storage/callback: add a post_volume_start callback

qubes/storage/callback.json.example

@@ -16,6 +16,7 @@
         "post_volume_remove": "Called after removal of a volume of the pool. Same as above otherwise.",
         "pre_volume_resize": "Called before resizing a volume of the pool. Same as above otherwise.",
         "pre_volume_start": "Called before starting a volume of the pool. Same as above otherwise.",
+        "post_volume_start": "Called after starting a volume of the pool. Same as above otherwise.",
         "post_volume_stop": "Called after stopping a volume of the pool. Same as above otherwise.",
         "pre_volume_import": "Called before importing a volume from elsewhere. Same as above otherwise.",
         "pre_volume_import_data": "Called before importing a volume from elsewhere. Same as above otherwise.",

qubes/storage/callback.py

@@ -85,13 +85,13 @@ class CallbackPool(qubes.storage.Pool):
     qvm-volume | grep test-vm
     grep test-vm /var/lib/qubes/qubes.xml
     ls /mnt/test02/appvms/
-    cat /tmp/callback.log (2x pre_volume_start should be added)
+    cat /tmp/callback.log (2x pre_volume_start & 2x post_volume_start should be added)
     qvm-shutdown test-vm
     cat /tmp/callback.log (2x post_volume_stop should be added)
     #reboot
     cat /tmp/callback.log (only (!) post_ctor should be there)
     qvm-start test-vm
-    cat /tmp/callback.log (pre_sinit & 2x pre_volume_start should be added)
+    cat /tmp/callback.log (pre_sinit & 2x pre_volume_start & 2x post_volume_start should be added)
     qvm-shutdown --wait test-vm && qvm-remove test-vm
     qvm-pool -r test && sudo rm -rf /mnt/test02
     less /tmp/callback.log (2x post_volume_stop, 2x post_volume_remove, post_destroy should be added)
@@ -468,7 +468,9 @@ def resize(self, size):
     def start(self):
         yield from self._assert_initialized()
         yield from self._callback('pre_volume_start')
-        return (yield from coro_maybe(self._cb_impl.start()))
+        ret = yield from coro_maybe(self._cb_impl.start())
+        yield from self._callback('post_volume_start')
+        return ret
 
     @asyncio.coroutine
     def stop(self):