From c147bc81e2ddabdc9a1e28ba88d404d97b82b293 Mon Sep 17 00:00:00 2001
From: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Date: Tue, 16 Sep 2025 15:50:21 -0400
Subject: [PATCH] cp_data_write: simplify

Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
---
 lib/maple_tree.c | 58 ++++++++++++++++++++++--------------------------
 1 file changed, 26 insertions(+), 32 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index a7e121109ba3..f84c8cef9b06 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -3229,12 +3229,14 @@ void cp_data_write(struct maple_copy *cp, struct ma_state *mas)
 	struct maple_node *dst, *src;
 	unsigned char s, d;
 	unsigned char dst_offset;
-	unsigned char data, data_offset;
+	unsigned char data_offset;
 	unsigned char src_end, s_offset;
-	unsigned char split, next_node, size;
+	unsigned char split;
 	unsigned long s_max, d_max;
+	unsigned char dst_size;
 	enum maple_type s_mt, d_mt;
 
+	data_offset = 0;
 	s = d = 0;
 	/* Readability help */
 	src = cp->src[s].node;
@@ -3245,31 +3247,27 @@ void cp_data_write(struct maple_copy *cp, struct ma_state *mas)
 	s_max = cp->src[s].max;
 	s_mt = cp->src[s].mt;
 	d_mt = cp->dst[d].mt;
-	data = cp->data;
-
-	dst_offset = 0;
-	data_offset = 0;
-	next_node = split;
-	/*
-	 * size (and split, and next_node will be 1 indexed while
-	 * src start/end dst start/end are 0 indexed
-	 */
+	dst_size = split + 1;
 	do {
-		do {
-			size = next_node - data_offset + 1;
-			/* Fill the destination */
-			if (src_end - s_offset + 1 < size)
-				size = src_end - s_offset + 1;
+		dst_offset = 0;
+		d_max = 0;
+		dst = cp->dst[d].node;
+		d_mt = cp->dst[d].mt;
+		dst_size = split;
+
+		while (dst_size) {
+			unsigned char size;
 
-			if (split - dst_offset + 1 < size)
-				size = split - dst_offset + 1;
+			if (src_end - s_offset + 1 < dst_size)
+				size = src_end - s_offset + 1;
+			else
+				size = dst_size;
 
 			d_max = node_copy(mas, src, s_offset, size, s_max, s_mt,
 					  dst, dst_offset, d_mt);
-			data_offset += size;
+
 			dst_offset += size;
 			s_offset += size;
-
 			if (s_offset > src_end) {
 				/* This source is exhausted */
 				s++;
@@ -3278,7 +3276,6 @@ void cp_data_write(struct maple_copy *cp, struct ma_state *mas)
 					node_finalise(dst, d_mt, dst_offset);
 					return;
 				}
-				d_max = s_max;
 				/* Reset local src */
 				src = cp->src[s].node;
 				s_offset = cp->src[s].start;
@@ -3286,11 +3283,10 @@ void cp_data_write(struct maple_copy *cp, struct ma_state *mas)
 				s_max = cp->src[s].max;
 				s_mt = cp->src[s].mt;
 			}
-		} while (data_offset <= next_node);
 
-		next_node *= 2;
-		if (next_node > data + 1)
-			next_node = data + 1;
+			dst_size -= size;
+			data_offset += size;
+		}
 
 		split = cp->split;
 		cp->dst[d].max = d_max;
@@ -3308,23 +3304,21 @@ void cp_data_write(struct maple_copy *cp, struct ma_state *mas)
 				s_offset--;
 			}
 			/* Set dst max and clear pivot */
-			next_node++;
 			split++;
 			data_offset--;
 			dst_offset--;
 			cp->dst[d].max = ma_pivots(dst, d_mt)[dst_offset - 1];
 		}
+
 		node_finalise(dst, d_mt, dst_offset);
 		if (d >= cp->d_count) {
-			WARN_ON(data_offset < data);
+			WARN_ON(data_offset < cp->data);
 			return;
 		}
-		/* Reset local dst */
+
+		/* Next dst */
 		++d;
-		dst = cp->dst[d].node;
-		d_mt = cp->dst[d].mt;
-		dst_offset = 0;
-	} while (data_offset <= data);
+	} while (data_offset <= cp->data);
 }
 
 
-- 
2.51.0