Re: [PATCH v4] btrfs: add regression test for remount with thread_pool resized

["gux.fnst" <gux.fnst@cn.fujitsu.com>]

On 01/24/2015 06:30 AM, Dave Chinner wrote:
> On Fri, Jan 23, 2015 at 08:36:37PM +0800, Eryu Guan wrote:
>> On Fri, Jan 23, 2015 at 03:28:59PM +0800, Xing Gu wrote:
>>> Regression test for a btrfs issue of resizing 'thread_pool' when
>>> remount the fs.
>>>
>>> This regression was introduced by the following linux kernel commit:
>>>      btrfs: Added btrfs_workqueue_struct implemented ordered
>>>      execution based on kernel workqueue
>>>      08a9ff3264181986d1d692a4e6fce3669700c9f8
>>> And it was fixed by the following linux kernel commit:
>>>      btrfs: fix crash in remount(thread_pool=) case
>>>      800ee2247f483b6d05ed47ef3bbc90b56451746c
>>>
>>> Signed-off-by: Xing Gu <gux.fnst@cn.fujitsu.com>
>>> ---
>>>   v3->v4: Remove the check for a bug message.
>>>
>>>   v2->v3: Add the regresssion commit in description.
>>>           Remove "dmesg -c > /dev/null".
>>>           Echo "Silence is golden" to indicate that an empty output
>>>           file is expected.
>>>
>>>   v1->v2: Add the fix commit in description.
>>>           Add the check for a bug message.
>>> ---
>>>   tests/btrfs/082     | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>>>   tests/btrfs/082.out |  2 ++
>>>   tests/btrfs/group   |  1 +
>>>   3 files changed, 68 insertions(+)
>>>   create mode 100755 tests/btrfs/082
>>>   create mode 100644 tests/btrfs/082.out
>>>
>>> diff --git a/tests/btrfs/082 b/tests/btrfs/082
>>> new file mode 100755
>>> index 0000000..7a6e4b5
>>> --- /dev/null
>>> +++ b/tests/btrfs/082
>>> @@ -0,0 +1,65 @@
>>> +#!/bin/bash
>>> +# FS QA Test No. btrfs/082
>>> +#
>>> +# Regression test for a btrfs issue of resizing 'thread_pool' when
>>> +# remount the fs.
>>> +#
>>> +# This regression was introduced by the following linux kernel commit:
>>> +#     btrfs: Added btrfs_workqueue_struct implemented ordered
>>> +#     execution based on kernel workqueue
>>> +#     08a9ff3264181986d1d692a4e6fce3669700c9f8
>>> +# And it was fixed by the following linux kernel commit:
>>> +#     btrfs: fix crash in remount(thread_pool=) case
>>> +#     800ee2247f483b6d05ed47ef3bbc90b56451746c
>>> +#
>>> +#-----------------------------------------------------------------------
>>> +# Copyright (c) 2015 Fujitsu.  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!
>>> +
>>> +_cleanup()
>>> +{
>>> +    rm -f $tmp.*
>>> +}
>>> +
>>> +trap "_cleanup ; exit \$status" 0 1 2 3 15
>>> +
>>> +# get standard environment, filters and checks
>>> +. ./common/rc
>>> +. ./common/filter
>>> +
>>> +# real QA test starts here
>>> +_supported_fs btrfs
>>> +_supported_os Linux
>>> +_require_scratch
>>> +
>>> +_scratch_mkfs > /dev/null
>>
>> Redirect stderr to /dev/null too, otherwise test fails if scratch device
>> supports trim.
>>
>> btrfs/082 0s ... - output mismatch (see /root/xfstests/results//btrfs/082.out.bad)
>>      --- tests/btrfs/082.out     2015-01-23 20:27:15.603689913 +0800
>>      +++ /root/xfstests/results//btrfs/082.out.bad       2015-01-23 20:33:46.514259626 +0800
>>      @@ -1,2 +1,3 @@
>>       QA output created by 082
>>      +Performing full device TRIM (5.00GiB) ...
>>       Silence is golden
>
> I think the internal btrfs mkfs call needs to filter that so that
> error messages are still caught by the test.
>
> In fact, I'll go as far as to suggest that outputting operational
> status information on stderr is a bug/regression in mkfs.btrfs.
>

I have sent a patch that fixes the above problem in mkfs.btrfs to
btrfs community，and a new version V5 about this patch which
modifies the redirect problem.
Thanks!

regards,
Xing Gu
> Cheers,
>
> Dave.
>