[PATCH] radix tree: code consolidation

Introduce helper any_tag_set() rather than repeat the same code sequence 4
times.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 88511c3..1403e2c 100644 (file)
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -151,6 +151,20 @@ static inline int tag_get(struct radix_tree_node *node, int tag, int offset)
        return test_bit(offset, &node->tags[tag][0]);
 }
 
+/*
+ * Returns 1 if any slot in the node has this tag set.
+ * Otherwise returns 0.
+ */
+static inline int any_tag_set(struct radix_tree_node *node, int tag)
+{
+       int idx;
+       for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) {
+               if (node->tags[tag][idx])
+                       return 1;
+       }
+       return 0;
+}
+
 /*
  *     Return the maximum key which can be store into a
  *     radix tree with height HEIGHT.
@@ -185,15 +199,9 @@ static int radix_tree_extend(struct radix_tree_root *root, unsigned long index)
         * into the newly-pushed top-level node(s)
         */
        for (tag = 0; tag < RADIX_TREE_TAGS; tag++) {
-               int idx;
-
                tags[tag] = 0;
-               for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) {
-                       if (root->rnode->tags[tag][idx]) {
-                               tags[tag] = 1;
-                               break;
-                       }
-               }
+               if (any_tag_set(root->rnode, tag))
+                       tags[tag] = 1;
        }
 
        do {
@@ -427,13 +435,9 @@ void *radix_tree_tag_clear(struct radix_tree_root *root,
                goto out;
 
        do {
-               int idx;
-
                tag_clear(pathp->node, tag, pathp->offset);
-               for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) {
-                       if (pathp->node->tags[tag][idx])
-                               goto out;
-               }
+               if (any_tag_set(pathp->node, tag))
+                       goto out;
                pathp--;
        } while (pathp->node);
 out:
@@ -729,19 +733,14 @@ void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
 
                nr_cleared_tags = RADIX_TREE_TAGS;
                for (tag = 0; tag < RADIX_TREE_TAGS; tag++) {
-                       int idx;
-
                        if (tags[tag])
                                continue;
 
                        tag_clear(pathp->node, tag, pathp->offset);
 
-                       for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) {
-                               if (pathp->node->tags[tag][idx]) {
-                                       tags[tag] = 1;
-                                       nr_cleared_tags--;
-                                       break;
-                               }
+                       if (any_tag_set(pathp->node, tag)) {
+                               tags[tag] = 1;
+                               nr_cleared_tags--;
                        }
                }
                pathp--;
@@ -770,15 +769,11 @@ EXPORT_SYMBOL(radix_tree_delete);
  */
 int radix_tree_tagged(struct radix_tree_root *root, int tag)
 {
-       int idx;
-
-       if (!root->rnode)
-               return 0;
-       for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) {
-               if (root->rnode->tags[tag][idx])
-                       return 1;
-       }
-       return 0;
+       struct radix_tree_node *rnode;
+       rnode = root->rnode;
+       if (!rnode)
+               return 0;
+       return any_tag_set(rnode, tag);
 }
 EXPORT_SYMBOL(radix_tree_tagged);