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-rw-r--r--lib/radix-tree.c46
1 files changed, 43 insertions, 3 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 8e6d552c40dd..7885796d35ae 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -220,10 +220,10 @@ static void dump_node(struct radix_tree_node *node, unsigned long index)
{
unsigned long i;
- pr_debug("radix node: %p offset %d tags %lx %lx %lx shift %d count %d parent %p\n",
+ pr_debug("radix node: %p offset %d tags %lx %lx %lx shift %d count %d exceptional %d parent %p\n",
node, node->offset,
node->tags[0][0], node->tags[1][0], node->tags[2][0],
- node->shift, node->count, node->parent);
+ node->shift, node->count, node->exceptional, node->parent);
for (i = 0; i < RADIX_TREE_MAP_SIZE; i++) {
unsigned long first = index | (i << node->shift);
@@ -522,8 +522,13 @@ static int radix_tree_extend(struct radix_tree_root *root,
node->offset = 0;
node->count = 1;
node->parent = NULL;
- if (radix_tree_is_internal_node(slot))
+ if (radix_tree_is_internal_node(slot)) {
entry_to_node(slot)->parent = node;
+ } else {
+ /* Moving an exceptional root->rnode to a node */
+ if (radix_tree_exceptional_entry(slot))
+ node->exceptional = 1;
+ }
node->slots[0] = slot;
slot = node_to_entry(node);
rcu_assign_pointer(root->rnode, slot);
@@ -649,6 +654,8 @@ int __radix_tree_insert(struct radix_tree_root *root, unsigned long index,
if (node) {
unsigned offset = get_slot_offset(node, slot);
node->count++;
+ if (radix_tree_exceptional_entry(item))
+ node->exceptional++;
BUG_ON(tag_get(node, 0, offset));
BUG_ON(tag_get(node, 1, offset));
BUG_ON(tag_get(node, 2, offset));
@@ -747,6 +754,37 @@ void *radix_tree_lookup(struct radix_tree_root *root, unsigned long index)
EXPORT_SYMBOL(radix_tree_lookup);
/**
+ * __radix_tree_replace - replace item in a slot
+ * @root: radix tree root
+ * @node: pointer to tree node
+ * @slot: pointer to slot in @node
+ * @item: new item to store in the slot.
+ *
+ * For use with __radix_tree_lookup(). Caller must hold tree write locked
+ * across slot lookup and replacement.
+ */
+void __radix_tree_replace(struct radix_tree_root *root,
+ struct radix_tree_node *node,
+ void **slot, void *item)
+{
+ void *old = rcu_dereference_raw(*slot);
+ int exceptional;
+
+ WARN_ON_ONCE(radix_tree_is_internal_node(item));
+ WARN_ON_ONCE(!!item - !!old);
+
+ exceptional = !!radix_tree_exceptional_entry(item) -
+ !!radix_tree_exceptional_entry(old);
+
+ WARN_ON_ONCE(exceptional && !node && slot != (void **)&root->rnode);
+
+ if (node)
+ node->exceptional += exceptional;
+
+ rcu_assign_pointer(*slot, item);
+}
+
+/**
* radix_tree_tag_set - set a tag on a radix tree node
* @root: radix tree root
* @index: index key
@@ -1561,6 +1599,8 @@ void *radix_tree_delete_item(struct radix_tree_root *root,
delete_sibling_entries(node, node_to_entry(slot), offset);
node->slots[offset] = NULL;
node->count--;
+ if (radix_tree_exceptional_entry(entry))
+ node->exceptional--;
__radix_tree_delete_node(root, node);