Error: concurrent.futures.process._RemoteTraceback: 
"""
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/middlewared/plugins/zfs.py", line 660, in inherit
    zprop.inherit(recursive=recursive)
  File "libzfs.pyx", line 367, in libzfs.ZFS.__exit__
  File "/usr/local/lib/python3.7/site-packages/middlewared/plugins/zfs.py", line 660, in inherit
    zprop.inherit(recursive=recursive)
  File "libzfs.pyx", line 1475, in libzfs.ZFSProperty.inherit
libzfs.ZFSException: Device busy

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.7/concurrent/futures/process.py", line 239, in _process_worker
    r = call_item.fn(*call_item.args, **call_item.kwargs)
  File "/usr/local/lib/python3.7/site-packages/middlewared/worker.py", line 95, in main_worker
    res = loop.run_until_complete(coro)
  File "/usr/local/lib/python3.7/asyncio/base_events.py", line 579, in run_until_complete
    return future.result()
  File "/usr/local/lib/python3.7/site-packages/middlewared/worker.py", line 51, in _run
    return await self._call(name, serviceobj, methodobj, params=args, job=job)
  File "/usr/local/lib/python3.7/site-packages/middlewared/worker.py", line 43, in _call
    return methodobj(*params)
  File "/usr/local/lib/python3.7/site-packages/middlewared/worker.py", line 43, in _call
    return methodobj(*params)
  File "/usr/local/lib/python3.7/site-packages/middlewared/plugins/zfs.py", line 662, in inherit
    raise CallError(str(e))
middlewared.service_exception.CallError: [EFAULT] Device busy
"""

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/middlewared/job.py", line 349, in run
    await self.future
  File "/usr/local/lib/python3.7/site-packages/middlewared/job.py", line 386, in __run_body
    rv = await self.method(*([self] + args))
  File "/usr/local/lib/python3.7/site-packages/middlewared/schema.py", line 949, in nf
    return await f(*args, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/middlewared/plugins/pool.py", line 1889, in import_pool
    await self.middleware.call('zfs.dataset.inherit', pool_name, 'mountpoint', True)
  File "/usr/local/lib/python3.7/site-packages/middlewared/main.py", line 1122, in call
    app=app, pipes=pipes, job_on_progress_cb=job_on_progress_cb, io_thread=True,
  File "/usr/local/lib/python3.7/site-packages/middlewared/main.py", line 1058, in _call
    return await self._call_worker(name, *args)
  File "/usr/local/lib/python3.7/site-packages/middlewared/main.py", line 1078, in _call_worker
    return await self.run_in_proc(main_worker, name, args, job)
  File "/usr/local/lib/python3.7/site-packages/middlewared/main.py", line 1013, in run_in_proc
    return await self.run_in_executor(self.__procpool, method, *args, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/middlewared/main.py", line 987, in run_in_executor
    return await loop.run_in_executor(pool, functools.partial(method, *args, **kwargs))
middlewared.service_exception.CallError: [EFAULT] Device busy