code: func (devices *DeviceSet) removeDevice(devname string) error {
  	var err error
  
  	logrus.WithField("storage-driver", "devicemapper").Debugf("removeDevice START(%s)", devname)
  	defer logrus.WithField("storage-driver", "devicemapper").Debugf("removeDevice END(%s)", devname)
  
  	for i := 0; i < 200; i++ {
  		err = devicemapper.RemoveDevice(devname)
  		if err == nil {
  			break
  		}
  		if err != devicemapper.ErrBusy {
  			return err
  		}
  
  		// If we see EBUSY it may be a transient error,
  		// sleep a bit a retry a few times.
  		devices.Unlock()
  		time.Sleep(100 * time.Millisecond)
  		devices.Lock()
  	}
  
  	return err
  }
docs: // Issues the underlying dm remove operation.