Re: [PATCH] iotests: 194: wait migration completion on target too

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Vladimir Sementsov-Ogievskiy (vsementsov@virtuozzo.com) wrote:
> It is possible, that shutdown on target occurs earlier than migration
> finish. In this case we crash in bdrv_release_dirty_bitmap_locked()
> on assertion "assert(!bdrv_dirty_bitmap_busy(bitmap));" as we do have
> busy bitmap, as bitmap migration is ongoing.
> 
> We'll fix bitmap migration to gracefully cancel on early shutdown soon.
> Now let's fix iotest 194 to wait migration completion before shutdown.
> 
> Note that in this test dest_vm.shutdown() is called implicitly, as vms
> used as context-providers, see __exit__() method of QEMUMachine class.
> 
> Actually, not waiting migration finish is a wrong thing, but the test
> started to crash after commit ae00aa239847682
> "iotests: 194: test also migration of dirty bitmap", which added dirty
> bitmaps here. So, Fixes: tag won't hurt.

Without knowing the iotests framework, the actual problem sounds right;
I just fixed a similar bug in the acceptance test migration code.
Every migration test seems to make the same mistake!

Dave

> Fixes: ae00aa2398476824f0eca80461da215e7cdc1c3b
> Reported-by: Thomas Huth <thuth@redhat.com>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>  tests/qemu-iotests/194     | 10 ++++++++++
>  tests/qemu-iotests/194.out |  5 +++++
>  2 files changed, 15 insertions(+)
> 
> diff --git a/tests/qemu-iotests/194 b/tests/qemu-iotests/194
> index 3fad7c6c1a..6dc2bc94d7 100755
> --- a/tests/qemu-iotests/194
> +++ b/tests/qemu-iotests/194
> @@ -87,4 +87,14 @@ with iotests.FilePath('source.img') as source_img_path, \
>              iotests.log(dest_vm.qmp('nbd-server-stop'))
>              break
>  
> +    iotests.log('Wait migration completion on target...')
> +    migr_events = (('MIGRATION', {'data': {'status': 'completed'}}),
> +                   ('MIGRATION', {'data': {'status': 'failed'}}))
> +    event = dest_vm.events_wait(migr_events)
> +    iotests.log(event, filters=[iotests.filter_qmp_event])
> +
> +    iotests.log('Check bitmaps on source:')
>      iotests.log(source_vm.qmp('query-block')['return'][0]['dirty-bitmaps'])
> +
> +    iotests.log('Check bitmaps on target:')
> +    iotests.log(dest_vm.qmp('query-block')['return'][0]['dirty-bitmaps'])
> diff --git a/tests/qemu-iotests/194.out b/tests/qemu-iotests/194.out
> index dd60dcc14f..f70cf7610e 100644
> --- a/tests/qemu-iotests/194.out
> +++ b/tests/qemu-iotests/194.out
> @@ -21,4 +21,9 @@ Gracefully ending the `drive-mirror` job on source...
>  {"data": {"device": "mirror-job0", "len": 1073741824, "offset": 1073741824, "speed": 0, "type": "mirror"}, "event": "BLOCK_JOB_COMPLETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
>  Stopping the NBD server on destination...
>  {"return": {}}
> +Wait migration completion on target...
> +{"data": {"status": "completed"}, "event": "MIGRATION", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
> +Check bitmaps on source:
> +[{"busy": false, "count": 0, "granularity": 65536, "name": "bitmap0", "persistent": false, "recording": true, "status": "active"}]
> +Check bitmaps on target:
>  [{"busy": false, "count": 0, "granularity": 65536, "name": "bitmap0", "persistent": false, "recording": true, "status": "active"}]
> -- 
> 2.21.0
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK