list_nulls: add hlist_nulls_add_head and hlist_nulls_del

This patch adds the hlist_nulls_add_head() function which is
based on hlist_nulls_add_head_rcu() but without the use of
rcu_assign_pointer(). It also adds hlist_nulls_del which is
exactly the same like hlist_nulls_del_rcu().

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

1 files changed, 18 insertions, 0 deletions

diff --git a/include/linux/list_nulls.h b/include/linux/list_nulls.h
index 93150ecf3ea4..5d10ae364b5e 100644
--- a/include/linux/list_nulls.h
+++ b/include/linux/list_nulls.h
@@ -56,6 +56,18 @@ static inline int hlist_nulls_empty(const struct hlist_nulls_head *h)
         return is_a_nulls(h->first);
 }
 
+static inline void hlist_nulls_add_head(struct hlist_nulls_node *n,
+                                        struct hlist_nulls_head *h)
+{
+        struct hlist_nulls_node *first = h->first;
+
+        n->next = first;
+        n->pprev = &h->first;
+        h->first = n;
+        if (!is_a_nulls(first))
+                first->pprev = &n->next;
+}
+
 static inline void __hlist_nulls_del(struct hlist_nulls_node *n)
 {
         struct hlist_nulls_node *next = n->next;
@@ -65,6 +77,12 @@ static inline void __hlist_nulls_del(struct hlist_nulls_node *n)
                 next->pprev = pprev;
 }
 
+static inline void hlist_nulls_del(struct hlist_nulls_node *n)
+{
+        __hlist_nulls_del(n);
+        n->pprev = LIST_POISON2;
+}
+
 /**
  * hlist_nulls_for_each_entry   - iterate over list of given type
  * @tpos:       the type * to use as a loop cursor.