Re: [Qemu-devel] [PATCH 5/5] iotests: add transactional failure race test

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

On 08.08.2016 22:09, John Snow wrote:
> Add a regression test for the case found by Vladimir.
>
> Reported-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> Signed-off-by: John Snow <jsnow@redhat.com>
> ---
>   tests/qemu-iotests/124     | 91 ++++++++++++++++++++++++++++++++++++++++++++++
>   tests/qemu-iotests/124.out |  4 +-
>   2 files changed, 93 insertions(+), 2 deletions(-)
>
> diff --git a/tests/qemu-iotests/124 b/tests/qemu-iotests/124
> index de7cdbe..a4a8c83 100644
> --- a/tests/qemu-iotests/124
> +++ b/tests/qemu-iotests/124
> @@ -509,6 +509,97 @@ class TestIncrementalBackup(TestIncrementalBackupBase):
>           self.check_backups()
>   
>   
> +    def test_transaction_failure_race(self):
> +        '''Test: Verify that transactions with jobs that have no data to
> +        transfer do not cause race conditions in the cancellation of the entire
> +        transaction job group.
> +        '''
> +
> +        # Create a second drive, with pattern:
> +        drive1 = self.add_node('drive1')
> +        self.img_create(drive1['file'], drive1['fmt'])
> +        io_write_patterns(drive1['file'], (('0x14', 0, 512),
> +                                           ('0x5d', '1M', '32k'),
> +                                           ('0xcd', '32M', '124k')))
> +
> +        # Create a blkdebug interface to this img as 'drive1'
> +        result = self.vm.qmp('blockdev-add', options={
> +            'id': drive1['id'],
> +            'driver': drive1['fmt'],
> +            'file': {
> +                'driver': 'blkdebug',
> +                'image': {
> +                    'driver': 'file',
> +                    'filename': drive1['file']
> +                },
> +                'set-state': [{
> +                    'event': 'flush_to_disk',
> +                    'state': 1,
> +                    'new_state': 2
> +                }],
> +                'inject-error': [{
> +                    'event': 'read_aio',
> +                    'errno': 5,
> +                    'state': 2,
> +                    'immediately': False,
> +                    'once': True
> +                }],
> +            }
> +        })
> +        self.assert_qmp(result, 'return', {})
> +
> +        # Create bitmaps and full backups for both drives
> +        drive0 = self.drives[0]
> +        dr0bm0 = self.add_bitmap('bitmap0', drive0)
> +        dr1bm0 = self.add_bitmap('bitmap0', drive1)
> +        self.create_anchor_backup(drive0)
> +        self.create_anchor_backup(drive1)
> +        self.assert_no_active_block_jobs()
> +        self.assertFalse(self.vm.get_qmp_events(wait=False))
> +
> +        # Emulate some writes
> +        self.hmp_io_writes(drive1['id'], (('0xba', 0, 512),
> +                                          ('0xef', '16M', '256k'),
> +                                          ('0x46', '32736k', '64k')))
> +
> +        # Create incremental backup targets
> +        target0 = self.prepare_backup(dr0bm0)
> +        target1 = self.prepare_backup(dr1bm0)
> +
> +        # Ask for a new incremental backup per-each drive, expecting drive1's
> +        # backup to fail and attempt to cancel the empty drive0 job.
> +        transaction = [
> +            transaction_drive_backup(drive0['id'], target0, sync='incremental',
> +                                     format=drive0['fmt'], mode='existing',
> +                                     bitmap=dr0bm0.name),
> +            transaction_drive_backup(drive1['id'], target1, sync='incremental',
> +                                     format=drive1['fmt'], mode='existing',
> +                                     bitmap=dr1bm0.name)
> +        ]
> +        result = self.vm.qmp('transaction', actions=transaction,
> +                             properties={'completion-mode': 'grouped'} )
> +        self.assert_qmp(result, 'return', {})
> +
> +        # Observe that drive0's backup is cancelled and drive1 completes with
> +        # an error.
> +        self.wait_qmp_backup_cancelled(drive0['id'])
> +        self.assertFalse(self.wait_qmp_backup(drive1['id']))
> +        error = self.vm.event_wait('BLOCK_JOB_ERROR')
> +        self.assert_qmp(error, 'data', {'device': drive1['id'],
> +                                        'action': 'report',
> +                                        'operation': 'read'})
> +        self.assertFalse(self.vm.get_qmp_events(wait=False))
> +        self.assert_no_active_block_jobs()
> +
> +        # Delete drive0's successful target and eliminate our record of the
> +        # unsuccessful drive1 target.
> +        dr0bm0.del_target()
> +        dr1bm0.del_target()
> +
> +        self.vm.shutdown()
> +
> +
> +

it is a almost duplication of test_transaction_failure, I think it would 
be better to make separate do_test_transaction_failure with parameter 
and two wrappers


>       def test_sync_dirty_bitmap_missing(self):
>           self.assert_no_active_block_jobs()
>           self.files.append(self.err_img)
> diff --git a/tests/qemu-iotests/124.out b/tests/qemu-iotests/124.out
> index 36376be..e56cae0 100644
> --- a/tests/qemu-iotests/124.out
> +++ b/tests/qemu-iotests/124.out
> @@ -1,5 +1,5 @@
> -..........
> +...........
>   ----------------------------------------------------------------------
> -Ran 10 tests
> +Ran 11 tests
>   
>   OK


-- 
Best regards,
Vladimir