Re: [PATCH v4 3/5] maple_tree: not necessary to check index/last again

["Liam R. Howlett" <Liam.Howlett@oracle.com>]

* Wei Yang <richard.weiyang@gmail.com> [241018 22:37]:
> Before calling mas_new_root(), the range has been checked.
> 
> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
> CC: Liam R. Howlett <Liam.Howlett@Oracle.com>
> CC: Sidhartha Kumar <sidhartha.kumar@oracle.com>
> CC: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
> 

Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>

> ---
> v4: add WARN_ON_ONCE() to check mis-usage.
> ---
>  lib/maple_tree.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index 517ddf2950e6..2226e77c00cb 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -3662,7 +3662,9 @@ static inline void mas_new_root(struct ma_state *mas, void *entry)
>  	void __rcu **slots;
>  	unsigned long *pivots;
>  
> -	if (!entry && !mas->index && mas->last == ULONG_MAX) {
> +	WARN_ON_ONCE(mas->index || mas->last != ULONG_MAX);
> +
> +	if (!entry) {
>  		mas->depth = 0;
>  		mas_set_height(mas);
>  		rcu_assign_pointer(mas->tree->ma_root, entry);
> -- 
> 2.34.1
>