X-Git-Url: https://code.grnet.gr/git/ganeti-local/blobdiff_plain/984f7c32208f7834c6d6ae22e98dfa126e175981..ac0930b925974d3bb1174cf3922bafc4fbe50596:/lib/mcpu.py

diff --git a/lib/mcpu.py b/lib/mcpu.py
index be9a372..4bdfb46 100644
--- a/lib/mcpu.py
+++ b/lib/mcpu.py
@@ -101,6 +101,51 @@ class Processor(object):
     self._feedback_fn = feedback
     self.exclusive_BGL = False
 
+  def _ExecLU(self, lu):
+    """Logical Unit execution sequence.
+
+    """
+    write_count = self.context.cfg.write_count
+    lu.CheckPrereq()
+    hm = HooksMaster(rpc.call_hooks_runner, self, lu)
+    h_results = hm.RunPhase(constants.HOOKS_PHASE_PRE)
+    lu.HooksCallBack(constants.HOOKS_PHASE_PRE, h_results,
+                     self._feedback_fn, None)
+    try:
+      result = lu.Exec(self._feedback_fn)
+      h_results = hm.RunPhase(constants.HOOKS_PHASE_POST)
+      result = lu.HooksCallBack(constants.HOOKS_PHASE_POST, h_results,
+                                self._feedback_fn, result)
+    finally:
+      # FIXME: This needs locks if not lu_class.REQ_BGL
+      if write_count != self.context.cfg.write_count:
+        hm.RunConfigUpdate()
+
+    return result
+
+  def _LockAndExecLU(self, lu, level):
+    """Execute a Logical Unit, with the needed locks.
+
+    This is a recursive function that starts locking the given level, and
+    proceeds up, till there are no more locks to acquire. Then it executes the
+    given LU and its opcodes.
+
+    """
+    if level in lu.needed_locks:
+      # This is always safe to do, as we can't acquire more/less locks than
+      # what was requested.
+      lu.needed_locks[level] = self.context.glm.acquire(level,
+                                                        lu.needed_locks[level])
+      try:
+        result = self._LockAndExecLU(lu, level + 1)
+      finally:
+        if lu.needed_locks[level]:
+          self.context.glm.release(level)
+    else:
+      result = self._ExecLU(lu)
+
+    return result
+
   def ExecOpCode(self, op):
     """Execute an opcode.
 
@@ -121,29 +166,16 @@ class Processor(object):
     else:
       sstore = ssconf.SimpleStore()
 
-    write_count = self.context.cfg.write_count
-
     # Acquire the Big Ganeti Lock exclusively if this LU requires it, and in a
     # shared fashion otherwise (to prevent concurrent run with an exclusive LU.
     self.context.glm.acquire(locking.LEVEL_CLUSTER, [locking.BGL],
                              shared=not lu_class.REQ_BGL)
     try:
       self.exclusive_BGL = lu_class.REQ_BGL
-      lu = lu_class(self, op, self.context.cfg, sstore)
-      lu.CheckPrereq()
-      hm = HooksMaster(rpc.call_hooks_runner, self, lu)
-      h_results = hm.RunPhase(constants.HOOKS_PHASE_PRE)
-      lu.HooksCallBack(constants.HOOKS_PHASE_PRE, h_results,
-                       self._feedback_fn, None)
-      try:
-        result = lu.Exec(self._feedback_fn)
-        h_results = hm.RunPhase(constants.HOOKS_PHASE_POST)
-        result = lu.HooksCallBack(constants.HOOKS_PHASE_POST, h_results,
-                                  self._feedback_fn, result)
-      finally:
-        # FIXME: This needs locks if not lu_class.REQ_BGL
-        if write_count != self.context.cfg.write_count:
-          hm.RunConfigUpdate()
+      lu = lu_class(self, op, self.context, sstore)
+      lu.ExpandNames()
+      assert lu.needed_locks is not None, "needed_locks not set by LU"
+      result = self._LockAndExecLU(lu, locking.LEVEL_NODE)
     finally:
       self.context.glm.release(locking.LEVEL_CLUSTER)
       self.exclusive_BGL = False
@@ -177,7 +209,7 @@ class Processor(object):
       sstore = ssconf.SimpleStore()
 
     #do_hooks = lu_class.HPATH is not None
-    lu = lu_class(self, op, self.context.cfg, sstore)
+    lu = lu_class(self, op, self.context, sstore)
     lu.CheckPrereq()
     #if do_hooks:
     #  hm = HooksMaster(rpc.call_hooks_runner, self, lu)