VServer 1.9.2 (patch-2.6.8.1-vs1.9.2.diff)

[linux-2.6.git] / include / linux / list.h

diff --git a/include/linux/list.h b/include/linux/list.h
index 9e0c971..33b863b 100644 (file)
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -620,13 +620,12 @@ static inline void hlist_add_after(struct hlist_node *n,
 
 #define hlist_entry(ptr, type, member) container_of(ptr,type,member)
 
-/* Cannot easily do prefetch unfortunately */
 #define hlist_for_each(pos, head) \
        for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \
             pos = pos->next)
 
 #define hlist_for_each_safe(pos, n, head) \
-       for (pos = (head)->first; n = pos ? pos->next : 0, pos; \
+       for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
             pos = n)
 
 /**
@@ -678,6 +677,24 @@ static inline void hlist_add_after(struct hlist_node *n,
             pos && ({ n = pos->next; 1; }) &&                           \
                ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
             pos = n)
+
+/**
+ * hlist_for_each_entry_rcu - iterate over rcu list of given type
+ * @pos:       the type * to use as a loop counter.
+ * @pos:       the &struct hlist_node to use as a loop counter.
+ * @head:      the head for your list.
+ * @member:    the name of the hlist_node within the struct.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as hlist_add_rcu()
+ * as long as the traversal is guarded by rcu_read_lock().
+ */
+#define hlist_for_each_entry_rcu(tpos, pos, head, member)               \
+       for (pos = (head)->first;                                        \
+            pos && ({ prefetch(pos->next); 1;}) &&                      \
+               ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
+            pos = pos->next, ({ smp_read_barrier_depends(); 0; }) )
+
 #else
 #warning "don't include kernel headers in userspace"
 #endif /* __KERNEL__ */