Re: [PATCH] Fstest: btrfs/151: test if device delete ends up with losing raid profile

[Liu Bo <bo.li.liu@oracle.com>]

On Thu, Oct 12, 2017 at 03:06:57PM +0800, Eryu Guan wrote:
> On Mon, Oct 09, 2017 at 11:39:21AM -0600, Liu Bo wrote:
> > Currently running 'btrfs device delete' can end up with losing data raid
> > profile (if any), this test is to reproduce the problem.
> > 
> > The fix is
> >      "Btrfs: avoid losing data raid profile when deleting a device"
> > 
> > Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
> > ---
> >  tests/btrfs/151     | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  tests/btrfs/151.out |  2 ++
> >  tests/btrfs/group   |  1 +
> >  3 files changed, 76 insertions(+)
> >  create mode 100755 tests/btrfs/151
> >  create mode 100644 tests/btrfs/151.out
> > 
> > diff --git a/tests/btrfs/151 b/tests/btrfs/151
> > new file mode 100755
> > index 0000000..1866cb6
> > --- /dev/null
> > +++ b/tests/btrfs/151
> > @@ -0,0 +1,73 @@
> > +#! /bin/bash
> > +# FS QA Test 151
> > +#
> > +# Test if it's losing data chunk's raid profile after 'btrfs device
> > +# remove'.
> > +#
> > +# The fix is
> > +#	Btrfs: avoid losing data raid profile when deleting a device
> > +#
> > +#-----------------------------------------------------------------------
> > +# Copyright (c) 2017 Oracle.  All Rights Reserved.
> > +#
> > +# This program is free software; you can redistribute it and/or
> > +# modify it under the terms of the GNU General Public License as
> > +# published by the Free Software Foundation.
> > +#
> > +# This program is distributed in the hope that it would be useful,
> > +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > +# GNU General Public License for more details.
> > +#
> > +# You should have received a copy of the GNU General Public License
> > +# along with this program; if not, write the Free Software Foundation,
> > +# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
> > +#-----------------------------------------------------------------------
> > +#
> > +
> > +seq=`basename $0`
> > +seqres=$RESULT_DIR/$seq
> > +echo "QA output created by $seq"
> > +
> > +here=`pwd`
> > +tmp=/tmp/$$
> > +status=1	# failure is the default!
> > +trap "_cleanup; exit \$status" 0 1 2 3 15
> > +
> > +_cleanup()
> > +{
> > +	cd /
> > +	rm -f $tmp.*
> > +}
> > +
> > +# get standard environment, filters and checks
> > +. ./common/rc
> > +. ./common/filter
> > +
> > +# remove previous $seqres.full before test
> > +rm -f $seqres.full
> > +
> > +# real QA test starts here
> > +
> > +# Modify as appropriate.
> > +_supported_fs btrfs
> > +_supported_os Linux
> > +_require_scratch
> 
> Better to have _require_btrfs_dev_del_by_devid too.
>

OK.

> > +_require_scratch_dev_pool 3
> 
> Hmm, this only reproduces for me if I have exact three devices in
> SCRATCH_DEV_POOL, large dev pool passed the test. If this can only be
> reproduced with a three-device setup, I think we need to limit the dev
> pool size to at most 3, e.g.
> 
> # <comments about why we need exact 3 devices>
> _scratch_dev_pool_get 3
> <do test here>
> _scratch_dev_pool_put
> status=0
> exit

Oops, you're totally right.

> 
> > +
> > +# create raid1 for data
> > +_scratch_pool_mkfs "-d raid1 -b 1G" >> $seqres.full 2>&1
> > +
> > +# we need an empty data chunk, so nospace_cache is required.
> > +_scratch_mount -onospace_cache
> > +
> > +# if data chunk is empty, 'btrfs device remove' can change raid1 to
> > +# single.
> > +$BTRFS_UTIL_PROG device delete 2 $SCRATCH_MNT >> $seqres.full
> > +
> > +df_ret=`$BTRFS_UTIL_PROG filesystem df $SCRATCH_MNT`
> > +echo $df_ret | $AWK_PROG -F ':' '/Data,/ {print $1}'
> 
> I'd like to avoid saving outputs in a variable, it's easy to cause
> subtle problems without proper quoting, as Dave found out in this thread
> 
> [whacky issue] xfs/277 endlessly looping in _require_xfs_io_command
> http://www.spinics.net/lists/fstests/msg07501.html
>
> How about:
> 
> # save btrfs filesystem df output for debug purpose
> $BTRFS_UTIL_PROG filesystem df $SCRATCH_MNT >>$seqres.full 2>&1
> $BTRFS_UTIL_PROG filesystem df $SCRATCH_MNT | \
> 	$AWK_PROG -F ':' '/Data,/ {print $1}'

That makes sense to me, will update it.

Thanks for the comments.

thanks,

-liubo

> 
> Thanks,
> Eryu
> 
> > +
> > +# success, all done
> > +status=0
> > +exit
> > diff --git a/tests/btrfs/151.out b/tests/btrfs/151.out
> > new file mode 100644
> > index 0000000..0a1de06
> > --- /dev/null
> > +++ b/tests/btrfs/151.out
> > @@ -0,0 +1,2 @@
> > +QA output created by 151
> > +Data, RAID1
> > diff --git a/tests/btrfs/group b/tests/btrfs/group
> > index e73bb1b..a7ff7b0 100644
> > --- a/tests/btrfs/group
> > +++ b/tests/btrfs/group
> > @@ -153,3 +153,4 @@
> >  148 auto quick rw
> >  149 auto quick send compress
> >  150 auto quick dangerous
> > +151 auto quick
> > -- 
> > 2.5.0
> > 
> > --
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