From: Liam R. Howlett <Liam.Howlett@oracle.com>
Date: Thu, 24 Feb 2022 18:27:22 +0000 (-0500)
Subject: maple_tree: Fix stack size again
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=f09e1b48f15cb4a60c009a1136bd5aa267d2d36a;p=users%2Fjedix%2Flinux-maple.git

maple_tree: Fix stack size again

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

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 64b8a6d6d3a3..bd19e087214e 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -118,7 +118,6 @@ struct maple_big_node {
 			unsigned long gap[MAPLE_BIG_NODE_GAPS];
 		};
 	};
-	unsigned long min;
 	unsigned char b_end;
 	enum maple_type type;
 };
@@ -1810,12 +1809,11 @@ static inline int mab_no_null_split(struct maple_big_node *b_node,
  * Return: The first split location.  The middle split is set in @mid_split.
  */
 static inline int mab_calc_split(struct ma_state *mas,
-				 struct maple_big_node *bn,
-				 unsigned char *mid_split)
+	 struct maple_big_node *bn, unsigned char *mid_split, unsigned long min)
 {
 	unsigned char b_end = bn->b_end;
 	int split = b_end / 2; /* Assume equal split. */
-	unsigned char min, slot_count = mt_slots[bn->type];
+	unsigned char slot_min, slot_count = mt_slots[bn->type];
 
 	/*
 	 * To support gap tracking, all NULL entries are kept together and a node cannot
@@ -1826,11 +1824,11 @@ static inline int mab_calc_split(struct ma_state *mas,
 	if (unlikely((mas->mas_flags & MA_STATE_BULK))) {
 		*mid_split = 0;
 		if (ma_is_leaf(bn->type))
-			min = 2;
+			slot_min = 2;
 		else
 			return b_end - mt_min_slots[bn->type];
 
-		split = b_end - min;
+		split = b_end - slot_min;
 		mas->mas_flags |= MA_STATE_REBALANCE;
 		if (!bn->slot[split])
 			split--;
@@ -1849,7 +1847,7 @@ static inline int mab_calc_split(struct ma_state *mas,
 		split = b_end / 3;
 		*mid_split = split * 2;
 	} else {
-		min = mt_min_slots[bn->type];
+		slot_min = mt_min_slots[bn->type];
 
 		*mid_split = 0;
 		/*
@@ -1857,8 +1855,8 @@ static inline int mab_calc_split(struct ma_state *mas,
 		 * causes one node to be deficient.
 		 * NOTE: mt_min_slots is 1 based, b_end and split are zero.
 		 */
-		while (((bn->pivot[split] - bn->min) < slot_count - 1) &&
-		       (split < slot_count - 1) && (b_end - split > min))
+		while (((bn->pivot[split] - min) < slot_count - 1) &&
+		       (split < slot_count - 1) && (b_end - split > slot_min))
 			split++;
 	}
 
@@ -2481,11 +2479,9 @@ static inline struct maple_enode
  * Return: the split of left.
  */
 static inline unsigned char mas_mab_to_node(struct ma_state *mas,
-					    struct maple_big_node *b_node,
-					    struct maple_enode **left,
-					    struct maple_enode **right,
-					    struct maple_enode **middle,
-					    unsigned char *mid_split)
+	struct maple_big_node *b_node, struct maple_enode **left,
+	struct maple_enode **right, struct maple_enode **middle,
+	unsigned char *mid_split, unsigned long min)
 {
 	unsigned char split = 0;
 	unsigned char slot_count = mt_slots[b_node->type];
@@ -2498,7 +2494,7 @@ static inline unsigned char mas_mab_to_node(struct ma_state *mas,
 	if (b_node->b_end < slot_count) {
 		split = b_node->b_end;
 	} else {
-		split = mab_calc_split(mas, b_node, mid_split);
+		split = mab_calc_split(mas, b_node, mid_split, min);
 		*right = mas_new_ma_node(mas, b_node);
 	}
 
@@ -2767,18 +2763,6 @@ static inline bool mast_overflow(struct maple_subtree_state *mast)
 	return false;
 }
 
-/*
- * mast_setup_bnode_for_split() - Prepare the subtree state big node for
- * splitting
- * @mast: The maple subtree state
- */
-static inline void mast_setup_bnode_for_split(struct maple_subtree_state *mast)
-{
-	mast->bn->b_end--;
-	mast->bn->min = mast->orig_l->min;
-	mast->bn->type = mte_node_type(mast->orig_l->node);
-}
-
 static inline void *mtree_range_walk(struct ma_state *mas)
 {
 	unsigned long *pivots;
@@ -2905,9 +2889,10 @@ static int mas_spanning_rebalance(struct ma_state *mas,
 	 * See mas_descend_adopt() for more information..
 	 */
 	while (count--) {
-		mast_setup_bnode_for_split(mast);
+		mast->bn->b_end--;
+		mast->bn->type = mte_node_type(mast->orig_l->node);
 		split = mas_mab_to_node(mas, mast->bn, &left, &right, &middle,
-					&mid_split);
+					&mid_split, mast->orig_l->min);
 		mast_set_split_parents(mast, left, middle, right, split,
 				       mid_split);
 		mast_cp_to_nodes(mast, left, middle, right, split, mid_split);
@@ -3227,7 +3212,6 @@ static inline void mast_fill_bnode(struct maple_subtree_state *mast,
 		mas->offset = mte_parent_slot(mas->node);
 	}
 
-	mast->bn->min = mas->min;
 	if (cp && mast->l->offset)
 		mas_mab_cp(mas, 0, mast->l->offset - 1, mast->bn, 0);
 
@@ -3424,7 +3408,7 @@ static int mas_split(struct ma_state *mas, struct maple_big_node *b_node)
 		if (mas_push_data(mas, height, &mast, false))
 			break;
 
-		split = mab_calc_split(mas, b_node, &mid_split);
+		split = mab_calc_split(mas, b_node, &mid_split, prev_l_mas.min);
 		mast_split_data(&mast, mas, split);
 		/*
 		 * Usually correct, mab_mas_cp in the above call overwrites
@@ -4239,7 +4223,6 @@ static inline void mas_wr_modify(struct ma_wr_state *wr_mas)
 
 slow_path:
 	b_node.b_end = mas_store_b_node(wr_mas, &b_node, wr_mas->offset_end);
-	b_node.min = mas->min;
 	zero = MAPLE_BIG_NODE_SLOTS - b_node.b_end - 1;
 	memset(b_node.slot + b_node.b_end + 1, 0, sizeof(void *) * zero--);
 	memset(b_node.pivot + b_node.b_end + 1, 0,