maple_tree: Remove fixed array size from mas_split and use ma_topiary instead.

Also, move common smp_wmb() from split and combine_separate function into a helper.

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

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 6edde8819e1990f684d24300d9362af49c20d309..5fc0ef6d9915aae7cc4ef42abe0afc70a7884e9b 100644 (file)
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -1837,6 +1837,31 @@ static inline void mas_separate_set_parent(struct ma_state *mas,
 
        (*slot)++;
 }
+
+static inline void mas_wmb_replace(struct ma_state *mas,
+                                  struct ma_topiary *free,
+                                  struct ma_topiary *destroy)
+{
+       smp_wmb();
+
+       // Insert the new data in the tree
+       mas_replace(mas, true);
+
+       if (!mte_is_leaf(mas->node))
+               mas_descend_adopt(mas);
+
+       mat_free(free, false);
+
+       if (destroy)
+               mat_free(destroy, true);
+
+       if (mte_is_leaf(mas->node))
+               return;
+
+       if (mt_is_alloc(mas->tree))
+               mas_update_gap(mas, false);
+}
+
 /* Private
  *
  * mas_combine_separate() - Follow the tree upwards from @l_mas and @r_mas for
@@ -2113,22 +2138,7 @@ done:
        mte_set_node_dead(mas->node);
        // Set up mas for insertion.
        mas_dup_state(mas, orig_l_mas);
-       smp_wmb();
-
-       // Insert new sub-tree
-       mas_replace(mas, true);
-       if (!mte_is_leaf(mas->node))
-               mas_descend_adopt(mas);
-
-       mat_free(&free, false);
-       mat_free(&destroy, true);
-
-       if (mte_is_leaf(mas->node))
-               return b_node->b_end;
-
-       if (mt_is_alloc(mas->tree))
-               mas_update_gap(mas, false);
-
+       mas_wmb_replace(mas, &free, &destroy);
        return b_node->b_end;
 }
 
@@ -2173,14 +2183,15 @@ static inline int mas_split(struct ma_state *mas,
 
        struct maple_enode *ancestor = MAS_NONE;
        unsigned char split = 0;
-       int j, i = 0, height = 0;
-       struct maple_enode *list[15]; // Enough for an 8 level tree.
+       int j, height = 0;
 
        MA_STATE(l_mas, mas->tree, mas->index, mas->last);
        MA_STATE(r_mas, mas->tree, mas->index, mas->last);
        MA_STATE(orig_l_mas, mas->tree, mas->index, mas->last);
        MA_STATE(orig_r_mas, mas->tree, mas->index, mas->last);
 
+       MA_TOPIARY(mat, mas->tree);
+
 
        // Allocation failures will happen early.
        // TODO: Increase this by one when optimizing with a rebalance.
@@ -2198,7 +2209,7 @@ static inline int mas_split(struct ma_state *mas,
         * into the highest common ancestor necessary to be modified (which may
         * be a new root).
         */
-       list[i++] = mas->node;
+       //list[i++] = mas->node;
        while (height++ <= mas->full_cnt) {
                struct maple_node *l, *r;
                enum maple_type type = mte_node_type(mas->node);
@@ -2308,9 +2319,11 @@ static inline int mas_split(struct ma_state *mas,
                if (mte_is_root(mas->node))
                        cp = false;
                else {
+                       struct maple_enode *old = mas->node;
+
                        mas_ascend(mas);
+                       mat_add(&mat, old);
                        mas_set_slot(mas, mte_parent_slot(mas->node));
-                       list[i++] = mas->node;
                }
 
                if (cp && mas_get_slot(&l_mas))
@@ -2336,24 +2349,10 @@ static inline int mas_split(struct ma_state *mas,
                                       j + 1);
        }
 
-
-       mas->node = ancestor;
-       BUG_ON(mas_is_none(mas));
        // Set the original node as dead
-       mte_set_node_dead(list[0]);
-       smp_wmb();
-
-       // Insert the new data in the tree
-       mas_replace(mas, true);
-
-       mas_descend_adopt(mas);
-       do {
-               mte_free(list[--i]);
-       } while (i);
-
-       if (mt_is_alloc(mas->tree))
-               mas_update_gap(mas, false);
-
+       mat_add(&mat, mas->node);
+       mas->node = ancestor;
+       mas_wmb_replace(mas, &mat, NULL);
        return 1;
 }