LVM: Activate LV before creating exports

In some circumstances (such as after a reboot),
especially with thin LVM, the LV may not be activated, so
creating a target from it will fail.

Activate the LV before creating a target.

When using permanent=True for activation, don't supply
the -K/ignoreskipactivation argument.  This is rejected
by LVM 2.02.171, and is not a reasonable request, since
it asks to simultaneously unset a flag, and also to ignore
the flag (which should now be unset) during the same
activation operation.

This fixes a failure to clone a volume from another thin
LVM volume in the same pool.

Closes-Bug: #1701545

Change-Id: I925ece8833cc99a95c4cf693804ca3698f8cb114

cinder/brick/local_dev/lvm.py

@@ -676,11 +676,12 @@ class LVM(executor.Executor):
         cmd = ['lvchange', '-a', 'y', '--yes']
 
         if self.supports_lvchange_ignoreskipactivation:
-            cmd.append('-K')
             # If permanent=True is specified, drop the skipactivation flag in
             # order to make this LV automatically activated after next reboot.
             if permanent:
                 cmd += ['-k', 'n']
+            else:
+                cmd.append('-K')
 
         cmd.append(lv_path)
 

cinder/volume/drivers/lvm.py

@@ -790,6 +790,8 @@ class LVMVolumeDriver(driver.VolumeDriver):
         volume_path = "/dev/%s/%s" % (self.configuration.volume_group,
                                       volume['name'])
 
+        self.vg.activate_lv(volume['name'])
+
         model_update = \
             self.target_driver.ensure_export(context, volume, volume_path)
         return model_update
@@ -800,6 +802,8 @@ class LVMVolumeDriver(driver.VolumeDriver):
 
         volume_path = "/dev/%s/%s" % (vg, volume['name'])
 
+        self.vg.activate_lv(volume['name'])
+
         export_info = self.target_driver.create_export(
             context,
             volume,