LUNodeQueryStorage: Use node allocation lock

Block instance allocations when all node locks will be acquired.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Michele Tartara <mtartara@google.com>

lib/cmdlib.py

@@ -5386,13 +5386,16 @@ class LUNodeQueryStorage(NoHooksLU):
   def ExpandNames(self):
     self.share_locks = _ShareAll()
-    self.needed_locks = {}
     if self.op.nodes:
-      self.needed_locks[locking.LEVEL_NODE] = \
-        _GetWantedNodes(self, self.op.nodes)
+      self.needed_locks = {
+        locking.LEVEL_NODE: _GetWantedNodes(self, self.op.nodes),
+        }
     else:
-      self.needed_locks[locking.LEVEL_NODE] = locking.ALL_SET
+      self.needed_locks = {
+        locking.LEVEL_NODE: locking.ALL_SET,
+        locking.LEVEL_NODE_ALLOC: locking.ALL_SET,
+        }
   def Exec(self, feedback_fn):
     """Computes the list of nodes and their attributes.