Export cinder volumes only if the status is 'in-use'

Currently, cinder volumes are exported both 'in-use' and 'available'
after restarting cinder-volume service.
This behavior was introduced following commit.

  commit ffefe18334
  Author: Zhiteng Huang <zhithuang@ebaysf.com>
  Date: Sat Aug 23 18:32:57 2014 +0000

If the volumes are attached to nova instances, they should be exported
via tgtd after restarting cinder-volume.
But the volumes which are not attached to instances must not be exported
because everyone can connect these volumes.

This patch changes volume export behavior that exports a volume only if
the volume status is 'in-use'.

Change-Id: I4c598c240b9290c81bd8001e5a0720c8c329aeb9
Signed-off-by: Mitsuhiro Tanino <mitsuhiro.tanino@hds.com>
Closes-bug: #1381106
(cherry picked from commit e2f28b9679)

cinder/volume/manager.py

@@ -272,7 +272,8 @@ class VolumeManager(manager.SchedulerDependentManager):
                     self._count_allocated_capacity(ctxt, volume)
 
                     try:
-                        self.driver.ensure_export(ctxt, volume)
+                        if volume['status'] in ['in-use']:
+                            self.driver.ensure_export(ctxt, volume)
                     except Exception as export_ex:
                         LOG.error(_("Failed to re-export volume %s: "
                                     "setting to error state"), volume['id'])