radix_tree: exceptional entries and indices
[linux-2.6.git] / lib / radix-tree.c
index 7ea2e03..348eaef 100644 (file)
@@ -823,8 +823,8 @@ unsigned long radix_tree_prev_hole(struct radix_tree_root *root,
 EXPORT_SYMBOL(radix_tree_prev_hole);
 
 static unsigned int
-__lookup(struct radix_tree_node *slot, void ***results, unsigned long index,
-       unsigned int max_items, unsigned long *next_index)
+__lookup(struct radix_tree_node *slot, void ***results, unsigned long *indices,
+       unsigned long index, unsigned int max_items, unsigned long *next_index)
 {
        unsigned int nr_found = 0;
        unsigned int shift, height;
@@ -857,12 +857,16 @@ __lookup(struct radix_tree_node *slot, void ***results, unsigned long index,
 
        /* Bottom level: grab some items */
        for (i = index & RADIX_TREE_MAP_MASK; i < RADIX_TREE_MAP_SIZE; i++) {
-               index++;
                if (slot->slots[i]) {
-                       results[nr_found++] = &(slot->slots[i]);
-                       if (nr_found == max_items)
+                       results[nr_found] = &(slot->slots[i]);
+                       if (indices)
+                               indices[nr_found] = index;
+                       if (++nr_found == max_items) {
+                               index++;
                                goto out;
+                       }
                }
+               index++;
        }
 out:
        *next_index = index;
@@ -918,8 +922,8 @@ radix_tree_gang_lookup(struct radix_tree_root *root, void **results,
 
                if (cur_index > max_index)
                        break;
-               slots_found = __lookup(node, (void ***)results + ret, cur_index,
-                                       max_items - ret, &next_index);
+               slots_found = __lookup(node, (void ***)results + ret, NULL,
+                               cur_index, max_items - ret, &next_index);
                nr_found = 0;
                for (i = 0; i < slots_found; i++) {
                        struct radix_tree_node *slot;
@@ -944,6 +948,7 @@ EXPORT_SYMBOL(radix_tree_gang_lookup);
  *     radix_tree_gang_lookup_slot - perform multiple slot lookup on radix tree
  *     @root:          radix tree root
  *     @results:       where the results of the lookup are placed
+ *     @indices:       where their indices should be placed (but usually NULL)
  *     @first_index:   start the lookup from this key
  *     @max_items:     place up to this many items at *results
  *
@@ -958,7 +963,8 @@ EXPORT_SYMBOL(radix_tree_gang_lookup);
  *     protection, radix_tree_deref_slot may fail requiring a retry.
  */
 unsigned int
-radix_tree_gang_lookup_slot(struct radix_tree_root *root, void ***results,
+radix_tree_gang_lookup_slot(struct radix_tree_root *root,
+                       void ***results, unsigned long *indices,
                        unsigned long first_index, unsigned int max_items)
 {
        unsigned long max_index;
@@ -974,6 +980,8 @@ radix_tree_gang_lookup_slot(struct radix_tree_root *root, void ***results,
                if (first_index > 0)
                        return 0;
                results[0] = (void **)&root->rnode;
+               if (indices)
+                       indices[0] = 0;
                return 1;
        }
        node = indirect_to_ptr(node);
@@ -987,8 +995,9 @@ radix_tree_gang_lookup_slot(struct radix_tree_root *root, void ***results,
 
                if (cur_index > max_index)
                        break;
-               slots_found = __lookup(node, results + ret, cur_index,
-                                       max_items - ret, &next_index);
+               slots_found = __lookup(node, results + ret,
+                               indices ? indices + ret : NULL,
+                               cur_index, max_items - ret, &next_index);
                ret += slots_found;
                if (next_index == 0)
                        break;