---
 mm/reserve.c |   17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

Index: linux-2.6/mm/reserve.c
===================================================================
--- linux-2.6.orig/mm/reserve.c
+++ linux-2.6/mm/reserve.c
@@ -191,6 +191,10 @@ int mem_reserve_connect(struct mem_reser
 	WARN_ON(!new_child->name);
 
 	mutex_lock(&mem_reserve_mutex);
+	if (new_child->parent) {
+		ret = -EEXIST;
+		goto unlock;
+	}
 	new_child->parent = node;
 	list_add(&new_child->siblings, &node->children);
 	ret = __mem_reserve_add(node, new_child->pages, new_child->limit);
@@ -198,6 +202,7 @@ int mem_reserve_connect(struct mem_reser
 		new_child->parent = NULL;
 		list_del_init(&new_child->siblings);
 	}
+unlock:
 	mutex_unlock(&mem_reserve_mutex);
 
 	return ret;
@@ -218,11 +223,16 @@ void mem_reserve_disconnect(struct mem_r
 	BUG_ON(!node->parent);
 
 	mutex_lock(&mem_reserve_mutex);
+	if (!node->parent) {
+		ret = -ENOENT;
+		goto unlock;
+	}
 	ret = __mem_reserve_add(node->parent, -node->pages, -node->limit);
 	if (!ret) {
 		node->parent = NULL;
 		list_del_init(&node->siblings);
 	}
+unlock:
 	mutex_unlock(&mem_reserve_mutex);
 
 	/*
@@ -545,6 +555,7 @@ struct page *__alloc_pages_reserve(int n
 {
 	struct page *page;
 	gfp_t gfp;
+	long pages = 1 << order;
 
 	gfp = flags | __GFP_NOMEMALLOC | __GFP_NOWARN;
 	page = alloc_pages_node(node, gfp, order);
@@ -552,16 +563,16 @@ struct page *__alloc_pages_reserve(int n
 	if (page || !(gfp_to_alloc_flags(flags) & ALLOC_NO_WATERMARKS))
 		goto out;
 
-	if (res && !mem_reserve_pages_charge(res, 1 << order)) {
+	if (res && !mem_reserve_pages_charge(res, pages)) {
 		if (!(flags & __GFP_WAIT))
 			goto out;
 
 		wait_event(res->waitqueue,
-				mem_reserve_pages_charge(res, 1 << order));
+				mem_reserve_pages_charge(res, pages));
 
 		page = alloc_pages_node(node, gfp, order);
 		if (page) {
-			mem_reserve_pages_charge(res, -(1 << order));
+			mem_reserve_pages_charge(res, -pages);
 			goto out;
 		}
 	}