2 files changed, 22 insertions, 4 deletions

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index f14ada9830ca..ff460423ff4b 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -165,6 +165,11 @@ static inline int root_tag_get(struct radix_tree_root *root, unsigned int tag)
         return (__force unsigned)root->gfp_mask & (1 << (tag + __GFP_BITS_SHIFT));
 }
 
+static inline unsigned root_tags_get(struct radix_tree_root *root)
+{
+        return (__force unsigned)root->gfp_mask >> __GFP_BITS_SHIFT;
+}
+
 /*
  * Returns 1 if any slot in the node has this tag set.
  * Otherwise returns 0.
@@ -604,12 +609,13 @@ int __radix_tree_insert(struct radix_tree_root *root, unsigned long index,
         rcu_assign_pointer(*slot, item);
 
         if (node) {
+                unsigned offset = get_slot_offset(node, slot);
                 node->count++;
-                BUG_ON(tag_get(node, 0, index & RADIX_TREE_MAP_MASK));
-                BUG_ON(tag_get(node, 1, index & RADIX_TREE_MAP_MASK));
+                BUG_ON(tag_get(node, 0, offset));
+                BUG_ON(tag_get(node, 1, offset));
+                BUG_ON(tag_get(node, 2, offset));
         } else {
-                BUG_ON(root_tag_get(root, 0));
-                BUG_ON(root_tag_get(root, 1));
+                BUG_ON(root_tags_get(root));
         }
 
         return 0;
diff --git a/tools/testing/radix-tree/multiorder.c b/tools/testing/radix-tree/multiorder.c
index 71f34a047002..0a311a5f39de 100644
--- a/tools/testing/radix-tree/multiorder.c
+++ b/tools/testing/radix-tree/multiorder.c
@@ -81,6 +81,17 @@ static void multiorder_shrink(unsigned long index, int order)
                 item_check_absent(&tree, i);
 }
 
+static void multiorder_insert_bug(void)
+{
+        RADIX_TREE(tree, GFP_KERNEL);
+
+        item_insert(&tree, 0);
+        radix_tree_tag_set(&tree, 0, 0);
+        item_insert_order(&tree, 3 << 6, 6);
+
+        item_kill_tree(&tree);
+}
+
 void multiorder_checks(void)
 {
         int i;
@@ -94,4 +105,5 @@ void multiorder_checks(void)
         for (i = 0; i < 15; i++)
                 multiorder_shrink((1UL << (i + RADIX_TREE_MAP_SHIFT)), i);
 
+        multiorder_insert_bug();
 }