On Thu, Jul 26, 2007 at 09:56:30PM -0700, Andrew Morton wrote:

On Thu, 26 Jul 2007 08:44:21 -0700 "Paul E. McKenney" [off-list ref] wrote:

quoted

On Thu, Jul 26, 2007 at 11:49:42AM +0100, Stephen Hemminger wrote:

quoted

Whitespace cleanup run code through lindent then cleanup results.
Applys after other two patches.

--- a/net/ipv4/fib_trie.c	2007-07-26 10:17:21.000000000 +0100
+++ b/net/ipv4/fib_trie.c	2007-07-26 11:47:52.000000000 +0100

@@ -156,7 +156,8 @@ struct trie {
 };

 static void put_child(struct trie *t, struct tnode *tn, int i, struct node *n);
-static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n, int wasfull);
+static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n,
+				  int wasfull);
 static struct node *resize(struct trie *t, struct tnode *tn);
 static struct tnode *inflate(struct trie *t, struct tnode *tn);
 static struct tnode *halve(struct trie *t, struct tnode *tn);

@@ -167,13 +168,12 @@ static struct trie *trie_local = NULL, *

 static inline struct tnode *node_parent(struct node *node)
 {
-	return rcu_dereference((struct tnode *) (node->parent & ~NODE_TYPE_MASK));
+	return rcu_dereference((struct tnode *)(node->parent & ~NODE_TYPE_MASK));

The potential issue is applying rcu_dereference() to an rvalue
as opposed to an lvalue.  So how about the following?

I did this:

static inline struct tnode *node_parent(struct node *node)
{
	struct tnode *ret;

	ret = (struct tnode *)(node->parent & ~NODE_TYPE_MASK);
	return rcu_dereference(ret);
}

I would feel more comfortable with the rcu_dereference() covering the
initial fetch from node->parent, but do not have any hard objections
to your approach.

						Thanx, Paul