Index: linux-2.6.17-rc6-mm2/fs/dcache.c
===================================================================
--- linux-2.6.17-rc6-mm2.orig/fs/dcache.c	2006-06-10 11:11:52.568029305 -0700
+++ linux-2.6.17-rc6-mm2/fs/dcache.c	2006-06-14 19:12:10.808183118 -0700
@@ -68,15 +68,6 @@ struct dentry_stat_t dentry_stat = {
 	.age_limit = 45,
 };
 
-static void d_callback(struct rcu_head *head)
-{
-	struct dentry * dentry = container_of(head, struct dentry, d_u.d_rcu);
-
-	if (dname_external(dentry))
-		kfree(dentry->d_name.name);
-	kmem_cache_free(dentry_cache, dentry); 
-}
-
 /*
  * no dcache_lock, please.  The caller must decrement dentry_stat.nr_dentry
  * inside dcache_lock.
@@ -85,7 +76,9 @@ static void d_free(struct dentry *dentry
 {
 	if (dentry->d_op && dentry->d_op->d_release)
 		dentry->d_op->d_release(dentry);
- 	call_rcu(&dentry->d_u.d_rcu, d_callback);
+	if (dname_external(dentry))
+		kfree(dentry->d_name.name);
+	kmem_cache_free(dentry_cache, dentry);
 }
 
 /*
@@ -1112,7 +1105,7 @@ struct dentry * __d_lookup(struct dentry
 	struct dentry *dentry;
 
 	rcu_read_lock();
-	
+
 	hlist_for_each_entry_rcu(dentry, node, head, d_hash) {
 		struct qstr *qstr;
 
@@ -1148,8 +1141,13 @@ struct dentry * __d_lookup(struct dentry
 
 		if (!d_unhashed(dentry)) {
 			atomic_inc(&dentry->d_count);
+			/*
+			 * Now we have a stable reference.
+			 * Check that the object was not switched by RCU
+			 */
 			found = dentry;
 		}
+
 		spin_unlock(&dentry->d_lock);
 		break;
 next:
@@ -1759,8 +1757,8 @@ static void __init dcache_init(unsigned 
 					 sizeof(struct dentry),
 					 0,
 					 (SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|
-					 SLAB_MEM_SPREAD),
-					 NULL, NULL);
+					 SLAB_MEM_SPREAD|SLAB_DESTROY_BY_RCU),
+					 dentry_ctor, NULL);
 	
 	shrinker = set_shrinker(DEFAULT_SEEKS, shrink_dcache_memory);
 	kmem_set_shrinker(dentry_cache, shrinker);
Index: linux-2.6.17-rc6-mm2/include/linux/dcache.h
===================================================================
--- linux-2.6.17-rc6-mm2.orig/include/linux/dcache.h	2006-06-10 11:11:56.696679941 -0700
+++ linux-2.6.17-rc6-mm2/include/linux/dcache.h	2006-06-14 18:11:22.399108536 -0700
@@ -94,13 +94,7 @@ struct dentry {
 	struct qstr d_name;
 
 	struct list_head d_lru;		/* LRU list */
-	/*
-	 * d_child and d_rcu can share memory
-	 */
-	union {
-		struct list_head d_child;	/* child of parent list */
-	 	struct rcu_head d_rcu;
-	} d_u;
+	struct list_head d_child;	/* child of parent list */
 	struct list_head d_subdirs;	/* our children */
 	struct list_head d_alias;	/* inode alias list */
 	unsigned long d_time;		/* used by d_revalidate */