[PATCH v2 02/29] maple_tree: Move mas_spanning_rebalance loop to function

["Liam R. Howlett" <Liam.Howlett@oracle.com>]

Move the loop over the tree levels to its own function.

No intended functional changes.

Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
---
 lib/maple_tree.c | 108 +++++++++++++++++++++++++----------------------
 1 file changed, 58 insertions(+), 50 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 0e0158ee7ba55..70ad474e6ed14 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -2595,49 +2595,16 @@ static inline void *mtree_range_walk(struct ma_state *mas)
 	return NULL;
 }
 
-/*
- * mas_spanning_rebalance() - Rebalance across two nodes which may not be peers.
- * @mas: The starting maple state
- * @mast: The maple_subtree_state, keeps track of 4 maple states.
- * @count: The estimated count of iterations needed.
- *
- * Follow the tree upwards from @l_mas and @r_mas for @count, or until the root
- * is hit.  First @b_node is split into two entries which are inserted into the
- * next iteration of the loop.  @b_node is returned populated with the final
- * iteration. @mas is used to obtain allocations.  orig_l_mas keeps track of the
- * nodes that will remain active by using orig_l_mas->index and orig_l_mas->last
- * to account of what has been copied into the new sub-tree.  The update of
- * orig_l_mas->last is used in mas_consume to find the slots that will need to
- * be either freed or destroyed.  orig_l_mas->depth keeps track of the height of
- * the new sub-tree in case the sub-tree becomes the full tree.
- */
-static void mas_spanning_rebalance(struct ma_state *mas,
+static void mas_spanning_rebalance_loop(struct ma_state *mas,
 		struct maple_subtree_state *mast, unsigned char count)
 {
+
 	unsigned char split, mid_split;
 	unsigned char slot = 0;
 	unsigned char new_height = 0; /* used if node is a new root */
 	struct maple_enode *left = NULL, *middle = NULL, *right = NULL;
 	struct maple_enode *old_enode;
 
-	MA_STATE(l_mas, mas->tree, mas->index, mas->index);
-	MA_STATE(r_mas, mas->tree, mas->index, mas->last);
-	MA_STATE(m_mas, mas->tree, mas->index, mas->index);
-
-	/*
-	 * The tree needs to be rebalanced and leaves need to be kept at the same level.
-	 * Rebalancing is done by use of the ``struct maple_topiary``.
-	 */
-	mast->l = &l_mas;
-	mast->m = &m_mas;
-	mast->r = &r_mas;
-	l_mas.status = r_mas.status = m_mas.status = ma_none;
-
-	/* Check if this is not root and has sufficient data.  */
-	if (((mast->orig_l->min != 0) || (mast->orig_r->max != ULONG_MAX)) &&
-	    unlikely(mast->bn->b_end <= mt_min_slots[mast->bn->type]))
-		mast_spanning_rebalance(mast);
-
 	/*
 	 * Each level of the tree is examined and balanced, pushing data to the left or
 	 * right, or rebalancing against left or right nodes is employed to avoid
@@ -2672,10 +2639,10 @@ static void mas_spanning_rebalance(struct ma_state *mas,
 
 		mast_ascend(mast);
 		mast_combine_cp_left(mast);
-		l_mas.offset = mast->bn->b_end;
-		mab_set_b_end(mast->bn, &l_mas, left);
-		mab_set_b_end(mast->bn, &m_mas, middle);
-		mab_set_b_end(mast->bn, &r_mas, right);
+		mast->l->offset = mast->bn->b_end;
+		mab_set_b_end(mast->bn, mast->l, left);
+		mab_set_b_end(mast->bn, mast->m, middle);
+		mab_set_b_end(mast->bn, mast->r, right);
 
 		/* Copy anything necessary out of the right node. */
 		mast_combine_cp_right(mast);
@@ -2708,17 +2675,17 @@ static void mas_spanning_rebalance(struct ma_state *mas,
 			count++;
 	}
 
-	l_mas.node = mt_mk_node(ma_mnode_ptr(mas_pop_node(mas)),
+	mast->l->node = mt_mk_node(ma_mnode_ptr(mas_pop_node(mas)),
 				mte_node_type(mast->orig_l->node));
 
-	mab_mas_cp(mast->bn, 0, mt_slots[mast->bn->type] - 1, &l_mas, true);
+	mab_mas_cp(mast->bn, 0, mt_slots[mast->bn->type] - 1, mast->l, true);
 	new_height++;
-	mas_set_parent(mas, left, l_mas.node, slot);
+	mas_set_parent(mas, left, mast->l->node, slot);
 	if (middle)
-		mas_set_parent(mas, middle, l_mas.node, ++slot);
+		mas_set_parent(mas, middle, mast->l->node, ++slot);
 
 	if (right)
-		mas_set_parent(mas, right, l_mas.node, ++slot);
+		mas_set_parent(mas, right, mast->l->node, ++slot);
 
 	if (mas_is_root_limits(mast->l)) {
 new_root:
@@ -2726,20 +2693,61 @@ static void mas_spanning_rebalance(struct ma_state *mas,
 		while (!mte_is_root(mast->orig_l->node))
 			mast_ascend(mast);
 	} else {
-		mas_mn(&l_mas)->parent = mas_mn(mast->orig_l)->parent;
+		mas_mn(mast->l)->parent = mas_mn(mast->orig_l)->parent;
 	}
 
 	old_enode = mast->orig_l->node;
-	mas->depth = l_mas.depth;
-	mas->node = l_mas.node;
-	mas->min = l_mas.min;
-	mas->max = l_mas.max;
-	mas->offset = l_mas.offset;
+	mas->depth = mast->l->depth;
+	mas->node = mast->l->node;
+	mas->min = mast->l->min;
+	mas->max = mast->l->max;
+	mas->offset = mast->l->offset;
 	mas_wmb_replace(mas, old_enode, new_height);
 	mtree_range_walk(mas);
 	return;
 }
 
+/*
+ * mas_spanning_rebalance() - Rebalance across two nodes which may not be peers.
+ * @mas: The starting maple state
+ * @mast: The maple_subtree_state, keeps track of 4 maple states.
+ * @count: The estimated count of iterations needed.
+ *
+ * Follow the tree upwards from @l_mas and @r_mas for @count, or until the root
+ * is hit.  First @b_node is split into two entries which are inserted into the
+ * next iteration of the loop.  @b_node is returned populated with the final
+ * iteration. @mas is used to obtain allocations.  orig_l_mas keeps track of the
+ * nodes that will remain active by using orig_l_mas->index and orig_l_mas->last
+ * to account of what has been copied into the new sub-tree.  The update of
+ * orig_l_mas->last is used in mas_consume to find the slots that will need to
+ * be either freed or destroyed.  orig_l_mas->depth keeps track of the height of
+ * the new sub-tree in case the sub-tree becomes the full tree.
+ */
+static void mas_spanning_rebalance(struct ma_state *mas,
+		struct maple_subtree_state *mast, unsigned char count)
+{
+
+	MA_STATE(l_mas, mas->tree, mas->index, mas->index);
+	MA_STATE(r_mas, mas->tree, mas->index, mas->last);
+	MA_STATE(m_mas, mas->tree, mas->index, mas->index);
+
+	/*
+	 * The tree needs to be rebalanced and leaves need to be kept at the same level.
+	 * Rebalancing is done by use of the ``struct maple_topiary``.
+	 */
+	mast->l = &l_mas;
+	mast->m = &m_mas;
+	mast->r = &r_mas;
+	l_mas.status = r_mas.status = m_mas.status = ma_none;
+
+	/* Check if this is not root and has sufficient data.  */
+	if (((mast->orig_l->min != 0) || (mast->orig_r->max != ULONG_MAX)) &&
+	    unlikely(mast->bn->b_end <= mt_min_slots[mast->bn->type]))
+		mast_spanning_rebalance(mast);
+
+	mas_spanning_rebalance_loop(mas, mast, count);
+}
+
 /*
  * mas_rebalance() - Rebalance a given node.
  * @mas: The maple state
-- 
2.47.3