fstests: btrfs: Check snapshot creation and deletion with dm-logwrites
diff mbox series

Message ID 20190814105544.18318-1-wqu@suse.com
State New
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  • fstests: btrfs: Check snapshot creation and deletion with dm-logwrites
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Commit Message

Qu Wenruo Aug. 14, 2019, 10:55 a.m. UTC
We have generic dm-logwrites with fsstress test case (generic/482), but
it doesn't cover fs specific operations like btrfs snapshot creation and
deletion.

Furthermore, that test is not heavy enough to bump btrfs tree height by
its short runtime.

And finally, btrfs check doesn't consider dirty log as an error, unlike
ext*/xfs, that's to say we don't need to mount the fs to replay the log,
but just run btrfs check on the fs is enough.

So introduce a similar test case but for btrfs only.

The test case will stress btrfs by:
- Using small nodesize to bump tree height
- Creating a base tree which is already high enough
- Trimming tree blocks to find possible trim bugs
- Calling snapshot creation and deletion along with fsstress

Also it includes certain workaround for btrfs:
- Use no-holes feature
  To avoid missing hole file extents.
  Although that behavior doesn't follow the on-disk format spec, it
  doesn't cause data loss. And will follow the new on-disk format spec
  of no-holes feature, so it's better to workaround it.

And an optimization for btrfs only:
- Use replay-log --fsck/--check command
  Since dm-log-writes records bios sequentially, there is no way to
  locate certain entry unless we iterate all entries.
  This is becoming a big performance penalty if we replay certain a
  range, check the fs, then re-execute replay-log to replay another
  range.

  We need to records the previous entry location, or we need to
  re-iterate all previous entries.

  Thankfully, replay-log has already addressed it by providing --fsck and
  --check command, thus we won't lose the replay status.

Please note, for fast storage (e.g. fast NVME or unsafe cache mode),
it's recommended to use log devices larger than 15G, or we can't record
the full log of just 30s fsstress run.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
For the log devices size problem, I have submitted dm-logwrites bio flag
filter support, to filter out data bios on the fly.

But that is not yet merged into kernel, thus we need a large log device
for short run.
---
 common/config               |   1 +
 common/dmlogwrites          |  28 ++++++++
 src/log-writes/replay-log.c |   2 +
 tests/btrfs/192             | 135 ++++++++++++++++++++++++++++++++++++
 tests/btrfs/192.out         |   2 +
 tests/btrfs/group           |   1 +
 6 files changed, 169 insertions(+)
 create mode 100755 tests/btrfs/192
 create mode 100644 tests/btrfs/192.out

Comments

Filipe Manana Aug. 16, 2019, 9:25 a.m. UTC | #1
On Wed, Aug 14, 2019 at 11:56 AM Qu Wenruo <wqu@suse.com> wrote:
>
> We have generic dm-logwrites with fsstress test case (generic/482), but
> it doesn't cover fs specific operations like btrfs snapshot creation and
> deletion.
>
> Furthermore, that test is not heavy enough to bump btrfs tree height by
> its short runtime.
>
> And finally, btrfs check doesn't consider dirty log as an error, unlike
> ext*/xfs, that's to say we don't need to mount the fs to replay the log,
> but just run btrfs check on the fs is enough.
>
> So introduce a similar test case but for btrfs only.
>
> The test case will stress btrfs by:
> - Using small nodesize to bump tree height
> - Creating a base tree which is already high enough
> - Trimming tree blocks to find possible trim bugs
> - Calling snapshot creation and deletion along with fsstress
>
> Also it includes certain workaround for btrfs:
> - Use no-holes feature
>   To avoid missing hole file extents.
>   Although that behavior doesn't follow the on-disk format spec, it
>   doesn't cause data loss. And will follow the new on-disk format spec
>   of no-holes feature, so it's better to workaround it.
>
> And an optimization for btrfs only:
> - Use replay-log --fsck/--check command
>   Since dm-log-writes records bios sequentially, there is no way to
>   locate certain entry unless we iterate all entries.
>   This is becoming a big performance penalty if we replay certain a
>   range, check the fs, then re-execute replay-log to replay another
>   range.
>
>   We need to records the previous entry location, or we need to
>   re-iterate all previous entries.
>
>   Thankfully, replay-log has already addressed it by providing --fsck and
>   --check command, thus we won't lose the replay status.
>
> Please note, for fast storage (e.g. fast NVME or unsafe cache mode),
> it's recommended to use log devices larger than 15G, or we can't record
> the full log of just 30s fsstress run.
>
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> ---
> For the log devices size problem, I have submitted dm-logwrites bio flag
> filter support, to filter out data bios on the fly.
>
> But that is not yet merged into kernel, thus we need a large log device
> for short run.
> ---
>  common/config               |   1 +
>  common/dmlogwrites          |  28 ++++++++
>  src/log-writes/replay-log.c |   2 +
>  tests/btrfs/192             | 135 ++++++++++++++++++++++++++++++++++++
>  tests/btrfs/192.out         |   2 +
>  tests/btrfs/group           |   1 +
>  6 files changed, 169 insertions(+)
>  create mode 100755 tests/btrfs/192
>  create mode 100644 tests/btrfs/192.out
>
> diff --git a/common/config b/common/config
> index bd64be62..4c86a492 100644
> --- a/common/config
> +++ b/common/config
> @@ -183,6 +183,7 @@ export LOGGER_PROG="$(type -P logger)"
>  export DBENCH_PROG="$(type -P dbench)"
>  export DMSETUP_PROG="$(type -P dmsetup)"
>  export WIPEFS_PROG="$(type -P wipefs)"
> +export BLKDISCARD_PROG="$(type -P blkdiscard)"
>  export DUMP_PROG="$(type -P dump)"
>  export RESTORE_PROG="$(type -P restore)"
>  export LVM_PROG="$(type -P lvm)"
> diff --git a/common/dmlogwrites b/common/dmlogwrites
> index ae2cbc6a..5eca7142 100644
> --- a/common/dmlogwrites
> +++ b/common/dmlogwrites
> @@ -175,3 +175,31 @@ _log_writes_replay_log_range()
>                 >> $seqres.full 2>&1
>         [ $? -ne 0 ] && _fail "replay failed"
>  }
> +
> +# Replay log range to specified entry
> +# Replay and check each fua/flush point.
> +# Since dm-log-writes records bio sequentially, even just replaying a range
> +# still needs to iterate all records before the end point.
> +# When number of records grows, it will be unacceptably slow, thus we need
> +# to use relay-log itself to trigger fsck, avoid unnecessary seek.
> +_log_writes_fast_replay_check()
> +{
> +       local check_point=$1
> +       local blkdev=$2
> +       local fsck_command
> +
> +       [ -z "$check_point" -o -z "$blkdev" ] && _fail \
> +       "check_point and blkdev must be specified for _log_writes_fast_replay_check"
> +
> +       # Check program must not treat dirty log as a problem.
> +       # So only btrfs can use this feature
> +       if [ $FSTYP = "btrfs" ]; then
> +               fsck_command="$BTRFS_PROG check $blkdev"
> +       else
> +               _notrun "fsck of $FSTYP may report false alert of dirty log"

"false alert of dirty log" gives the idea fsck thinks there's a dirty
log (named journal is most filesystems) when there isn't any.
Rephrasing that as something like "fsck of $FSTYP reports dirty
journal/log as error, skipping test" would be more clear.

> +       fi
> +       $here/src/log-writes/replay-log --log $LOGWRITES_DEV \"
> +               --replay $blkdev --check $check_point --fsck "$fsck_command" \
> +               >> $seqres.full 2>&1
> +       [ $? -ne 0 ] && _fail "fsck failed during replay"
> +}
> diff --git a/src/log-writes/replay-log.c b/src/log-writes/replay-log.c
> index 829b18e2..1e1cd524 100644
> --- a/src/log-writes/replay-log.c
> +++ b/src/log-writes/replay-log.c
> @@ -1,5 +1,6 @@
>  // SPDX-License-Identifier: GPL-2.0
>  #include <stdio.h>
> +#include <errno.h>
>  #include <unistd.h>
>  #include <getopt.h>
>  #include <stdlib.h>
> @@ -375,6 +376,7 @@ int main(int argc, char **argv)
>                                 fprintf(stderr, "Fsck errored out on entry "
>                                         "%llu\n",
>                                         (unsigned long long)log->cur_entry - 1);
> +                               ret = -EUCLEAN;
>                                 break;
>                         }
>                 }
> diff --git a/tests/btrfs/192 b/tests/btrfs/192
> new file mode 100755
> index 00000000..e919f703
> --- /dev/null
> +++ b/tests/btrfs/192
> @@ -0,0 +1,135 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2019 YOUR NAME HERE.  All Rights Reserved.
> +#
> +# FS QA Test 192
> +#
> +# Test btrfs consistency after each FUA operation
> +# Mostly the same test as generic/482, with some btrfs specific operations
> +# like snapshot creation and deletion.
> +# Alone with some btrfs specific workaround.

"Test btrfs consistency after each FUA for a workload with snapshot
creation and removal."

Much simpler and shorter.


> +#
> +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 /
> +       kill -q $pid1 &> /dev/null
> +       kill -q $pid2 &> /dev/null
> +       wait
> +       $KILLALL_PROG -q $FSSTRESS_PROG &> /dev/null
> +       _log_writes_cleanup &> /dev/null
> +       rm -f $tmp.*
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/filter
> +. ./common/dmlogwrites
> +
> +# remove previous $seqres.full before test
> +rm -f $seqres.full
> +
> +# real QA test starts here
> +
> +# Modify as appropriate.
> +_supported_fs btrfs
> +_supported_os Linux
> +
> +_require_command "$KILLALL_PROG" killall
> +_require_command "$BLKDISCARD_PROG" blkdiscard
> +_require_log_writes
> +_require_scratch
> +
> +runtime=30
> +nr_cpus=$("$here/src/feature" -o)
> +# cap nr_cpus to 8 to avoid spending too much time on hosts with many cpus
> +if [ $nr_cpus -gt 8 ]; then
> +       nr_cpus=8
> +fi
> +fsstress_args=$(_scale_fsstress_args -w -d $SCRATCH_MNT -n 99999 -p $nr_cpus \
> +               $FSSTRESS_AVOID)
> +_log_writes_init $SCRATCH_DEV
> +# Discard the whole devices so when some tree pointer is wrong, it won't point
> +# to some older tree blocks, and we can detect it.
> +blkdiscard $LOGWRITES_DMDEV 2>&1
> +
> +# Workaround minor file extent discountinous.
> +# Also, use small node size 4K to bump up tree height.
> +_log_writes_mkfs -O no-holes -n 4k >> $seqres.full 2>&1

If using no-holes, then it misses the following at the top:

_require_btrfs_fs_feature "no_holes"
_require_btrfs_mkfs_feature "no-holes"

That will also make the test fail on systems with a page size > 4Kb.
So either make it "_notrun" for systems with a page size != 4Kb or,
preferably make the test independent of the page size.
If you want to increase the tree height easily, you can set large
xattrs for files, like I did in btrfs/187, where even if with a 64Kb
page size, I get a 3 levels fs tree.

> +
> +# We need inline extents to quickly bump the tree height
> +_log_writes_mount -o max_inline=2048

Again, setting large xatts (3800 bytes so that it works for any page
size) is even faster then inline extents.

> +
> +$BTRFS_UTIL_PROG subvolume create $SCRATCH_MNT/src > /dev/null 2>&1

We should catch failures here. Just remove the redirection, pass the
_filter_scratch filter and update the golden output.

> +mkdir -p $SCRATCH_MNT/snapshots
> +mkdir -p $SCRATCH_MNT/src/padding
> +
> +random_file() {

The coding style is "{" on the beginning of the next line.
Like the _cleanup() function, and the _log_writes_fast_replay_check()
function you added previously.

> +       local basedir=$1
> +       echo "$basedir/$(ls $basedir | sort -R | tail -1)"
> +}
> +
> +snapshot_workload() {

Same comment as above.

> +       while true; do
> +               $BTRFS_UTIL_PROG subvolume snapshot \
> +                       $SCRATCH_MNT/src $SCRATCH_MNT/snapshots/$i \
> +                       > /dev/null 2>&1
> +               # Remove two random padding so each snapshot is different
> +               rm "$(random_file $SCRATCH_MNT/src/padding)"

I would pass -f to rm. Having an alias "alias rm='rm -i'" is not very
uncommon (I have such alias for my accounts).

> +               rm "$(random_file $SCRATCH_MNT/src/padding)"

Might be interesting to add a few files to each snapshot too (modify
existing ones, etc).

> +               sleep 1
> +       done
> +}
> +
> +delete_workload() {

Same comment as above.

> +       while true; do
> +               sleep 2
> +               $BTRFS_UTIL_PROG subvolume delete \
> +                       "$(random_file $SCRATCH_MNT/snapshots)" \
> +                       > /dev/null 2>&1
> +       done
> +}
> +
> +# Bump the tree height to 2 at least
> +for ((i = 0; i < 256; i++)); do
> +       _pwrite_byte 0xcd 0 2k "$SCRATCH_MNT/src/padding/inline_$i" > /dev/null 2>&1
> +       _pwrite_byte 0xcd 0 4k "$SCRATCH_MNT/src/padding/regular_$i" > /dev/null 2>&1
> +done
> +sync

Why the call to 'sync'?
Not needed, snapshot creation flushes delalloc and commits a transaction.

> +
> +_log_writes_mark prepare
> +
> +snapshot_workload &
> +pid1=$!
> +delete_workload &
> +pid2=$!
> +
> +$FSSTRESS_PROG $fsstress_args > /dev/null 2>&1 &
> +sleep $runtime
> +
> +$KILLALL_PROG -q $FSSTRESS_PROG &> /dev/null

You're very inconsistent within the same test :) Using both ">
/dev/null 2>&1" and "&> /dev/null".

> +kill $pid1 &> /dev/null
> +kill $pid2 &> /dev/null
> +wait
> +_log_writes_unmount
> +_log_writes_remove
> +
> +# Since we have a lot of work to replay, and relay-log will search
> +# from the first record to the needed entry, we need to use --fsck option
> +# to reduce unnecessary search, or it will be too slow
> +$here/src/log-writes/replay-log --log $LOGWRITES_DEV --replay $SCRATCH_DEV \
> +       --fsck "btrfs check $SCRATCH_DEV" --check fua >> $seqres.full 2>&1
> +
> +echo "Silence is golden"
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/btrfs/192.out b/tests/btrfs/192.out
> new file mode 100644
> index 00000000..6779aa77
> --- /dev/null
> +++ b/tests/btrfs/192.out
> @@ -0,0 +1,2 @@
> +QA output created by 192
> +Silence is golden
> diff --git a/tests/btrfs/group b/tests/btrfs/group
> index 2474d43e..24723bf1 100644
> --- a/tests/btrfs/group
> +++ b/tests/btrfs/group
> @@ -194,3 +194,4 @@
>  189 auto quick send clone
>  190 auto quick replay balance qgroup
>  191 auto quick send dedupe
> +192 auto replay

Missing "snapshot" group.

Thanks.

> --
> 2.22.0
>
Qu Wenruo Aug. 16, 2019, 9:47 a.m. UTC | #2
On 2019/8/16 下午5:25, Filipe Manana wrote:
[...]
> 
> That will also make the test fail on systems with a page size > 4Kb.
> So either make it "_notrun" for systems with a page size != 4Kb or,
> preferably make the test independent of the page size.
> If you want to increase the tree height easily, you can set large
> xattrs for files, like I did in btrfs/187, where even if with a 64Kb
> page size, I get a 3 levels fs tree.
> 
>> +
>> +# We need inline extents to quickly bump the tree height
>> +_log_writes_mount -o max_inline=2048
> 
> Again, setting large xatts (3800 bytes so that it works for any page
> size) is even faster then inline extents.

Greater advice for that!

> 
>> +
>> +$BTRFS_UTIL_PROG subvolume create $SCRATCH_MNT/src > /dev/null 2>&1
> 
> We should catch failures here. Just remove the redirection, pass the
> _filter_scratch filter and update the golden output.
> 
>> +mkdir -p $SCRATCH_MNT/snapshots
>> +mkdir -p $SCRATCH_MNT/src/padding
>> +
>> +random_file() {
> 
> The coding style is "{" on the beginning of the next line.
> Like the _cleanup() function, and the _log_writes_fast_replay_check()
> function you added previously.
> 
>> +       local basedir=$1
>> +       echo "$basedir/$(ls $basedir | sort -R | tail -1)"
>> +}
>> +
>> +snapshot_workload() {
> 
> Same comment as above.
> 
>> +       while true; do
>> +               $BTRFS_UTIL_PROG subvolume snapshot \
>> +                       $SCRATCH_MNT/src $SCRATCH_MNT/snapshots/$i \
>> +                       > /dev/null 2>&1
>> +               # Remove two random padding so each snapshot is different
>> +               rm "$(random_file $SCRATCH_MNT/src/padding)"
> 
> I would pass -f to rm. Having an alias "alias rm='rm -i'" is not very
> uncommon (I have such alias for my accounts).
> 
>> +               rm "$(random_file $SCRATCH_MNT/src/padding)"
> 
> Might be interesting to add a few files to each snapshot too (modify
> existing ones, etc).

No problem.

> 
>> +               sleep 1
>> +       done
>> +}
>> +
>> +delete_workload() {
> 
> Same comment as above.
> 
>> +       while true; do
>> +               sleep 2
>> +               $BTRFS_UTIL_PROG subvolume delete \
>> +                       "$(random_file $SCRATCH_MNT/snapshots)" \
>> +                       > /dev/null 2>&1
>> +       done
>> +}
>> +
>> +# Bump the tree height to 2 at least
>> +for ((i = 0; i < 256; i++)); do
>> +       _pwrite_byte 0xcd 0 2k "$SCRATCH_MNT/src/padding/inline_$i" > /dev/null 2>&1
>> +       _pwrite_byte 0xcd 0 4k "$SCRATCH_MNT/src/padding/regular_$i" > /dev/null 2>&1
>> +done
>> +sync
> 
> Why the call to 'sync'?
> Not needed, snapshot creation flushes delalloc and commits a transaction.
> 
>> +
>> +_log_writes_mark prepare
>> +
>> +snapshot_workload &
>> +pid1=$!
>> +delete_workload &
>> +pid2=$!
>> +
>> +$FSSTRESS_PROG $fsstress_args > /dev/null 2>&1 &
>> +sleep $runtime
>> +
>> +$KILLALL_PROG -q $FSSTRESS_PROG &> /dev/null
> 
> You're very inconsistent within the same test :) Using both ">
> /dev/null 2>&1" and "&> /dev/null".

My bad, I mean 2>&1 > /dev/null.
What I mean is output stderr while skip stdout in previous calls.

Thanks,
Qu

> 
>> +kill $pid1 &> /dev/null
>> +kill $pid2 &> /dev/null
>> +wait
>> +_log_writes_unmount
>> +_log_writes_remove
>> +
>> +# Since we have a lot of work to replay, and relay-log will search
>> +# from the first record to the needed entry, we need to use --fsck option
>> +# to reduce unnecessary search, or it will be too slow
>> +$here/src/log-writes/replay-log --log $LOGWRITES_DEV --replay $SCRATCH_DEV \
>> +       --fsck "btrfs check $SCRATCH_DEV" --check fua >> $seqres.full 2>&1
>> +
>> +echo "Silence is golden"
>> +
>> +# success, all done
>> +status=0
>> +exit
>> diff --git a/tests/btrfs/192.out b/tests/btrfs/192.out
>> new file mode 100644
>> index 00000000..6779aa77
>> --- /dev/null
>> +++ b/tests/btrfs/192.out
>> @@ -0,0 +1,2 @@
>> +QA output created by 192
>> +Silence is golden
>> diff --git a/tests/btrfs/group b/tests/btrfs/group
>> index 2474d43e..24723bf1 100644
>> --- a/tests/btrfs/group
>> +++ b/tests/btrfs/group
>> @@ -194,3 +194,4 @@
>>  189 auto quick send clone
>>  190 auto quick replay balance qgroup
>>  191 auto quick send dedupe
>> +192 auto replay
> 
> Missing "snapshot" group.
> 
> Thanks.
> 
>> --
>> 2.22.0
>>
> 
>
Eryu Guan Aug. 16, 2019, 11:30 a.m. UTC | #3
On Fri, Aug 16, 2019 at 05:47:33PM +0800, Qu Wenruo wrote:
[...]
> >> +$KILLALL_PROG -q $FSSTRESS_PROG &> /dev/null
> > 
> > You're very inconsistent within the same test :) Using both ">
> > /dev/null 2>&1" and "&> /dev/null".
> 
> My bad, I mean 2>&1 > /dev/null.
> What I mean is output stderr while skip stdout in previous calls.

Then just do "2>/dev/null", the test harness will capture both stdout
and stderr. "2>&1 > /dev/null" is less used and usually indicates a
mis-usage :)

Thanks,
Eryu

Patch
diff mbox series

diff --git a/common/config b/common/config
index bd64be62..4c86a492 100644
--- a/common/config
+++ b/common/config
@@ -183,6 +183,7 @@  export LOGGER_PROG="$(type -P logger)"
 export DBENCH_PROG="$(type -P dbench)"
 export DMSETUP_PROG="$(type -P dmsetup)"
 export WIPEFS_PROG="$(type -P wipefs)"
+export BLKDISCARD_PROG="$(type -P blkdiscard)"
 export DUMP_PROG="$(type -P dump)"
 export RESTORE_PROG="$(type -P restore)"
 export LVM_PROG="$(type -P lvm)"
diff --git a/common/dmlogwrites b/common/dmlogwrites
index ae2cbc6a..5eca7142 100644
--- a/common/dmlogwrites
+++ b/common/dmlogwrites
@@ -175,3 +175,31 @@  _log_writes_replay_log_range()
 		>> $seqres.full 2>&1
 	[ $? -ne 0 ] && _fail "replay failed"
 }
+
+# Replay log range to specified entry
+# Replay and check each fua/flush point.
+# Since dm-log-writes records bio sequentially, even just replaying a range
+# still needs to iterate all records before the end point.
+# When number of records grows, it will be unacceptably slow, thus we need
+# to use relay-log itself to trigger fsck, avoid unnecessary seek.
+_log_writes_fast_replay_check()
+{
+	local check_point=$1
+	local blkdev=$2
+	local fsck_command
+
+	[ -z "$check_point" -o -z "$blkdev" ] && _fail \
+	"check_point and blkdev must be specified for _log_writes_fast_replay_check"
+
+	# Check program must not treat dirty log as a problem.
+	# So only btrfs can use this feature
+	if [ $FSTYP = "btrfs" ]; then
+		fsck_command="$BTRFS_PROG check $blkdev"
+	else
+		_notrun "fsck of $FSTYP may report false alert of dirty log"
+	fi
+	$here/src/log-writes/replay-log --log $LOGWRITES_DEV \
+		--replay $blkdev --check $check_point --fsck "$fsck_command" \
+		>> $seqres.full 2>&1
+	[ $? -ne 0 ] && _fail "fsck failed during replay"
+}
diff --git a/src/log-writes/replay-log.c b/src/log-writes/replay-log.c
index 829b18e2..1e1cd524 100644
--- a/src/log-writes/replay-log.c
+++ b/src/log-writes/replay-log.c
@@ -1,5 +1,6 @@ 
 // SPDX-License-Identifier: GPL-2.0
 #include <stdio.h>
+#include <errno.h>
 #include <unistd.h>
 #include <getopt.h>
 #include <stdlib.h>
@@ -375,6 +376,7 @@  int main(int argc, char **argv)
 				fprintf(stderr, "Fsck errored out on entry "
 					"%llu\n",
 					(unsigned long long)log->cur_entry - 1);
+				ret = -EUCLEAN;
 				break;
 			}
 		}
diff --git a/tests/btrfs/192 b/tests/btrfs/192
new file mode 100755
index 00000000..e919f703
--- /dev/null
+++ b/tests/btrfs/192
@@ -0,0 +1,135 @@ 
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2019 YOUR NAME HERE.  All Rights Reserved.
+#
+# FS QA Test 192
+#
+# Test btrfs consistency after each FUA operation
+# Mostly the same test as generic/482, with some btrfs specific operations
+# like snapshot creation and deletion.
+# Alone with some btrfs specific workaround.
+#
+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 /
+	kill -q $pid1 &> /dev/null
+	kill -q $pid2 &> /dev/null
+	wait
+	$KILLALL_PROG -q $FSSTRESS_PROG &> /dev/null
+	_log_writes_cleanup &> /dev/null
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+. ./common/dmlogwrites
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+
+# Modify as appropriate.
+_supported_fs btrfs
+_supported_os Linux
+
+_require_command "$KILLALL_PROG" killall
+_require_command "$BLKDISCARD_PROG" blkdiscard
+_require_log_writes
+_require_scratch
+
+runtime=30
+nr_cpus=$("$here/src/feature" -o)
+# cap nr_cpus to 8 to avoid spending too much time on hosts with many cpus
+if [ $nr_cpus -gt 8 ]; then
+	nr_cpus=8
+fi
+fsstress_args=$(_scale_fsstress_args -w -d $SCRATCH_MNT -n 99999 -p $nr_cpus \
+		$FSSTRESS_AVOID)
+_log_writes_init $SCRATCH_DEV
+# Discard the whole devices so when some tree pointer is wrong, it won't point
+# to some older tree blocks, and we can detect it.
+blkdiscard $LOGWRITES_DMDEV 2>&1
+
+# Workaround minor file extent discountinous.
+# Also, use small node size 4K to bump up tree height.
+_log_writes_mkfs -O no-holes -n 4k >> $seqres.full 2>&1
+
+# We need inline extents to quickly bump the tree height
+_log_writes_mount -o max_inline=2048
+
+$BTRFS_UTIL_PROG subvolume create $SCRATCH_MNT/src > /dev/null 2>&1
+mkdir -p $SCRATCH_MNT/snapshots
+mkdir -p $SCRATCH_MNT/src/padding
+
+random_file() {
+	local basedir=$1
+	echo "$basedir/$(ls $basedir | sort -R | tail -1)"
+}
+
+snapshot_workload() {
+	while true; do
+		$BTRFS_UTIL_PROG subvolume snapshot \
+			$SCRATCH_MNT/src $SCRATCH_MNT/snapshots/$i \
+			> /dev/null 2>&1
+		# Remove two random padding so each snapshot is different
+		rm "$(random_file $SCRATCH_MNT/src/padding)"
+		rm "$(random_file $SCRATCH_MNT/src/padding)"
+		sleep 1
+	done
+}
+
+delete_workload() {
+	while true; do
+		sleep 2
+		$BTRFS_UTIL_PROG subvolume delete \
+			"$(random_file $SCRATCH_MNT/snapshots)" \
+			> /dev/null 2>&1
+	done
+}
+
+# Bump the tree height to 2 at least
+for ((i = 0; i < 256; i++)); do
+	_pwrite_byte 0xcd 0 2k "$SCRATCH_MNT/src/padding/inline_$i" > /dev/null 2>&1
+	_pwrite_byte 0xcd 0 4k "$SCRATCH_MNT/src/padding/regular_$i" > /dev/null 2>&1
+done
+sync
+
+_log_writes_mark prepare
+
+snapshot_workload &
+pid1=$!
+delete_workload &
+pid2=$!
+
+$FSSTRESS_PROG $fsstress_args > /dev/null 2>&1 &
+sleep $runtime
+
+$KILLALL_PROG -q $FSSTRESS_PROG &> /dev/null
+kill $pid1 &> /dev/null
+kill $pid2 &> /dev/null
+wait
+_log_writes_unmount
+_log_writes_remove
+
+# Since we have a lot of work to replay, and relay-log will search
+# from the first record to the needed entry, we need to use --fsck option
+# to reduce unnecessary search, or it will be too slow
+$here/src/log-writes/replay-log --log $LOGWRITES_DEV --replay $SCRATCH_DEV \
+	--fsck "btrfs check $SCRATCH_DEV" --check fua >> $seqres.full 2>&1
+
+echo "Silence is golden"
+
+# success, all done
+status=0
+exit
diff --git a/tests/btrfs/192.out b/tests/btrfs/192.out
new file mode 100644
index 00000000..6779aa77
--- /dev/null
+++ b/tests/btrfs/192.out
@@ -0,0 +1,2 @@ 
+QA output created by 192
+Silence is golden
diff --git a/tests/btrfs/group b/tests/btrfs/group
index 2474d43e..24723bf1 100644
--- a/tests/btrfs/group
+++ b/tests/btrfs/group
@@ -194,3 +194,4 @@ 
 189 auto quick send clone
 190 auto quick replay balance qgroup
 191 auto quick send dedupe
+192 auto replay