[PATCH 1/2] maple_tree: Fix mt_destroy_walk() on root leaf node

Liam R. Howlett Liam.Howlett at oracle.com
Tue Jun 24 12:18:40 PDT 2025


From: Wei Yang <richard.weiyang at gmail.com>

On destroy, we should set each node dead. But current code miss this
when the maple tree has only the root node.

The reason is mt_destroy_walk() leverage mte_destroy_descend() to set
node dead, but this is skipped since the only root node is a leaf.

Fixes this by setting the node dead if it is a leaf.

Link: https://lore.kernel.org/all/20250407231354.11771-1-richard.weiyang@gmail.com/
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Wei Yang <richard.weiyang at gmail.com>
CC: Liam R. Howlett <Liam.Howlett at Oracle.com>
Cc: <stable at vger.kernel.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett at oracle.com>
---
 lib/maple_tree.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 6b0fc6ebbe363..85d17d943753d 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -5319,6 +5319,7 @@ static void mt_destroy_walk(struct maple_enode *enode, struct maple_tree *mt,
 	struct maple_enode *start;
 
 	if (mte_is_leaf(enode)) {
+		mte_set_node_dead(enode);
 		node->type = mte_node_type(enode);
 		goto free_leaf;
 	}
-- 
2.47.2




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