LUClusterVerifyConfig: Share BGL, acquire all locks in shared mode

Instead of acquiring the BGL in exclusive mode (which blocks all other
operations), we acquire all locks for groups, nodes and instances in
shared mode before verifying the configuration.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Bernardo Dal Seno <bdalseno@google.com>

diff --git a/lib/cmdlib.py b/lib/cmdlib.py
index b432794..005d493 100644 (file)
--- a/lib/cmdlib.py
+++ b/lib/cmdlib.py
@@ -1555,7 +1555,7 @@ class LUClusterVerifyConfig(NoHooksLU, _VerifyErrors):
   """Verifies the cluster config.
 
   """
-  REQ_BGL = True
+  REQ_BGL = False
 
   def _VerifyHVP(self, hvp_data):
     """Verifies locally the syntax of the hypervisor parameters.
@@ -1572,13 +1572,17 @@ class LUClusterVerifyConfig(NoHooksLU, _VerifyErrors):
         self._ErrorIf(True, self.ECLUSTERCFG, None, msg % str(err))
 
   def ExpandNames(self):
-    # Information can be safely retrieved as the BGL is acquired in exclusive
-    # mode
-    assert locking.BGL in self.owned_locks(locking.LEVEL_CLUSTER)
+    self.needed_locks = dict.fromkeys(locking.LEVELS, locking.ALL_SET)
+    self.share_locks = _ShareAll()
+
+  def CheckPrereq(self):
+    """Check prerequisites.
+
+    """
+    # Retrieve all information
     self.all_group_info = self.cfg.GetAllNodeGroupsInfo()
     self.all_node_info = self.cfg.GetAllNodesInfo()
     self.all_inst_info = self.cfg.GetAllInstancesInfo()
-    self.needed_locks = {}
 
   def Exec(self, feedback_fn):
     """Verify integrity of cluster, performing various test on nodes.