Re: [Qemu-devel] [PATCH 3/3] iotests/124: Add cluster_size mismatch test

[Fam Zheng <famz@redhat.com>]

On Fri, 02/12 18:06, John Snow wrote:
> If a backing file isn't specified in the target image and the
> cluster_size is larger than the bitmap granularity, we run the risk of
> creating bitmaps with allocated clusters but empty/no data which will
> prevent the proper reading of the backup in the future.
> 
> Signed-off-by: John Snow <jsnow@redhat.com>
> ---
>  tests/qemu-iotests/124     | 58 ++++++++++++++++++++++++++++++++++++++++++----
>  tests/qemu-iotests/124.out |  4 ++--
>  2 files changed, 55 insertions(+), 7 deletions(-)
> 
> diff --git a/tests/qemu-iotests/124 b/tests/qemu-iotests/124
> index 7d33422..efbb5bd 100644
> --- a/tests/qemu-iotests/124
> +++ b/tests/qemu-iotests/124
> @@ -132,14 +132,16 @@ class TestIncrementalBackupBase(iotests.QMPTestCase):
>  
>  
>      def img_create(self, img, fmt=iotests.imgfmt, size='64M',
> -                   parent=None, parentFormat=None):
> +                   parent=None, parentFormat=None, **kwargs):
> +        optargs = []
> +        for k,v in kwargs.iteritems():
> +            optargs = optargs + ['-o', '%s=%s' % (k,v)]
> +        args = ['create', '-f', fmt] + optargs + [img, size]
>          if parent:
>              if parentFormat is None:
>                  parentFormat = fmt
> -            iotests.qemu_img('create', '-f', fmt, img, size,
> -                             '-b', parent, '-F', parentFormat)
> -        else:
> -            iotests.qemu_img('create', '-f', fmt, img, size)
> +            args = args + ['-b', parent, '-F', parentFormat]
> +        iotests.qemu_img(*args)
>          self.files.append(img)
>  
>  
> @@ -307,6 +309,52 @@ class TestIncrementalBackup(TestIncrementalBackupBase):
>          return self.do_incremental_simple(granularity=131072)
>  
>  
> +    def test_larger_cluster_target(self):
> +        '''
> +        Test: Create and verify backups made to a larger cluster size target.
> +
> +        With a default granularity of 64KiB, verify that backups made to a
> +        larger cluster size target of 128KiB works as expected.
> +        '''
> +        drive0 = self.drives[0]
> +
> +        # Create a cluster_size=128k full backup / "anchor" backup
> +        self.img_create(drive0['backup'], cluster_size='128k')
> +        self.assertTrue(self.do_qmp_backup(device=drive0['id'], sync='full',
> +                                           format=drive0['fmt'],
> +                                           target=drive0['backup'],
> +                                           mode='existing'))
> +
> +        # Create bitmap and dirty it with some new writes.
> +        # overwrite [32736, 32799] which will dirty bitmap clusters at
> +        # 32M-64K and 32M. 32M+64K will be left undirtied.
> +        bitmap0 = self.add_bitmap('bitmap0', drive0)
> +        self.hmp_io_writes(drive0['id'],
> +                           (('0xab', 0, 512),
> +                            ('0xfe', '16M', '256k'),
> +                            ('0x64', '32736k', '64k')))
> +
> +
> +        # Prepare a cluster_size=128k backup target without a backing file.
> +        (target, _) = bitmap0.new_target()
> +        self.img_create(target, bitmap0.drive['fmt'], cluster_size='128k')
> +
> +        # Perform Incremental Backup
> +        self.assertTrue(self.do_qmp_backup(device=bitmap0.drive['id'],
> +                                           sync='incremental',
> +                                           bitmap=bitmap0.name,
> +                                           format=bitmap0.drive['fmt'],
> +                                           target=target,
> +                                           mode='existing'))
> +        self.make_reference_backup(bitmap0)
> +
> +        # Add the backing file, then compare and exit.
> +        iotests.qemu_img('rebase', '-f', drive0['fmt'], '-u', '-b',
> +                         drive0['backup'], '-F', drive0['fmt'], target)
> +        self.vm.shutdown()
> +        self.check_backups()
> +
> +
>      def test_incremental_transaction(self):
>          '''Test: Verify backups made from transactionally created bitmaps.
>  
> diff --git a/tests/qemu-iotests/124.out b/tests/qemu-iotests/124.out
> index dae404e..36376be 100644
> --- a/tests/qemu-iotests/124.out
> +++ b/tests/qemu-iotests/124.out
> @@ -1,5 +1,5 @@
> -.........
> +..........
>  ----------------------------------------------------------------------
> -Ran 9 tests
> +Ran 10 tests
>  
>  OK
> -- 
> 2.4.3
> 

Reviewed-by: Fam Zheng <famz@redhat.com>