* as long as the traversal is guarded by rcu_read_lock().
*/
#define list_for_each_rcu(pos, head) \
- for (pos = (head)->next; prefetch(pos->next), pos != (head); \
- pos = rcu_dereference(pos->next))
+ for (pos = (head)->next; \
+ prefetch(rcu_dereference(pos)->next), pos != (head); \
+ pos = pos->next)
#define __list_for_each_rcu(pos, head) \
- for (pos = (head)->next; pos != (head); \
- pos = rcu_dereference(pos->next))
+ for (pos = (head)->next; \
+ rcu_dereference(pos) != (head); \
+ pos = pos->next)
/**
* list_for_each_safe_rcu - iterate over an rcu-protected list safe
* as long as the traversal is guarded by rcu_read_lock().
*/
#define list_for_each_safe_rcu(pos, n, head) \
- for (pos = (head)->next, n = pos->next; pos != (head); \
- pos = rcu_dereference(n), n = pos->next)
+ for (pos = (head)->next; \
+ n = rcu_dereference(pos)->next, pos != (head); \
+ pos = n)
/**
* list_for_each_entry_rcu - iterate over rcu list of given type
* the _rcu list-mutation primitives such as list_add_rcu()
* as long as the traversal is guarded by rcu_read_lock().
*/
-#define list_for_each_entry_rcu(pos, head, member) \
- for (pos = list_entry((head)->next, typeof(*pos), member); \
- prefetch(pos->member.next), &pos->member != (head); \
- pos = rcu_dereference(list_entry(pos->member.next, \
- typeof(*pos), member)))
+#define list_for_each_entry_rcu(pos, head, member) \
+ for (pos = list_entry((head)->next, typeof(*pos), member); \
+ prefetch(rcu_dereference(pos)->member.next), \
+ &pos->member != (head); \
+ pos = list_entry(pos->member.next, typeof(*pos), member))
/**
* as long as the traversal is guarded by rcu_read_lock().
*/
#define list_for_each_continue_rcu(pos, head) \
- for ((pos) = (pos)->next; prefetch((pos)->next), (pos) != (head); \
- (pos) = rcu_dereference((pos)->next))
+ for ((pos) = (pos)->next; \
+ prefetch(rcu_dereference((pos))->next), (pos) != (head); \
+ (pos) = (pos)->next)
/*
* Double linked lists with a single pointer list head.
next->next->pprev = &next->next;
}
+/**
+ * hlist_add_before_rcu - adds the specified element to the specified hlist
+ * before the specified node while permitting racing traversals.
+ * @n: the new element to add to the hash list.
+ * @next: the existing element to add the new element before.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as hlist_add_head_rcu()
+ * or hlist_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * hlist_for_each_rcu(), used to prevent memory-consistency
+ * problems on Alpha CPUs.
+ */
static inline void hlist_add_before_rcu(struct hlist_node *n,
struct hlist_node *next)
{
*(n->pprev) = n;
}
+/**
+ * hlist_add_after_rcu - adds the specified element to the specified hlist
+ * after the specified node while permitting racing traversals.
+ * @prev: the existing element to add the new element after.
+ * @n: the new element to add to the hash list.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as hlist_add_head_rcu()
+ * or hlist_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * hlist_for_each_rcu(), used to prevent memory-consistency
+ * problems on Alpha CPUs.
+ */
static inline void hlist_add_after_rcu(struct hlist_node *prev,
struct hlist_node *n)
{
pos = n)
#define hlist_for_each_rcu(pos, head) \
- for ((pos) = (head)->first; pos && ({ prefetch((pos)->next); 1; }); \
- (pos) = rcu_dereference((pos)->next))
+ for ((pos) = (head)->first; \
+ rcu_dereference((pos)) && ({ prefetch((pos)->next); 1; }); \
+ (pos) = (pos)->next)
/**
* hlist_for_each_entry - iterate over list of given type
*/
#define hlist_for_each_entry_rcu(tpos, pos, head, member) \
for (pos = (head)->first; \
- pos && ({ prefetch(pos->next); 1;}) && \
+ rcu_dereference(pos) && ({ prefetch(pos->next); 1;}) && \
({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
- pos = rcu_dereference(pos->next))
+ pos = pos->next)
#else
#warning "don't include kernel headers in userspace"