From f1aa2072c80dc8d4fb7a776801537172a656dbdd Mon Sep 17 00:00:00 2001
From: Ben Pfaff <blp@nicira.com>
Date: Wed, 17 Jun 2009 12:41:30 -0700
Subject: [PATCH] datapath: Get rid of query operations for single flows.

---
 datapath/datapath.c                     | 44 ++++++++++---------------
 include/openvswitch/datapath-protocol.h |  3 +-
 lib/dpif.c                              | 21 +++++++++---
 3 files changed, 36 insertions(+), 32 deletions(-)

diff --git a/datapath/datapath.c b/datapath/datapath.c
index 27bc5ce4..f76b51f9 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -831,6 +831,7 @@ static void get_stats(struct sw_flow *flow, struct odp_flow_stats *stats)
 	stats->n_bytes = flow->byte_count;
 	stats->ip_tos = flow->ip_tos;
 	stats->tcp_flags = flow->tcp_flags;
+	stats->error = 0;
 }
 
 static void clear_stats(struct sw_flow *flow)
@@ -984,9 +985,7 @@ static int answer_query(struct sw_flow *flow, struct odp_flow __user *ufp)
 	return put_actions(flow, ufp);
 }
 
-static int del_or_query_flow(struct datapath *dp,
-			     struct odp_flow __user *ufp,
-			     unsigned int cmd)
+static int del_flow(struct datapath *dp, struct odp_flow __user *ufp)
 {
 	struct dp_table *table = rcu_dereference(dp->table);
 	struct odp_flow uf;
@@ -1003,29 +1002,24 @@ static int del_or_query_flow(struct datapath *dp,
 	if (!flow)
 		goto error;
 
-	if (cmd == ODP_FLOW_DEL) {
-		/* XXX redundant lookup */
-		error = dp_table_delete(table, flow);
-		if (error)
-			goto error;
+	/* XXX redundant lookup */
+	error = dp_table_delete(table, flow);
+	if (error)
+		goto error;
 
-		/* XXX These statistics might lose a few packets, since other
-		 * CPUs can be using this flow.  We used to synchronize_rcu()
-		 * to make sure that we get completely accurate stats, but that
-		 * blows our performance, badly. */
-		dp->n_flows--;
-		error = answer_query(flow, ufp);
-		flow_deferred_free(flow);
-	} else {
-		error = answer_query(flow, ufp);
-	}
+	/* XXX These statistics might lose a few packets, since other CPUs can
+	 * be using this flow.  We used to synchronize_rcu() to make sure that
+	 * we get completely accurate stats, but that blows our performance,
+	 * badly. */
+	dp->n_flows--;
+	error = answer_query(flow, ufp);
+	flow_deferred_free(flow);
 
 error:
 	return error;
 }
 
-static int query_multiple_flows(struct datapath *dp,
-				const struct odp_flowvec *flowvec)
+static int query_flows(struct datapath *dp, const struct odp_flowvec *flowvec)
 {
 	struct dp_table *table = rcu_dereference(dp->table);
 	int i;
@@ -1041,7 +1035,7 @@ static int query_multiple_flows(struct datapath *dp,
 
 		flow = dp_table_lookup(table, &uf.key);
 		if (!flow)
-			error = __clear_user(&ufp->stats, sizeof ufp->stats);
+			error = __put_user(ENOENT, &ufp->stats.error);
 		else
 			error = answer_query(flow, ufp);
 		if (error)
@@ -1430,13 +1424,11 @@ static long openvswitch_ioctl(struct file *f, unsigned int cmd,
 		break;
 
 	case ODP_FLOW_DEL:
-	case ODP_FLOW_GET:
-		err = del_or_query_flow(dp, (struct odp_flow __user *)argp,
-					cmd);
+		err = del_flow(dp, (struct odp_flow __user *)argp);
 		break;
 
-	case ODP_FLOW_GET_MULTIPLE:
-		err = do_flowvec_ioctl(dp, argp, query_multiple_flows);
+	case ODP_FLOW_GET:
+		err = do_flowvec_ioctl(dp, argp, query_flows);
 		break;
 
 	case ODP_FLOW_LIST:
diff --git a/include/openvswitch/datapath-protocol.h b/include/openvswitch/datapath-protocol.h
index beaba32d..9b601a3c 100644
--- a/include/openvswitch/datapath-protocol.h
+++ b/include/openvswitch/datapath-protocol.h
@@ -70,7 +70,6 @@
 #define ODP_PORT_GROUP_GET      _IOWR('O', 12, struct odp_port_group)
 
 #define ODP_FLOW_GET            _IOWR('O', 13, struct odp_flow)
-#define ODP_FLOW_GET_MULTIPLE   _IOWR('O', 14, struct odp_flowvec)
 #define ODP_FLOW_LIST           _IOWR('O', 15, struct odp_flowvec)
 
 #define ODP_FLOW_FLUSH          _IO('O', 16)
@@ -149,7 +148,7 @@ struct odp_flow_stats {
     __u32 used_nsec;
     __u8 tcp_flags;
     __u8 ip_tos;
-    __u16 reserved;
+    __u16 error;                /* Used by ODP_FLOW_GET. */
 };
 
 struct odp_flow_key {
diff --git a/lib/dpif.c b/lib/dpif.c
index 5558631e..e0e5f364 100644
--- a/lib/dpif.c
+++ b/lib/dpif.c
@@ -522,10 +522,23 @@ dpif_flow_del(struct dpif *dpif, struct odp_flow *flow)
 int
 dpif_flow_get(const struct dpif *dpif, struct odp_flow *flow)
 {
-    COVERAGE_INC(dpif_flow_query);
+    struct odp_flowvec fv;
+    int error;
+
+    COVERAGE_INC(dpif_flow_get);
+
     check_rw_odp_flow(flow);
-    memset(&flow->stats, 0, sizeof flow->stats);
-    return do_flow_ioctl(dpif, ODP_FLOW_GET, flow, "get flow", true);
+    fv.flows = flow;
+    fv.n_flows = 1;
+    error = do_ioctl(dpif, ODP_FLOW_GET, "ODP_FLOW_GET", &fv);
+    if (!error) {
+        error = flow->stats.error;
+        if (error) {
+            VLOG_WARN_RL(&error_rl, "%s: ioctl(ODP_FLOW_GET) failed (%s)",
+                         dpif_name(dpif), strerror(error));
+        }
+    }
+    return error;
 }
 
 int
@@ -541,7 +554,7 @@ dpif_flow_get_multiple(const struct dpif *dpif,
     for (i = 0; i < n; i++) {
         check_rw_odp_flow(&flows[i]);
     }
-    return do_ioctl(dpif, ODP_FLOW_GET_MULTIPLE, "ODP_FLOW_GET_MULTIPLE",
+    return do_ioctl(dpif, ODP_FLOW_GET, "ODP_FLOW_GET",
                     &fv);
 }
 
-- 
2.30.2