Re: [PATCH v3 RESEND 2/2] fstests: btrfs/089: Test for incorrect exclusive refernce number after file clone.

[Qu Wenruo <quwenruo@cn.fujitsu.com>]

-------- Original Message  --------
Subject: Re: [PATCH v3 RESEND 2/2] fstests: btrfs/089: Test for 
incorrect exclusive refernce number after file clone.
From: Filipe David Manana <fdmanana@gmail.com>
To: Qu Wenruo <quwenruo@cn.fujitsu.com>
Date: 2015年04月07日 17:52

> On Tue, Apr 7, 2015 at 10:04 AM, Qu Wenruo <quwenruo@cn.fujitsu.com> wrote:
>> [Problem]
>> Since commit fcebe4562dec83b3f8d308 ("Btrfs: rework qgroup accounting"),
>> quota data update is delayed after delayed_ref calculation, and lacks
>> correct protection to detect root reference which shouldn't be counted
>> in current sequence number but already written into extent backref.
>>
>> This makes exclusive reference not decreased correctly and give incorrect
>> result.
>>
>> [Test procedure]
>> 1. Create a btrfs with 3 subvolumes, quota enabled and rescanned.
>> 2. Create a file in 1st subvolume
>> 3. Clone the file to 2nd and 3rd subvolume
>> 4. Sync the fs to reflect the changes in qgroup.
>> 5. Check the qgroup data
>>
>> [Expected result]
>> None of the subvolume has exclusive reference to the file.
>>
>> [Actual result]
>> The first subvolume still have exclusive reference to the file.
>>
>> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
>
> Reviewed-by: Filipe Manana <fdmanana@suse.com>
> Tested-by: Filipe Manana <fdmanana@suse.com>
>
> Thanks Qu, only a couple minor nitpicks below.
>
>> ---
>> changelog:
>> v2:
>>     Redirect error output of dd to seqres.full for debug in case dd
>>     failed.
>> v3:
>>     Add support and check for old kernel which doesn't support
>>     noinode_cache mount option.
>>     Change nodesize to 64K to support arch whose page size can be larger
>>     than 4K.
>> RESEND:
>>     Rebase to latest xfstests.
>> ---
>> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
>> ---
>>   tests/btrfs/089     | 103 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>>   tests/btrfs/089.out |   5 +++
>>   tests/btrfs/group   |   1 +
>>   3 files changed, 109 insertions(+)
>>   create mode 100755 tests/btrfs/089
>>   create mode 100644 tests/btrfs/089.out
>>
>> diff --git a/tests/btrfs/089 b/tests/btrfs/089
>> new file mode 100755
>> index 0000000..2f1adac
>> --- /dev/null
>> +++ b/tests/btrfs/089
>> @@ -0,0 +1,103 @@
>> +#! /bin/bash
>> +# FS QA Test No. 089
>> +#
>> +# Test for incorrect exclusive reference count after cloning file
>> +# between subvolumes.
>> +#
>> +#-----------------------------------------------------------------------
>> +# 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!
>> +trap "_cleanup; exit \$status" 0 1 2 3 15
>> +
>> +_cleanup()
>> +{
>> +    rm -f $tmp.*
>> +}
>> +
>> +# get standard environment, filters and checks
>> +. ./common/rc
>> +. ./common/filter
>> +
>> +# real QA test starts here
>> +
>> +_need_to_be_root
>> +_supported_fs btrfs
>> +_supported_os Linux
>> +_require_scratch
>> +_require_cp_reflink
>> +
>> +rm -f $seqres.full
>> +
>> +# use largest node/leaf size (64K) to allow the test to be run on arch with
>> +# page size > 4k.
>> +NODESIZE=65536
>> +SUPPORT_NOINODE_CACHE="yes"
>> +
>> +run_check _scratch_mkfs "--nodesize $NODESIZE"
>> +
>> +# inode cache will also take space in fs tree, disable them to get consistent
>> +# result.
>> +# discard error output since we will check return value manually.
>> +_scratch_mount "-o noinode_cache" 2> /dev/null
>> +
>> +# Check for old kernel which doesn't support 'noinode_cache' mount option
>> +if [ $? -ne 0 ]
>> +then
>
> Should be:
>
> if [ $? -ne 0 ]; then
>     ....
> fi
>
> Which is the preferred style for fstests.
True, I forgot the style when rebasing...
>
>> +       support_noinode_cache="no"
>> +       run_check _scratch_mount
>> +fi
>> +
>> +_run_btrfs_util_prog subvolume create $SCRATCH_MNT/subv1
>> +_run_btrfs_util_prog subvolume create $SCRATCH_MNT/subv2
>> +_run_btrfs_util_prog subvolume create $SCRATCH_MNT/subv3
>> +
>> +_run_btrfs_util_prog quota enable $SCRATCH_MNT
>> +_run_btrfs_util_prog quota rescan -w $SCRATCH_MNT
>> +
>> +# if we don't support noinode_cache mount option, then we should double check
>> +# whether inode cache is enabled before executing the real test payload.
>> +if [ $SUPPORT_NOINODE_CACHE == "no" ]; then
>> +       EMPTY_SIZE=`$BTRFS_UTIL_PROG qgroup show $units $SCRATCH_MNT | \
>> +               $SED_PROG -n '/[0-9]/p' | $AWK_PROG '{print $2}' | head -n1`
>> +       if [ $EMPTY_SIZE != $NODESIZE ]; then
>> +               _notrun "Kernel doesn't support to disable inode cache"
>> +       fi
>> +fi
>> +
>> +dd if=/dev/zero of=$SCRATCH_MNT/subv1/file1 bs=4K count=64 2>> $seqres.full
>
> Sorry I didn't ask in previous versions of the patch, but is dd really
> necessary here for some reason? Wouldn't the following work:
>
> $XFS_IO_PROG -f -c "pwrite 0 256K" $SCRATCH_MNT/subv1/file1 | _filter_xfs_io
>
> I tried your test, and using xfs_io worked as well here.
Thanks for pwrite method, this is much better than dd.

Thanks,
Qu
>
>> +cp --reflink $SCRATCH_MNT/subv1/file1 $SCRATCH_MNT/subv2/file1
>> +cp --reflink $SCRATCH_MNT/subv1/file1 $SCRATCH_MNT/subv3/file1
>> +
>> +# Current btrfs use tree search ioctl to show quota, which will only show info
>> +# in commit tree. So need to sync to update the qgroup commit tree.
>> +sync
>> +
>> +units=`_btrfs_qgroup_units`
>> +$BTRFS_UTIL_PROG qgroup show $units $SCRATCH_MNT | $SED_PROG -n '/[0-9]/p' | \
>> +       $AWK_PROG '{print $2" "$3}'
>> +
>> +# success, all done
>> +status=0
>> +exit
>> diff --git a/tests/btrfs/089.out b/tests/btrfs/089.out
>> new file mode 100644
>> index 0000000..09a1077
>> --- /dev/null
>> +++ b/tests/btrfs/089.out
>> @@ -0,0 +1,5 @@
>> +QA output created by 089
>> +65536 65536
>> +327680 65536
>> +327680 65536
>> +327680 65536
>> diff --git a/tests/btrfs/group b/tests/btrfs/group
>> index a053d14..82f6fe6 100644
>> --- a/tests/btrfs/group
>> +++ b/tests/btrfs/group
>> @@ -90,3 +90,4 @@
>>   085 auto quick metadata subvol
>>   086 auto quick clone
>>   088 auto quick
>> +089 auto quick qgroup
>> --
>> 2.3.5
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe fstests" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>
>