From: Liam R. Howlett <Liam.Howlett@oracle.com>
Date: Wed, 3 Sep 2025 16:09:47 +0000 (-0400)
Subject: Fix ascending on l and r on the same node
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=868c914004b64891e77dc84d651e7ea67daf2331;p=users%2Fjedix%2Flinux-maple.git

Fix ascending on l and r on the same node

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

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index b31140f48397..636a4d35fd67 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -3381,18 +3381,16 @@ static bool spanning_ascend(struct maple_copy *cp, struct ma_state *mas,
 		while (!mte_is_root(mas->node))
 			mas_ascend(mas);
 		return false;
-	} else if (l_wr_mas->mas->node == r_wr_mas->mas->node) {
-		/* Converged, but caused a cascading split. */
-		if (cp->d_count != 1) {
-			//mt_dump(mas->tree, mt_dump_hex);
-			//printk("At %p\n", l_wr_mas->mas->node);
-			//printk("Writing %lx -%lx => %p\n", mas->index, mas->last, l_wr_mas->entry);
-		}
-		//WARN_ON_ONCE(cp->d_count != 1);
-		//cp->dst[0].node->parent = mas_mn(mas)->parent;
-		//return false;
 	}
 
+	/* Converged and has a single destination */
+	if ((cp->d_count == 1) &&
+	    (l_wr_mas->mas->node == r_wr_mas->mas->node)) {
+		cp->dst[0].node->parent = ma_parent_ptr(mas_mn(mas)->parent);
+		return false;
+	}
+
+	MAS_WR_BUG_ON(l_wr_mas, cp->height > 4);
 	cp->height++;
 	wr_mas_ascend(l_wr_mas);
 	wr_mas_ascend(r_wr_mas);