From cfdf561dade73ad224d0e7272591b969af8ff458 Mon Sep 17 00:00:00 2001
From: Michael Hanselmann <hansmi@google.com>
Date: Wed, 18 Apr 2012 23:15:38 +0200
Subject: [PATCH] Stop using locks in LUXI "QueryTags"

Also mark it as deprecated in NEWS as normal queries can be used
instead.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>
---
 NEWS                  |    6 +++---
 lib/cmdlib.py         |   15 +++++++++++++--
 lib/opcodes.py        |    2 ++
 lib/server/masterd.py |    2 +-
 4 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/NEWS b/NEWS
index 8b90d0d..97bfcb9 100644
--- a/NEWS
+++ b/NEWS
@@ -16,9 +16,9 @@ Version 2.6.0 beta1
   ``Query(what=QR_LOCK, ...)`` instead.
 - The LUXI requests :pyeval:`luxi.REQ_QUERY_JOBS`,
   :pyeval:`luxi.REQ_QUERY_INSTANCES`, :pyeval:`luxi.REQ_QUERY_NODES`,
-  :pyeval:`luxi.REQ_QUERY_GROUPS` and :pyeval:`luxi.REQ_QUERY_EXPORTS`
-  are deprecated and will be removed in a future version.
-  :pyeval:`luxi.REQ_QUERY` should be used instead.
+  :pyeval:`luxi.REQ_QUERY_GROUPS`, :pyeval:`luxi.REQ_QUERY_EXPORTS` and
+  :pyeval:`luxi.REQ_QUERY_TAGS` are deprecated and will be removed in a
+  future version. :pyeval:`luxi.REQ_QUERY` should be used instead.
 
 
 Version 2.5.0
diff --git a/lib/cmdlib.py b/lib/cmdlib.py
index 06b90f2..3fd50c1 100644
--- a/lib/cmdlib.py
+++ b/lib/cmdlib.py
@@ -14292,14 +14292,25 @@ class TagsLU(NoHooksLU): # pylint: disable=W0223
   def ExpandNames(self):
     self.group_uuid = None
     self.needed_locks = {}
+
     if self.op.kind == constants.TAG_NODE:
       self.op.name = _ExpandNodeName(self.cfg, self.op.name)
-      self.needed_locks[locking.LEVEL_NODE] = self.op.name
+      lock_level = locking.LEVEL_NODE
+      lock_name = self.op.name
     elif self.op.kind == constants.TAG_INSTANCE:
       self.op.name = _ExpandInstanceName(self.cfg, self.op.name)
-      self.needed_locks[locking.LEVEL_INSTANCE] = self.op.name
+      lock_level = locking.LEVEL_INSTANCE
+      lock_name = self.op.name
     elif self.op.kind == constants.TAG_NODEGROUP:
       self.group_uuid = self.cfg.LookupNodeGroup(self.op.name)
+      lock_level = locking.LEVEL_NODEGROUP
+      lock_name = self.group_uuid
+    else:
+      lock_level = None
+      lock_name = None
+
+    if lock_level and getattr(self.op, "use_locking", True):
+      self.needed_locks[lock_level] = lock_name
 
     # FIXME: Acquire BGL for cluster tag operations (as of this writing it's
     # not possible to acquire the BGL based on opcode parameters)
diff --git a/lib/opcodes.py b/lib/opcodes.py
index 828497f..2464c93 100644
--- a/lib/opcodes.py
+++ b/lib/opcodes.py
@@ -1737,6 +1737,8 @@ class OpTagsGet(OpCode):
   OP_DSC_FIELD = "name"
   OP_PARAMS = [
     _PTagKind,
+    # Not using _PUseLocking as the default is different for historical reasons
+    ("use_locking", True, ht.TBool, "Whether to use synchronization"),
     # Name is only meaningful for nodes and instances
     ("name", ht.NoDefault, ht.TMaybeString, None),
     ]
diff --git a/lib/server/masterd.py b/lib/server/masterd.py
index 4284e71..d799faa 100644
--- a/lib/server/masterd.py
+++ b/lib/server/masterd.py
@@ -393,7 +393,7 @@ class ClientOps:
     elif method == luxi.REQ_QUERY_TAGS:
       (kind, name) = args
       logging.info("Received tags query request")
-      op = opcodes.OpTagsGet(kind=kind, name=name)
+      op = opcodes.OpTagsGet(kind=kind, name=name, use_locking=False)
       return self._Query(op)
 
     elif method == luxi.REQ_QUEUE_SET_DRAIN_FLAG:
-- 
1.7.10.4