From 511fc5e7ec70a47b03d3819bf682da11a8fe01bb Mon Sep 17 00:00:00 2001
From: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Date: Sat, 30 Aug 2025 20:43:17 -0400
Subject: [PATCH] node_copy(): try to fix max of nodes

Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
---
 lib/maple_tree.c | 53 ++++++++++++++++++++++++++++++++++++------------
 1 file changed, 40 insertions(+), 13 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 6a00380b7d35..75cec454d050 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -2936,19 +2936,35 @@ unsigned long node_copy(struct ma_state *mas, struct maple_node *src,
 		memcpy(d_gaps, s_gaps, size * sizeof(unsigned long));
 	}
 
-	d_max = s_max;
-	if (start + size < mt_pivots[s_mt])
+	/* This is wrong.. */
+	printk("\t\tAssume s_max..\n");
+	printk("\t\tLast src is %u\n", start + size);
+#if 0
+	d_max = 0;
+	if (start + size <= mt_pivots[s_mt])
 		d_max = s_pivots[size - 1];
 
-	if (d_start + size  - 1 < mt_pivots[d_mt])
+	if (d_max > s_max)
+		d_max = s_max;
+#else
+	d_max = s_max;
+	printk("\t\t d_start + size = %u\n", d_start + size);
+	if (start + size < mt_pivots[s_mt]) {
+		if (s_max > s_pivots[size - 1])
+			d_max = s_pivots[size - 1];
+		printk("\t\td_max %lx\n", d_max);
+	}
+#endif
+	if (d_start + size <= mt_pivots[d_mt]) {
+		printk("Set final pivot at %u to %lx\n", size + d_start - 1, d_max);
 		d_pivots[size - 1] = d_max;
+	}
 
-	printk("cp from %p -> %p %u\n", d_pivots, s_pivots, size);
+//	printk("cp from %p -> %p %u\n", d_pivots, s_pivots, size);
 	fflush(stdout);
-	if (size) {
-		size--;
+	size--;
+	if (size)
 		memcpy(d_pivots, s_pivots, size * sizeof(unsigned long));
-	}
 
 	return d_max;
 }
@@ -3218,10 +3234,9 @@ void spanning_data_write(struct maple_copy *cp, struct ma_state *mas)
 			}
 			printk("%d: size %u\n", __LINE__, size);
 
-			cp->dst[d].max = node_copy(mas, src, s_offset, size,
-						   s_max, s_mt, dst, dst_offset,
-						   d_mt);
-			printk("%d: set dest max %lx\n", __LINE__, cp->dst[d].max);
+			node_copy(mas, src, s_offset, size, s_max, s_mt, dst,
+				  dst_offset, d_mt);
+			//printk("%d: set dest max %lx\n", __LINE__, cp->dst[d].max);
 #if 0
 			{
 				unsigned long min = cp->min;
@@ -3242,8 +3257,10 @@ void spanning_data_write(struct maple_copy *cp, struct ma_state *mas)
 			if (s_offset > src_end) {
 				printk("\t\tnext src %u / %u\n", s  +1, cp->s_count);
 				/* This source is exhausted */
+				cp->dst[d].max = s_max;
 				s++;
 				if (s >= cp->s_count) {
+					printk("Forced final\n");
 					node_finalise(dst, d_mt, dst_offset);
 					return;
 				}
@@ -3266,11 +3283,21 @@ void spanning_data_write(struct maple_copy *cp, struct ma_state *mas)
 		split = cp->split;
 		printk("reset split %u\n", split);
 		/* Handle null entries */
-		if (s_max != ULONG_MAX && !ma_slots(dst, d_mt)[dst_offset - 1]) {
+		if (dst_offset <= mt_pivots[d_mt]) {
+			cp->dst[d].max = ma_pivots(dst, d_mt)[dst_offset - 1];
+			printk("%d: set dest max %lx\n", __LINE__, cp->dst[d].max);
+			printk("===================>slot is %p\n", ma_slots(dst,d_mt)[dst_offset - 1]);
+		} else {
+			cp->dst[d].max = s_max;
+			printk("%d: set dest max %lx\n", __LINE__, cp->dst[d].max);
+		}
+		if (cp->dst[d].max != ULONG_MAX &&
+		    !ma_slots(dst, d_mt)[dst_offset - 1]) {
 			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;
+				s--;
+				src = cp->src[s].node;
 				src_end = cp->src[s].end;
 				s_max = cp->src[s].max;
 				s_mt = cp->src[s].mt;
-- 
2.51.0