[PATCH 3/6] maple_tree: introduce mas_put_in_tree()

From: Liam R. Howlett
Date: Fri Aug 04 2023 - 13:00:54 EST


mas_replace() has a single user that takes a flag which is now always
true. Replace this function with mas_put_in_tree() to better align with
mas_replace_node(). Inline the remaining logic into the only caller;
mas_wmb_replace().

Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
---
lib/maple_tree.c | 73 ++++++++++++++++++------------------------------
1 file changed, 27 insertions(+), 46 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 0d4573a8d134..c01b1be1480c 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -1715,45 +1715,32 @@ static inline void mas_adopt_children(struct ma_state *mas,
}

/*
- * mas_replace() - Replace a maple node in the tree with mas->node. Uses the
- * parent encoding to locate the maple node in the tree.
- * @mas - the ma_state to use for operations.
- * @advanced - boolean to adopt the child nodes and free the old node (false) or
- * leave the node (true) and handle the adoption and free elsewhere.
+ * mas_put_in_tree() - Put a new node in the tree, smp_wmb(), and mark the old
+ * node as dead.
+ * @mas - the maple state with the new node
+ * @old_enode - The old maple encoded node to replace.
*/
-static inline void mas_replace(struct ma_state *mas, bool advanced)
+static inline void mas_put_in_tree(struct ma_state *mas,
+ struct maple_enode *old_enode)
__must_hold(mas->tree->ma_lock)
{
- struct maple_node *mn = mas_mn(mas);
- struct maple_enode *old_enode;
- unsigned char offset = 0;
- void __rcu **slots = NULL;
-
- if (ma_is_root(mn)) {
- old_enode = mas_root_locked(mas);
- } else {
- offset = mte_parent_slot(mas->node);
- slots = ma_slots(mte_parent(mas->node),
- mas_parent_type(mas, mas->node));
- old_enode = mas_slot_locked(mas, slots, offset);
- }
-
- if (!advanced && !mte_is_leaf(mas->node))
- mas_adopt_children(mas, mas->node);
+ unsigned char offset;
+ void __rcu **slots;

if (mte_is_root(mas->node)) {
- mn->parent = ma_parent_ptr(
+ mas_mn(mas)->parent = ma_parent_ptr(
((unsigned long)mas->tree | MA_ROOT_PARENT));
rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node));
mas_set_height(mas);
} else {
+
+ offset = mte_parent_slot(mas->node);
+ slots = ma_slots(mte_parent(mas->node),
+ mas_parent_type(mas, mas->node));
rcu_assign_pointer(slots[offset], mas->node);
}

- if (!advanced) {
- mte_set_node_dead(old_enode);
- mas_free(mas, old_enode);
- }
+ mte_set_node_dead(old_enode);
}

/*
@@ -1767,22 +1754,7 @@ static inline void mas_replace_node(struct ma_state *mas,
struct maple_enode *old_enode)
__must_hold(mas->tree->ma_lock)
{
- if (mte_is_root(mas->node)) {
- mas_mn(mas)->parent = ma_parent_ptr(
- ((unsigned long)mas->tree | MA_ROOT_PARENT));
- rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node));
- mas_set_height(mas);
- } else {
- unsigned char offset = 0;
- void __rcu **slots = NULL;
-
- offset = mte_parent_slot(mas->node);
- slots = ma_slots(mte_parent(mas->node),
- mas_parent_type(mas, mas->node));
- rcu_assign_pointer(slots[offset], mas->node);
- }
-
- mte_set_node_dead(old_enode);
+ mas_put_in_tree(mas, old_enode);
mas_free(mas, old_enode);
}

@@ -2789,11 +2761,20 @@ static inline void mas_wmb_replace(struct ma_state *mas,
struct ma_topiary *free,
struct ma_topiary *destroy)
{
- /* All nodes must see old data as dead prior to replacing that data */
- smp_wmb(); /* Needed for RCU */
+ struct maple_enode *old_enode;
+
+ if (mte_is_root(mas->node)) {
+ old_enode = mas_root_locked(mas);
+ } else {
+ unsigned char offset = mte_parent_slot(mas->node);
+ void __rcu **slots = ma_slots(mte_parent(mas->node),
+ mas_parent_type(mas, mas->node));
+
+ old_enode = mas_slot_locked(mas, slots, offset);
+ }

/* Insert the new data in the tree */
- mas_replace(mas, true);
+ mas_put_in_tree(mas, old_enode);

if (!mte_is_leaf(mas->node))
mas_descend_adopt(mas);
--
2.39.2