Re: [PATCH 2/2] dm-thinp demo test

[Eric Sandeen <sandeen@sandeen.net>]

On 10/22/15 4:47 AM, Eryu Guan wrote:
> On Wed, Oct 21, 2015 at 03:56:08PM -0500, Eric Sandeen wrote:
>> Fairly trivial test to use the dm-thin infrastructure.
>>
>> Right now it exhausts space in queue-on-error mode,
>> adds more space, does a bit more IO, then unmounts &
>> checks the fs.
>>
>> Not sure if that's valid to test, but it works here and
>> demonstrates the common/dmthin helpers.
>>
>> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
>> ---
>>
>>
>>
>> diff --git a/tests/generic/115 b/tests/generic/115
>> new file mode 100755
>> index 0000000..ef9d881
>> --- /dev/null
>> +++ b/tests/generic/115
>> @@ -0,0 +1,85 @@
>> +#! /bin/bash
>> +# FS QA Test No. generic/115
>> +#
>> +# Test very basic thin device usage, exhaustion, and growth
>> +#
>> +# Copyright (c) 2015 Red Hat, Inc.  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
>> +
>> +BACKING_SIZE=$((500 * 1024 * 1024 / 512))	# 500M
>> +VIRTUAL_SIZE=$((10 * $BACKING_SIZE))		# 5000M
>> +GROW_SIZE=$((100 * 1024 * 1024 / 512))		# 100M
>> +
>> +_cleanup()
>> +{
>> +	_dmthin_cleanup
>> +	rm -f $tmp.*
>> +}
>> +
>> +_setup_thin()
>> +{
>> +	_dmthin_init $BACKING_SIZE $VIRTUAL_SIZE
>> +	_dmthin_set_queue
>> +	_mkfs_dev $DMTHIN_VOL_DEV
>> +	_dmthin_mount
>> +}
>> +
>> +_workout()
>> +{
>> +	# Overfill it by a bit
>> +	for I in `seq 1 500`; do
>> +		$XFS_IO_PROG -f -c "pwrite -W 0 1M" $SCRATCH_MNT/file$I &>/dev/null
>> +	done
>> +
>> +	sync
>> +
>> +	_dmthin_grow  $GROW_SIZE
>> +
>> +	# Write a little more, but don't fill
>> +	for I in `seq 501 510`; do
>> +		$XFS_IO_PROG -f -c "pwrite 0 1M" $SCRATCH_MNT/file$I &>/dev/null
>> +	done
>> +}
>> +
>> +# get standard environment, filters and checks
>> +. ./common/rc
>> +. ./common/dmthin
>> +
>> +_supported_fs generic
>> +_supported_os Linux
>> +_need_to_be_root
>> +_require_dm_target thin
> 
> This doesn't work for me with 4.3-rc4 kernel. I have to
> "_require_dm_target thin-pool", modprobe dm-thin reports no module
> found.

whoops, yep, sorry - i already had it loaded, and the modprobe
failure isn't fatal.  Should be thin-pool - thanks.

>> +
>> +_setup_thin
>> +_dmthin_set_queue
> 
> This one or the one in _setup_thin can be removed?

Yep, will do.

>> +_workout
>> +_dmthin_check_fs
> 
> btrfs fails the fs check, because btrfs changes lv device name in df
> output, from /dev/mapper/xxx to /dev/dm-x, so _check_scratch_fs couldn't
> umount it and btrfsck runs on mounted btrfs.

Huh, weird.  I'll admit that I did not test btrfs.  Other filesystems
worked for you?  I'm not sure how btrfs can change df output...

mapper symlinks have been a constant source of pain for fstests.  :(

> Adding "$UMOUNT_PROG $SCRATCH_MNT" before _dmthin_check_fs is a
> workaround, though I think it's a btrfs issue.

Hm, ok, thanks; easy enough to do that I guess.

-Eric