From: Ben Pfaff <blp@nicira.com>
Date: Thu, 29 Aug 2013 23:49:51 +0000 (-0700)
Subject: ofproto: Avoid removing rules from meter lists twice.
X-Git-Tag: sliver-openvswitch-2.0.90-1~16^2~43
X-Git-Url: http://git.onelab.eu/?a=commitdiff_plain;h=51b50dfd0bbbaba9cd62d42530a3538b47785b15;p=sliver-openvswitch.git

ofproto: Avoid removing rules from meter lists twice.

Since the meter code was introduced, the oftable_remove_rule() function
(recently renamed oftable_remove_rule__()) has had two blocks of code to
remove a rule from its meter's list of rules that reference that meter.
This commit reduces that to one.

Also modifies oftable_remove_rule__() to maintain the invariant that
'rule' is in a meter's list if and only if
!list_is_empty(&rule->meter_list_node).  I don't believe that that fixes
a real bug, but it seems like a good idea.

(This seemed like a serious bug at first, but in fact list_remove() is
idempotent: calling it two times in a row has the same effect as calling
it once.)

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
---

diff --git a/ofproto/ofproto.c b/ofproto/ofproto.c
index 1173936e9..0b054e74d 100644
--- a/ofproto/ofproto.c
+++ b/ofproto/ofproto.c
@@ -5573,9 +5573,6 @@ oftable_remove_rule__(struct ofproto *ofproto, struct classifier *cls,
     OVS_REQ_WRLOCK(cls->rwlock) OVS_RELEASES(rule->evict)
 {
     classifier_remove(cls, &rule->cr);
-    if (rule->meter_id) {
-        list_remove(&rule->meter_list_node);
-    }
     cookies_remove(ofproto, rule);
     eviction_group_remove_rule(rule);
     ovs_mutex_lock(&ofproto->expirable_mutex);
@@ -5585,6 +5582,7 @@ oftable_remove_rule__(struct ofproto *ofproto, struct classifier *cls,
     ovs_mutex_unlock(&ofproto->expirable_mutex);
     if (!list_is_empty(&rule->meter_list_node)) {
         list_remove(&rule->meter_list_node);
+        list_init(&rule->meter_list_node);
     }
     ovs_rwlock_unlock(&rule->evict);
 }