maple_tree: Remove possibility of having mas->node null

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index ee319fe06c5c3ada3dfc4e16e5e1c0822cad4448..d12ad07ea628aeddfbd582f44636ba5583378bcf 100644 (file)
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -312,7 +312,7 @@ static inline enum maple_type mas_parent_enum(struct ma_state *mas,
        return mte_parent_range_enum(parent);
 }
 
-/*
+/* Private
  * mte_set_parent() - Set the parent node and encode the slot.
  *
  * Type is encoded in the node->parent
@@ -653,7 +653,7 @@ void mte_destroy_walk(struct maple_enode *mn, struct maple_tree *mtree)
        mte_free(mn);
 
 }
-/*
+/* Private
  * mat_add() - Add a @dead_enode to the ma_topiary of a list of dead nodes.
  *
  * Add the %dead_enode to the linked list in %mat.
@@ -1766,7 +1766,7 @@ static inline struct maple_enode *mte_node_or_none(struct maple_enode *enode)
 
        return ma_enode_ptr(MAS_NONE);
 }
-/*
+/* Private
  * mast_topiary() - Add the portions of the tree to the removal list; either to
  * be freed or discarded (destroy walk).
  *
@@ -2011,7 +2011,7 @@ static inline void mab_set_b_end(struct maple_big_node *b_node,
        b_node->pivot[b_node->b_end++] = mas->max;
 }
 
-/*
+/* Private
  * mas_set_split_parent() - combine_then_separate helper function.  Sets the parent
  * of @mas->node to either @left or @right, depending on @slot and @split
  *
@@ -2075,28 +2075,14 @@ static inline void mast_set_split_parents(struct maple_subtree_state *mast,
                                          unsigned char mid_split)
 {
        unsigned char slot;
-       struct maple_enode *l = left;
-       struct maple_enode *r = right;
 
        if (mas_is_none(mast->l))
                return;
 
-       if (middle)
-               r = middle;
-
        slot = mas_get_slot(mast->l);
-
-       mte_mid_split_check(&l, &r, right, slot, &split, mid_split);
-       // Set left parent.
-       mas_set_split_parent(mast->l, l, r, &slot, split);
-
-       mte_mid_split_check(&l, &r, right, slot, &split, mid_split);
-       // Set middle parent.
-       mas_set_split_parent(mast->m, l, r, &slot, split);
-
-       mte_mid_split_check(&l, &r, right, slot, &split, mid_split);
-       // Set right parent.
-       mas_set_split_parent(mast->r, l, r, &slot, split);
+       mas_set_split_parent(mast->l, left, right, &slot, split);
+       mas_set_split_parent(mast->m, left, right, &slot, split);
+       mas_set_split_parent(mast->r, left, right, &slot, split);
 }
 static inline void mas_wmb_replace(struct ma_state *mas,
                                   struct ma_topiary *free,
@@ -2222,9 +2208,10 @@ static inline void mast_setup_bnode_for_split(struct maple_subtree_state *mast)
        mast->bn->type = mte_node_type(mast->orig_l->node);
 }
 
-/*
+/* Private
  *
- * mas_spanning_rebalance() - Rebalance across two nodes which may not be peers.
+ * mas_combine_then_separate() - Combine two nodes and then separate them as
+ * needed.
  * @mas: The starting maple state
  * @mast: The maple_subtree_state, keeps track of 4 maple states.
  * @count: The estimated count of iterations needed.
@@ -2241,7 +2228,7 @@ static inline void mast_setup_bnode_for_split(struct maple_subtree_state *mast)
  *
  * Returns the number of elements in b_node during the last loop.
  */
-static inline int mas_spanning_rebalance(struct ma_state *mas,
+static inline int mas_combine_then_separate(struct ma_state *mas,
                                            struct maple_subtree_state *mast,
                                            unsigned char count)
 {
@@ -2262,12 +2249,6 @@ static inline int mas_spanning_rebalance(struct ma_state *mas,
        mast->destroy = &destroy;
        l_mas.node = r_mas.node = m_mas.node = MAS_NONE;
 
-       if (mast->orig_l->depth != mast->orig_r->depth) {
-               printk("Error: %d != %d\n",
-                      mast->orig_l->depth, mast->orig_r->depth);
-       }
-       MT_BUG_ON(mas->tree, mast->orig_l->depth != mast->orig_r->depth);
-       mast->orig_l->depth = 0;
        mast_topiary(mast);
        while (count--) {
                mast_setup_bnode_for_split(mast);
@@ -2341,7 +2322,7 @@ new_root:
        return mast->bn->b_end;
 }
 
-/*
+/* Private
  * mas_rebalance() - Rebalance a given node.
  *
  * @mas: The maple state
@@ -2388,7 +2369,7 @@ static inline int mas_rebalance(struct ma_state *mas,
                l_mas.index = l_mas.last = l_mas.min;
        }
 
-       return mas_spanning_rebalance(mas, &mast, empty_cnt);
+       return mas_combine_then_separate(mas, &mast, empty_cnt);
 }
 
 static inline bool mas_split_final_node(struct maple_subtree_state *mast,
@@ -2940,7 +2921,8 @@ static inline int mas_spanning_store(struct ma_state *mas, void *entry)
        count = mas_cnt_positive(mas) + mas->tree->ma_height - mas->depth + 1;
 
        // Combine l_mas and r_mas and split them up evenly again.
-       return mas_spanning_rebalance(mas, &mast, count);
+       l_mas.depth = 0;
+       return mas_combine_then_separate(mas, &mast, count);
 }
 
 static inline void *_mas_store(struct ma_state *mas, void *entry, bool overwrite)