[PATCH 1/2] fstests: btrfs/028: Don't pollute golden output for killing already finished process

[PATCH 1/2] fstests: btrfs/028: Don't pollute golden output for killing already finished process

[Qu Wenruo]

Sometimes on fast enough test vm, btrfs/028 fails like:

  btrfs/028 31s ... - output mismatch (see /home/adam/xfstests-dev/results//btrfs/028.out.bad)
    --- tests/btrfs/028.out     2019-07-22 14:13:44.646666660 +0800
    +++ /home/adam/xfstests-dev/results//btrfs/028.out.bad      2019-09-18 14:14:45.442131411 +0800
    @@ -1,2 +1,3 @@
     QA output created by 028
    +/home/adam/xfstests-dev/tests/btrfs/028: line 64: kill: (2459) - No such process
     Silence is golden
    ...

It's caused by killing already finished process.
There is no need for kill command to pollute the golden output, so just
redirect all of its stdout and stderr to null.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 tests/btrfs/028 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/btrfs/028 b/tests/btrfs/028
index efa87ab3..98b9c8b9 100755
--- a/tests/btrfs/028
+++ b/tests/btrfs/028
@@ -61,7 +61,7 @@ balance_pid=$!
 
 # 30s is enough to trigger bug
 sleep $((30*$TIME_FACTOR))
-kill $fsstress_pid $balance_pid
+kill $fsstress_pid $balance_pid &> /dev/null
 wait
 
 # kill _btrfs_stress_balance can't end balance, so call btrfs balance cancel
-- 
2.22.0

[PATCH 2/2] fstests: btrfs/011: Handle finished scrub/replace operation gracefully

[Qu Wenruo]

[BUG]
When btrfs/011 is executed on a fast enough system (fully memory backed
VM, with test device has unsafe cache mode), the test can fail like
this:

  btrfs/011 43s ... [failed, exit status 1]- output mismatch (see /home/adam/xfstests-dev/results//btrfs/011.out.bad)
    --- tests/btrfs/011.out     2019-07-22 14:13:44.643333326 +0800
    +++ /home/adam/xfstests-dev/results//btrfs/011.out.bad      2019-09-18 14:49:28.308798022 +0800
    @@ -1,3 +1,4 @@
     QA output created by 011
     *** test btrfs replace
    -*** done
    +failed: '/usr/bin/btrfs replace cancel /mnt/scratch'
    +(see /home/adam/xfstests-dev/results//btrfs/011.full for details)
    ...

[CAUSE]
Looking into the full output, it shows:
  ...
  Replace from /dev/mapper/test-scratch1 to /dev/mapper/test-scratch2

  # /usr/bin/btrfs replace start -f /dev/mapper/test-scratch1 /dev/mapper/test-scratch2 /mnt/scratch
  # /usr/bin/btrfs replace cancel /mnt/scratch
  INFO: ioctl(DEV_REPLACE_CANCEL)"/mnt/scratch": not started
  failed: '/usr/bin/btrfs replace cancel /mnt/scratch'

So this means the replace is already finished before we cancel it.
For fast system, it's very common.

[FIX]
Instead of using _run_btrfs_util_prog which requires 0 as return value,
we just call "$BTRFS_UTIL_PROG replace cancel" and ignore all its
stderr/stdout, and completely rely on "$BTRFS_UTIL_PROG replace status"
output to verify the work.

Furthermore if we finished replac before cancelling it, we should
replace again to switch the device back, or after the test case, btrfs
check will fail as there is no valid btrfs on that replaced device.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 tests/btrfs/011 | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/tests/btrfs/011 b/tests/btrfs/011
index 89bb4d11..858b00e8 100755
--- a/tests/btrfs/011
+++ b/tests/btrfs/011
@@ -148,13 +148,25 @@ btrfs_replace_test()
 		# background the replace operation (no '-B' option given)
 		_run_btrfs_util_prog replace start -f $replace_options $source_dev $target_dev $SCRATCH_MNT
 		sleep 1
-		_run_btrfs_util_prog replace cancel $SCRATCH_MNT
+		# 1s is enough for fast system to finish replace, so here we
+		# ignore all the output, completely rely on later status
+		# output to determine
+		$BTRFS_UTIL_PROG replace cancel $SCRATCH_MNT &> /dev/null
 
 		# 'replace status' waits for the replace operation to finish
 		# before the status is printed
 		$BTRFS_UTIL_PROG replace status $SCRATCH_MNT > $tmp.tmp 2>&1
 		cat $tmp.tmp >> $seqres.full
-		grep -q canceled $tmp.tmp || _fail "btrfs replace status (canceled) failed"
+		grep -q -e canceled -e finished $tmp.tmp ||\
+			_fail "btrfs replace status (canceled) failed"
+
+		# If replace finished before cancel, replace them back or
+		# the final fsck after test case will fail as there is no btrfs
+		# on the $source_dev anymore
+		if grep -q -e finished $tmp.tmp ; then
+			$BTRFS_UTIL_PROG replace start -Bf $replace_options \
+				$target_dev $source_dev $SCRATCH_MNT
+		fi
 	else
 		if [ "${quick}Q" = "thoroughQ" ]; then
 			# On current hardware, the thorough test runs
-- 
2.22.0

Re: [PATCH 1/2] fstests: btrfs/028: Don't pollute golden output for killing already finished process

[Anand Jain]

Reviewed-by: Anand Jain <anand.jain@oracle.com>

Re: [PATCH 2/2] fstests: btrfs/011: Handle finished scrub/replace operation gracefully

[Anand Jain]

On 18/9/19 2:56 PM, Qu Wenruo wrote:
> [BUG]
> When btrfs/011 is executed on a fast enough system (fully memory backed
> VM, with test device has unsafe cache mode), the test can fail like
> this:
> 
>    btrfs/011 43s ... [failed, exit status 1]- output mismatch (see /home/adam/xfstests-dev/results//btrfs/011.out.bad)
>      --- tests/btrfs/011.out     2019-07-22 14:13:44.643333326 +0800
>      +++ /home/adam/xfstests-dev/results//btrfs/011.out.bad      2019-09-18 14:49:28.308798022 +0800
>      @@ -1,3 +1,4 @@
>       QA output created by 011
>       *** test btrfs replace
>      -*** done
>      +failed: '/usr/bin/btrfs replace cancel /mnt/scratch'
>      +(see /home/adam/xfstests-dev/results//btrfs/011.full for details)
>      ...
> 
> [CAUSE]
> Looking into the full output, it shows:
>    ...
>    Replace from /dev/mapper/test-scratch1 to /dev/mapper/test-scratch2
> 
>    # /usr/bin/btrfs replace start -f /dev/mapper/test-scratch1 /dev/mapper/test-scratch2 /mnt/scratch
>    # /usr/bin/btrfs replace cancel /mnt/scratch
>    INFO: ioctl(DEV_REPLACE_CANCEL)"/mnt/scratch": not started
>    failed: '/usr/bin/btrfs replace cancel /mnt/scratch'
> 
> So this means the replace is already finished before we cancel it.
> For fast system, it's very common.
> 
> [FIX]
> Instead of using _run_btrfs_util_prog which requires 0 as return value,
> we just call "$BTRFS_UTIL_PROG replace cancel" and ignore all its
> stderr/stdout, and completely rely on "$BTRFS_UTIL_PROG replace status"
> output to verify the work.
> 
> Furthermore if we finished replac before cancelling it, we should
> replace again to switch the device back, or after the test case, btrfs
> check will fail as there is no valid btrfs on that replaced device.
> 
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> ---
>   tests/btrfs/011 | 16 ++++++++++++++--
>   1 file changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/tests/btrfs/011 b/tests/btrfs/011
> index 89bb4d11..858b00e8 100755
> --- a/tests/btrfs/011
> +++ b/tests/btrfs/011
> @@ -148,13 +148,25 @@ btrfs_replace_test()
>   		# background the replace operation (no '-B' option given)
>   		_run_btrfs_util_prog replace start -f $replace_options $source_dev $target_dev $SCRATCH_MNT
>   		sleep 1
> -		_run_btrfs_util_prog replace cancel $SCRATCH_MNT
> +		# 1s is enough for fast system to finish replace, so here we
> +		# ignore all the output, completely rely on later status
> +		# output to determine
> +		$BTRFS_UTIL_PROG replace cancel $SCRATCH_MNT &> /dev/null
>   
>   		# 'replace status' waits for the replace operation to finish
>   		# before the status is printed
>   		$BTRFS_UTIL_PROG replace status $SCRATCH_MNT > $tmp.tmp 2>&1
>   		cat $tmp.tmp >> $seqres.full
> -		grep -q canceled $tmp.tmp || _fail "btrfs replace status (canceled) failed"
> +		grep -q -e canceled -e finished $tmp.tmp ||\
> +			_fail "btrfs replace status (canceled) failed"
> +
> +		# If replace finished before cancel, replace them back or
> +		# the final fsck after test case will fail as there is no btrfs
> +		# on the $source_dev anymore
> +		if grep -q -e finished $tmp.tmp ; then
> +			$BTRFS_UTIL_PROG replace start -Bf $replace_options \
> +				$target_dev $source_dev $SCRATCH_MNT
> +		fi
>   	else
>   		if [ "${quick}Q" = "thoroughQ" ]; then
>   			# On current hardware, the thorough test runs
> 

Faced the same problem before. But I don't have a good solution
to fix. Because the idea of the test case appears to test the replace
cancel. This change makes it not to error if replace is not running
in the first place.

Thanks, Anand

Re: [PATCH 2/2] fstests: btrfs/011: Handle finished scrub/replace operation gracefully

[Qu Wenruo]

[-- Attachment #1.1: Type: text/plain, Size: 4577 bytes --]



On 2019/9/18 下午3:54, Anand Jain wrote:
> On 18/9/19 2:56 PM, Qu Wenruo wrote:
>> [BUG]
>> When btrfs/011 is executed on a fast enough system (fully memory backed
>> VM, with test device has unsafe cache mode), the test can fail like
>> this:
>>
>>    btrfs/011 43s ... [failed, exit status 1]- output mismatch (see
>> /home/adam/xfstests-dev/results//btrfs/011.out.bad)
>>      --- tests/btrfs/011.out     2019-07-22 14:13:44.643333326 +0800
>>      +++ /home/adam/xfstests-dev/results//btrfs/011.out.bad     
>> 2019-09-18 14:49:28.308798022 +0800
>>      @@ -1,3 +1,4 @@
>>       QA output created by 011
>>       *** test btrfs replace
>>      -*** done
>>      +failed: '/usr/bin/btrfs replace cancel /mnt/scratch'
>>      +(see /home/adam/xfstests-dev/results//btrfs/011.full for details)
>>      ...
>>
>> [CAUSE]
>> Looking into the full output, it shows:
>>    ...
>>    Replace from /dev/mapper/test-scratch1 to /dev/mapper/test-scratch2
>>
>>    # /usr/bin/btrfs replace start -f /dev/mapper/test-scratch1
>> /dev/mapper/test-scratch2 /mnt/scratch
>>    # /usr/bin/btrfs replace cancel /mnt/scratch
>>    INFO: ioctl(DEV_REPLACE_CANCEL)"/mnt/scratch": not started
>>    failed: '/usr/bin/btrfs replace cancel /mnt/scratch'
>>
>> So this means the replace is already finished before we cancel it.
>> For fast system, it's very common.
>>
>> [FIX]
>> Instead of using _run_btrfs_util_prog which requires 0 as return value,
>> we just call "$BTRFS_UTIL_PROG replace cancel" and ignore all its
>> stderr/stdout, and completely rely on "$BTRFS_UTIL_PROG replace status"
>> output to verify the work.
>>
>> Furthermore if we finished replac before cancelling it, we should
>> replace again to switch the device back, or after the test case, btrfs
>> check will fail as there is no valid btrfs on that replaced device.
>>
>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>> ---
>>   tests/btrfs/011 | 16 ++++++++++++++--
>>   1 file changed, 14 insertions(+), 2 deletions(-)
>>
>> diff --git a/tests/btrfs/011 b/tests/btrfs/011
>> index 89bb4d11..858b00e8 100755
>> --- a/tests/btrfs/011
>> +++ b/tests/btrfs/011
>> @@ -148,13 +148,25 @@ btrfs_replace_test()
>>           # background the replace operation (no '-B' option given)
>>           _run_btrfs_util_prog replace start -f $replace_options
>> $source_dev $target_dev $SCRATCH_MNT
>>           sleep 1
>> -        _run_btrfs_util_prog replace cancel $SCRATCH_MNT
>> +        # 1s is enough for fast system to finish replace, so here we
>> +        # ignore all the output, completely rely on later status
>> +        # output to determine
>> +        $BTRFS_UTIL_PROG replace cancel $SCRATCH_MNT &> /dev/null
>>             # 'replace status' waits for the replace operation to finish
>>           # before the status is printed
>>           $BTRFS_UTIL_PROG replace status $SCRATCH_MNT > $tmp.tmp 2>&1
>>           cat $tmp.tmp >> $seqres.full
>> -        grep -q canceled $tmp.tmp || _fail "btrfs replace status
>> (canceled) failed"
>> +        grep -q -e canceled -e finished $tmp.tmp ||\
>> +            _fail "btrfs replace status (canceled) failed"
>> +
>> +        # If replace finished before cancel, replace them back or
>> +        # the final fsck after test case will fail as there is no btrfs
>> +        # on the $source_dev anymore
>> +        if grep -q -e finished $tmp.tmp ; then
>> +            $BTRFS_UTIL_PROG replace start -Bf $replace_options \
>> +                $target_dev $source_dev $SCRATCH_MNT
>> +        fi
>>       else
>>           if [ "${quick}Q" = "thoroughQ" ]; then
>>               # On current hardware, the thorough test runs
>>
> 
> Faced the same problem before. But I don't have a good solution
> to fix. Because the idea of the test case appears to test the replace
> cancel. This change makes it not to error if replace is not running
> in the first place.

Then what about _notrun if we find that replace/scrub finished too early?

BTW, if we really want to test all regular scrub/replace with
cancel/finish combination, we should split this test into 4 test cases,
then we can completely afford to skip 2 while still allow the finish
cases to run...

Thanks,
Qu

> 
> Thanks, Anand
> 


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Re: [PATCH 2/2] fstests: btrfs/011: Handle finished scrub/replace operation gracefully

[Eryu Guan]

On Wed, Sep 18, 2019 at 02:56:26PM +0800, Qu Wenruo wrote:
> [BUG]
> When btrfs/011 is executed on a fast enough system (fully memory backed
> VM, with test device has unsafe cache mode), the test can fail like
> this:
> 
>   btrfs/011 43s ... [failed, exit status 1]- output mismatch (see /home/adam/xfstests-dev/results//btrfs/011.out.bad)
>     --- tests/btrfs/011.out     2019-07-22 14:13:44.643333326 +0800
>     +++ /home/adam/xfstests-dev/results//btrfs/011.out.bad      2019-09-18 14:49:28.308798022 +0800
>     @@ -1,3 +1,4 @@
>      QA output created by 011
>      *** test btrfs replace
>     -*** done
>     +failed: '/usr/bin/btrfs replace cancel /mnt/scratch'
>     +(see /home/adam/xfstests-dev/results//btrfs/011.full for details)
>     ...
> 
> [CAUSE]
> Looking into the full output, it shows:
>   ...
>   Replace from /dev/mapper/test-scratch1 to /dev/mapper/test-scratch2
> 
>   # /usr/bin/btrfs replace start -f /dev/mapper/test-scratch1 /dev/mapper/test-scratch2 /mnt/scratch
>   # /usr/bin/btrfs replace cancel /mnt/scratch
>   INFO: ioctl(DEV_REPLACE_CANCEL)"/mnt/scratch": not started
>   failed: '/usr/bin/btrfs replace cancel /mnt/scratch'
> 
> So this means the replace is already finished before we cancel it.
> For fast system, it's very common.

Does generate heavier load & more data make replace operation last
longer? e.g. make more 'noise' by running fsstress instead of dumping
/dev/urandom before starting replace.

And does sleep shorter time (0.5s?) before cancel work?

Thanks,
Eryu

> 
> [FIX]
> Instead of using _run_btrfs_util_prog which requires 0 as return value,
> we just call "$BTRFS_UTIL_PROG replace cancel" and ignore all its
> stderr/stdout, and completely rely on "$BTRFS_UTIL_PROG replace status"
> output to verify the work.
> 
> Furthermore if we finished replac before cancelling it, we should
> replace again to switch the device back, or after the test case, btrfs
> check will fail as there is no valid btrfs on that replaced device.
> 
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> ---
>  tests/btrfs/011 | 16 ++++++++++++++--
>  1 file changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/tests/btrfs/011 b/tests/btrfs/011
> index 89bb4d11..858b00e8 100755
> --- a/tests/btrfs/011
> +++ b/tests/btrfs/011
> @@ -148,13 +148,25 @@ btrfs_replace_test()
>  		# background the replace operation (no '-B' option given)
>  		_run_btrfs_util_prog replace start -f $replace_options $source_dev $target_dev $SCRATCH_MNT
>  		sleep 1
> -		_run_btrfs_util_prog replace cancel $SCRATCH_MNT
> +		# 1s is enough for fast system to finish replace, so here we
> +		# ignore all the output, completely rely on later status
> +		# output to determine
> +		$BTRFS_UTIL_PROG replace cancel $SCRATCH_MNT &> /dev/null
>  
>  		# 'replace status' waits for the replace operation to finish
>  		# before the status is printed
>  		$BTRFS_UTIL_PROG replace status $SCRATCH_MNT > $tmp.tmp 2>&1
>  		cat $tmp.tmp >> $seqres.full
> -		grep -q canceled $tmp.tmp || _fail "btrfs replace status (canceled) failed"
> +		grep -q -e canceled -e finished $tmp.tmp ||\
> +			_fail "btrfs replace status (canceled) failed"
> +
> +		# If replace finished before cancel, replace them back or
> +		# the final fsck after test case will fail as there is no btrfs
> +		# on the $source_dev anymore
> +		if grep -q -e finished $tmp.tmp ; then
> +			$BTRFS_UTIL_PROG replace start -Bf $replace_options \
> +				$target_dev $source_dev $SCRATCH_MNT
> +		fi
>  	else
>  		if [ "${quick}Q" = "thoroughQ" ]; then
>  			# On current hardware, the thorough test runs
> -- 
> 2.22.0

Re: [PATCH 2/2] fstests: btrfs/011: Handle finished scrub/replace operation gracefully

[Qu Wenruo]

[-- Attachment #1.1: Type: text/plain, Size: 4062 bytes --]



On 2019/9/18 下午4:47, Eryu Guan wrote:
> On Wed, Sep 18, 2019 at 02:56:26PM +0800, Qu Wenruo wrote:
>> [BUG]
>> When btrfs/011 is executed on a fast enough system (fully memory backed
>> VM, with test device has unsafe cache mode), the test can fail like
>> this:
>>
>>   btrfs/011 43s ... [failed, exit status 1]- output mismatch (see /home/adam/xfstests-dev/results//btrfs/011.out.bad)
>>     --- tests/btrfs/011.out     2019-07-22 14:13:44.643333326 +0800
>>     +++ /home/adam/xfstests-dev/results//btrfs/011.out.bad      2019-09-18 14:49:28.308798022 +0800
>>     @@ -1,3 +1,4 @@
>>      QA output created by 011
>>      *** test btrfs replace
>>     -*** done
>>     +failed: '/usr/bin/btrfs replace cancel /mnt/scratch'
>>     +(see /home/adam/xfstests-dev/results//btrfs/011.full for details)
>>     ...
>>
>> [CAUSE]
>> Looking into the full output, it shows:
>>   ...
>>   Replace from /dev/mapper/test-scratch1 to /dev/mapper/test-scratch2
>>
>>   # /usr/bin/btrfs replace start -f /dev/mapper/test-scratch1 /dev/mapper/test-scratch2 /mnt/scratch
>>   # /usr/bin/btrfs replace cancel /mnt/scratch
>>   INFO: ioctl(DEV_REPLACE_CANCEL)"/mnt/scratch": not started
>>   failed: '/usr/bin/btrfs replace cancel /mnt/scratch'
>>
>> So this means the replace is already finished before we cancel it.
>> For fast system, it's very common.
> 
> Does generate heavier load & more data make replace operation last
> longer? e.g. make more 'noise' by running fsstress instead of dumping
> /dev/urandom before starting replace.

That's a great idea.

In fact we can try to write as much data as possible for 3s (using
Direct IO), so that we know we have some data which will take at least
3s to read/write.

I'd take a try on this method.

Thanks,
Qu
> 
> And does sleep shorter time (0.5s?) before cancel work?
> 
> Thanks,
> Eryu
> 
>>
>> [FIX]
>> Instead of using _run_btrfs_util_prog which requires 0 as return value,
>> we just call "$BTRFS_UTIL_PROG replace cancel" and ignore all its
>> stderr/stdout, and completely rely on "$BTRFS_UTIL_PROG replace status"
>> output to verify the work.
>>
>> Furthermore if we finished replac before cancelling it, we should
>> replace again to switch the device back, or after the test case, btrfs
>> check will fail as there is no valid btrfs on that replaced device.
>>
>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>> ---
>>  tests/btrfs/011 | 16 ++++++++++++++--
>>  1 file changed, 14 insertions(+), 2 deletions(-)
>>
>> diff --git a/tests/btrfs/011 b/tests/btrfs/011
>> index 89bb4d11..858b00e8 100755
>> --- a/tests/btrfs/011
>> +++ b/tests/btrfs/011
>> @@ -148,13 +148,25 @@ btrfs_replace_test()
>>  		# background the replace operation (no '-B' option given)
>>  		_run_btrfs_util_prog replace start -f $replace_options $source_dev $target_dev $SCRATCH_MNT
>>  		sleep 1
>> -		_run_btrfs_util_prog replace cancel $SCRATCH_MNT
>> +		# 1s is enough for fast system to finish replace, so here we
>> +		# ignore all the output, completely rely on later status
>> +		# output to determine
>> +		$BTRFS_UTIL_PROG replace cancel $SCRATCH_MNT &> /dev/null
>>  
>>  		# 'replace status' waits for the replace operation to finish
>>  		# before the status is printed
>>  		$BTRFS_UTIL_PROG replace status $SCRATCH_MNT > $tmp.tmp 2>&1
>>  		cat $tmp.tmp >> $seqres.full
>> -		grep -q canceled $tmp.tmp || _fail "btrfs replace status (canceled) failed"
>> +		grep -q -e canceled -e finished $tmp.tmp ||\
>> +			_fail "btrfs replace status (canceled) failed"
>> +
>> +		# If replace finished before cancel, replace them back or
>> +		# the final fsck after test case will fail as there is no btrfs
>> +		# on the $source_dev anymore
>> +		if grep -q -e finished $tmp.tmp ; then
>> +			$BTRFS_UTIL_PROG replace start -Bf $replace_options \
>> +				$target_dev $source_dev $SCRATCH_MNT
>> +		fi
>>  	else
>>  		if [ "${quick}Q" = "thoroughQ" ]; then
>>  			# On current hardware, the thorough test runs
>> -- 
>> 2.22.0


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