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>

diff --git a/include/linux/rculist.h b/include/linux/rculist.h
index aa9b3eb1568325bbcd4a80e53fa09e82a8b566c6..8d2c81fccfe50b80d8e9426c8462e595afb1ca18 100644 (file)
--- 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;
 }