netflow: Fold netflow_expire() into netflow_flow_clear().

netflow_flow_clear() asserted that no packets or bytes were included
in the statistics for the flow being cleared.  Before threading Open
vSwitch, this assertion was always true because netflow_expire() was
always called before calling netflow_flow_clear().  Since Open
vSwitch was threaded, however, it was possible that a packet arrived
after netflow_expire() but before netflow_flow_clear(), since each of
these function separately took the netflow mutex.

This commit fixes the problem by merging netflow_expire() into
netflow_flow_clear(), under a single acquisition of the netflow
mutex.

Signed-off-by: Anoob Soman <anoob.soman@citrix.com>
[blp@nicira.com modified the patch to remove netflow_expire() and
 rewrote the commit message]
Signed-off-by: Ben Pfaff <blp@nicira.com>

1 files changed, 1 insertions, 15 deletions

diff --git a/ofproto/netflow.c b/ofproto/netflow.c
index e9382afe9..c7af01042 100644
--- a/ofproto/netflow.c
+++ b/ofproto/netflow.c
@@ -276,19 +276,6 @@ netflow_expire__(struct netflow *nf, struct netflow_flow *nf_flow)
 }
 
 void
-netflow_expire(struct netflow *nf, struct flow *flow) OVS_EXCLUDED(mutex)
-{
-    struct netflow_flow *nf_flow;
-
-    ovs_mutex_lock(&mutex);
-    nf_flow = netflow_flow_lookup(nf, flow);
-    if (nf_flow) {
-        netflow_expire__(nf, nf_flow);
-    }
-    ovs_mutex_unlock(&mutex);
-}
-
-void
 netflow_flow_clear(struct netflow *nf, struct flow *flow) OVS_EXCLUDED(mutex)
 {
     struct netflow_flow *nf_flow;
@@ -296,8 +283,7 @@ netflow_flow_clear(struct netflow *nf, struct flow *flow) OVS_EXCLUDED(mutex)
     ovs_mutex_lock(&mutex);
     nf_flow = netflow_flow_lookup(nf, flow);
     if (nf_flow) {
-        ovs_assert(!nf_flow->packet_count);
-        ovs_assert(!nf_flow->byte_count);
+        netflow_expire__(nf, nf_flow);
         hmap_remove(&nf->flows, &nf_flow->hmap_node);
         free(nf_flow);
     }