rculist: allow reverse RCU traversal

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/urcu/rculist.h b/urcu/rculist.h
index 1fd2df388f57cefc0ea19fa02a0c8c0b627847e8..9a01dad2c8930f882763585d9ffc8f3c71e8d307 100644 (file)
--- a/urcu/rculist.h
+++ b/urcu/rculist.h
@@ -35,8 +35,8 @@ void cds_list_add_rcu(struct cds_list_head *newp, struct cds_list_head *head)
 {
        newp->next = head->next;
        newp->prev = head;
-       head->next->prev = newp;
-       rcu_assign_pointer(head->next, newp);
+       rcu_assign_pointer(head->next->prev, newp);
+       CMM_STORE_SHARED(head->next, newp);
 }
 
 /* Add new element at the tail of the list. */
@@ -47,7 +47,7 @@ void cds_list_add_tail_rcu(struct cds_list_head *newp,
        newp->next = head;
        newp->prev = head->prev;
        rcu_assign_pointer(head->prev->next, newp);
-       head->prev = newp;
+       CMM_STORE_SHARED(head->prev, newp);
 }
 
 /*
@@ -61,14 +61,14 @@ void cds_list_replace_rcu(struct cds_list_head *old, struct cds_list_head *_new)
        _new->next = old->next;
        _new->prev = old->prev;
        rcu_assign_pointer(_new->prev->next, _new);
-       _new->next->prev = _new;
+       CMM_STORE_SHARED(_new->next->prev, _new);
 }
 
 /* Remove element from list. */
 static inline
 void cds_list_del_rcu(struct cds_list_head *elem)
 {
-       elem->next->prev = elem->prev;
+       CMM_STORE_SHARED(elem->next->prev, elem->prev);
        CMM_STORE_SHARED(elem->prev->next, elem->next);
 }