From: Peter Zijlstra The comment states: 'Setting a tag on a not-present item is a BUG.' Hence if 'index' is larger than the maxindex; the item _cannot_ be presen; it should also be a BUG. Also, this allows the following statement (assume a fresh tree): radix_tree_tag_set(root, 16, 1); to fail silently, but when preceded by: radix_tree_insert(root, 32, item); it would BUG, because the height has been extended by the insert. In neither case was 16 present. Signed-off-by: Peter Zijlstra Acked-by: Nick Piggin Signed-off-by: Andrew Morton --- lib/radix-tree.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff -puN lib/radix-tree.c~buglet-in-radix_tree_tag_set lib/radix-tree.c --- devel/lib/radix-tree.c~buglet-in-radix_tree_tag_set 2006-06-02 18:59:10.000000000 -0700 +++ devel-akpm/lib/radix-tree.c 2006-06-02 18:59:10.000000000 -0700 @@ -389,8 +389,7 @@ void *radix_tree_tag_set(struct radix_tr struct radix_tree_node *slot; height = root->height; - if (index > radix_tree_maxindex(height)) - return NULL; + BUG_ON(index > radix_tree_maxindex(height)); slot = root->rnode; shift = (height - 1) * RADIX_TREE_MAP_SHIFT; _