From: Liam R. Howlett <Liam.Howlett@oracle.com>
Date: Mon, 1 Sep 2025 06:07:05 +0000 (-0400)
Subject: spanning_ascend fixes
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=94af0d9135c447a0f926fcbd12f6731a954ab173;p=users%2Fjedix%2Flinux-maple.git

spanning_ascend fixes

fix gaps by moving sibling check earlier
fix node_finalise by making cp->end +1, was skipping last node
Continue if left and right meet (l_wr_mas->mas->noded == r_wr_mas..

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

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index f4566e5d4ef9..90c080bb318b 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -3334,8 +3334,22 @@ 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;
+	unsigned long min;
+
+	printk("%s: %d\n", __func__, cp->d_count);
+
+	if (sib->end) {
+		printk("sib is at %p\n", sib->node);
+		if (sib->max < l_wr_mas->mas->min) {
+			*l_wr_mas->mas = *sib;
+			printk("Shift left\n");
+		} else {
+			*r_wr_mas->mas = *sib;
+			printk("Shift Right: %p\n", r_wr_mas->mas->node);
+		}
+	}
 
+	min = l_wr_mas->mas->min;
 	for (d = 0; d < cp->d_count; d++) {
 		struct maple_node *mn = cp->dst[d].node;
 		enum maple_type mt = cp->dst[d].mt;
@@ -3345,34 +3359,26 @@ static bool spanning_ascend(struct maple_copy *cp, struct ma_state *mas,
 		cp->slot[d] = mt_mk_node(mn, mt);
 		cp->pivot[d] = max;
 		printk("%p %lx - %lx\n", cp->slot[d], min, 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));
-			printk("New gap for %p = %lx\n", mn, cp->gap[d]);
-		} else {
-			unsigned long *gaps = ma_gaps(mn, mt);
+		if (mt_is_alloc(mas->tree)) {
+			if (ma_is_leaf(mt)) {
+				cp->gap[d] = ma_leaf_max_gap(mn, mt, min, max,
+						     ma_pivots(mn, mt),
+						     ma_slots(mn,mt));
+			} else {
+				unsigned long *gaps = ma_gaps(mn, mt);
 
-			if (gaps) {
-				unsigned char gap_slot;
+				if (gaps) {
+					unsigned char gap_slot;
 
-				gap_slot = ma_meta_gap(mn);
-				cp->gap[d] = gaps[gap_slot];
+					gap_slot = ma_meta_gap(mn);
+					cp->gap[d] = gaps[gap_slot];
+				}
 			}
+			printk("gap %lx\n", cp->gap[d]);
 		}
 		min = max + 1;
 	}
 
-	if (sib->end) {
-		printk("sib is at %p\n", sib->node);
-		if (sib->max < l_wr_mas->mas->min) {
-			*l_wr_mas->mas = *sib;
-			printk("Shift left\n");
-		} else {
-			*r_wr_mas->mas = *sib;
-			printk("Shift Right: %p\n", r_wr_mas->mas->node);
-		}
-	}
-
 	cp->end = cp->d_count - 1;
 	cp->min = l_wr_mas->mas->min;
 	cp->max = r_wr_mas->mas->max;
@@ -3391,12 +3397,12 @@ static bool spanning_ascend(struct maple_copy *cp, struct ma_state *mas,
 			spanning_init_cp_src(cp);
 			node_copy(mas, cp->src[0].node, 0, cp->data, cp->max, maple_copy,
 				  cp->dst[0].node, 0, mt);
-			node_finalise(cp->dst[0].node, mt, cp->end);
+			node_finalise(cp->dst[0].node, mt, cp->end + 1);
 			cp->slot[0] = mt_mk_node(cp->dst[0].node, mt);
 			cp->height++;
 		}
 
-		printk("CONVERGED\n");
+		printk("CONVERGED d_count is %u\n", cp->d_count);
 		WARN_ON_ONCE(cp->dst[0].node != mte_to_node(cp->slot[0]));
 		cp->dst[0].node->parent = ma_parent_ptr(mas_tree_parent(mas));
 		while (!mte_is_root(mas->node))
@@ -3404,10 +3410,12 @@ static bool spanning_ascend(struct maple_copy *cp, struct ma_state *mas,
 		printk("parent %p vs %p\n", cp->dst[0].node->parent, mas_mn(mas)->parent);
 		printk("cp->dst %p cp->slot %p\n", cp->dst[0].node, mte_to_node(cp->slot[0]));
 		return false;
-	} else if (l_wr_mas->mas->node == r_wr_mas->mas->node){
+	} else if (l_wr_mas->mas->node == r_wr_mas->mas->node) {
+		/* Converged, but caused a cascading split. */
 		WARN_ON_ONCE(cp->d_count != 1);
-		cp->dst[0].node->parent = mas_mn(mas)->parent;
-		return false;
+		printk("WARNING! CONVERGED d_count is %u\n", cp->d_count);
+		//cp->dst[0].node->parent = mas_mn(mas)->parent;
+		//return false;
 	}
 
 	printk("more nodes.. %u\n", cp->end);