[L3][QoS] L3 agent QoS extension to handle duplicated FIPs

The L3 agent QoS extension should be able to handle duplicated floating
IP addresses from different registers. Those floating IP addresses can
be hosted in different networks and routers but the same compute node
and L3 agent.

Now, instead of using the IP address as unique identifier, this patch
stores the (ID, IP address) tuple. This tuple is unique per floating IP
register and holds the IP address, needed by the "tc" library to set
the QoS rules.

Closes-Bug: #1962465
Change-Id: I3a09718c6e79fd1f37eb75264389c4e5043076a7
(cherry picked from commit 132905d)

Author: ralonsoh

neutron/agent/l3/extensions/qos/base.py

@@ -53,9 +53,12 @@
 class RateLimitMaps(object):
 
     def __init__(self, lock_name):
-        self.qos_policy_resources = collections.defaultdict(dict)
+        # qos_policy_2_resources = {qos_id_1: {res_1, res_2, res_3, ...} }
+        self.qos_policy_2_resources = collections.defaultdict(set)
+        # known_policies = {qos_id_1: qos_policy_1, ...}
         self.known_policies = {}
-        self.resource_policies = {}
+        # resource_2_qos_policies = {res1: qos_id_1, ...}
+        self.resource_2_qos_policies = {}
         self.lock_name = lock_name
 
     def update_policy(self, policy):
@@ -78,15 +81,15 @@ def get_resources(self, policy):
 
         @lockutils.synchronized(self.lock_name)
         def _get_resources():
-            return self.qos_policy_resources[policy.id].values()
+            return self.qos_policy_2_resources[policy.id]
 
         return _get_resources()
 
     def get_resource_policy(self, resource):
 
         @lockutils.synchronized(self.lock_name)
         def _get_resource_policy():
-            policy_id = self.resource_policies.get(resource)
+            policy_id = self.resource_2_qos_policies.get(resource)
             return self.known_policies.get(policy_id)
 
         return _get_resource_policy()
@@ -99,13 +102,13 @@ def set_resource_policy(self, resource, policy):
 
         @lockutils.synchronized(self.lock_name)
         def _set_resource_policy():
-            policy_id = self.resource_policies.get(resource)
+            policy_id = self.resource_2_qos_policies.get(resource)
             old_policy = self.known_policies.get(policy_id)
             self.known_policies[policy.id] = policy
-            self.resource_policies[resource] = policy.id
-            self.qos_policy_resources[policy.id][resource] = resource
+            self.resource_2_qos_policies[resource] = policy.id
+            self.qos_policy_2_resources[policy.id].add(resource)
             if old_policy and old_policy.id != policy.id:
-                del self.qos_policy_resources[old_policy.id][resource]
+                self.qos_policy_2_resources[old_policy.id].remove(resource)
 
         _set_resource_policy()
 
@@ -117,22 +120,21 @@ def clean_by_resource(self, resource):
 
         @lockutils.synchronized(self.lock_name)
         def _clean_by_resource():
-            if resource in self.resource_policies:
-                del self.resource_policies[resource]
-                for (qos_policy_id,
-                     res_dict) in self.qos_policy_resources.items():
-                    if resource in res_dict:
-                        del res_dict[resource]
-                        if not res_dict:
-                            self._clean_policy_info(qos_policy_id)
-                        return
-            LOG.debug("L3 QoS extension did not have "
-                      "information on floating IP %s", resource)
+            qos_policy_id = self.resource_2_qos_policies.pop(resource, None)
+            if not qos_policy_id:
+                LOG.debug("L3 QoS extension did not have "
+                          "information on floating IP %s", resource)
+                return
+
+            resources = self.qos_policy_2_resources[qos_policy_id]
+            resources.discard(resource)
+            if not resources:
+                self._clean_policy_info(qos_policy_id)
 
         _clean_by_resource()
 
     def _clean_policy_info(self, qos_policy_id):
-        del self.qos_policy_resources[qos_policy_id]
+        del self.qos_policy_2_resources[qos_policy_id]
         del self.known_policies[qos_policy_id]