radix-tree: Store a pointer to the root in each node
Instead of having this mysterious private_data in each radix_tree_node,
store a pointer to the root, which can be useful for debugging. This also
relieves the mm code from the duty of updating it.
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
diff --git a/mm/workingset.c b/mm/workingset.c
index abb58ff..80c913c 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -354,10 +354,8 @@
* as node->private_list is protected by &mapping->tree_lock.
*/
if (node->count && node->count == node->exceptional) {
- if (list_empty(&node->private_list)) {
- node->private_data = mapping;
+ if (list_empty(&node->private_list))
list_lru_add(&shadow_nodes, &node->private_list);
- }
} else {
if (!list_empty(&node->private_list))
list_lru_del(&shadow_nodes, &node->private_list);
@@ -435,7 +433,7 @@
*/
node = container_of(item, struct radix_tree_node, private_list);
- mapping = node->private_data;
+ mapping = container_of(node->root, struct address_space, page_tree);
/* Coming from the list, invert the lock order */
if (!spin_trylock(&mapping->tree_lock)) {