diff mbox series

[v3] fstests: btrfs: zoned: verify RAID conversion with write pointer mismatch

Message ID 05f928908a7949fb1787680176840b5ab23fde0b.1742303818.git.jth@kernel.org (mailing list archive)
State New
Headers show
Series [v3] fstests: btrfs: zoned: verify RAID conversion with write pointer mismatch | expand

Commit Message

Johannes Thumshirn March 18, 2025, 1:17 p.m. UTC 
From: Johannes Thumshirn <johannes.thumshirn@wdc.com>

Recently we had a bug report about a kernel crash that happened when the
user was converting a filesystem to use RAID1 for metadata, but for some
reason the device's write pointers got out of sync.

Test this scenario by manually injecting de-synchronized write pointer
positions and then running conversion to a metadata RAID1 filesystem.

In the testcase also repair the broken filesystem and check if both system
and metadata block groups are back to the default 'DUP' profile
afterwards.

Link: https://lore.kernel.org/linux-btrfs/CAB_b4sBhDe3tscz=duVyhc9hNE+gu=B8CrgLO152uMyanR8BEA@mail.gmail.com/
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>

---
Changes to v2:
- Filter SCRATCH_MNT in golden output
Changes to v1:
- Add test description
- Don't redirect stderr to $seqres.full
- Use xfs_io instead of dd
- Use $SCRATCH_MNT instead of hardcoded mount path
- Check that 1st balance command actually fails as it's supposed to
---
 tests/btrfs/329     | 62 +++++++++++++++++++++++++++++++++++++++++++++
 tests/btrfs/329.out |  7 +++++
 2 files changed, 69 insertions(+)
 create mode 100755 tests/btrfs/329
 create mode 100644 tests/btrfs/329.out

Comments

Filipe Manana March 18, 2025, 3:14 p.m. UTC | #1 
On Tue, Mar 18, 2025 at 1:17 PM Johannes Thumshirn <jth@kernel.org> wrote:
>
> From: Johannes Thumshirn <johannes.thumshirn@wdc.com>
>
> Recently we had a bug report about a kernel crash that happened when the
> user was converting a filesystem to use RAID1 for metadata, but for some
> reason the device's write pointers got out of sync.
>
> Test this scenario by manually injecting de-synchronized write pointer
> positions and then running conversion to a metadata RAID1 filesystem.
>
> In the testcase also repair the broken filesystem and check if both system
> and metadata block groups are back to the default 'DUP' profile
> afterwards.
>
> Link: https://lore.kernel.org/linux-btrfs/CAB_b4sBhDe3tscz=duVyhc9hNE+gu=B8CrgLO152uMyanR8BEA@mail.gmail.com/
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>

Reviewed-by: Filipe Manana <fdmanana@suse.com>

Looks good now, thanks.

>
> ---
> Changes to v2:
> - Filter SCRATCH_MNT in golden output
> Changes to v1:
> - Add test description
> - Don't redirect stderr to $seqres.full
> - Use xfs_io instead of dd
> - Use $SCRATCH_MNT instead of hardcoded mount path
> - Check that 1st balance command actually fails as it's supposed to
> ---
>  tests/btrfs/329     | 62 +++++++++++++++++++++++++++++++++++++++++++++
>  tests/btrfs/329.out |  7 +++++
>  2 files changed, 69 insertions(+)
>  create mode 100755 tests/btrfs/329
>  create mode 100644 tests/btrfs/329.out
>
> diff --git a/tests/btrfs/329 b/tests/btrfs/329
> new file mode 100755
> index 000000000000..5496866ac325
> --- /dev/null
> +++ b/tests/btrfs/329
> @@ -0,0 +1,62 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2025 Western Digital Corporation.  All Rights Reserved.
> +#
> +# FS QA Test 329
> +#
> +# Regression test for a kernel crash when converting a zoned BTRFS from
> +# metadata DUP to RAID1 and one of the devices has a non 0 write pointer
> +# position in the target zone.
> +#
> +. ./common/preamble
> +_begin_fstest zone quick volume
> +
> +. ./common/filter
> +
> +_fixed_by_kernel_commit XXXXXXXXXXXX \
> +       "btrfs: zoned: return EIO on RAID1 block group write pointer mismatch"
> +
> +_require_scratch_dev_pool 2
> +declare -a devs="( $SCRATCH_DEV_POOL )"
> +_require_zoned_device ${devs[0]}
> +_require_zoned_device ${devs[1]}
> +_require_command "$BLKZONE_PROG" blkzone
> +
> +_scratch_mkfs >> $seqres.full 2>&1 || _fail "mkfs failed"
> +_scratch_mount
> +
> +# Write some data to the FS to dirty it
> +$XFS_IO_PROG -fc "pwrite 0 128M" $SCRATCH_MNT/test | _filter_xfs_io
> +
> +# Add device two to the FS
> +$BTRFS_UTIL_PROG device add ${devs[1]} $SCRATCH_MNT >> $seqres.full
> +
> +# Move write pointers of all empty zones by 4k to simulate write pointer
> +# mismatch.
> +zones=$($BLKZONE_PROG report ${devs[1]} | $AWK_PROG '/em/ { print $2 }' |\
> +       sed 's/,//')
> +for zone in $zones;
> +do
> +       # We have to ignore the output here, as a) we don't know the number of
> +       # zones that have dirtied and b) if we run over the maximal number of
> +       # active zones, xfs_io will output errors, both we don't care.
> +       $XFS_IO_PROG -fdc "pwrite $(($zone << 9)) 4096" ${devs[1]} > /dev/null 2>&1
> +done
> +
> +# expected to fail
> +$BTRFS_UTIL_PROG balance start -mconvert=raid1 $SCRATCH_MNT 2>&1 |\
> +       _filter_scratch
> +
> +_scratch_unmount
> +
> +$MOUNT_PROG -t btrfs -odegraded ${devs[0]} $SCRATCH_MNT
> +
> +$BTRFS_UTIL_PROG device remove --force missing $SCRATCH_MNT >> $seqres.full
> +$BTRFS_UTIL_PROG balance start --full-balance $SCRATCH_MNT >> $seqres.full
> +
> +# Check that both System and Metadata are back to the DUP profile
> +$BTRFS_UTIL_PROG filesystem df $SCRATCH_MNT |\
> +       grep -o -e "System, DUP" -e "Metadata, DUP"
> +
> +status=0
> +exit
> diff --git a/tests/btrfs/329.out b/tests/btrfs/329.out
> new file mode 100644
> index 000000000000..e47a2a6ff04b
> --- /dev/null
> +++ b/tests/btrfs/329.out
> @@ -0,0 +1,7 @@
> +QA output created by 329
> +wrote 134217728/134217728 bytes at offset 0
> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> +ERROR: error during balancing 'SCRATCH_MNT': Input/output error
> +There may be more info in syslog - try dmesg | tail
> +System, DUP
> +Metadata, DUP
> --
> 2.43.0
>
>
Naohiro Aota March 19, 2025, 1:18 a.m. UTC | #2 
On Tue Mar 18, 2025 at 10:17 PM JST, Johannes Thumshirn wrote:
> From: Johannes Thumshirn <johannes.thumshirn@wdc.com>
>
> Recently we had a bug report about a kernel crash that happened when the
> user was converting a filesystem to use RAID1 for metadata, but for some
> reason the device's write pointers got out of sync.
>
> Test this scenario by manually injecting de-synchronized write pointer
> positions and then running conversion to a metadata RAID1 filesystem.
>
> In the testcase also repair the broken filesystem and check if both system
> and metadata block groups are back to the default 'DUP' profile
> afterwards.
>
> Link: https://lore.kernel.org/linux-btrfs/CAB_b4sBhDe3tscz=duVyhc9hNE+gu=B8CrgLO152uMyanR8BEA@mail.gmail.com/
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
>
> ---
> Changes to v2:
> - Filter SCRATCH_MNT in golden output
> Changes to v1:
> - Add test description
> - Don't redirect stderr to $seqres.full
> - Use xfs_io instead of dd
> - Use $SCRATCH_MNT instead of hardcoded mount path
> - Check that 1st balance command actually fails as it's supposed to
> ---
>  tests/btrfs/329     | 62 +++++++++++++++++++++++++++++++++++++++++++++
>  tests/btrfs/329.out |  7 +++++
>  2 files changed, 69 insertions(+)
>  create mode 100755 tests/btrfs/329
>  create mode 100644 tests/btrfs/329.out
>
> diff --git a/tests/btrfs/329 b/tests/btrfs/329
> new file mode 100755
> index 000000000000..5496866ac325
> --- /dev/null
> +++ b/tests/btrfs/329
> @@ -0,0 +1,62 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2025 Western Digital Corporation.  All Rights Reserved.
> +#
> +# FS QA Test 329
> +#
> +# Regression test for a kernel crash when converting a zoned BTRFS from
> +# metadata DUP to RAID1 and one of the devices has a non 0 write pointer
> +# position in the target zone.
> +#
> +. ./common/preamble
> +_begin_fstest zone quick volume
> +
> +. ./common/filter
> +
> +_fixed_by_kernel_commit XXXXXXXXXXXX \
> +	"btrfs: zoned: return EIO on RAID1 block group write pointer mismatch"
> +
> +_require_scratch_dev_pool 2
> +declare -a devs="( $SCRATCH_DEV_POOL )"
> +_require_zoned_device ${devs[0]}
> +_require_zoned_device ${devs[1]}
> +_require_command "$BLKZONE_PROG" blkzone
> +
> +_scratch_mkfs >> $seqres.full 2>&1 || _fail "mkfs failed"
> +_scratch_mount
> +
> +# Write some data to the FS to dirty it
> +$XFS_IO_PROG -fc "pwrite 0 128M" $SCRATCH_MNT/test | _filter_xfs_io
> +
> +# Add device two to the FS
> +$BTRFS_UTIL_PROG device add ${devs[1]} $SCRATCH_MNT >> $seqres.full
> +
> +# Move write pointers of all empty zones by 4k to simulate write pointer
> +# mismatch.
> +zones=$($BLKZONE_PROG report ${devs[1]} | $AWK_PROG '/em/ { print $2 }' |\
> +	sed 's/,//')

Can we limit the number of zones to work with, in case we run this test
on a huge device? I guess 2*(128M/4M)=64 would be enough.

> +for zone in $zones;
> +do
> +	# We have to ignore the output here, as a) we don't know the number of
> +	# zones that have dirtied and b) if we run over the maximal number of
> +	# active zones, xfs_io will output errors, both we don't care.
> +	$XFS_IO_PROG -fdc "pwrite $(($zone << 9)) 4096" ${devs[1]} > /dev/null 2>&1
> +done
> +
> +# expected to fail
> +$BTRFS_UTIL_PROG balance start -mconvert=raid1 $SCRATCH_MNT 2>&1 |\
> +	_filter_scratch
> +
> +_scratch_unmount
> +
> +$MOUNT_PROG -t btrfs -odegraded ${devs[0]} $SCRATCH_MNT
> +
> +$BTRFS_UTIL_PROG device remove --force missing $SCRATCH_MNT >> $seqres.full
> +$BTRFS_UTIL_PROG balance start --full-balance $SCRATCH_MNT >> $seqres.full
> +
> +# Check that both System and Metadata are back to the DUP profile
> +$BTRFS_UTIL_PROG filesystem df $SCRATCH_MNT |\
> +	grep -o -e "System, DUP" -e "Metadata, DUP"
> +
> +status=0
> +exit
> diff --git a/tests/btrfs/329.out b/tests/btrfs/329.out
> new file mode 100644
> index 000000000000..e47a2a6ff04b
> --- /dev/null
> +++ b/tests/btrfs/329.out
> @@ -0,0 +1,7 @@
> +QA output created by 329
> +wrote 134217728/134217728 bytes at offset 0
> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> +ERROR: error during balancing 'SCRATCH_MNT': Input/output error
> +There may be more info in syslog - try dmesg | tail
> +System, DUP
> +Metadata, DUP
Johannes Thumshirn March 19, 2025, 11:03 a.m. UTC | #3 
On 19.03.25 02:18, Naohiro Aota wrote:
> On Tue Mar 18, 2025 at 10:17 PM JST, Johannes Thumshirn wrote:
>> From: Johannes Thumshirn <johannes.thumshirn@wdc.com>
>>
>> Recently we had a bug report about a kernel crash that happened when the
>> user was converting a filesystem to use RAID1 for metadata, but for some
>> reason the device's write pointers got out of sync.
>>
>> Test this scenario by manually injecting de-synchronized write pointer
>> positions and then running conversion to a metadata RAID1 filesystem.
>>
>> In the testcase also repair the broken filesystem and check if both system
>> and metadata block groups are back to the default 'DUP' profile
>> afterwards.
>>
>> Link: https://lore.kernel.org/linux-btrfs/CAB_b4sBhDe3tscz=duVyhc9hNE+gu=B8CrgLO152uMyanR8BEA@mail.gmail.com/
>> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
>>
>> ---
>> Changes to v2:
>> - Filter SCRATCH_MNT in golden output
>> Changes to v1:
>> - Add test description
>> - Don't redirect stderr to $seqres.full
>> - Use xfs_io instead of dd
>> - Use $SCRATCH_MNT instead of hardcoded mount path
>> - Check that 1st balance command actually fails as it's supposed to
>> ---
>>   tests/btrfs/329     | 62 +++++++++++++++++++++++++++++++++++++++++++++
>>   tests/btrfs/329.out |  7 +++++
>>   2 files changed, 69 insertions(+)
>>   create mode 100755 tests/btrfs/329
>>   create mode 100644 tests/btrfs/329.out
>>
>> diff --git a/tests/btrfs/329 b/tests/btrfs/329
>> new file mode 100755
>> index 000000000000..5496866ac325
>> --- /dev/null
>> +++ b/tests/btrfs/329
>> @@ -0,0 +1,62 @@
>> +#! /bin/bash
>> +# SPDX-License-Identifier: GPL-2.0
>> +# Copyright (c) 2025 Western Digital Corporation.  All Rights Reserved.
>> +#
>> +# FS QA Test 329
>> +#
>> +# Regression test for a kernel crash when converting a zoned BTRFS from
>> +# metadata DUP to RAID1 and one of the devices has a non 0 write pointer
>> +# position in the target zone.
>> +#
>> +. ./common/preamble
>> +_begin_fstest zone quick volume
>> +
>> +. ./common/filter
>> +
>> +_fixed_by_kernel_commit XXXXXXXXXXXX \
>> +	"btrfs: zoned: return EIO on RAID1 block group write pointer mismatch"
>> +
>> +_require_scratch_dev_pool 2
>> +declare -a devs="( $SCRATCH_DEV_POOL )"
>> +_require_zoned_device ${devs[0]}
>> +_require_zoned_device ${devs[1]}
>> +_require_command "$BLKZONE_PROG" blkzone
>> +
>> +_scratch_mkfs >> $seqres.full 2>&1 || _fail "mkfs failed"
>> +_scratch_mount
>> +
>> +# Write some data to the FS to dirty it
>> +$XFS_IO_PROG -fc "pwrite 0 128M" $SCRATCH_MNT/test | _filter_xfs_io
>> +
>> +# Add device two to the FS
>> +$BTRFS_UTIL_PROG device add ${devs[1]} $SCRATCH_MNT >> $seqres.full
>> +
>> +# Move write pointers of all empty zones by 4k to simulate write pointer
>> +# mismatch.
>> +zones=$($BLKZONE_PROG report ${devs[1]} | $AWK_PROG '/em/ { print $2 }' |\
>> +	sed 's/,//')
> 
> Can we limit the number of zones to work with, in case we run this test
> on a huge device? I guess 2*(128M/4M)=64 would be enough.
> 

I.e. something like the following:

diff --git a/tests/btrfs/329 b/tests/btrfs/329
index 5496866ac325..24d34852db1f 100755
--- a/tests/btrfs/329
+++ b/tests/btrfs/329
@@ -33,8 +33,14 @@ $BTRFS_UTIL_PROG device add ${devs[1]} $SCRATCH_MNT >> $seqres.full

  # Move write pointers of all empty zones by 4k to simulate write pointer
  # mismatch.
+
+nzones=$($BLKZONE_PROG report ${devs[1]} | wc -l)
+if [ $nzones -gt 64 ]; then
+       nzones=64
+fi
+
  zones=$($BLKZONE_PROG report ${devs[1]} | $AWK_PROG '/em/ { print $2 }' |\
-       sed 's/,//')
+       sed 's/,//' | head -n $nzones)
  for zone in $zones;
  do

Yup this still triggers the bug on an unpatched kernel in my case and the
fix also fixes it.

So yes I'll update the testcase (I guess Filipe's R-b remains with this change).
Filipe Manana March 19, 2025, 11:07 a.m. UTC | #4 
On Wed, Mar 19, 2025 at 11:05 AM Johannes Thumshirn
<Johannes.Thumshirn@wdc.com> wrote:
>
> On 19.03.25 02:18, Naohiro Aota wrote:
> > On Tue Mar 18, 2025 at 10:17 PM JST, Johannes Thumshirn wrote:
> >> From: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> >>
> >> Recently we had a bug report about a kernel crash that happened when the
> >> user was converting a filesystem to use RAID1 for metadata, but for some
> >> reason the device's write pointers got out of sync.
> >>
> >> Test this scenario by manually injecting de-synchronized write pointer
> >> positions and then running conversion to a metadata RAID1 filesystem.
> >>
> >> In the testcase also repair the broken filesystem and check if both system
> >> and metadata block groups are back to the default 'DUP' profile
> >> afterwards.
> >>
> >> Link: https://lore.kernel.org/linux-btrfs/CAB_b4sBhDe3tscz=duVyhc9hNE+gu=B8CrgLO152uMyanR8BEA@mail.gmail.com/
> >> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> >>
> >> ---
> >> Changes to v2:
> >> - Filter SCRATCH_MNT in golden output
> >> Changes to v1:
> >> - Add test description
> >> - Don't redirect stderr to $seqres.full
> >> - Use xfs_io instead of dd
> >> - Use $SCRATCH_MNT instead of hardcoded mount path
> >> - Check that 1st balance command actually fails as it's supposed to
> >> ---
> >>   tests/btrfs/329     | 62 +++++++++++++++++++++++++++++++++++++++++++++
> >>   tests/btrfs/329.out |  7 +++++
> >>   2 files changed, 69 insertions(+)
> >>   create mode 100755 tests/btrfs/329
> >>   create mode 100644 tests/btrfs/329.out
> >>
> >> diff --git a/tests/btrfs/329 b/tests/btrfs/329
> >> new file mode 100755
> >> index 000000000000..5496866ac325
> >> --- /dev/null
> >> +++ b/tests/btrfs/329
> >> @@ -0,0 +1,62 @@
> >> +#! /bin/bash
> >> +# SPDX-License-Identifier: GPL-2.0
> >> +# Copyright (c) 2025 Western Digital Corporation.  All Rights Reserved.
> >> +#
> >> +# FS QA Test 329
> >> +#
> >> +# Regression test for a kernel crash when converting a zoned BTRFS from
> >> +# metadata DUP to RAID1 and one of the devices has a non 0 write pointer
> >> +# position in the target zone.
> >> +#
> >> +. ./common/preamble
> >> +_begin_fstest zone quick volume
> >> +
> >> +. ./common/filter
> >> +
> >> +_fixed_by_kernel_commit XXXXXXXXXXXX \
> >> +    "btrfs: zoned: return EIO on RAID1 block group write pointer mismatch"
> >> +
> >> +_require_scratch_dev_pool 2
> >> +declare -a devs="( $SCRATCH_DEV_POOL )"
> >> +_require_zoned_device ${devs[0]}
> >> +_require_zoned_device ${devs[1]}
> >> +_require_command "$BLKZONE_PROG" blkzone
> >> +
> >> +_scratch_mkfs >> $seqres.full 2>&1 || _fail "mkfs failed"
> >> +_scratch_mount
> >> +
> >> +# Write some data to the FS to dirty it
> >> +$XFS_IO_PROG -fc "pwrite 0 128M" $SCRATCH_MNT/test | _filter_xfs_io
> >> +
> >> +# Add device two to the FS
> >> +$BTRFS_UTIL_PROG device add ${devs[1]} $SCRATCH_MNT >> $seqres.full
> >> +
> >> +# Move write pointers of all empty zones by 4k to simulate write pointer
> >> +# mismatch.
> >> +zones=$($BLKZONE_PROG report ${devs[1]} | $AWK_PROG '/em/ { print $2 }' |\
> >> +    sed 's/,//')
> >
> > Can we limit the number of zones to work with, in case we run this test
> > on a huge device? I guess 2*(128M/4M)=64 would be enough.
> >
>
> I.e. something like the following:
>
> diff --git a/tests/btrfs/329 b/tests/btrfs/329
> index 5496866ac325..24d34852db1f 100755
> --- a/tests/btrfs/329
> +++ b/tests/btrfs/329
> @@ -33,8 +33,14 @@ $BTRFS_UTIL_PROG device add ${devs[1]} $SCRATCH_MNT >> $seqres.full
>
>   # Move write pointers of all empty zones by 4k to simulate write pointer
>   # mismatch.
> +
> +nzones=$($BLKZONE_PROG report ${devs[1]} | wc -l)
> +if [ $nzones -gt 64 ]; then
> +       nzones=64
> +fi
> +
>   zones=$($BLKZONE_PROG report ${devs[1]} | $AWK_PROG '/em/ { print $2 }' |\
> -       sed 's/,//')
> +       sed 's/,//' | head -n $nzones)
>   for zone in $zones;
>   do
>
> Yup this still triggers the bug on an unpatched kernel in my case and the
> fix also fixes it.
>
> So yes I'll update the testcase (I guess Filipe's R-b remains with this change).

Yes.

>
diff mbox series

Patch

diff --git a/tests/btrfs/329 b/tests/btrfs/329
new file mode 100755
index 000000000000..5496866ac325
--- /dev/null
+++ b/tests/btrfs/329
@@ -0,0 +1,62 @@ 
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2025 Western Digital Corporation.  All Rights Reserved.
+#
+# FS QA Test 329
+#
+# Regression test for a kernel crash when converting a zoned BTRFS from
+# metadata DUP to RAID1 and one of the devices has a non 0 write pointer
+# position in the target zone.
+#
+. ./common/preamble
+_begin_fstest zone quick volume
+
+. ./common/filter
+
+_fixed_by_kernel_commit XXXXXXXXXXXX \
+	"btrfs: zoned: return EIO on RAID1 block group write pointer mismatch"
+
+_require_scratch_dev_pool 2
+declare -a devs="( $SCRATCH_DEV_POOL )"
+_require_zoned_device ${devs[0]}
+_require_zoned_device ${devs[1]}
+_require_command "$BLKZONE_PROG" blkzone
+
+_scratch_mkfs >> $seqres.full 2>&1 || _fail "mkfs failed"
+_scratch_mount
+
+# Write some data to the FS to dirty it
+$XFS_IO_PROG -fc "pwrite 0 128M" $SCRATCH_MNT/test | _filter_xfs_io
+
+# Add device two to the FS
+$BTRFS_UTIL_PROG device add ${devs[1]} $SCRATCH_MNT >> $seqres.full
+
+# Move write pointers of all empty zones by 4k to simulate write pointer
+# mismatch.
+zones=$($BLKZONE_PROG report ${devs[1]} | $AWK_PROG '/em/ { print $2 }' |\
+	sed 's/,//')
+for zone in $zones;
+do
+	# We have to ignore the output here, as a) we don't know the number of
+	# zones that have dirtied and b) if we run over the maximal number of
+	# active zones, xfs_io will output errors, both we don't care.
+	$XFS_IO_PROG -fdc "pwrite $(($zone << 9)) 4096" ${devs[1]} > /dev/null 2>&1
+done
+
+# expected to fail
+$BTRFS_UTIL_PROG balance start -mconvert=raid1 $SCRATCH_MNT 2>&1 |\
+	_filter_scratch
+
+_scratch_unmount
+
+$MOUNT_PROG -t btrfs -odegraded ${devs[0]} $SCRATCH_MNT
+
+$BTRFS_UTIL_PROG device remove --force missing $SCRATCH_MNT >> $seqres.full
+$BTRFS_UTIL_PROG balance start --full-balance $SCRATCH_MNT >> $seqres.full
+
+# Check that both System and Metadata are back to the DUP profile
+$BTRFS_UTIL_PROG filesystem df $SCRATCH_MNT |\
+	grep -o -e "System, DUP" -e "Metadata, DUP"
+
+status=0
+exit
diff --git a/tests/btrfs/329.out b/tests/btrfs/329.out
new file mode 100644
index 000000000000..e47a2a6ff04b
--- /dev/null
+++ b/tests/btrfs/329.out
@@ -0,0 +1,7 @@ 
+QA output created by 329
+wrote 134217728/134217728 bytes at offset 0
+XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+ERROR: error during balancing 'SCRATCH_MNT': Input/output error
+There may be more info in syslog - try dmesg | tail
+System, DUP
+Metadata, DUP