Re: [RESEND Patch v2 1/3] maple_tree: Fix mt_destroy_walk() on root leaf node
From: Liam R. Howlett
Date: Mon Apr 07 2025 - 21:44:36 EST
* Wei Yang <richard.weiyang@xxxxxxxxx> [250407 19:14]:
> 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.
>
> Fixes: 54a611b60590 ("Maple Tree: add new data structure")
> Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
> CC: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx>
Reviewed-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
>
> ---
> v2:
> * move the operation into mt_destroy_walk()
> * adjust the title accordingly
> ---
> lib/maple_tree.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index 4bd5a5be1440..0696e8d1c4e9 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -5284,6 +5284,7 @@ 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;
> }
> --
> 2.34.1
>