Re: [PATCH v2 1/2] iotests: Refactor blockdev-reopen test for iothreads

[John Snow <jsnow@redhat.com>]

On 3/6/20 9:14 AM, Kevin Wolf wrote:
> We'll want to test more than one successful case in the future, so
> prepare the test for that by a refactoring that runs each scenario in a
> separate VM.
> 
> test_iothreads_switch_{backing,overlay} currently produce errors, but
> these are cases that should actually work, by switching either the
> backing file node or the overlay node to the AioContext of the other
> node.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> Tested-by: Peter Krempa <pkrempa@redhat.com>

Reviewed-by: John Snow <jsnow@redhat.com>

> ---
>  tests/qemu-iotests/245     | 47 ++++++++++++++++++++++++++++++--------
>  tests/qemu-iotests/245.out |  4 ++--
>  2 files changed, 39 insertions(+), 12 deletions(-)
> 
> diff --git a/tests/qemu-iotests/245 b/tests/qemu-iotests/245
> index 489bf78bd0..7d9eb6285c 100755
> --- a/tests/qemu-iotests/245
> +++ b/tests/qemu-iotests/245
> @@ -970,8 +970,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
>          self.assertEqual(self.get_node('hd1'), None)
>          self.assert_qmp(self.get_node('hd2'), 'ro', True)
>  
> -    # We don't allow setting a backing file that uses a different AioContext
> -    def test_iothreads(self):
> +    def run_test_iothreads(self, iothread_a, iothread_b, errmsg = None):
>          opts = hd_opts(0)
>          result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
>          self.assert_qmp(result, 'return', {})
> @@ -986,20 +985,48 @@ class TestBlockdevReopen(iotests.QMPTestCase):
>          result = self.vm.qmp('object-add', qom_type='iothread', id='iothread1')
>          self.assert_qmp(result, 'return', {})
>  
> -        result = self.vm.qmp('x-blockdev-set-iothread', node_name='hd0', iothread='iothread0')
> +        result = self.vm.qmp('device_add', driver='virtio-scsi', id='scsi0',
> +                             iothread=iothread_a)
>          self.assert_qmp(result, 'return', {})
>  
> -        self.reopen(opts, {'backing': 'hd2'}, "Cannot use a new backing file with a different AioContext")
> -
> -        result = self.vm.qmp('x-blockdev-set-iothread', node_name='hd2', iothread='iothread1')
> +        result = self.vm.qmp('device_add', driver='virtio-scsi', id='scsi1',
> +                             iothread=iothread_b)
>          self.assert_qmp(result, 'return', {})
>  
> -        self.reopen(opts, {'backing': 'hd2'}, "Cannot use a new backing file with a different AioContext")
> +        if iothread_a:
> +            result = self.vm.qmp('device_add', driver='scsi-hd', drive='hd0',
> +                                 share_rw=True, bus="scsi0.0")
> +            self.assert_qmp(result, 'return', {})
>  
> -        result = self.vm.qmp('x-blockdev-set-iothread', node_name='hd2', iothread='iothread0')
> -        self.assert_qmp(result, 'return', {})
> +        if iothread_b:
> +            result = self.vm.qmp('device_add', driver='scsi-hd', drive='hd2',
> +                                 share_rw=True, bus="scsi1.0")
> +            self.assert_qmp(result, 'return', {})
>  
> -        self.reopen(opts, {'backing': 'hd2'})
> +        # Attaching the backing file may or may not work
> +        self.reopen(opts, {'backing': 'hd2'}, errmsg)
> +
> +        # But removing the backing file should always work
> +        self.reopen(opts, {'backing': None})
> +
> +        self.vm.shutdown()
> +
> +    # We don't allow setting a backing file that uses a different AioContext if
> +    # neither of them can switch to the other AioContext
> +    def test_iothreads_error(self):
> +        self.run_test_iothreads('iothread0', 'iothread1',
> +                                "Cannot use a new backing file with a different AioContext")
> +
> +    def test_iothreads_compatible_users(self):
> +        self.run_test_iothreads('iothread0', 'iothread0')
> +
> +    def test_iothreads_switch_backing(self):
> +        self.run_test_iothreads('iothread0', None,
> +                                "Cannot use a new backing file with a different AioContext")
> +
> +    def test_iothreads_switch_overlay(self):
> +        self.run_test_iothreads(None, 'iothread0',
> +                                "Cannot use a new backing file with a different AioContext")
>  
>  if __name__ == '__main__':
>      iotests.main(supported_fmts=["qcow2"],
> diff --git a/tests/qemu-iotests/245.out b/tests/qemu-iotests/245.out
> index a19de5214d..682b93394d 100644
> --- a/tests/qemu-iotests/245.out
> +++ b/tests/qemu-iotests/245.out
> @@ -1,6 +1,6 @@
> -..................
> +.....................
>  ----------------------------------------------------------------------
> -Ran 18 tests
> +Ran 21 tests
>  
>  OK
>  {"execute": "job-finalize", "arguments": {"id": "commit0"}}
> 

-- 
—js