radix-tree: rewrite radix_tree_tag_clear

Use the new multi-order support functions to rewrite
radix_tree_tag_clear()

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Jan Kara <jack@suse.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 5234a95..ee56562 100644 (file)
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -768,44 +768,40 @@ EXPORT_SYMBOL(radix_tree_tag_set);
 void *radix_tree_tag_clear(struct radix_tree_root *root,
                        unsigned long index, unsigned int tag)
 {
-       struct radix_tree_node *node = NULL;
-       struct radix_tree_node *slot = NULL;
-       unsigned int height, shift;
+       struct radix_tree_node *node, *parent;
+       unsigned long maxindex;
+       unsigned int shift;
        int uninitialized_var(offset);
 
-       height = root->height;
-       if (index > radix_tree_maxindex(height))
-               goto out;
-
-       shift = height * RADIX_TREE_MAP_SHIFT;
-       slot = root->rnode;
+       shift = radix_tree_load_root(root, &node, &maxindex);
+       if (index > maxindex)
+               return NULL;
 
-       while (shift) {
-               if (slot == NULL)
-                       goto out;
-               if (!radix_tree_is_indirect_ptr(slot))
-                       break;
-               slot = indirect_to_ptr(slot);
+       parent = NULL;
 
+       while (radix_tree_is_indirect_ptr(node)) {
                shift -= RADIX_TREE_MAP_SHIFT;
                offset = (index >> shift) & RADIX_TREE_MAP_MASK;
-               node = slot;
-               slot = slot->slots[offset];
+
+               parent = indirect_to_ptr(node);
+               offset = radix_tree_descend(parent, &node, offset);
        }
 
-       if (slot == NULL)
+       if (node == NULL)
                goto out;
 
-       while (node) {
-               if (!tag_get(node, tag, offset))
+       index >>= shift;
+
+       while (parent) {
+               if (!tag_get(parent, tag, offset))
                        goto out;
-               tag_clear(node, tag, offset);
-               if (any_tag_set(node, tag))
+               tag_clear(parent, tag, offset);
+               if (any_tag_set(parent, tag))
                        goto out;
 
                index >>= RADIX_TREE_MAP_SHIFT;
                offset = index & RADIX_TREE_MAP_MASK;
-               node = node->parent;
+               parent = parent->parent;
        }
 
        /* clear the root's tag bit */
@@ -813,7 +809,7 @@ void *radix_tree_tag_clear(struct radix_tree_root *root,
                root_tag_clear(root, tag);
 
 out:
-       return slot;
+       return node;
 }
 EXPORT_SYMBOL(radix_tree_tag_clear);