---

yaml
---
r: 121527
b: refs/heads/master
c: 96631ed
h: refs/heads/master
i:
  121525: 873d04c
  121523: 78c7a7c
  121519: 16d6ece
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: f52b5054ec108aaa9e903850d6b62af8ae3fe6ae
+refs/heads/master: 96631ed16c514cf8b28fab991a076985ce378c26

trunk/include/linux/rculist.h

@@ -383,5 +383,22 @@ static inline void hlist_add_after_rcu(struct hlist_node *prev,
 		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1; }); \
 		pos = rcu_dereference(pos->next))
 
+/**
+ * hlist_for_each_entry_rcu_safenext - iterate over rcu list of given type
+ * @tpos:	the type * to use as a loop cursor.
+ * @pos:	the &struct hlist_node to use as a loop cursor.
+ * @head:	the head for your list.
+ * @member:	the name of the hlist_node within the struct.
+ * @next:       the &struct hlist_node to use as a next cursor
+ *
+ * Special version of hlist_for_each_entry_rcu that make sure
+ * each next pointer is fetched before each iteration.
+ */
+#define hlist_for_each_entry_rcu_safenext(tpos, pos, head, member, next) \
+	for (pos = rcu_dereference((head)->first);			 \
+		pos && ({ next = pos->next; smp_rmb(); prefetch(next); 1; }) &&	\
+		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1; }); \
+		pos = rcu_dereference(next))
+
 #endif	/* __KERNEL__ */
 #endif

trunk/include/net/sock.h

@@ -419,8 +419,8 @@ static __inline__ void sk_add_bind_node(struct sock *sk,
 
 #define sk_for_each(__sk, node, list) \
 	hlist_for_each_entry(__sk, node, list, sk_node)
-#define sk_for_each_rcu(__sk, node, list) \
-	hlist_for_each_entry_rcu(__sk, node, list, sk_node)
+#define sk_for_each_rcu_safenext(__sk, node, list, next) \
+	hlist_for_each_entry_rcu_safenext(__sk, node, list, sk_node, next)
 #define sk_for_each_from(__sk, node) \
 	if (__sk && ({ node = &(__sk)->sk_node; 1; })) \
 		hlist_for_each_entry_from(__sk, node, sk_node)

trunk/net/ipv4/udp.c

@@ -256,7 +256,7 @@ static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
 		int dif, struct udp_table *udptable)
 {
 	struct sock *sk, *result;
-	struct hlist_node *node;
+	struct hlist_node *node, *next;
 	unsigned short hnum = ntohs(dport);
 	unsigned int hash = udp_hashfn(net, hnum);
 	struct udp_hslot *hslot = &udptable->hash[hash];
@@ -266,7 +266,7 @@ static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
 begin:
 	result = NULL;
 	badness = -1;
-	sk_for_each_rcu(sk, node, &hslot->head) {
+	sk_for_each_rcu_safenext(sk, node, &hslot->head, next) {
 		/*
 		 * lockless reader, and SLAB_DESTROY_BY_RCU items:
 		 * We must check this item was not moved to another chain

trunk/net/ipv6/udp.c

@@ -98,7 +98,7 @@ static struct sock *__udp6_lib_lookup(struct net *net,
 				      int dif, struct udp_table *udptable)
 {
 	struct sock *sk, *result;
-	struct hlist_node *node;
+	struct hlist_node *node, *next;
 	unsigned short hnum = ntohs(dport);
 	unsigned int hash = udp_hashfn(net, hnum);
 	struct udp_hslot *hslot = &udptable->hash[hash];
@@ -108,7 +108,7 @@ static struct sock *__udp6_lib_lookup(struct net *net,
 begin:
 	result = NULL;
 	badness = -1;
-	sk_for_each_rcu(sk, node, &hslot->head) {
+	sk_for_each_rcu_safenext(sk, node, &hslot->head, next) {
 		/*
 		 * lockless reader, and SLAB_DESTROY_BY_RCU items:
 		 * We must check this item was not moved to another chain