X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fradix-tree.c;h=65f0e758ec3819d57f1799e5563a9f90dc0e41eb;hb=3d7e6cf8f5837c6dace759734c987e03021a4015;hp=53fd44d78716cfb3d0b9f77c1372737e49a1a12b;hpb=4ba9b9d0ba0a49d91fa6417c7510ee36f48cf957;p=linux-2.6

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 53fd44d787..65f0e758ec 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -95,14 +95,17 @@ static inline gfp_t root_gfp_mask(struct radix_tree_root *root)
 static struct radix_tree_node *
 radix_tree_node_alloc(struct radix_tree_root *root)
 {
-	struct radix_tree_node *ret;
+	struct radix_tree_node *ret = NULL;
 	gfp_t gfp_mask = root_gfp_mask(root);
 
-	ret = kmem_cache_alloc(radix_tree_node_cachep,
-				set_migrateflags(gfp_mask, __GFP_RECLAIMABLE));
-	if (ret == NULL && !(gfp_mask & __GFP_WAIT)) {
+	if (!(gfp_mask & __GFP_WAIT)) {
 		struct radix_tree_preload *rtp;
 
+		/*
+		 * Provided the caller has preloaded here, we will always
+		 * succeed in getting a node here (and never reach
+		 * kmem_cache_alloc)
+		 */
 		rtp = &__get_cpu_var(radix_tree_preloads);
 		if (rtp->nr) {
 			ret = rtp->nodes[rtp->nr - 1];
@@ -110,6 +113,10 @@ radix_tree_node_alloc(struct radix_tree_root *root)
 			rtp->nr--;
 		}
 	}
+	if (ret == NULL)
+		ret = kmem_cache_alloc(radix_tree_node_cachep,
+				set_migrateflags(gfp_mask, __GFP_RECLAIMABLE));
+
 	BUG_ON(radix_tree_is_indirect_ptr(ret));
 	return ret;
 }
@@ -1049,12 +1056,14 @@ radix_tree_node_ctor(struct kmem_cache *cachep, void *node)
 
 static __init unsigned long __maxindex(unsigned int height)
 {
-	unsigned int tmp = height * RADIX_TREE_MAP_SHIFT;
-	unsigned long index = (~0UL >> (RADIX_TREE_INDEX_BITS - tmp - 1)) >> 1;
-
-	if (tmp >= RADIX_TREE_INDEX_BITS)
-		index = ~0UL;
-	return index;
+	unsigned int width = height * RADIX_TREE_MAP_SHIFT;
+	int shift = RADIX_TREE_INDEX_BITS - width;
+
+	if (shift < 0)
+		return ~0UL;
+	if (shift >= BITS_PER_LONG)
+		return 0UL;
+	return ~0UL >> shift;
 }
 
 static __init void radix_tree_init_maxindex(void)