X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;ds=sidebyside;f=include%2Flinux%2Frculist.h;h=e649bd3f2c976c3f5bed58c067c351a336403e75;hb=a993b542bb4cd3e5a64863b7ef892bbebec2239b;hp=b0f39be08b6c31a6d723f107e52cc31a7f3b1f78;hpb=5554b35933245e95710d709175e14c02cbc956a4;p=linux-2.6-omap-h63xx.git

diff --git a/include/linux/rculist.h b/include/linux/rculist.h
index b0f39be08b6..e649bd3f2c9 100644
--- a/include/linux/rculist.h
+++ b/include/linux/rculist.h
@@ -97,6 +97,34 @@ static inline void list_del_rcu(struct list_head *entry)
 	entry->prev = LIST_POISON2;
 }
 
+/**
+ * hlist_del_init_rcu - deletes entry from hash list with re-initialization
+ * @n: the element to delete from the hash list.
+ *
+ * Note: list_unhashed() on the node return true after this. It is
+ * useful for RCU based read lockfree traversal if the writer side
+ * must know if the list entry is still hashed or already unhashed.
+ *
+ * In particular, it means that we can not poison the forward pointers
+ * that may still be used for walking the hash list and we can only
+ * zero the pprev pointer so list_unhashed() will return true after
+ * this.
+ *
+ * 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_entry_rcu().
+ */
+static inline void hlist_del_init_rcu(struct hlist_node *n)
+{
+	if (!hlist_unhashed(n)) {
+		__hlist_del(n);
+		n->pprev = NULL;
+	}
+}
+
 /**
  * list_replace_rcu - replace old entry by new one
  * @old : the element to be replaced
@@ -170,20 +198,6 @@ static inline void list_splice_init_rcu(struct list_head *list,
 	at->prev = last;
 }
 
-/**
- * list_for_each_rcu	-	iterate over an rcu-protected list
- * @pos:	the &struct list_head to use as a loop cursor.
- * @head:	the head for your list.
- *
- * This list-traversal primitive may safely run concurrently with
- * 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_rcu(pos, head) \
-	for (pos = rcu_dereference((head)->next); \
-		prefetch(pos->next), pos != (head); \
-		pos = rcu_dereference(pos->next))
-
 #define __list_for_each_rcu(pos, head) \
 	for (pos = rcu_dereference((head)->next); \
 		pos != (head); \