From c93bcef36f5bbabdaa1a7b67c1503d2fa23c1d6f Mon Sep 17 00:00:00 2001
From: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Date: Fri, 29 Aug 2025 15:09:21 -0400
Subject: [PATCH] readability of d increment and gap fix

Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
---
 lib/maple_tree.c                 | 46 ++++++++++++++++++++++++++------
 tools/testing/radix-tree/maple.c |  3 ++-
 2 files changed, 40 insertions(+), 9 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index cc5648a4089c..1649dadbdba9 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -2959,13 +2959,14 @@ void node_finalise(struct maple_node *node, enum maple_type mt, unsigned char en
 	unsigned char max_end = mt_slots[mt];
 	unsigned char size;
 	unsigned long *gaps;
+	unsigned char gap_slot;
 
 	printk("Finalise %p end %u max end %u\n", node, end, max_end);
+	gaps = ma_gaps(node, mt);
 	if (end < max_end - 1) {
 		size = max_end - end;
 		memset(ma_slots(node, mt) + end, 0, size * sizeof(void*));
 
-		gaps = ma_gaps(node, mt);
 		if (gaps)
 			memset(gaps + end, 0, size * sizeof(unsigned long));
 
@@ -2973,10 +2974,22 @@ void node_finalise(struct maple_node *node, enum maple_type mt, unsigned char en
 			memset(ma_pivots(node, mt) + end, 0, size * sizeof(unsigned long));
 	}
 
+	gap_slot = 0;
+	if (gaps && !ma_is_leaf(mt)) {
+		unsigned long max_gap;
+
+		max_gap = 0;
+		for (int i = 0; i <= end; i++)
+			if (gaps[i] > max_gap) {
+				gap_slot = i;
+				max_gap = gaps[i];
+			}
+	}
+
 	if (mt == maple_arange_64)
-		ma_set_meta(node, mt, 0, end - 1);
+		ma_set_meta(node, mt, gap_slot, end - 1);
 	else if (end <= max_end - 1)
-		ma_set_meta(node, mt, 0, end - 1);
+		ma_set_meta(node, mt, gap_slot, end - 1);
 }
 
 static inline void append_node_cp(struct maple_copy *cp,
@@ -3254,7 +3267,7 @@ void spanning_data_write(struct maple_copy *cp, struct ma_state *mas)
 		printk("reset split %u\n", split);
 		/* Handle null entries */
 		if (s_max != ULONG_MAX && !ma_slots(dst, d_mt)[dst_offset - 1]) {
-			printk("NULL entry end %u and max %lx\n", dst_offset - 1, s_max);
+			printk("NULL entry end %u and max %lx\n", dst_offset - 1, cp->dst[d].max);
 			//BUG_ON(1);
 			if (s_offset == cp->src[s].start) {
 				src = cp->src[--s].node;
@@ -3281,7 +3294,8 @@ void spanning_data_write(struct maple_copy *cp, struct ma_state *mas)
 		}
 		printk("\t\tnext dst\n");
 		/* Reset local dst */
-		dst = cp->dst[++d].node;
+		++d;
+		dst = cp->dst[d].node;
 		d_mt = cp->dst[d].mt;
 		dst_offset = 0;
 	} while (data_offset <= data);
@@ -3293,11 +3307,21 @@ static bool spanning_ascend(struct maple_copy *cp, struct ma_state *mas,
 		struct ma_state *sib)
 {
 	unsigned char d;
+	unsigned long min = l_wr_mas->mas->min;
 
 	for (d = 0; d < cp->d_count; d++) {
-		cp->slot[d] = mt_mk_node(cp->dst[d].node, cp->dst[d].mt);
-		cp->pivot[d] = cp->dst[d].max;
-		printk("cp slot %u => %p piv %lx\n", d, cp->slot[d], cp->pivot[d]);
+		struct maple_node *mn = cp->dst[d].node;
+		enum maple_type mt = cp->dst[d].mt;
+		unsigned long max = cp->dst[d].max;
+
+
+		cp->slot[d] = mt_mk_node(mn, mt);
+		cp->pivot[d] = max;
+		if (ma_is_leaf(mt)) {
+			cp->gap[d] = ma_leaf_max_gap(mn, mt, min, max,
+					ma_pivots(mn, mt), ma_slots(mn,mt));
+			min = max + 1;
+		}
 	}
 
 	if (sib->end) {
@@ -3561,10 +3585,15 @@ static void mas_wr_spanning_rebalance(struct ma_state *mas,
 		printk("\nlmas %p rmas %p\n", l_wr_mas->node, r_wr_mas->node);
 
 		cp.height++;
+		printk("%d: cp min %lx\n", __LINE__, cp.min);
 		spanning_data_calc(&cp, mas, l_wr_mas, r_wr_mas, &sib);
+		printk("%d: cp min %lx\n", __LINE__, cp.min);
 		spanning_split_dest_setup(&cp, mas, l_wr_mas->type);
+		printk("%d: cp min %lx\n", __LINE__, cp.min);
 		spanning_split_src_setup(&cp, mas, l_wr_mas, r_wr_mas, &sib);
+		printk("%d: cp min %lx\n", __LINE__, cp.min);
 		spanning_data_write(&cp, mas);
+		printk("%d: cp min %lx\n", __LINE__, cp.min);
 #if 0
 		if (debug < 2)
 	{
@@ -3580,6 +3609,7 @@ static void mas_wr_spanning_rebalance(struct ma_state *mas,
 #endif
 		printk ("NEXT LEVEL %d\n", debug++);
 		BUG_ON(debug > 4);
+		printk("%d: cp min %lx\n", __LINE__, cp.min);
 	} while (spanning_ascend(&cp, mas, l_wr_mas, r_wr_mas, &sib));
 
 	old_enode = mas->node;
diff --git a/tools/testing/radix-tree/maple.c b/tools/testing/radix-tree/maple.c
index b3ce89fc6d1a..7118eea67fa5 100644
--- a/tools/testing/radix-tree/maple.c
+++ b/tools/testing/radix-tree/maple.c
@@ -35895,13 +35895,14 @@ static noinline void __init check_spanning_write(struct maple_tree *mt)
 	for (i = 0; i <= max; i++)
 		mtree_test_store_range(mt, i * 10, i * 10 + 5, &i);
 	mtree_lock(mt);
-	mt_dump(mt, mt_dump_dec);
+	mt_dump(mt, mt_dump_hex);
 	/* Store a null across a boundary that ends in a null */
 	mas_set(&mas, 49835);
 	MT_BUG_ON(mt, mas_walk(&mas) == NULL);
 	MT_BUG_ON(mt, mas.end != mas.offset);
 	MT_BUG_ON(mt, mas_next_range(&mas, ULONG_MAX) != NULL);
 	mas_set_range(&mas, 49835, mas.last - 1);
+	printk("Storing %lx - %lx\n", 49835, mas.last - 1);
 	mas_store_gfp(&mas, NULL, GFP_KERNEL);
 	mt_validate(mt);
 
-- 
2.51.0