test_instances_with_cinder_volumes_on_all_compute_nodes fails with device or resource busy

[Martin Kopec]

test_instances_with_cinder_volumes_on_all_compute_nodes[compute,id-d0e3c1a3-4b0a-4b0e-8b0a-4b0e8b0a4b0e,image,multinode,network,slow,volume] fails from time to time with the following traceback:

Traceback (most recent call last):
  File "/opt/stack/tempest/tempest/common/utils/__init__.py", line 70, in wrapper
    return f(*func_args, **func_kwargs)
  File "/opt/stack/tempest/tempest/scenario/test_instances_with_cinder_volumes.py", line 200, in test_instances_with_cinder_volumes_on_all_compute_nodes
    timestamp_before = self.create_timestamp(
  File "/opt/stack/tempest/tempest/scenario/manager.py", line 1233, in create_timestamp
    ssh_client.exec_command('sudo mount /dev/%s %s' % (dev_name,
  File "/opt/stack/tempest/tempest/lib/common/utils/linux/remote_client.py", line 31, in wrapper
    return function(self, *args, **kwargs)
  File "/opt/stack/tempest/tempest/lib/common/utils/linux/remote_client.py", line 115, in exec_command
    return self.ssh_client.exec_command(cmd)
  File "/opt/stack/tempest/tempest/lib/common/ssh.py", line 238, in exec_command
    raise exceptions.SSHExecCommandFailed(
tempest.lib.exceptions.SSHExecCommandFailed: Command 'set -eu -o pipefail; PATH=$PATH:/sbin:/usr/sbin; sudo mount /dev/vdb /mnt/vdb', exit status: 255, stderr:
mount: mounting /dev/vdb on /mnt/vdb failed: Device or resource busy

https://db09a60de13cd5f710fa-aace7598638ebd17f7ac5b5df39ccb78.ssl.cf2.rackcdn.com/918725/8/gate/tempest-slow-py3/bb1d0f2/testr_results.html

https://351b6d2d044e61a2ad00-13b744a8e90ddbccef6c4bc9edcf0403.ssl.cf1.rackcdn.com/918725/8/gate/tempest-multinode-full-py3/ddee735/testr_results.html

[Martin Kopec (mkopec)]

also failed in tempest-all job
https://storage.gra.cloud.ovh.net/v1/AUTH_dcaab5e32b234d56b626f72581e3644c/zuul_opendev_logs_ea7/periodic/opendev.org/openstack/tempest/master/tempest-all/ea74d49/testr_results.html