On 01.08.19 19:25, Vladimir Sementsov-Ogievskiy wrote:
> 01.08.2019 20:06, Max Reitz wrote:
>> On 01.08.19 18:03, Vladimir Sementsov-Ogievskiy wrote:
>>> 01.08.2019 18:12, Max Reitz wrote:
>>>> Perform two guest writes to not yet backed up areas of an image, where
>>>> the former touches an inner area of the latter.
>>>>
>>>> Before HEAD^, copy offloading broke this in two ways:
>>>> (1) The output differs from the reference output (what the source was
>>>> before the guest writes).
>>>> (2) But you will not see that in the failing output, because the job
>>>> offset is reported as being greater than the job length. This is
>>>> because one cluster is copied twice, and thus accounted for twice,
>>>> but of course the job length does not increase.
>>>>
>>>> Signed-off-by: Max Reitz <mre...@redhat.com>
>>>> ---
>>>> tests/qemu-iotests/056 | 34 ++++++++++++++++++++++++++++++++++
>>>> tests/qemu-iotests/056.out | 4 ++--
>>>> 2 files changed, 36 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/tests/qemu-iotests/056 b/tests/qemu-iotests/056
>>>> index f40fc11a09..d7198507f5 100755
>>>> --- a/tests/qemu-iotests/056
>>>> +++ b/tests/qemu-iotests/056
>>>> @@ -133,6 +133,7 @@ class BackupTest(iotests.QMPTestCase):
>>>> self.vm = iotests.VM()
>>>> self.test_img = img_create('test')
>>>> self.dest_img = img_create('dest')
>>>> + self.ref_img = img_create('ref')
>>>> self.vm.add_drive(self.test_img)
>>>> self.vm.launch()
>>>>
>>>> @@ -140,6 +141,7 @@ class BackupTest(iotests.QMPTestCase):
>>>> self.vm.shutdown()
>>>> try_remove(self.test_img)
>>>> try_remove(self.dest_img)
>>>> + try_remove(self.ref_img)
>>>>
>>>> def hmp_io_writes(self, drive, patterns):
>>>> for pattern in patterns:
>>>> @@ -177,6 +179,38 @@ class BackupTest(iotests.QMPTestCase):
>>>> self.assert_qmp(event, 'data/error', qerror)
>>>> return False
>>>>
>>>> + def test_overlapping_writes(self):
>>>> + # Write something to back up
>>>> + self.hmp_io_writes('drive0', [('42', '0M', '2M')])
>>>> +
>>>> + # Create a reference backup
>>>> + self.qmp_backup_and_wait(device='drive0', format=iotests.imgfmt,
>>>> + sync='full', target=self.ref_img)
>>>> +
>>>> + # Now to the test backup: We simulate the following guest
>>>> + # writes:
>>>> + # (1) [1M + 64k, 1M + 128k): Afterwards, everything in that
>>>> + # area should be in the target image, and we must not copy
>>>> + # it again (because the source image has changed now)
>>>> + # (64k is the job's cluster size)
>>>> + # (2) [1M, 2M): The backup job must not get overeager. It
>>>> + # must copy [1M, 1M + 64k) and [1M + 128k, 2M) separately,
>>>> + # but not the area in between.
>>>> +
>>>> + self.qmp_backup(device='drive0', format=iotests.imgfmt,
>>>> sync='full',
>>>> + target=self.dest_img, speed=1)
>>>> +
>>>> + self.hmp_io_writes('drive0', [('23', '%ik' % (1024 + 64), '64k'),
>>>> + ('66', '1M', '1M')])
>>>> +
>>>> + # Let the job complete
>>>> + res = self.vm.qmp('block-job-set-speed', device='drive0', speed=0)
>>>> + self.assert_qmp(res, 'return', {})
>>>> + self.qmp_backup_wait('drive0')
>>>> +
>>>> + self.assertTrue(iotests.compare_images(self.ref_img,
>>>> self.dest_img),
>>>> + 'target image does not match reference image')
>>>> +
>>>> def test_dismiss_false(self):
>>>> res = self.vm.qmp('query-block-jobs')
>>>> self.assert_qmp(res, 'return', [])
>>>> diff --git a/tests/qemu-iotests/056.out b/tests/qemu-iotests/056.out
>>>> index dae404e278..36376bed87 100644
>>>> --- a/tests/qemu-iotests/056.out
>>>> +++ b/tests/qemu-iotests/056.out
>>>> @@ -1,5 +1,5 @@
>>>> -.........
>>>> +..........
>>>> ----------------------------------------------------------------------
>>>> -Ran 9 tests
>>>> +Ran 10 tests
>>>>
>>>> OK
>>>>
>>>
>>> Failed for me:
>>> -..........
>>> +qemu-img: Could not open
>>> '/work/src/qemu/master/tests/qemu-iotests/scratch/dest.qcow2': Failed to
>>> get shared "write" lock
>>> +Is another process using the image
>>> [/work/src/qemu/master/tests/qemu-iotests/scratch/dest.qcow2]?
>>> +......F...
>>> +======================================================================
>>> +FAIL: test_overlapping_writes (__main__.BackupTest)
>>> +----------------------------------------------------------------------
>>> +Traceback (most recent call last):
>>> + File "056", line 212, in test_overlapping_writes
>>> + 'target image does not match reference image')
>>> +AssertionError: False is not true : target image does not match reference
>>> image
>>> +
>>> ----------------------------------------------------------------------
>>> Ran 10 tests
>>>
>>> -OK
>>> +FAILED (failures=1)
>>
>> Hm. I hoped seeing BLOCK_JOB_COMPLETED would be enough.
>
> The problem is higher: "Failed to get shared "write" lock". Because of this
> iotests.compare_images
> can't work. So, because of locking, we need to shutdown qemu before starting
> qemu-img.
> And it's done so in test_complete_top() (I just looked at it as it's the only
> other user of compare_images
> in 056)
The destination image shouldn’t be in use by qemu after the block job is
done, though. Therefore, there shouldn’t be a lock issue. That’s what
I meant.
Max
>>> So, with applied
>>>
>>> @@ -207,6 +207,7 @@ class BackupTest(iotests.QMPTestCase):
>>> res = self.vm.qmp('block-job-set-speed', device='drive0',
>>> speed=0)
>>> self.assert_qmp(res, 'return', {})
>>> self.qmp_backup_wait('drive0')
>>> + self.vm.shutdown()
>>>
>>> self.assertTrue(iotests.compare_images(self.ref_img,
>>> self.dest_img),
>>> 'target image does not match reference image')
>>
>> I’d personally prefer auto_dismiss=False and then block-job-dismiss.
>> Although I can’t give a reason why.
>>
>>> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
>>> Tested-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
>>
>> In any case, thanks!
>>
>> Max
>>
>
>
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