of the tests can use -N to reduce runtime.

Come to think of it, this really ought to have a _require_fs_space call
to make sure that fallocating the log space succeeds.

--D

> Thanks,
> Zorro
> 
> > 
> > --D
> > 
> > > Cheers,
> > > 
> > > Dave.
> > > -- 
> > > Dave Chinner
> > > david@fromorbit.com
> > 
>