From cce84e4a24c37e6055769208503437c47787fa2a Mon Sep 17 00:00:00 2001
From: Michael Blizek <michi1@michaelblizek.twilightparadox.com>
Date: Tue, 23 Mar 2010 19:48:21 +0100
Subject: [PATCH] ping locking

---
 net/cor/cor.h      |  6 ++++--
 net/cor/neighbor.c | 29 ++++++++++++++++++++++++-----
 2 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/net/cor/cor.h b/net/cor/cor.h
index cac396aefe1..323e33f2e79 100644
--- a/net/cor/cor.h
+++ b/net/cor/cor.h
@@ -282,8 +282,10 @@ struct neighbor{
 	__u32 length;
 	
 	
-	unsigned long last_ping_time;
-	__u32 noping_cnt;
+	unsigned long last_ping_time; /* protected by cmsg_lock */
+	__u32 noping_cnt;/* protected by cmsg_lock */
+	
+	struct mutex pingcookie_lock;
 	__u32 ping_intransit;
 	struct ping_cookie cookies[PING_COOKIES_PER_NEIGH];
 	__u32 lastcookie;
diff --git a/net/cor/neighbor.c b/net/cor/neighbor.c
index 7b68aef31bf..73238a6dc19 100644
--- a/net/cor/neighbor.c
+++ b/net/cor/neighbor.c
@@ -130,6 +130,7 @@ static struct neighbor *alloc_neighbor(gfp_t allocflags)
 	nb->last_ping_time = jiffies;
 	atomic_set(&(nb->ooo_packets), 0);
 	get_random_bytes((char *) &seqno, sizeof(seqno));
+	mutex_init(&(nb->pingcookie_lock));
 	atomic_set(&(nb->kpacket_seqno), seqno);
 	atomic_set(&(nb->latency), 0);
 	mutex_init(&(nb->conn_list_lock));
@@ -284,13 +285,17 @@ static struct ping_cookie *find_cookie(struct neighbor *nb, __u32 cookie)
 
 void ping_resp(struct neighbor *nb, __u32 cookie, __u32 respdelay)
 {
-	struct ping_cookie *c = find_cookie(nb, cookie);
+	struct ping_cookie *c;
 	int i;
 	
 	__s64 newlatency;
 	
+	mutex_lock(&(nb->pingcookie_lock));
+	
+	c = find_cookie(nb, cookie);
+	
 	if (c == 0)
-		return;
+		goto out;
 	
 	newlatency = ((((__s64) ((__u32)atomic_read(&(nb->latency)))) * 15 +
 			jiffies_to_usecs(jiffies - c->time) - respdelay) / 16);
@@ -315,6 +320,8 @@ void ping_resp(struct neighbor *nb, __u32 cookie, __u32 respdelay)
 			}
 		}
 	}
+out:
+	mutex_unlock(&(nb->pingcookie_lock));
 }
 
 __u32 add_ping_req(struct neighbor *nb)
@@ -322,6 +329,10 @@ __u32 add_ping_req(struct neighbor *nb)
 	struct ping_cookie *c;
 	int i;
 	
+	__u32 cookie;
+	
+	mutex_lock(&(nb->pingcookie_lock));
+	
 	for (i=0;i<PING_COOKIES_PER_NEIGH;i++) {
 		if (nb->cookies[i].cookie == 0)
 			goto found;
@@ -341,8 +352,12 @@ found:
 	c->cookie = nb->lastcookie;
 	
 	nb->ping_intransit++;
+	
+	cookie = c->cookie;
+	
+	mutex_unlock(&(nb->pingcookie_lock));
 
-	return c->cookie;
+	return cookie;
 }
 
 
@@ -355,6 +370,9 @@ found:
  */
 int time_to_send_ping(struct neighbor *nb)
 {
+	int rc = 1;
+	
+	mutex_lock(&(nb->pingcookie_lock));
 	if (nb->ping_intransit >= PING_COOKIES_NOTHROTTLE) {
 		__u32 mindelay = (((__u32)atomic_read(&(nb->latency)))/1000) <<
 				(nb->ping_intransit + 1 -
@@ -363,10 +381,11 @@ int time_to_send_ping(struct neighbor *nb)
 			mindelay = PING_THROTTLE_LIMIT_MS;
 
 		if (jiffies_to_msecs(jiffies - nb->last_ping_time) <  mindelay)
-			return 0;
+			rc = 0;
 	}
+	mutex_unlock(&(nb->pingcookie_lock));
 	
-	return 1;
+	return rc;
 }
 
 static void add_neighbor(struct neighbor *nb)
-- 
2.11.4.GIT