rculist.h: use the rcu API

Make almost all list mutation primitives use rcu_assign_pointer().

The main point of this being readability improvement.

Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Josh Triplett <josh@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 9 insertions, 14 deletions

diff --git a/include/linux/rculist.h b/include/linux/rculist.h
index aa9b3eb15683..8d2c81fccfe5 100644
--- a/include/linux/rculist.h
+++ b/include/linux/rculist.h
@@ -7,6 +7,7 @@
  * RCU-protected list version
  */
 #include <linux/list.h>
+#include <linux/rcupdate.h>
 
 /*
  * Insert a new entry between two known consecutive entries.
@@ -19,9 +20,8 @@ static inline void __list_add_rcu(struct list_head *new,
 {
         new->next = next;
         new->prev = prev;
-        smp_wmb();
+        rcu_assign_pointer(prev->next, new);
         next->prev = new;
-        prev->next = new;
 }
 
 /**
@@ -110,9 +110,8 @@ static inline void list_replace_rcu(struct list_head *old,
 {
         new->next = old->next;
         new->prev = old->prev;
-        smp_wmb();
+        rcu_assign_pointer(new->prev->next, new);
         new->next->prev = new;
-        new->prev->next = new;
         old->prev = LIST_POISON2;
 }
 
@@ -166,8 +165,7 @@ static inline void list_splice_init_rcu(struct list_head *list,
          */
 
         last->next = at;
-        smp_wmb();
-        head->next = first;
+        rcu_assign_pointer(head->next, first);
         first->prev = head;
         at->prev = last;
 }
@@ -280,10 +278,9 @@ static inline void hlist_replace_rcu(struct hlist_node *old,
 
         new->next = next;
         new->pprev = old->pprev;
-        smp_wmb();
+        rcu_assign_pointer(*new->pprev, new);
         if (next)
                 new->next->pprev = &new->next;
-        *new->pprev = new;
         old->pprev = LIST_POISON2;
 }
 
@@ -310,12 +307,12 @@ static inline void hlist_add_head_rcu(struct hlist_node *n,
                                         struct hlist_head *h)
 {
         struct hlist_node *first = h->first;
+
         n->next = first;
         n->pprev = &h->first;
-        smp_wmb();
+        rcu_assign_pointer(h->first, n);
         if (first)
                 first->pprev = &n->next;
-        h->first = n;
 }
 
 /**
@@ -341,9 +338,8 @@ static inline void hlist_add_before_rcu(struct hlist_node *n,
 {
         n->pprev = next->pprev;
         n->next = next;
-        smp_wmb();
+        rcu_assign_pointer(*(n->pprev), n);
         next->pprev = &n->next;
-        *(n->pprev) = n;
 }
 
 /**
@@ -369,8 +365,7 @@ static inline void hlist_add_after_rcu(struct hlist_node *prev,
 {
         n->next = prev->next;
         n->pprev = &prev->next;
-        smp_wmb();
-        prev->next = n;
+        rcu_assign_pointer(prev->next, n);
         if (n->next)
                 n->next->pprev = &n->next;
 }