diff mbox

[v2] btrfs/154: test for device dynamic rescan

Message ID 20171115030515.19922-1-anand.jain@oracle.com (mailing list archive)
State New, archived
Headers show

Commit Message

Anand Jain Nov. 15, 2017, 3:05 a.m. UTC 
Make sure missing device is included in the alloc list when it is
scanned on a mounted FS.

This test case needs btrfs kernel patch which is in the ML
  [PATCH] btrfs: handle dynamically reappearing missing device
Without the kernel patch, the test will run, but reports as
failed, as the device scanned won't appear in the alloc_list.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
v2: Fixed review comments.
 tests/btrfs/154     | 186 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 tests/btrfs/154.out |  10 +++
 tests/btrfs/group   |   1 +
 3 files changed, 197 insertions(+)
 create mode 100755 tests/btrfs/154
 create mode 100644 tests/btrfs/154.out

Comments

Eryu Guan Nov. 15, 2017, 6:47 a.m. UTC | #1 
On Wed, Nov 15, 2017 at 11:05:15AM +0800, Anand Jain wrote:
> Make sure missing device is included in the alloc list when it is
> scanned on a mounted FS.
> 
> This test case needs btrfs kernel patch which is in the ML
>   [PATCH] btrfs: handle dynamically reappearing missing device
> Without the kernel patch, the test will run, but reports as
> failed, as the device scanned won't appear in the alloc_list.
> 
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> ---
> v2: Fixed review comments.
>  tests/btrfs/154     | 186 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  tests/btrfs/154.out |  10 +++
>  tests/btrfs/group   |   1 +
>  3 files changed, 197 insertions(+)
>  create mode 100755 tests/btrfs/154
>  create mode 100644 tests/btrfs/154.out
> 
> diff --git a/tests/btrfs/154 b/tests/btrfs/154
> new file mode 100755
> index 000000000000..73a185157389
> --- /dev/null
> +++ b/tests/btrfs/154
> @@ -0,0 +1,186 @@
> +#! /bin/bash
> +# FS QA Test 154
> +#
> +# Test for reappearing missing device functionality.
> +#   This test will fail without the btrfs kernel patch
> +#   [PATCH] btrfs: handle dynamically reappearing missing device
> +#
> +#---------------------------------------------------------------------
> +# Copyright (c) 2017 Oracle.  All Rights Reserved.
> +# Author: Anand Jain <anand.jain@oracle.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()
> +{
> +	cd /
> +	rm -f $tmp.*
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/filter
> +. ./common/module
> +
> +# remove previous $seqres.full before test
> +rm -f $seqres.full
> +
> +# real QA test starts here
> +
> +_supported_fs btrfs
> +_supported_os Linux
> +_require_scratch_dev_pool 2
> +_require_loadable_fs_module "btrfs"
> +
> +_scratch_dev_pool_get 2
> +
> +DEV1=`echo $SCRATCH_DEV_POOL | awk '{print $1}'`
> +DEV2=`echo $SCRATCH_DEV_POOL | awk '{print $2}'`
> +
> +echo DEV1=$DEV1 >> $seqres.full
> +echo DEV2=$DEV2 >> $seqres.full
> +
> +# Balance won't be successful if filled too much
> +DEV1_SZ=`blockdev --getsize64 $DEV1`
> +DEV2_SZ=`blockdev --getsize64 $DEV2`
> +
> +# get min
> +MAX_FS_SZ=`echo -e "$DEV1_SZ\n$DEV2_SZ" | sort | head -1`
> +# Need disks with more than 2G
> +if [ $MAX_FS_SZ -lt 2000000000 ]; then
> +	_scratch_dev_pool_put
> +	_notrun "Smallest dev size $MAX_FS_SZ, Need at least 2G"
> +fi
> +
> +MAX_FS_SZ=100000000
> +bs="1M"
> +COUNT=$(($MAX_FS_SZ / 1000000))
> +CHECKPOINT1=0
> +CHECKPOINT2=0
> +
> +setup()
> +{
> +	echo >> $seqres.full
> +	echo "MAX_FS_SZ=$MAX_FS_SZ COUNT=$COUNT" >> $seqres.full
> +	echo "setup"
> +	echo "-----setup-----" >> $seqres.full
> +	_scratch_pool_mkfs "-mraid1 -draid1" >> $seqres.full 2>&1
> +	_scratch_mount >> $seqres.full 2>&1
> +	dd if=/dev/urandom of="$SCRATCH_MNT"/tf bs=$bs count=1 \
> +					>>$seqres.full 2>&1
> +	_run_btrfs_util_prog filesystem show -m ${SCRATCH_MNT}
> +	_run_btrfs_util_prog filesystem df $SCRATCH_MNT
> +	COUNT=$(( $COUNT - 1 ))
> +	echo "unmount" >> $seqres.full
> +	_scratch_unmount
> +}
> +
> +degrade_mount_write()
> +{
> +	echo >> $seqres.full
> +	echo "--degraded mount: max_fs_sz $max_fs_sz bytes--" >> $seqres.full
> +	echo
> +	echo "degraded mount"
> +
> +	echo "clean btrfs ko" >> $seqres.full
> +	# un-scan the btrfs devices
> +	_reload_fs_module "btrfs"
> +	_mount -o degraded $DEV1 $SCRATCH_MNT >>$seqres.full 2>&1
> +	cnt=$(( $COUNT/10 ))
> +	dd if=/dev/urandom of="$SCRATCH_MNT"/tf1 bs=$bs count=$cnt \
> +					>>$seqres.full 2>&1
> +	COUNT=$(( $COUNT - $cnt ))
> +	_run_btrfs_util_prog filesystem show -m $SCRATCH_MNT
> +	_run_btrfs_util_prog filesystem df $SCRATCH_MNT
> +	CHECKPOINT1=`md5sum $SCRATCH_MNT/tf1`
> +	echo $SCRATCH_MNT/tf1:$CHECKPOINT1 >> $seqres.full
> +}
> +
> +scan_missing_dev_and_write()
> +{
> +	echo >> $seqres.full
> +	echo "--scan missing $DEV2--" >> $seqres.full
> +	echo
> +	echo "scan missing dev and write"
> +
> +	_run_btrfs_util_prog device scan $DEV2
> +
> +	echo >> $seqres.full
> +
> +	_run_btrfs_util_prog filesystem show -m ${SCRATCH_MNT}
> +	_run_btrfs_util_prog filesystem df ${SCRATCH_MNT}
> +
> +	dd if=/dev/urandom of="$SCRATCH_MNT"/tf2 bs=$bs count=$COUNT \
> +						>>$seqres.full 2>&1
> +	CHECKPOINT2=`md5sum $SCRATCH_MNT/tf2`
> +	echo $SCRATCH_MNT/tf2:$CHECKPOINT2 >> $seqres.full
> +}
> +
> +balance_convert()
> +{
> +	echo >> $seqres.full
> +	echo "----- run balance -----" >> $seqres.full
> +	echo
> +	echo "run balance"
> +
> +	_run_btrfs_util_prog balance start --full-balance -dconvert=raid1 \
> +				-mconvert=raid1 ${SCRATCH_MNT}
> +}
> +
> +verify()
> +{
> +	echo >> $seqres.full
> +	echo "--mount reconstructed dev only and check md5sum--" >> $seqres.full
> +	echo
> +	echo "mount reconstructed dev only and check md5sum"
> +	echo "unmount" >> $seqres.full
> +
> +	_scratch_unmount
> +	_reload_fs_module "btrfs"
> +	_mount -o degraded $DEV2 $SCRATCH_MNT >>$seqres.full 2>&1
> +	verify_checkpoint1=`md5sum $SCRATCH_MNT/tf1`
> +	verify_checkpoint2=`md5sum $SCRATCH_MNT/tf2`
> +
> +	if [ "$verify_checkpoint1" != "$CHECKPOINT1" ]; then
> +		echo "checkpoint1 on reappeared disk does not match after balance"
> +	fi
> +
> +	if [ "$verify_checkpoint2" != "$CHECKPOINT2" ]; then
> +		echo "checkpoint2 on reappeared disk does not match after balance"
> +	fi
> +}
> +
> +setup
> +degrade_mount_write
> +scan_missing_dev_and_write
> +balance_convert
> +verify
> +
> +$UMOUNT_PROG $DEV2
> +_scratch_dev_pool_put
> +_test_mount

This _test_mount is not needed either, and it breaks test now as

   +mount: /dev/sdc1 is already mounted or /sdc1 busy
   +       /dev/sdc1 is already mounted on /sdc1

I'll fix it on commit.

Thanks,
Eryu

> +
> +status=0
> +exit
> diff --git a/tests/btrfs/154.out b/tests/btrfs/154.out
> new file mode 100644
> index 000000000000..4a4939d448aa
> --- /dev/null
> +++ b/tests/btrfs/154.out
> @@ -0,0 +1,10 @@
> +QA output created by 154
> +setup
> +
> +degraded mount
> +
> +scan missing dev and write
> +
> +run balance
> +
> +mount reconstructed dev only and check md5sum
> diff --git a/tests/btrfs/group b/tests/btrfs/group
> index 15c2ecbf553c..c98cf823224e 100644
> --- a/tests/btrfs/group
> +++ b/tests/btrfs/group
> @@ -156,3 +156,4 @@
>  151 auto quick
>  152 auto quick metadata qgroup send
>  153 auto quick qgroup
> +154 auto quick
> -- 
> 2.13.1
> 
> --
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Anand Jain Nov. 15, 2017, 10:13 a.m. UTC | #2 
On 11/15/2017 02:47 PM, Eryu Guan wrote:
> On Wed, Nov 15, 2017 at 11:05:15AM +0800, Anand Jain wrote:
>> Make sure missing device is included in the alloc list when it is
>> scanned on a mounted FS.
>>
>> This test case needs btrfs kernel patch which is in the ML
>>    [PATCH] btrfs: handle dynamically reappearing missing device
>> Without the kernel patch, the test will run, but reports as
>> failed, as the device scanned won't appear in the alloc_list.
>>
>> Signed-off-by: Anand Jain <anand.jain@oracle.com>
>> ---
>> v2: Fixed review comments.
>>   tests/btrfs/154     | 186 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>>   tests/btrfs/154.out |  10 +++
>>   tests/btrfs/group   |   1 +
>>   3 files changed, 197 insertions(+)
>>   create mode 100755 tests/btrfs/154
>>   create mode 100644 tests/btrfs/154.out
>>
>> diff --git a/tests/btrfs/154 b/tests/btrfs/154
>> new file mode 100755
>> index 000000000000..73a185157389
>> --- /dev/null
>> +++ b/tests/btrfs/154
>> @@ -0,0 +1,186 @@
>> +#! /bin/bash
>> +# FS QA Test 154
>> +#
>> +# Test for reappearing missing device functionality.
>> +#   This test will fail without the btrfs kernel patch
>> +#   [PATCH] btrfs: handle dynamically reappearing missing device
>> +#
>> +#---------------------------------------------------------------------
>> +# Copyright (c) 2017 Oracle.  All Rights Reserved.
>> +# Author: Anand Jain <anand.jain@oracle.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()
>> +{
>> +	cd /
>> +	rm -f $tmp.*
>> +}
>> +
>> +# get standard environment, filters and checks
>> +. ./common/rc
>> +. ./common/filter
>> +. ./common/module
>> +
>> +# remove previous $seqres.full before test
>> +rm -f $seqres.full
>> +
>> +# real QA test starts here
>> +
>> +_supported_fs btrfs
>> +_supported_os Linux
>> +_require_scratch_dev_pool 2
>> +_require_loadable_fs_module "btrfs"
>> +
>> +_scratch_dev_pool_get 2
>> +
>> +DEV1=`echo $SCRATCH_DEV_POOL | awk '{print $1}'`
>> +DEV2=`echo $SCRATCH_DEV_POOL | awk '{print $2}'`
>> +
>> +echo DEV1=$DEV1 >> $seqres.full
>> +echo DEV2=$DEV2 >> $seqres.full
>> +
>> +# Balance won't be successful if filled too much
>> +DEV1_SZ=`blockdev --getsize64 $DEV1`
>> +DEV2_SZ=`blockdev --getsize64 $DEV2`
>> +
>> +# get min
>> +MAX_FS_SZ=`echo -e "$DEV1_SZ\n$DEV2_SZ" | sort | head -1`
>> +# Need disks with more than 2G
>> +if [ $MAX_FS_SZ -lt 2000000000 ]; then
>> +	_scratch_dev_pool_put
>> +	_notrun "Smallest dev size $MAX_FS_SZ, Need at least 2G"
>> +fi
>> +
>> +MAX_FS_SZ=100000000
>> +bs="1M"
>> +COUNT=$(($MAX_FS_SZ / 1000000))
>> +CHECKPOINT1=0
>> +CHECKPOINT2=0
>> +
>> +setup()
>> +{
>> +	echo >> $seqres.full
>> +	echo "MAX_FS_SZ=$MAX_FS_SZ COUNT=$COUNT" >> $seqres.full
>> +	echo "setup"
>> +	echo "-----setup-----" >> $seqres.full
>> +	_scratch_pool_mkfs "-mraid1 -draid1" >> $seqres.full 2>&1
>> +	_scratch_mount >> $seqres.full 2>&1
>> +	dd if=/dev/urandom of="$SCRATCH_MNT"/tf bs=$bs count=1 \
>> +					>>$seqres.full 2>&1
>> +	_run_btrfs_util_prog filesystem show -m ${SCRATCH_MNT}
>> +	_run_btrfs_util_prog filesystem df $SCRATCH_MNT
>> +	COUNT=$(( $COUNT - 1 ))
>> +	echo "unmount" >> $seqres.full
>> +	_scratch_unmount
>> +}
>> +
>> +degrade_mount_write()
>> +{
>> +	echo >> $seqres.full
>> +	echo "--degraded mount: max_fs_sz $max_fs_sz bytes--" >> $seqres.full
>> +	echo
>> +	echo "degraded mount"
>> +
>> +	echo "clean btrfs ko" >> $seqres.full
>> +	# un-scan the btrfs devices
>> +	_reload_fs_module "btrfs"
>> +	_mount -o degraded $DEV1 $SCRATCH_MNT >>$seqres.full 2>&1
>> +	cnt=$(( $COUNT/10 ))
>> +	dd if=/dev/urandom of="$SCRATCH_MNT"/tf1 bs=$bs count=$cnt \
>> +					>>$seqres.full 2>&1
>> +	COUNT=$(( $COUNT - $cnt ))
>> +	_run_btrfs_util_prog filesystem show -m $SCRATCH_MNT
>> +	_run_btrfs_util_prog filesystem df $SCRATCH_MNT
>> +	CHECKPOINT1=`md5sum $SCRATCH_MNT/tf1`
>> +	echo $SCRATCH_MNT/tf1:$CHECKPOINT1 >> $seqres.full
>> +}
>> +
>> +scan_missing_dev_and_write()
>> +{
>> +	echo >> $seqres.full
>> +	echo "--scan missing $DEV2--" >> $seqres.full
>> +	echo
>> +	echo "scan missing dev and write"
>> +
>> +	_run_btrfs_util_prog device scan $DEV2
>> +
>> +	echo >> $seqres.full
>> +
>> +	_run_btrfs_util_prog filesystem show -m ${SCRATCH_MNT}
>> +	_run_btrfs_util_prog filesystem df ${SCRATCH_MNT}
>> +
>> +	dd if=/dev/urandom of="$SCRATCH_MNT"/tf2 bs=$bs count=$COUNT \
>> +						>>$seqres.full 2>&1
>> +	CHECKPOINT2=`md5sum $SCRATCH_MNT/tf2`
>> +	echo $SCRATCH_MNT/tf2:$CHECKPOINT2 >> $seqres.full
>> +}
>> +
>> +balance_convert()
>> +{
>> +	echo >> $seqres.full
>> +	echo "----- run balance -----" >> $seqres.full
>> +	echo
>> +	echo "run balance"
>> +
>> +	_run_btrfs_util_prog balance start --full-balance -dconvert=raid1 \
>> +				-mconvert=raid1 ${SCRATCH_MNT}
>> +}
>> +
>> +verify()
>> +{
>> +	echo >> $seqres.full
>> +	echo "--mount reconstructed dev only and check md5sum--" >> $seqres.full
>> +	echo
>> +	echo "mount reconstructed dev only and check md5sum"
>> +	echo "unmount" >> $seqres.full
>> +
>> +	_scratch_unmount
>> +	_reload_fs_module "btrfs"
>> +	_mount -o degraded $DEV2 $SCRATCH_MNT >>$seqres.full 2>&1
>> +	verify_checkpoint1=`md5sum $SCRATCH_MNT/tf1`
>> +	verify_checkpoint2=`md5sum $SCRATCH_MNT/tf2`
>> +
>> +	if [ "$verify_checkpoint1" != "$CHECKPOINT1" ]; then
>> +		echo "checkpoint1 on reappeared disk does not match after balance"
>> +	fi
>> +
>> +	if [ "$verify_checkpoint2" != "$CHECKPOINT2" ]; then
>> +		echo "checkpoint2 on reappeared disk does not match after balance"
>> +	fi
>> +}
>> +
>> +setup
>> +degrade_mount_write
>> +scan_missing_dev_and_write
>> +balance_convert
>> +verify
>> +
>> +$UMOUNT_PROG $DEV2
>> +_scratch_dev_pool_put
>> +_test_mount
> 
> This _test_mount is not needed either, and it breaks test now as
> 
>     +mount: /dev/sdc1 is already mounted or /sdc1 busy
>     +       /dev/sdc1 is already mounted on /sdc1
> 
> I'll fix it on commit.

  oops. I just verified _reload_fs_module() and missed to remove
  _test_mount here. Thanks for fixing Eryu.

-Anand

> Thanks,
> Eryu
> 
>> +
>> +status=0
>> +exit
>> diff --git a/tests/btrfs/154.out b/tests/btrfs/154.out
>> new file mode 100644
>> index 000000000000..4a4939d448aa
>> --- /dev/null
>> +++ b/tests/btrfs/154.out
>> @@ -0,0 +1,10 @@
>> +QA output created by 154
>> +setup
>> +
>> +degraded mount
>> +
>> +scan missing dev and write
>> +
>> +run balance
>> +
>> +mount reconstructed dev only and check md5sum
>> diff --git a/tests/btrfs/group b/tests/btrfs/group
>> index 15c2ecbf553c..c98cf823224e 100644
>> --- a/tests/btrfs/group
>> +++ b/tests/btrfs/group
>> @@ -156,3 +156,4 @@
>>   151 auto quick
>>   152 auto quick metadata qgroup send
>>   153 auto quick qgroup
>> +154 auto quick
>> -- 
>> 2.13.1
>>
>> --
>> 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
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
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diff mbox

Patch

diff --git a/tests/btrfs/154 b/tests/btrfs/154
new file mode 100755
index 000000000000..73a185157389
--- /dev/null
+++ b/tests/btrfs/154
@@ -0,0 +1,186 @@ 
+#! /bin/bash
+# FS QA Test 154
+#
+# Test for reappearing missing device functionality.
+#   This test will fail without the btrfs kernel patch
+#   [PATCH] btrfs: handle dynamically reappearing missing device
+#
+#---------------------------------------------------------------------
+# Copyright (c) 2017 Oracle.  All Rights Reserved.
+# Author: Anand Jain <anand.jain@oracle.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()
+{
+	cd /
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+. ./common/module
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+
+_supported_fs btrfs
+_supported_os Linux
+_require_scratch_dev_pool 2
+_require_loadable_fs_module "btrfs"
+
+_scratch_dev_pool_get 2
+
+DEV1=`echo $SCRATCH_DEV_POOL | awk '{print $1}'`
+DEV2=`echo $SCRATCH_DEV_POOL | awk '{print $2}'`
+
+echo DEV1=$DEV1 >> $seqres.full
+echo DEV2=$DEV2 >> $seqres.full
+
+# Balance won't be successful if filled too much
+DEV1_SZ=`blockdev --getsize64 $DEV1`
+DEV2_SZ=`blockdev --getsize64 $DEV2`
+
+# get min
+MAX_FS_SZ=`echo -e "$DEV1_SZ\n$DEV2_SZ" | sort | head -1`
+# Need disks with more than 2G
+if [ $MAX_FS_SZ -lt 2000000000 ]; then
+	_scratch_dev_pool_put
+	_notrun "Smallest dev size $MAX_FS_SZ, Need at least 2G"
+fi
+
+MAX_FS_SZ=100000000
+bs="1M"
+COUNT=$(($MAX_FS_SZ / 1000000))
+CHECKPOINT1=0
+CHECKPOINT2=0
+
+setup()
+{
+	echo >> $seqres.full
+	echo "MAX_FS_SZ=$MAX_FS_SZ COUNT=$COUNT" >> $seqres.full
+	echo "setup"
+	echo "-----setup-----" >> $seqres.full
+	_scratch_pool_mkfs "-mraid1 -draid1" >> $seqres.full 2>&1
+	_scratch_mount >> $seqres.full 2>&1
+	dd if=/dev/urandom of="$SCRATCH_MNT"/tf bs=$bs count=1 \
+					>>$seqres.full 2>&1
+	_run_btrfs_util_prog filesystem show -m ${SCRATCH_MNT}
+	_run_btrfs_util_prog filesystem df $SCRATCH_MNT
+	COUNT=$(( $COUNT - 1 ))
+	echo "unmount" >> $seqres.full
+	_scratch_unmount
+}
+
+degrade_mount_write()
+{
+	echo >> $seqres.full
+	echo "--degraded mount: max_fs_sz $max_fs_sz bytes--" >> $seqres.full
+	echo
+	echo "degraded mount"
+
+	echo "clean btrfs ko" >> $seqres.full
+	# un-scan the btrfs devices
+	_reload_fs_module "btrfs"
+	_mount -o degraded $DEV1 $SCRATCH_MNT >>$seqres.full 2>&1
+	cnt=$(( $COUNT/10 ))
+	dd if=/dev/urandom of="$SCRATCH_MNT"/tf1 bs=$bs count=$cnt \
+					>>$seqres.full 2>&1
+	COUNT=$(( $COUNT - $cnt ))
+	_run_btrfs_util_prog filesystem show -m $SCRATCH_MNT
+	_run_btrfs_util_prog filesystem df $SCRATCH_MNT
+	CHECKPOINT1=`md5sum $SCRATCH_MNT/tf1`
+	echo $SCRATCH_MNT/tf1:$CHECKPOINT1 >> $seqres.full
+}
+
+scan_missing_dev_and_write()
+{
+	echo >> $seqres.full
+	echo "--scan missing $DEV2--" >> $seqres.full
+	echo
+	echo "scan missing dev and write"
+
+	_run_btrfs_util_prog device scan $DEV2
+
+	echo >> $seqres.full
+
+	_run_btrfs_util_prog filesystem show -m ${SCRATCH_MNT}
+	_run_btrfs_util_prog filesystem df ${SCRATCH_MNT}
+
+	dd if=/dev/urandom of="$SCRATCH_MNT"/tf2 bs=$bs count=$COUNT \
+						>>$seqres.full 2>&1
+	CHECKPOINT2=`md5sum $SCRATCH_MNT/tf2`
+	echo $SCRATCH_MNT/tf2:$CHECKPOINT2 >> $seqres.full
+}
+
+balance_convert()
+{
+	echo >> $seqres.full
+	echo "----- run balance -----" >> $seqres.full
+	echo
+	echo "run balance"
+
+	_run_btrfs_util_prog balance start --full-balance -dconvert=raid1 \
+				-mconvert=raid1 ${SCRATCH_MNT}
+}
+
+verify()
+{
+	echo >> $seqres.full
+	echo "--mount reconstructed dev only and check md5sum--" >> $seqres.full
+	echo
+	echo "mount reconstructed dev only and check md5sum"
+	echo "unmount" >> $seqres.full
+
+	_scratch_unmount
+	_reload_fs_module "btrfs"
+	_mount -o degraded $DEV2 $SCRATCH_MNT >>$seqres.full 2>&1
+	verify_checkpoint1=`md5sum $SCRATCH_MNT/tf1`
+	verify_checkpoint2=`md5sum $SCRATCH_MNT/tf2`
+
+	if [ "$verify_checkpoint1" != "$CHECKPOINT1" ]; then
+		echo "checkpoint1 on reappeared disk does not match after balance"
+	fi
+
+	if [ "$verify_checkpoint2" != "$CHECKPOINT2" ]; then
+		echo "checkpoint2 on reappeared disk does not match after balance"
+	fi
+}
+
+setup
+degrade_mount_write
+scan_missing_dev_and_write
+balance_convert
+verify
+
+$UMOUNT_PROG $DEV2
+_scratch_dev_pool_put
+_test_mount
+
+status=0
+exit
diff --git a/tests/btrfs/154.out b/tests/btrfs/154.out
new file mode 100644
index 000000000000..4a4939d448aa
--- /dev/null
+++ b/tests/btrfs/154.out
@@ -0,0 +1,10 @@ 
+QA output created by 154
+setup
+
+degraded mount
+
+scan missing dev and write
+
+run balance
+
+mount reconstructed dev only and check md5sum
diff --git a/tests/btrfs/group b/tests/btrfs/group
index 15c2ecbf553c..c98cf823224e 100644
--- a/tests/btrfs/group
+++ b/tests/btrfs/group
@@ -156,3 +156,4 @@ 
 151 auto quick
 152 auto quick metadata qgroup send
 153 auto quick qgroup
+154 auto quick