* success, return zero, with preemption disabled. On error, return -ENOMEM
* with preemption not disabled.
*/
-int radix_tree_preload(int gfp_mask)
+int radix_tree_preload(gfp_t gfp_mask)
{
struct radix_tree_preload *rtp;
struct radix_tree_node *node;
}
EXPORT_SYMBOL(radix_tree_insert);
-/**
- * radix_tree_lookup - perform lookup operation on a radix tree
- * @root: radix tree root
- * @index: index key
- *
- * Lookup the item at the position @index in the radix tree @root.
- */
-void *radix_tree_lookup(struct radix_tree_root *root, unsigned long index)
+static inline void **__lookup_slot(struct radix_tree_root *root,
+ unsigned long index)
{
unsigned int height, shift;
- struct radix_tree_node *slot;
+ struct radix_tree_node **slot;
height = root->height;
if (index > radix_tree_maxindex(height))
return NULL;
shift = (height-1) * RADIX_TREE_MAP_SHIFT;
- slot = root->rnode;
+ slot = &root->rnode;
while (height > 0) {
- if (slot == NULL)
+ if (*slot == NULL)
return NULL;
- slot = slot->slots[(index >> shift) & RADIX_TREE_MAP_MASK];
+ slot = (struct radix_tree_node **)
+ ((*slot)->slots +
+ ((index >> shift) & RADIX_TREE_MAP_MASK));
shift -= RADIX_TREE_MAP_SHIFT;
height--;
}
- return slot;
+ return (void **)slot;
+}
+
+/**
+ * radix_tree_lookup_slot - lookup a slot in a radix tree
+ * @root: radix tree root
+ * @index: index key
+ *
+ * Lookup the slot corresponding to the position @index in the radix tree
+ * @root. This is useful for update-if-exists operations.
+ */
+void **radix_tree_lookup_slot(struct radix_tree_root *root, unsigned long index)
+{
+ return __lookup_slot(root, index);
+}
+EXPORT_SYMBOL(radix_tree_lookup_slot);
+
+/**
+ * radix_tree_lookup - perform lookup operation on a radix tree
+ * @root: radix tree root
+ * @index: index key
+ *
+ * Lookup the item at the position @index in the radix tree @root.
+ */
+void *radix_tree_lookup(struct radix_tree_root *root, unsigned long index)
+{
+ void **slot;
+
+ slot = __lookup_slot(root, index);
+ return slot != NULL ? *slot : NULL;
}
EXPORT_SYMBOL(radix_tree_lookup);
#ifndef __KERNEL__ /* Only the test harness uses this at present */
/**
- * radix_tree_tag_get - get a tag on a radix tree node
- * @root: radix tree root
- * @index: index key
- * @tag: tag index
+ * radix_tree_tag_get - get a tag on a radix tree node
+ * @root: radix tree root
+ * @index: index key
+ * @tag: tag index
*
- * Return the search tag corresponging to @index in the radix tree.
+ * Return values:
*
- * Returns zero if the tag is unset, or if there is no corresponding item
- * in the tree.
+ * 0: tag not present
+ * 1: tag present, set
+ * -1: tag present, unset
*/
int radix_tree_tag_get(struct radix_tree_root *root,
unsigned long index, int tag)
int ret = tag_get(slot, tag, offset);
BUG_ON(ret && saw_unset_tag);
- return ret;
+ return ret ? 1 : -1;
}
slot = slot->slots[offset];
shift -= RADIX_TREE_MAP_SHIFT;