radix-tree: introduce radix_tree_replace_clear_tags()

[cascardo/linux.git] / lib / radix-tree.c

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 9d9b4b9..c7114d2 100644 (file)
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -740,6 +740,26 @@ void *radix_tree_tag_set(struct radix_tree_root *root,
 }
 EXPORT_SYMBOL(radix_tree_tag_set);
 
+static void node_tag_clear(struct radix_tree_root *root,
+                               struct radix_tree_node *node,
+                               unsigned int tag, unsigned int offset)
+{
+       while (node) {
+               if (!tag_get(node, tag, offset))
+                       return;
+               tag_clear(node, tag, offset);
+               if (any_tag_set(node, tag))
+                       return;
+
+               offset = node->offset;
+               node = node->parent;
+       }
+
+       /* clear the root's tag bit */
+       if (root_tag_get(root, tag))
+               root_tag_clear(root, tag);
+}
+
 /**
  *     radix_tree_tag_clear - clear a tag on a radix tree node
  *     @root:          radix tree root
@@ -776,28 +796,9 @@ void *radix_tree_tag_clear(struct radix_tree_root *root,
                offset = radix_tree_descend(parent, &node, offset);
        }
 
-       if (node == NULL)
-               goto out;
+       if (node)
+               node_tag_clear(root, parent, tag, offset);
 
-       index >>= shift;
-
-       while (parent) {
-               if (!tag_get(parent, tag, offset))
-                       goto out;
-               tag_clear(parent, tag, offset);
-               if (any_tag_set(parent, tag))
-                       goto out;
-
-               index >>= RADIX_TREE_MAP_SHIFT;
-               offset = index & RADIX_TREE_MAP_MASK;
-               parent = parent->parent;
-       }
-
-       /* clear the root's tag bit */
-       if (root_tag_get(root, tag))
-               root_tag_clear(root, tag);
-
-out:
        return node;
 }
 EXPORT_SYMBOL(radix_tree_tag_clear);
@@ -1525,14 +1526,9 @@ void *radix_tree_delete_item(struct radix_tree_root *root,
 
        offset = get_slot_offset(node, slot);
 
-       /*
-        * Clear all tags associated with the item to be deleted.
-        * This way of doing it would be inefficient, but seldom is any set.
-        */
-       for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
-               if (tag_get(node, tag, offset))
-                       radix_tree_tag_clear(root, index, tag);
-       }
+       /* Clear all tags associated with the item to be deleted.  */
+       for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
+               node_tag_clear(root, node, tag, offset);
 
        delete_sibling_entries(node, node_to_entry(slot), offset);
        node->slots[offset] = NULL;
@@ -1559,6 +1555,28 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
 }
 EXPORT_SYMBOL(radix_tree_delete);
 
+struct radix_tree_node *radix_tree_replace_clear_tags(
+                       struct radix_tree_root *root,
+                       unsigned long index, void *entry)
+{
+       struct radix_tree_node *node;
+       void **slot;
+
+       __radix_tree_lookup(root, index, &node, &slot);
+
+       if (node) {
+               unsigned int tag, offset = get_slot_offset(node, slot);
+               for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
+                       node_tag_clear(root, node, tag, offset);
+       } else {
+               /* Clear root node tags */
+               root->gfp_mask &= __GFP_BITS_MASK;
+       }
+
+       radix_tree_replace_slot(slot, entry);
+       return node;
+}
+
 /**
  *     radix_tree_tagged - test whether any items in the tree are tagged
  *     @root:          radix tree root