1 files changed, 27 insertions, 4 deletions

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index bd4a8dfdf0b8..d832117e7d94 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -1337,15 +1337,18 @@ static inline void radix_tree_shrink(struct radix_tree_root *root)
 }
 
 /**
- *      radix_tree_delete    -    delete an item from a radix tree
+ *      radix_tree_delete_item    -    delete an item from a radix tree
  *      @root:          radix tree root
  *      @index:         index key
+ *      @item:          expected item
  *
- *      Remove the item at @index from the radix tree rooted at @root.
+ *      Remove @item at @index from the radix tree rooted at @root.
  *
- *      Returns the address of the deleted item, or NULL if it was not present.
+ *      Returns the address of the deleted item, or NULL if it was not present
+ *      or the entry at the given @index was not @item.
  */
-void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
+void *radix_tree_delete_item(struct radix_tree_root *root,
+                             unsigned long index, void *item)
 {
         struct radix_tree_node *node = NULL;
         struct radix_tree_node *slot = NULL;
@@ -1380,6 +1383,11 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
         if (slot == NULL)
                 goto out;
 
+        if (item && slot != item) {
+                slot = NULL;
+                goto out;
+        }
+
         /*
          * Clear all tags associated with the item to be deleted.
          * This way of doing it would be inefficient, but seldom is any set.
@@ -1424,6 +1432,21 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
 out:
         return slot;
 }
+EXPORT_SYMBOL(radix_tree_delete_item);
+
+/**
+ *      radix_tree_delete    -    delete an item from a radix tree
+ *      @root:          radix tree root
+ *      @index:         index key
+ *
+ *      Remove the item at @index from the radix tree rooted at @root.
+ *
+ *      Returns the address of the deleted item, or NULL if it was not present.
+ */
+void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
+{
+        return radix_tree_delete_item(root, index, NULL);
+}
 EXPORT_SYMBOL(radix_tree_delete);
 
 /**