[PATCH] xfs: test a race between dio reads and mapped writes

[PATCH] xfs: test a race between dio reads and mapped writes

[Xiao Yang]

This regression test reproduces a race between a direct
I/O read and a mapped write to a hole in a file.  If the
race occurs, it will trigger a BUG_ON().  This XFS bug
has been fixed by:

04197b3 (xfs: don't BUG() on mixed direct and mapped I/O)

Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
---
 tests/xfs/422     | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 tests/xfs/422.out |  2 ++
 tests/xfs/group   |  1 +
 3 files changed, 89 insertions(+)
 create mode 100755 tests/xfs/422
 create mode 100644 tests/xfs/422.out

diff --git a/tests/xfs/422 b/tests/xfs/422
new file mode 100755
index 0000000..a57ffab
--- /dev/null
+++ b/tests/xfs/422
@@ -0,0 +1,86 @@
+#! /bin/bash
+# FS QA Test No. 422
+#
+# Regression test for commit:
+# 04197b3 ("xfs: don't BUG() on mixed direct and mapped I/O)
+#
+# This case tests a race between a direct I/O read and a
+# mapped write to a hole in a file.  If the race occurs,
+# it will trigger a BUG_ON().
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2017 Fujitsu.  All Rights Reserved.
+# Author: Xiao Yang <yangx.jy@cn.fujitsu.com>
+#
+# 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 -rf $tmp.*
+}
+
+# get standard environment and checks
+. ./common/rc
+
+# real QA test starts here
+_supported_os Linux
+_supported_fs xfs
+_require_scratch
+_disable_dmesg_check
+_require_xfs_io_command "truncate"
+_require_xfs_io_command "fpunch"
+
+rm -f $seqres.full
+
+# format and mount
+_scratch_mkfs > $seqres.full 2>&1
+_scratch_mount >> $seqres.full 2>&1
+
+filesz=$((65536 * 2))
+
+# create a test file with a hole
+$XFS_IO_PROG -f -c "truncate $((filesz * 2))" $SCRATCH_MNT/file >> $seqres.full
+
+# run a background dio read to a hole in a loop
+while true; do
+	$XFS_IO_PROG -d -c "pread 0 $filesz" $SCRATCH_MNT/file > /dev/null 2>&1
+done &
+
+dread_pid=$!
+
+# run mapped write to the same hole as dio read
+for i in `seq 0 999`; do
+	$XFS_IO_PROG -c "mmap 0 $filesz" -c "mwrite 0 $filesz" $SCRATCH_MNT/file \
+		> /dev/null
+	$XFS_IO_PROG -c "fpunch 0 $filesz" $SCRATCH_MNT/file > /dev/null
+done
+
+kill -9 $dread_pid > /dev/null 2>&1
+wait $dread_pid > /dev/null 2>&1
+
+echo "Silence is golden"
+
+# success, all done
+status=0
+exit
diff --git a/tests/xfs/422.out b/tests/xfs/422.out
new file mode 100644
index 0000000..f70693f
--- /dev/null
+++ b/tests/xfs/422.out
@@ -0,0 +1,2 @@
+QA output created by 422
+Silence is golden
diff --git a/tests/xfs/group b/tests/xfs/group
index 2a3b950..f43ffcf 100644
--- a/tests/xfs/group
+++ b/tests/xfs/group
@@ -419,3 +419,4 @@
 419 auto quick
 420 auto quick clone dedupe
 421 auto quick clone dedupe
+422 auto quick dangerous
-- 
1.8.3.1

Re: [PATCH] xfs: test a race between dio reads and mapped writes

[Eryu Guan]

On Tue, Jun 27, 2017 at 05:03:52PM +0800, Xiao Yang wrote:
> This regression test reproduces a race between a direct
> I/O read and a mapped write to a hole in a file.  If the
> race occurs, it will trigger a BUG_ON().  This XFS bug
> has been fixed by:
> 
> 04197b3 (xfs: don't BUG() on mixed direct and mapped I/O)
> 
> Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
> ---
>  tests/xfs/422     | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  tests/xfs/422.out |  2 ++
>  tests/xfs/group   |  1 +
>  3 files changed, 89 insertions(+)
>  create mode 100755 tests/xfs/422
>  create mode 100644 tests/xfs/422.out
> 
> diff --git a/tests/xfs/422 b/tests/xfs/422
> new file mode 100755
> index 0000000..a57ffab
> --- /dev/null
> +++ b/tests/xfs/422
> @@ -0,0 +1,86 @@
> +#! /bin/bash
> +# FS QA Test No. 422
> +#
> +# Regression test for commit:
> +# 04197b3 ("xfs: don't BUG() on mixed direct and mapped I/O)
             ^^ missing ending " :)
> +#
> +# This case tests a race between a direct I/O read and a
> +# mapped write to a hole in a file.  If the race occurs,
> +# it will trigger a BUG_ON().
> +#
> +#-----------------------------------------------------------------------
> +# Copyright (c) 2017 Fujitsu.  All Rights Reserved.
> +# Author: Xiao Yang <yangx.jy@cn.fujitsu.com>
> +#
> +# 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 -rf $tmp.*
> +}
> +
> +# get standard environment and checks
> +. ./common/rc
> +
> +# real QA test starts here
> +_supported_os Linux
> +_supported_fs xfs

I see nothing xfs specific in this test, I think it can be made generic
easily.

> +_require_scratch
> +_disable_dmesg_check

Better to add comments on ignoring dmesg check result.

Thanks,
Eryu

> +_require_xfs_io_command "truncate"
> +_require_xfs_io_command "fpunch"
> +
> +rm -f $seqres.full
> +
> +# format and mount
> +_scratch_mkfs > $seqres.full 2>&1
> +_scratch_mount >> $seqres.full 2>&1
> +
> +filesz=$((65536 * 2))
> +
> +# create a test file with a hole
> +$XFS_IO_PROG -f -c "truncate $((filesz * 2))" $SCRATCH_MNT/file >> $seqres.full
> +
> +# run a background dio read to a hole in a loop
> +while true; do
> +	$XFS_IO_PROG -d -c "pread 0 $filesz" $SCRATCH_MNT/file > /dev/null 2>&1
> +done &
> +
> +dread_pid=$!
> +
> +# run mapped write to the same hole as dio read
> +for i in `seq 0 999`; do
> +	$XFS_IO_PROG -c "mmap 0 $filesz" -c "mwrite 0 $filesz" $SCRATCH_MNT/file \
> +		> /dev/null
> +	$XFS_IO_PROG -c "fpunch 0 $filesz" $SCRATCH_MNT/file > /dev/null
> +done
> +
> +kill -9 $dread_pid > /dev/null 2>&1
> +wait $dread_pid > /dev/null 2>&1
> +
> +echo "Silence is golden"
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/xfs/422.out b/tests/xfs/422.out
> new file mode 100644
> index 0000000..f70693f
> --- /dev/null
> +++ b/tests/xfs/422.out
> @@ -0,0 +1,2 @@
> +QA output created by 422
> +Silence is golden
> diff --git a/tests/xfs/group b/tests/xfs/group
> index 2a3b950..f43ffcf 100644
> --- a/tests/xfs/group
> +++ b/tests/xfs/group
> @@ -419,3 +419,4 @@
>  419 auto quick
>  420 auto quick clone dedupe
>  421 auto quick clone dedupe
> +422 auto quick dangerous
> -- 
> 1.8.3.1
> 
> 
> 
> --
> 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

Re: [PATCH] xfs: test a race between dio reads and mapped writes

[Xiao Yang]

On 2017/06/28 18:13, Eryu Guan wrote:
> On Tue, Jun 27, 2017 at 05:03:52PM +0800, Xiao Yang wrote:
>> This regression test reproduces a race between a direct
>> I/O read and a mapped write to a hole in a file.  If the
>> race occurs, it will trigger a BUG_ON().  This XFS bug
>> has been fixed by:
>>
>> 04197b3 (xfs: don't BUG() on mixed direct and mapped I/O)
>>
>> Signed-off-by: Xiao Yang<yangx.jy@cn.fujitsu.com>
>> ---
>>   tests/xfs/422     | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>   tests/xfs/422.out |  2 ++
>>   tests/xfs/group   |  1 +
>>   3 files changed, 89 insertions(+)
>>   create mode 100755 tests/xfs/422
>>   create mode 100644 tests/xfs/422.out
>>
>> diff --git a/tests/xfs/422 b/tests/xfs/422
>> new file mode 100755
>> index 0000000..a57ffab
>> --- /dev/null
>> +++ b/tests/xfs/422
>> @@ -0,0 +1,86 @@
>> +#! /bin/bash
>> +# FS QA Test No. 422
>> +#
>> +# Regression test for commit:
>> +# 04197b3 ("xfs: don't BUG() on mixed direct and mapped I/O)
>               ^^ missing ending " :)
>> +#
>> +# This case tests a race between a direct I/O read and a
>> +# mapped write to a hole in a file.  If the race occurs,
>> +# it will trigger a BUG_ON().
>> +#
>> +#-----------------------------------------------------------------------
>> +# Copyright (c) 2017 Fujitsu.  All Rights Reserved.
>> +# Author: Xiao Yang<yangx.jy@cn.fujitsu.com>
>> +#
>> +# 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 -rf $tmp.*
>> +}
>> +
>> +# get standard environment and checks
>> +. ./common/rc
>> +
>> +# real QA test starts here
>> +_supported_os Linux
>> +_supported_fs xfs
> I see nothing xfs specific in this test, I think it can be made generic
> easily.
Hi Eryu,

Agreed.  It could be moved into generic.
>> +_require_scratch
>> +_disable_dmesg_check
> Better to add comments on ignoring dmesg check result.
For xfs filesystem, this race triggers various warnings on some 
distributions(RHEL7) and upstream kernel.
e.g,
1) This race triggers the following warnings on RHEL7.3GA
-----------------------------------------------------------------------------------------------------------------------------
[    0.297084] WARNING: at arch/x86/mm/ioremap.c:101 
__ioremap_caller+0x238/0x320()
[  648.745481] WARNING: at fs/xfs/xfs_aops.c:1244 
xfs_vm_releasepage+0xcb/0x100 [xfs]()
[  648.745694] WARNING: at fs/xfs/xfs_file.c:377 
xfs_file_aio_read+0x2dd/0x340 [xfs]()
-----------------------------------------------------------------------------------------------------------------------------
2) It triggers the following warnings on RHEL7.4Beta
----------------------------------------------------------------------------------------------------------------------------
[  497.575319] WARNING: CPU: 0 PID: 26865 at fs/xfs/xfs_file.c:361 
xfs_file_dio_aio_read+0x1ba/0x2a0 [xfs]
[  497.577651] WARNING: CPU: 0 PID: 26865 at fs/xfs/xfs_aops.c:1285 
__xfs_get_blocks+0x8ca/0x8e0 [xfs]
----------------------------------------------------------------------------------------------------------------------------
3) It triggers the following warnings on upstream kernel
----------------------------------------------------------------------------------------------------------------------------
[   57.946882] WARNING: CPU: 1 PID: 4053 at fs/iomap.c:890 
iomap_dio_rw+0x37a/0x390
[   57.947066] WARNING: CPU: 1 PID: 4053 at fs/iomap.c:766 
iomap_dio_actor+0xca/0x370
----------------------------------------------------------------------------------------------------------------------------

It focus on the oops due to this race, and the warnings are different 
based on different kernel.
So we may ignore dmesg check.

I will add comments on ignoring dmesg check result as you said.

Thanks,
Xiao Yang
> Thanks,
> Eryu
>
>> +_require_xfs_io_command "truncate"
>> +_require_xfs_io_command "fpunch"
>> +
>> +rm -f $seqres.full
>> +
>> +# format and mount
>> +_scratch_mkfs>  $seqres.full 2>&1
>> +_scratch_mount>>  $seqres.full 2>&1
>> +
>> +filesz=$((65536 * 2))
>> +
>> +# create a test file with a hole
>> +$XFS_IO_PROG -f -c "truncate $((filesz * 2))" $SCRATCH_MNT/file>>  $seqres.full
>> +
>> +# run a background dio read to a hole in a loop
>> +while true; do
>> +	$XFS_IO_PROG -d -c "pread 0 $filesz" $SCRATCH_MNT/file>  /dev/null 2>&1
>> +done&
>> +
>> +dread_pid=$!
>> +
>> +# run mapped write to the same hole as dio read
>> +for i in `seq 0 999`; do
>> +	$XFS_IO_PROG -c "mmap 0 $filesz" -c "mwrite 0 $filesz" $SCRATCH_MNT/file \
>> +		>  /dev/null
>> +	$XFS_IO_PROG -c "fpunch 0 $filesz" $SCRATCH_MNT/file>  /dev/null
>> +done
>> +
>> +kill -9 $dread_pid>  /dev/null 2>&1
>> +wait $dread_pid>  /dev/null 2>&1
>> +
>> +echo "Silence is golden"
>> +
>> +# success, all done
>> +status=0
>> +exit
>> diff --git a/tests/xfs/422.out b/tests/xfs/422.out
>> new file mode 100644
>> index 0000000..f70693f
>> --- /dev/null
>> +++ b/tests/xfs/422.out
>> @@ -0,0 +1,2 @@
>> +QA output created by 422
>> +Silence is golden
>> diff --git a/tests/xfs/group b/tests/xfs/group
>> index 2a3b950..f43ffcf 100644
>> --- a/tests/xfs/group
>> +++ b/tests/xfs/group
>> @@ -419,3 +419,4 @@
>>   419 auto quick
>>   420 auto quick clone dedupe
>>   421 auto quick clone dedupe
>> +422 auto quick dangerous
>> -- 
>> 1.8.3.1
>>
>>
>>
>> --
>> 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
>
> .
>

Re: [PATCH] xfs: test a race between dio reads and mapped writes

[Eryu Guan]

On Thu, Jun 29, 2017 at 12:01:25PM +0800, Xiao Yang wrote:
> On 2017/06/28 18:13, Eryu Guan wrote:
> > On Tue, Jun 27, 2017 at 05:03:52PM +0800, Xiao Yang wrote:
> > > This regression test reproduces a race between a direct
> > > I/O read and a mapped write to a hole in a file.  If the
> > > race occurs, it will trigger a BUG_ON().  This XFS bug
> > > has been fixed by:
> > > 
> > > 04197b3 (xfs: don't BUG() on mixed direct and mapped I/O)
> > > 
> > > Signed-off-by: Xiao Yang<yangx.jy@cn.fujitsu.com>
> > > ---
> > >   tests/xfs/422     | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > >   tests/xfs/422.out |  2 ++
> > >   tests/xfs/group   |  1 +
> > >   3 files changed, 89 insertions(+)
> > >   create mode 100755 tests/xfs/422
> > >   create mode 100644 tests/xfs/422.out
> > > 
> > > diff --git a/tests/xfs/422 b/tests/xfs/422
> > > new file mode 100755
> > > index 0000000..a57ffab
> > > --- /dev/null
> > > +++ b/tests/xfs/422
> > > @@ -0,0 +1,86 @@
> > > +#! /bin/bash
> > > +# FS QA Test No. 422
> > > +#
> > > +# Regression test for commit:
> > > +# 04197b3 ("xfs: don't BUG() on mixed direct and mapped I/O)
> >               ^^ missing ending " :)
> > > +#
> > > +# This case tests a race between a direct I/O read and a
> > > +# mapped write to a hole in a file.  If the race occurs,
> > > +# it will trigger a BUG_ON().
> > > +#
> > > +#-----------------------------------------------------------------------
> > > +# Copyright (c) 2017 Fujitsu.  All Rights Reserved.
> > > +# Author: Xiao Yang<yangx.jy@cn.fujitsu.com>
> > > +#
> > > +# 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 -rf $tmp.*
> > > +}
> > > +
> > > +# get standard environment and checks
> > > +. ./common/rc
> > > +
> > > +# real QA test starts here
> > > +_supported_os Linux
> > > +_supported_fs xfs
> > I see nothing xfs specific in this test, I think it can be made generic
> > easily.
> Hi Eryu,
> 
> Agreed.  It could be moved into generic.
> > > +_require_scratch
> > > +_disable_dmesg_check
> > Better to add comments on ignoring dmesg check result.
> For xfs filesystem, this race triggers various warnings on some
> distributions(RHEL7) and upstream kernel.
> e.g,
> 1) This race triggers the following warnings on RHEL7.3GA
> -----------------------------------------------------------------------------------------------------------------------------
> [    0.297084] WARNING: at arch/x86/mm/ioremap.c:101
> __ioremap_caller+0x238/0x320()

I'm not sure about this one, but the other xfs or iomap warnings are
"known issues" when mixing direct I/O and mmap I/O on the same file.
We've filtered out these intentional warnings in generic/095, and Brian
has just sent a patch[1] to move this filter to common/xfs and added it
to generic/247. I think you can do the same to this new test, filter out
these known warnings so we won't miss any other potential bug.

I don't think disable dmesg check only because it triggers warnings is a
good idea :)

Thanks,
Eryu

[1] [PATCH] generic/247: filter out expected XFS warnings for mixed mmap/direct I/O

> [  648.745481] WARNING: at fs/xfs/xfs_aops.c:1244
> xfs_vm_releasepage+0xcb/0x100 [xfs]()
> [  648.745694] WARNING: at fs/xfs/xfs_file.c:377
> xfs_file_aio_read+0x2dd/0x340 [xfs]()
> -----------------------------------------------------------------------------------------------------------------------------
> 2) It triggers the following warnings on RHEL7.4Beta
> ----------------------------------------------------------------------------------------------------------------------------
> [  497.575319] WARNING: CPU: 0 PID: 26865 at fs/xfs/xfs_file.c:361
> xfs_file_dio_aio_read+0x1ba/0x2a0 [xfs]
> [  497.577651] WARNING: CPU: 0 PID: 26865 at fs/xfs/xfs_aops.c:1285
> __xfs_get_blocks+0x8ca/0x8e0 [xfs]
> ----------------------------------------------------------------------------------------------------------------------------
> 3) It triggers the following warnings on upstream kernel
> ----------------------------------------------------------------------------------------------------------------------------
> [   57.946882] WARNING: CPU: 1 PID: 4053 at fs/iomap.c:890
> iomap_dio_rw+0x37a/0x390
> [   57.947066] WARNING: CPU: 1 PID: 4053 at fs/iomap.c:766
> iomap_dio_actor+0xca/0x370
> ----------------------------------------------------------------------------------------------------------------------------
> 
> It focus on the oops due to this race, and the warnings are different based
> on different kernel.
> So we may ignore dmesg check.
> 
> I will add comments on ignoring dmesg check result as you said.
> 
> Thanks,
> Xiao Yang
> > Thanks,
> > Eryu
> > 
> > > +_require_xfs_io_command "truncate"
> > > +_require_xfs_io_command "fpunch"
> > > +
> > > +rm -f $seqres.full
> > > +
> > > +# format and mount
> > > +_scratch_mkfs>  $seqres.full 2>&1
> > > +_scratch_mount>>  $seqres.full 2>&1
> > > +
> > > +filesz=$((65536 * 2))
> > > +
> > > +# create a test file with a hole
> > > +$XFS_IO_PROG -f -c "truncate $((filesz * 2))" $SCRATCH_MNT/file>>  $seqres.full
> > > +
> > > +# run a background dio read to a hole in a loop
> > > +while true; do
> > > +	$XFS_IO_PROG -d -c "pread 0 $filesz" $SCRATCH_MNT/file>  /dev/null 2>&1
> > > +done&
> > > +
> > > +dread_pid=$!
> > > +
> > > +# run mapped write to the same hole as dio read
> > > +for i in `seq 0 999`; do
> > > +	$XFS_IO_PROG -c "mmap 0 $filesz" -c "mwrite 0 $filesz" $SCRATCH_MNT/file \
> > > +		>  /dev/null
> > > +	$XFS_IO_PROG -c "fpunch 0 $filesz" $SCRATCH_MNT/file>  /dev/null
> > > +done
> > > +
> > > +kill -9 $dread_pid>  /dev/null 2>&1
> > > +wait $dread_pid>  /dev/null 2>&1
> > > +
> > > +echo "Silence is golden"
> > > +
> > > +# success, all done
> > > +status=0
> > > +exit
> > > diff --git a/tests/xfs/422.out b/tests/xfs/422.out
> > > new file mode 100644
> > > index 0000000..f70693f
> > > --- /dev/null
> > > +++ b/tests/xfs/422.out
> > > @@ -0,0 +1,2 @@
> > > +QA output created by 422
> > > +Silence is golden
> > > diff --git a/tests/xfs/group b/tests/xfs/group
> > > index 2a3b950..f43ffcf 100644
> > > --- a/tests/xfs/group
> > > +++ b/tests/xfs/group
> > > @@ -419,3 +419,4 @@
> > >   419 auto quick
> > >   420 auto quick clone dedupe
> > >   421 auto quick clone dedupe
> > > +422 auto quick dangerous
> > > -- 
> > > 1.8.3.1
> > > 
> > > 
> > > 
> > > --
> > > 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
> > 
> > .
> > 
> 
> 
> 

Re: [PATCH] xfs: test a race between dio reads and mapped writes

[Xiao Yang]

On 2017/06/29 12:34, Eryu Guan wrote:
> On Thu, Jun 29, 2017 at 12:01:25PM +0800, Xiao Yang wrote:
>> On 2017/06/28 18:13, Eryu Guan wrote:
>>> On Tue, Jun 27, 2017 at 05:03:52PM +0800, Xiao Yang wrote:
>>>> This regression test reproduces a race between a direct
>>>> I/O read and a mapped write to a hole in a file.  If the
>>>> race occurs, it will trigger a BUG_ON().  This XFS bug
>>>> has been fixed by:
>>>>
>>>> 04197b3 (xfs: don't BUG() on mixed direct and mapped I/O)
>>>>
>>>> Signed-off-by: Xiao Yang<yangx.jy@cn.fujitsu.com>
>>>> ---
>>>>    tests/xfs/422     | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>>>    tests/xfs/422.out |  2 ++
>>>>    tests/xfs/group   |  1 +
>>>>    3 files changed, 89 insertions(+)
>>>>    create mode 100755 tests/xfs/422
>>>>    create mode 100644 tests/xfs/422.out
>>>>
>>>> diff --git a/tests/xfs/422 b/tests/xfs/422
>>>> new file mode 100755
>>>> index 0000000..a57ffab
>>>> --- /dev/null
>>>> +++ b/tests/xfs/422
>>>> @@ -0,0 +1,86 @@
>>>> +#! /bin/bash
>>>> +# FS QA Test No. 422
>>>> +#
>>>> +# Regression test for commit:
>>>> +# 04197b3 ("xfs: don't BUG() on mixed direct and mapped I/O)
>>>                ^^ missing ending " :)
>>>> +#
>>>> +# This case tests a race between a direct I/O read and a
>>>> +# mapped write to a hole in a file.  If the race occurs,
>>>> +# it will trigger a BUG_ON().
>>>> +#
>>>> +#-----------------------------------------------------------------------
>>>> +# Copyright (c) 2017 Fujitsu.  All Rights Reserved.
>>>> +# Author: Xiao Yang<yangx.jy@cn.fujitsu.com>
>>>> +#
>>>> +# 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 -rf $tmp.*
>>>> +}
>>>> +
>>>> +# get standard environment and checks
>>>> +. ./common/rc
>>>> +
>>>> +# real QA test starts here
>>>> +_supported_os Linux
>>>> +_supported_fs xfs
>>> I see nothing xfs specific in this test, I think it can be made generic
>>> easily.
>> Hi Eryu,
>>
>> Agreed.  It could be moved into generic.
>>>> +_require_scratch
>>>> +_disable_dmesg_check
>>> Better to add comments on ignoring dmesg check result.
>> For xfs filesystem, this race triggers various warnings on some
>> distributions(RHEL7) and upstream kernel.
>> e.g,
>> 1) This race triggers the following warnings on RHEL7.3GA
>> -----------------------------------------------------------------------------------------------------------------------------
>> [    0.297084] WARNING: at arch/x86/mm/ioremap.c:101
>> __ioremap_caller+0x238/0x320()
> I'm not sure about this one, but the other xfs or iomap warnings are
> "known issues" when mixing direct I/O and mmap I/O on the same file.
> We've filtered out these intentional warnings in generic/095, and Brian
> has just sent a patch[1] to move this filter to common/xfs and added it
> to generic/247. I think you can do the same to this new test, filter out
> these known warnings so we won't miss any other potential bug.
>
> I don't think disable dmesg check only because it triggers warnings is a
> good idea :)
Hi Eryu

It sounds reasonable to me.   I will filter out these known warnings 
instead of disabling dmesg check.
> Thanks,
> Eryu
>
> [1] [PATCH] generic/247: filter out expected XFS warnings for mixed mmap/direct I/O
>
>> [  648.745481] WARNING: at fs/xfs/xfs_aops.c:1244
>> xfs_vm_releasepage+0xcb/0x100 [xfs]()
>> [  648.745694] WARNING: at fs/xfs/xfs_file.c:377
>> xfs_file_aio_read+0x2dd/0x340 [xfs]()
>> -----------------------------------------------------------------------------------------------------------------------------
>> 2) It triggers the following warnings on RHEL7.4Beta
>> ----------------------------------------------------------------------------------------------------------------------------
>> [  497.575319] WARNING: CPU: 0 PID: 26865 at fs/xfs/xfs_file.c:361
>> xfs_file_dio_aio_read+0x1ba/0x2a0 [xfs]
>> [  497.577651] WARNING: CPU: 0 PID: 26865 at fs/xfs/xfs_aops.c:1285
>> __xfs_get_blocks+0x8ca/0x8e0 [xfs]
Could we add __xfs_get_blocks into filter_xfs_dmesg? :-)

This known warning was introduced by:
04197b3 (xfs: don't BUG() on mixed direct and mapped I/O)

It has been removed by:
acdda3a (xfs: use iomap_dio_rw)

Thanks,
Xiao Yang
>> ----------------------------------------------------------------------------------------------------------------------------
>> 3) It triggers the following warnings on upstream kernel
>> ----------------------------------------------------------------------------------------------------------------------------
>> [   57.946882] WARNING: CPU: 1 PID: 4053 at fs/iomap.c:890
>> iomap_dio_rw+0x37a/0x390
>> [   57.947066] WARNING: CPU: 1 PID: 4053 at fs/iomap.c:766
>> iomap_dio_actor+0xca/0x370
>> ----------------------------------------------------------------------------------------------------------------------------
>>
>> It focus on the oops due to this race, and the warnings are different based
>> on different kernel.
>> So we may ignore dmesg check.
>>
>> I will add comments on ignoring dmesg check result as you said.
>>
>> Thanks,
>> Xiao Yang
>>> Thanks,
>>> Eryu
>>>
>>>> +_require_xfs_io_command "truncate"
>>>> +_require_xfs_io_command "fpunch"
>>>> +
>>>> +rm -f $seqres.full
>>>> +
>>>> +# format and mount
>>>> +_scratch_mkfs>   $seqres.full 2>&1
>>>> +_scratch_mount>>   $seqres.full 2>&1
>>>> +
>>>> +filesz=$((65536 * 2))
>>>> +
>>>> +# create a test file with a hole
>>>> +$XFS_IO_PROG -f -c "truncate $((filesz * 2))" $SCRATCH_MNT/file>>   $seqres.full
>>>> +
>>>> +# run a background dio read to a hole in a loop
>>>> +while true; do
>>>> +	$XFS_IO_PROG -d -c "pread 0 $filesz" $SCRATCH_MNT/file>   /dev/null 2>&1
>>>> +done&
>>>> +
>>>> +dread_pid=$!
>>>> +
>>>> +# run mapped write to the same hole as dio read
>>>> +for i in `seq 0 999`; do
>>>> +	$XFS_IO_PROG -c "mmap 0 $filesz" -c "mwrite 0 $filesz" $SCRATCH_MNT/file \
>>>> +		>   /dev/null
>>>> +	$XFS_IO_PROG -c "fpunch 0 $filesz" $SCRATCH_MNT/file>   /dev/null
>>>> +done
>>>> +
>>>> +kill -9 $dread_pid>   /dev/null 2>&1
>>>> +wait $dread_pid>   /dev/null 2>&1
>>>> +
>>>> +echo "Silence is golden"
>>>> +
>>>> +# success, all done
>>>> +status=0
>>>> +exit
>>>> diff --git a/tests/xfs/422.out b/tests/xfs/422.out
>>>> new file mode 100644
>>>> index 0000000..f70693f
>>>> --- /dev/null
>>>> +++ b/tests/xfs/422.out
>>>> @@ -0,0 +1,2 @@
>>>> +QA output created by 422
>>>> +Silence is golden
>>>> diff --git a/tests/xfs/group b/tests/xfs/group
>>>> index 2a3b950..f43ffcf 100644
>>>> --- a/tests/xfs/group
>>>> +++ b/tests/xfs/group
>>>> @@ -419,3 +419,4 @@
>>>>    419 auto quick
>>>>    420 auto quick clone dedupe
>>>>    421 auto quick clone dedupe
>>>> +422 auto quick dangerous
>>>> -- 
>>>> 1.8.3.1
>>>>
>>>>
>>>>
>>>> --
>>>> 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
>>> .
>>>
>>
>>
>
> .
>

Re: [PATCH] xfs: test a race between dio reads and mapped writes

[Eryu Guan]

On Thu, Jun 29, 2017 at 01:21:12PM +0800, Xiao Yang wrote:
> On 2017/06/29 12:34, Eryu Guan wrote:
> > On Thu, Jun 29, 2017 at 12:01:25PM +0800, Xiao Yang wrote:
> > > On 2017/06/28 18:13, Eryu Guan wrote:
> > > > On Tue, Jun 27, 2017 at 05:03:52PM +0800, Xiao Yang wrote:
> > > > > This regression test reproduces a race between a direct
> > > > > I/O read and a mapped write to a hole in a file.  If the
> > > > > race occurs, it will trigger a BUG_ON().  This XFS bug
> > > > > has been fixed by:
> > > > > 
> > > > > 04197b3 (xfs: don't BUG() on mixed direct and mapped I/O)
> > > > > 
> > > > > Signed-off-by: Xiao Yang<yangx.jy@cn.fujitsu.com>
> > > > > ---
> > > > >    tests/xfs/422     | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> > > > >    tests/xfs/422.out |  2 ++
> > > > >    tests/xfs/group   |  1 +
> > > > >    3 files changed, 89 insertions(+)
> > > > >    create mode 100755 tests/xfs/422
> > > > >    create mode 100644 tests/xfs/422.out
> > > > > 
> > > > > diff --git a/tests/xfs/422 b/tests/xfs/422
> > > > > new file mode 100755
> > > > > index 0000000..a57ffab
> > > > > --- /dev/null
> > > > > +++ b/tests/xfs/422
> > > > > @@ -0,0 +1,86 @@
> > > > > +#! /bin/bash
> > > > > +# FS QA Test No. 422
> > > > > +#
> > > > > +# Regression test for commit:
> > > > > +# 04197b3 ("xfs: don't BUG() on mixed direct and mapped I/O)
> > > >                ^^ missing ending " :)
> > > > > +#
> > > > > +# This case tests a race between a direct I/O read and a
> > > > > +# mapped write to a hole in a file.  If the race occurs,
> > > > > +# it will trigger a BUG_ON().
> > > > > +#
> > > > > +#-----------------------------------------------------------------------
> > > > > +# Copyright (c) 2017 Fujitsu.  All Rights Reserved.
> > > > > +# Author: Xiao Yang<yangx.jy@cn.fujitsu.com>
> > > > > +#
> > > > > +# 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 -rf $tmp.*
> > > > > +}
> > > > > +
> > > > > +# get standard environment and checks
> > > > > +. ./common/rc
> > > > > +
> > > > > +# real QA test starts here
> > > > > +_supported_os Linux
> > > > > +_supported_fs xfs
> > > > I see nothing xfs specific in this test, I think it can be made generic
> > > > easily.
> > > Hi Eryu,
> > > 
> > > Agreed.  It could be moved into generic.
> > > > > +_require_scratch
> > > > > +_disable_dmesg_check
> > > > Better to add comments on ignoring dmesg check result.
> > > For xfs filesystem, this race triggers various warnings on some
> > > distributions(RHEL7) and upstream kernel.
> > > e.g,
> > > 1) This race triggers the following warnings on RHEL7.3GA
> > > -----------------------------------------------------------------------------------------------------------------------------
> > > [    0.297084] WARNING: at arch/x86/mm/ioremap.c:101
> > > __ioremap_caller+0x238/0x320()
> > I'm not sure about this one, but the other xfs or iomap warnings are
> > "known issues" when mixing direct I/O and mmap I/O on the same file.
> > We've filtered out these intentional warnings in generic/095, and Brian
> > has just sent a patch[1] to move this filter to common/xfs and added it
> > to generic/247. I think you can do the same to this new test, filter out
> > these known warnings so we won't miss any other potential bug.
> > 
> > I don't think disable dmesg check only because it triggers warnings is a
> > good idea :)
> Hi Eryu
> 
> It sounds reasonable to me.   I will filter out these known warnings instead
> of disabling dmesg check.
> > Thanks,
> > Eryu
> > 
> > [1] [PATCH] generic/247: filter out expected XFS warnings for mixed mmap/direct I/O
> > 
> > > [  648.745481] WARNING: at fs/xfs/xfs_aops.c:1244
> > > xfs_vm_releasepage+0xcb/0x100 [xfs]()
> > > [  648.745694] WARNING: at fs/xfs/xfs_file.c:377
> > > xfs_file_aio_read+0x2dd/0x340 [xfs]()
> > > -----------------------------------------------------------------------------------------------------------------------------
> > > 2) It triggers the following warnings on RHEL7.4Beta
> > > ----------------------------------------------------------------------------------------------------------------------------
> > > [  497.575319] WARNING: CPU: 0 PID: 26865 at fs/xfs/xfs_file.c:361
> > > xfs_file_dio_aio_read+0x1ba/0x2a0 [xfs]
> > > [  497.577651] WARNING: CPU: 0 PID: 26865 at fs/xfs/xfs_aops.c:1285
> > > __xfs_get_blocks+0x8ca/0x8e0 [xfs]
> Could we add __xfs_get_blocks into filter_xfs_dmesg? :-)
> 
> This known warning was introduced by:
> 04197b3 (xfs: don't BUG() on mixed direct and mapped I/O)
> 
> It has been removed by:
> acdda3a (xfs: use iomap_dio_rw)

Please send another patch with detailed background information to add it
to the filter and cc linux-xfs list, perhaps after both Brian's patch
and this new test patch being merged & pushed out to upstream. Thanks a
lot!

Eryu

Re: [PATCH] xfs: test a race between dio reads and mapped writes

[Xiao Yang]

On 2017/06/29 13:39, Eryu Guan wrote:
> On Thu, Jun 29, 2017 at 01:21:12PM +0800, Xiao Yang wrote:
>> On 2017/06/29 12:34, Eryu Guan wrote:
>>> On Thu, Jun 29, 2017 at 12:01:25PM +0800, Xiao Yang wrote:
>>>> On 2017/06/28 18:13, Eryu Guan wrote:
>>>>> On Tue, Jun 27, 2017 at 05:03:52PM +0800, Xiao Yang wrote:
>>>>>> This regression test reproduces a race between a direct
>>>>>> I/O read and a mapped write to a hole in a file.  If the
>>>>>> race occurs, it will trigger a BUG_ON().  This XFS bug
>>>>>> has been fixed by:
>>>>>>
>>>>>> 04197b3 (xfs: don't BUG() on mixed direct and mapped I/O)
>>>>>>
>>>>>> Signed-off-by: Xiao Yang<yangx.jy@cn.fujitsu.com>
>>>>>> ---
>>>>>>     tests/xfs/422     | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>>>>>     tests/xfs/422.out |  2 ++
>>>>>>     tests/xfs/group   |  1 +
>>>>>>     3 files changed, 89 insertions(+)
>>>>>>     create mode 100755 tests/xfs/422
>>>>>>     create mode 100644 tests/xfs/422.out
>>>>>>
>>>>>> diff --git a/tests/xfs/422 b/tests/xfs/422
>>>>>> new file mode 100755
>>>>>> index 0000000..a57ffab
>>>>>> --- /dev/null
>>>>>> +++ b/tests/xfs/422
>>>>>> @@ -0,0 +1,86 @@
>>>>>> +#! /bin/bash
>>>>>> +# FS QA Test No. 422
>>>>>> +#
>>>>>> +# Regression test for commit:
>>>>>> +# 04197b3 ("xfs: don't BUG() on mixed direct and mapped I/O)
>>>>>                 ^^ missing ending " :)
>>>>>> +#
>>>>>> +# This case tests a race between a direct I/O read and a
>>>>>> +# mapped write to a hole in a file.  If the race occurs,
>>>>>> +# it will trigger a BUG_ON().
>>>>>> +#
>>>>>> +#-----------------------------------------------------------------------
>>>>>> +# Copyright (c) 2017 Fujitsu.  All Rights Reserved.
>>>>>> +# Author: Xiao Yang<yangx.jy@cn.fujitsu.com>
>>>>>> +#
>>>>>> +# 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 -rf $tmp.*
>>>>>> +}
>>>>>> +
>>>>>> +# get standard environment and checks
>>>>>> +. ./common/rc
>>>>>> +
>>>>>> +# real QA test starts here
>>>>>> +_supported_os Linux
>>>>>> +_supported_fs xfs
>>>>> I see nothing xfs specific in this test, I think it can be made generic
>>>>> easily.
>>>> Hi Eryu,
>>>>
>>>> Agreed.  It could be moved into generic.
>>>>>> +_require_scratch
>>>>>> +_disable_dmesg_check
>>>>> Better to add comments on ignoring dmesg check result.
>>>> For xfs filesystem, this race triggers various warnings on some
>>>> distributions(RHEL7) and upstream kernel.
>>>> e.g,
>>>> 1) This race triggers the following warnings on RHEL7.3GA
>>>> -----------------------------------------------------------------------------------------------------------------------------
>>>> [    0.297084] WARNING: at arch/x86/mm/ioremap.c:101
>>>> __ioremap_caller+0x238/0x320()
>>> I'm not sure about this one, but the other xfs or iomap warnings are
>>> "known issues" when mixing direct I/O and mmap I/O on the same file.
>>> We've filtered out these intentional warnings in generic/095, and Brian
>>> has just sent a patch[1] to move this filter to common/xfs and added it
>>> to generic/247. I think you can do the same to this new test, filter out
>>> these known warnings so we won't miss any other potential bug.
>>>
>>> I don't think disable dmesg check only because it triggers warnings is a
>>> good idea :)
>> Hi Eryu
>>
>> It sounds reasonable to me.   I will filter out these known warnings instead
>> of disabling dmesg check.
>>> Thanks,
>>> Eryu
>>>
>>> [1] [PATCH] generic/247: filter out expected XFS warnings for mixed mmap/direct I/O
>>>
>>>> [  648.745481] WARNING: at fs/xfs/xfs_aops.c:1244
>>>> xfs_vm_releasepage+0xcb/0x100 [xfs]()
>>>> [  648.745694] WARNING: at fs/xfs/xfs_file.c:377
>>>> xfs_file_aio_read+0x2dd/0x340 [xfs]()
>>>> -----------------------------------------------------------------------------------------------------------------------------
>>>> 2) It triggers the following warnings on RHEL7.4Beta
>>>> ----------------------------------------------------------------------------------------------------------------------------
>>>> [  497.575319] WARNING: CPU: 0 PID: 26865 at fs/xfs/xfs_file.c:361
>>>> xfs_file_dio_aio_read+0x1ba/0x2a0 [xfs]
>>>> [  497.577651] WARNING: CPU: 0 PID: 26865 at fs/xfs/xfs_aops.c:1285
>>>> __xfs_get_blocks+0x8ca/0x8e0 [xfs]
>> Could we add __xfs_get_blocks into filter_xfs_dmesg? :-)
>>
>> This known warning was introduced by:
>> 04197b3 (xfs: don't BUG() on mixed direct and mapped I/O)
>>
>> It has been removed by:
>> acdda3a (xfs: use iomap_dio_rw)
> Please send another patch with detailed background information to add it
> to the filter and cc linux-xfs list, perhaps after both Brian's patch
> and this new test patch being merged&  pushed out to upstream. Thanks a
> lot!
Hi Eryu

Thanks for your suggestion, I will send another patch as you said. :-)

Thanks,
Xiao Yang.
> Eryu
>
>
> .
>

[PATCH v2] generic: test a race between dio reads and mapped writes

[Xiao Yang]

This test reproduces a race between a direct I/O read and
a mapped write to a hole in a file.  On xfs filesystem, it
will trigger a BUG_ON(), and this XFS bug has been fixed by:

04197b3 ("xfs: don't BUG() on mixed direct and mapped I/O")

Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
---
 tests/generic/445     | 89 +++++++++++++++++++++++++++++++++++++++++++++++++++
 tests/generic/445.out |  2 ++
 tests/generic/group   |  1 +
 3 files changed, 92 insertions(+)
 create mode 100755 tests/generic/445
 create mode 100644 tests/generic/445.out

diff --git a/tests/generic/445 b/tests/generic/445
new file mode 100755
index 0000000..28dfcbe
--- /dev/null
+++ b/tests/generic/445
@@ -0,0 +1,89 @@
+#! /bin/bash
+# FS QA Test No. 445
+#
+# Regression test for commit:
+# 04197b3 ("xfs: don't BUG() on mixed direct and mapped I/O")
+#
+# This case tests a race between a direct I/O read and a
+# mapped write to a hole in a file.  On xfs filesystem, it
+# will trigger a BUG_ON().
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2017 Fujitsu.  All Rights Reserved.
+# Author: Xiao Yang <yangx.jy@cn.fujitsu.com>
+#
+# 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 -rf $tmp.*
+}
+
+# get standard environment and checks
+. ./common/rc
+
+# real QA test starts here
+_supported_os Linux
+_require_scratch
+_require_xfs_io_command "truncate"
+_require_xfs_io_command "fpunch"
+
+rm -f $seqres.full
+
+# format and mount
+_scratch_mkfs > $seqres.full 2>&1
+_scratch_mount >> $seqres.full 2>&1
+
+filesz=$((65536 * 2))
+
+# create a test file with a hole
+$XFS_IO_PROG -f -c "truncate $((filesz * 2))" $SCRATCH_MNT/file >> $seqres.full
+
+# run a background dio read to a hole in a loop
+while true; do
+	$XFS_IO_PROG -d -c "pread 0 $filesz" $SCRATCH_MNT/file > /dev/null 2>&1
+done &
+
+dread_pid=$!
+
+# run mapped write to the same hole as dio read
+for i in `seq 0 999`; do
+	$XFS_IO_PROG -c "mmap 0 $filesz" -c "mwrite 0 $filesz" $SCRATCH_MNT/file \
+		> /dev/null
+	$XFS_IO_PROG -c "fpunch 0 $filesz" $SCRATCH_MNT/file > /dev/null
+done
+
+kill -9 $dread_pid > /dev/null 2>&1
+wait $dread_pid > /dev/null 2>&1
+
+echo "Silence is golden"
+
+# check dmesg, filtering out expected XFS warnings about mixed mmap/dio
+if [ "$FSTYP" == "xfs" ]; then
+	_check_dmesg _filter_xfs_dmesg
+else
+	_check_dmesg
+fi
+status=$?
+exit
diff --git a/tests/generic/445.out b/tests/generic/445.out
new file mode 100644
index 0000000..44e55d2
--- /dev/null
+++ b/tests/generic/445.out
@@ -0,0 +1,2 @@
+QA output created by 445
+Silence is golden
diff --git a/tests/generic/group b/tests/generic/group
index ced111c..39991b1 100644
--- a/tests/generic/group
+++ b/tests/generic/group
@@ -447,3 +447,4 @@
 442 blockdev
 443 auto quick rw
 444 auto quick acl
+445 auto quick dangerous
-- 
1.8.3.1

Re: [PATCH v2] generic: test a race between dio reads and mapped writes

[Eryu Guan]

On Thu, Jun 29, 2017 at 02:36:41PM +0800, Xiao Yang wrote:
> This test reproduces a race between a direct I/O read and
> a mapped write to a hole in a file.  On xfs filesystem, it
> will trigger a BUG_ON(), and this XFS bug has been fixed by:
> 
> 04197b3 ("xfs: don't BUG() on mixed direct and mapped I/O")
> 
> Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>

Thanks for the updated version!

Add linux-xfs list to cc because I noticed an unexpected WARNING when
testing on XFS. Please see below.

> ---
>  tests/generic/445     | 89 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  tests/generic/445.out |  2 ++
>  tests/generic/group   |  1 +
>  3 files changed, 92 insertions(+)
>  create mode 100755 tests/generic/445
>  create mode 100644 tests/generic/445.out
> 
> diff --git a/tests/generic/445 b/tests/generic/445
> new file mode 100755
> index 0000000..28dfcbe
> --- /dev/null
> +++ b/tests/generic/445
> @@ -0,0 +1,89 @@
> +#! /bin/bash
> +# FS QA Test No. 445
> +#
> +# Regression test for commit:
> +# 04197b3 ("xfs: don't BUG() on mixed direct and mapped I/O")
> +#
> +# This case tests a race between a direct I/O read and a
> +# mapped write to a hole in a file.  On xfs filesystem, it
> +# will trigger a BUG_ON().
> +#
> +#-----------------------------------------------------------------------
> +# Copyright (c) 2017 Fujitsu.  All Rights Reserved.
> +# Author: Xiao Yang <yangx.jy@cn.fujitsu.com>
> +#
> +# 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 -rf $tmp.*
> +}
> +
> +# get standard environment and checks
> +. ./common/rc
> +
> +# real QA test starts here
> +_supported_os Linux
> +_require_scratch
> +_require_xfs_io_command "truncate"
> +_require_xfs_io_command "fpunch"
> +
> +rm -f $seqres.full
> +
> +# format and mount
> +_scratch_mkfs > $seqres.full 2>&1
> +_scratch_mount >> $seqres.full 2>&1
> +
> +filesz=$((65536 * 2))
> +
> +# create a test file with a hole
> +$XFS_IO_PROG -f -c "truncate $((filesz * 2))" $SCRATCH_MNT/file >> $seqres.full
> +
> +# run a background dio read to a hole in a loop
> +while true; do
> +	$XFS_IO_PROG -d -c "pread 0 $filesz" $SCRATCH_MNT/file > /dev/null 2>&1
> +done &
> +
> +dread_pid=$!
> +
> +# run mapped write to the same hole as dio read
> +for i in `seq 0 999`; do
> +	$XFS_IO_PROG -c "mmap 0 $filesz" -c "mwrite 0 $filesz" $SCRATCH_MNT/file \
> +		> /dev/null
> +	$XFS_IO_PROG -c "fpunch 0 $filesz" $SCRATCH_MNT/file > /dev/null
> +done
> +
> +kill -9 $dread_pid > /dev/null 2>&1
> +wait $dread_pid > /dev/null 2>&1
> +
> +echo "Silence is golden"
> +
> +# check dmesg, filtering out expected XFS warnings about mixed mmap/dio

BTW, I added _scratch_unmount before _check_dmesg, in case umount
triggers other warnings.

> +if [ "$FSTYP" == "xfs" ]; then
> +	_check_dmesg _filter_xfs_dmesg
> +else
> +	_check_dmesg
> +fi

I hit unexpected warning at fs/iomap.c:766 iomap_dio_actor+0xca/0x370,
which indicates an unknown IOMAP type:

        switch (iomap->type) {
        case IOMAP_HOLE:
                ...
        case IOMAP_UNWRITTEN:
                ...
        case IOMAP_MAPPED:
                ...
        default:
766             WARN_ON_ONCE(1);
                return -EIO;
        }

But shouldn't this be fixed by commit a008c31c7ef9 ("iomap_dio_rw: Prevent
reading file data beyond iomap_dio->i_size")? Another code path that
needs fix?

[   30.894989] ------------[ cut here ]------------
[   30.895400] WARNING: CPU: 2 PID: 3456 at fs/iomap.c:766 iomap_dio_actor+0xca/0x370
[   30.896025] Modules linked in: btrfs xor raid6_pq ppdev i2c_piix4 parport_pc sg virtio_balloon parport i2c_core pcspkr nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sd_mod ata_generic pata_acpi ata_piix virtio_scsi libata virtio_pci virtio_ring 8139too virtio 8139cp serio_raw mii floppy
[   30.898224] CPU: 2 PID: 3456 Comm: xfs_io Tainted: G        W       4.12.0-rc7 #172
[   30.898851] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2007
[   30.899348] task: ffff880210e38000 task.stack: ffffc90004a28000
[   30.899830] RIP: 0010:iomap_dio_actor+0xca/0x370
[   30.900222] RSP: 0018:ffffc90004a2bc20 EFLAGS: 00010202
[   30.900656] RAX: 0000000000000002 RBX: ffffc90004a2bcb0 RCX: 00000000006c1000
[   30.901244] RDX: 00000000000001ff RSI: ffffc90004a2be30 RDI: ffffc90004a2be68
[   30.901829] RBP: ffffc90004a2bc90 R08: ffffc90004a2bcb0 R09: ffff880213f965a0
[   30.902428] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
[   30.903020] R13: ffffffffa0169b60 R14: ffff880213f965a0 R15: 0000000000000009
[   30.903604] FS:  00007f7570f77740(0000) GS:ffff88021fd00000(0000) knlGS:0000000000000000
[   30.904541] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   30.905025] CR2: 00000000006c1000 CR3: 00000002145df000 CR4: 00000000000006e0
[   30.905614] Call Trace:
[   30.905820]  ? iomap_dio_zero+0x100/0x100
[   30.906167]  iomap_apply+0xa1/0x110
[   30.906464]  iomap_dio_rw+0x20b/0x390
[   30.906764]  ? iomap_dio_zero+0x100/0x100
[   30.907138]  xfs_file_dio_aio_read+0x6e/0xf0 [xfs]
[   30.907560]  xfs_file_read_iter+0xab/0xc0 [xfs]
[   30.907933]  __vfs_read+0xe0/0x150
[   30.908236]  vfs_read+0x8c/0x130
[   30.908790]  SyS_pread64+0x87/0xb0
[   30.909093]  do_syscall_64+0x67/0x150
[   30.909404]  entry_SYSCALL64_slow_path+0x25/0x25
[   30.909776] RIP: 0033:0x7f7570b59f73
[   30.910087] RSP: 002b:00007fffd34ce9a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000011
[   30.910705] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7570b59f73
[   30.911297] RDX: 0000000000001000 RSI: 00000000006c1000 RDI: 0000000000000003
[   30.911875] RBP: 00007fffd34cea60 R08: 0000000000000000 R09: 0000000000000000
[   30.912473] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
[   30.913062] R13: 0000000000020000 R14: 0000000000000000 R15: 0000000000000000
[   30.913645] Code: e1 48 09 c1 48 85 ca 0f 85 82 02 00 00 0f b7 43 18 66 83 f8 03 0f 84 fb 01 00 00 66 83 f8 04 74 35 66 83 f8 01 0f 84 07 02 00 00 <0f> ff 48 c7 c0 fb ff ff ff 48 8b 4d d0 65 48 33 0c 25 28 00 00
[   30.915181] ---[ end trace 82f9af72bfb35f21 ]---

Thanks,
Eryu

> +status=$?
> +exit
> diff --git a/tests/generic/445.out b/tests/generic/445.out
> new file mode 100644
> index 0000000..44e55d2
> --- /dev/null
> +++ b/tests/generic/445.out
> @@ -0,0 +1,2 @@
> +QA output created by 445
> +Silence is golden
> diff --git a/tests/generic/group b/tests/generic/group
> index ced111c..39991b1 100644
> --- a/tests/generic/group
> +++ b/tests/generic/group
> @@ -447,3 +447,4 @@
>  442 blockdev
>  443 auto quick rw
>  444 auto quick acl
> +445 auto quick dangerous
> -- 
> 1.8.3.1
> 
> 
> 

Re: [PATCH v2] generic: test a race between dio reads and mapped writes

[Brian Foster]

On Thu, Jun 29, 2017 at 03:45:50PM +0800, Eryu Guan wrote:
> On Thu, Jun 29, 2017 at 02:36:41PM +0800, Xiao Yang wrote:
> > This test reproduces a race between a direct I/O read and
> > a mapped write to a hole in a file.  On xfs filesystem, it
> > will trigger a BUG_ON(), and this XFS bug has been fixed by:
> > 
> > 04197b3 ("xfs: don't BUG() on mixed direct and mapped I/O")
> > 
> > Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
> 
> Thanks for the updated version!
> 
> Add linux-xfs list to cc because I noticed an unexpected WARNING when
> testing on XFS. Please see below.
> 
> > ---
> >  tests/generic/445     | 89 +++++++++++++++++++++++++++++++++++++++++++++++++++
> >  tests/generic/445.out |  2 ++
> >  tests/generic/group   |  1 +
> >  3 files changed, 92 insertions(+)
> >  create mode 100755 tests/generic/445
> >  create mode 100644 tests/generic/445.out
> > 
> > diff --git a/tests/generic/445 b/tests/generic/445
> > new file mode 100755
> > index 0000000..28dfcbe
> > --- /dev/null
> > +++ b/tests/generic/445
> > @@ -0,0 +1,89 @@
> > +#! /bin/bash
> > +# FS QA Test No. 445
> > +#
> > +# Regression test for commit:
> > +# 04197b3 ("xfs: don't BUG() on mixed direct and mapped I/O")
> > +#
> > +# This case tests a race between a direct I/O read and a
> > +# mapped write to a hole in a file.  On xfs filesystem, it
> > +# will trigger a BUG_ON().
> > +#
> > +#-----------------------------------------------------------------------
> > +# Copyright (c) 2017 Fujitsu.  All Rights Reserved.
> > +# Author: Xiao Yang <yangx.jy@cn.fujitsu.com>
> > +#
> > +# 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 -rf $tmp.*
> > +}
> > +
> > +# get standard environment and checks
> > +. ./common/rc
> > +
> > +# real QA test starts here
> > +_supported_os Linux
> > +_require_scratch
> > +_require_xfs_io_command "truncate"
> > +_require_xfs_io_command "fpunch"
> > +
> > +rm -f $seqres.full
> > +
> > +# format and mount
> > +_scratch_mkfs > $seqres.full 2>&1
> > +_scratch_mount >> $seqres.full 2>&1
> > +
> > +filesz=$((65536 * 2))
> > +
> > +# create a test file with a hole
> > +$XFS_IO_PROG -f -c "truncate $((filesz * 2))" $SCRATCH_MNT/file >> $seqres.full
> > +
> > +# run a background dio read to a hole in a loop
> > +while true; do
> > +	$XFS_IO_PROG -d -c "pread 0 $filesz" $SCRATCH_MNT/file > /dev/null 2>&1
> > +done &
> > +
> > +dread_pid=$!
> > +
> > +# run mapped write to the same hole as dio read
> > +for i in `seq 0 999`; do
> > +	$XFS_IO_PROG -c "mmap 0 $filesz" -c "mwrite 0 $filesz" $SCRATCH_MNT/file \
> > +		> /dev/null
> > +	$XFS_IO_PROG -c "fpunch 0 $filesz" $SCRATCH_MNT/file > /dev/null
> > +done
> > +
> > +kill -9 $dread_pid > /dev/null 2>&1
> > +wait $dread_pid > /dev/null 2>&1
> > +
> > +echo "Silence is golden"
> > +
> > +# check dmesg, filtering out expected XFS warnings about mixed mmap/dio
> 
> BTW, I added _scratch_unmount before _check_dmesg, in case umount
> triggers other warnings.
> 
> > +if [ "$FSTYP" == "xfs" ]; then
> > +	_check_dmesg _filter_xfs_dmesg
> > +else
> > +	_check_dmesg
> > +fi
> 
> I hit unexpected warning at fs/iomap.c:766 iomap_dio_actor+0xca/0x370,
> which indicates an unknown IOMAP type:
> 
>         switch (iomap->type) {
>         case IOMAP_HOLE:
>                 ...
>         case IOMAP_UNWRITTEN:
>                 ...
>         case IOMAP_MAPPED:
>                 ...
>         default:
> 766             WARN_ON_ONCE(1);
>                 return -EIO;
>         }
> 
> But shouldn't this be fixed by commit a008c31c7ef9 ("iomap_dio_rw: Prevent
> reading file data beyond iomap_dio->i_size")? Another code path that
> needs fix?
> 
> [   30.894989] ------------[ cut here ]------------
> [   30.895400] WARNING: CPU: 2 PID: 3456 at fs/iomap.c:766 iomap_dio_actor+0xca/0x370

Hmm, so I suspect this occurs due to a dio read to a delayed allocation
mapping..? This seems possible because the dio read (and associated
filemap flush) occurs under the shared iolock and mapped write occurs
under the separate mmap lock. IIRC, the patch mentioned in the commit
log above was to remove a BUG() caused by a known bad mix of dio/mapped
I/O to avoid a kernel crash, but that doesn't make the situation safe.
IOW, it seems to me that this warning and an accompanying dio error are
probably expected..?

Brian

> [   30.896025] Modules linked in: btrfs xor raid6_pq ppdev i2c_piix4 parport_pc sg virtio_balloon parport i2c_core pcspkr nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c sd_mod ata_generic pata_acpi ata_piix virtio_scsi libata virtio_pci virtio_ring 8139too virtio 8139cp serio_raw mii floppy
> [   30.898224] CPU: 2 PID: 3456 Comm: xfs_io Tainted: G        W       4.12.0-rc7 #172
> [   30.898851] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2007
> [   30.899348] task: ffff880210e38000 task.stack: ffffc90004a28000
> [   30.899830] RIP: 0010:iomap_dio_actor+0xca/0x370
> [   30.900222] RSP: 0018:ffffc90004a2bc20 EFLAGS: 00010202
> [   30.900656] RAX: 0000000000000002 RBX: ffffc90004a2bcb0 RCX: 00000000006c1000
> [   30.901244] RDX: 00000000000001ff RSI: ffffc90004a2be30 RDI: ffffc90004a2be68
> [   30.901829] RBP: ffffc90004a2bc90 R08: ffffc90004a2bcb0 R09: ffff880213f965a0
> [   30.902428] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
> [   30.903020] R13: ffffffffa0169b60 R14: ffff880213f965a0 R15: 0000000000000009
> [   30.903604] FS:  00007f7570f77740(0000) GS:ffff88021fd00000(0000) knlGS:0000000000000000
> [   30.904541] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [   30.905025] CR2: 00000000006c1000 CR3: 00000002145df000 CR4: 00000000000006e0
> [   30.905614] Call Trace:
> [   30.905820]  ? iomap_dio_zero+0x100/0x100
> [   30.906167]  iomap_apply+0xa1/0x110
> [   30.906464]  iomap_dio_rw+0x20b/0x390
> [   30.906764]  ? iomap_dio_zero+0x100/0x100
> [   30.907138]  xfs_file_dio_aio_read+0x6e/0xf0 [xfs]
> [   30.907560]  xfs_file_read_iter+0xab/0xc0 [xfs]
> [   30.907933]  __vfs_read+0xe0/0x150
> [   30.908236]  vfs_read+0x8c/0x130
> [   30.908790]  SyS_pread64+0x87/0xb0
> [   30.909093]  do_syscall_64+0x67/0x150
> [   30.909404]  entry_SYSCALL64_slow_path+0x25/0x25
> [   30.909776] RIP: 0033:0x7f7570b59f73
> [   30.910087] RSP: 002b:00007fffd34ce9a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000011
> [   30.910705] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7570b59f73
> [   30.911297] RDX: 0000000000001000 RSI: 00000000006c1000 RDI: 0000000000000003
> [   30.911875] RBP: 00007fffd34cea60 R08: 0000000000000000 R09: 0000000000000000
> [   30.912473] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
> [   30.913062] R13: 0000000000020000 R14: 0000000000000000 R15: 0000000000000000
> [   30.913645] Code: e1 48 09 c1 48 85 ca 0f 85 82 02 00 00 0f b7 43 18 66 83 f8 03 0f 84 fb 01 00 00 66 83 f8 04 74 35 66 83 f8 01 0f 84 07 02 00 00 <0f> ff 48 c7 c0 fb ff ff ff 48 8b 4d d0 65 48 33 0c 25 28 00 00
> [   30.915181] ---[ end trace 82f9af72bfb35f21 ]---
> 
> Thanks,
> Eryu
> 
> > +status=$?
> > +exit
> > diff --git a/tests/generic/445.out b/tests/generic/445.out
> > new file mode 100644
> > index 0000000..44e55d2
> > --- /dev/null
> > +++ b/tests/generic/445.out
> > @@ -0,0 +1,2 @@
> > +QA output created by 445
> > +Silence is golden
> > diff --git a/tests/generic/group b/tests/generic/group
> > index ced111c..39991b1 100644
> > --- a/tests/generic/group
> > +++ b/tests/generic/group
> > @@ -447,3 +447,4 @@
> >  442 blockdev
> >  443 auto quick rw
> >  444 auto quick acl
> > +445 auto quick dangerous
> > -- 
> > 1.8.3.1
> > 
> > 
> > 
> --
> To unsubscribe from this list: send the line "unsubscribe fstests" in
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