[PATCH 1/2] maple_tree: Fix mas_alloc_cyclic() second search

[yangerkun]

在 2024/12/17 3:01, Liam R. Howlett 写道:
> From: "Liam R. Howlett" <Liam.Howlett at Oracle.com>
> 
> The first search may leave the maple state in an error state.  Reset the
> maple state before the second search so that the search has a chance of
> executing correctly after an exhausted first search.
> 
> Link: https://lore.kernel.org/all/20241216060600.287B4C4CED0@smtp.kernel.org/
> Fixes: 9b6713cc7522 ("maple_tree: Add mtree_alloc_cyclic()")
> Cc: Yang Erkun <yangerkun at huaweicloud.com>
> Cc: chuck.lever at oracle.com
> Cc: brauner at kernel.org
> Signed-off-by: Liam R. Howlett <Liam.Howlett at Oracle.com>
> ---
>   lib/maple_tree.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)

This looks more clear!

Reviewed-by: Yang Erkun <yangerkun at huawei.com>

> 
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index 940d30653407b..f7153ade1be5f 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -4335,7 +4335,6 @@ int mas_alloc_cyclic(struct ma_state *mas, unsigned long *startp,
>   {
>   	unsigned long min = range_lo;
>   	int ret = 0;
> -	struct ma_state m = *mas;
>   
>   	range_lo = max(min, *next);
>   	ret = mas_empty_area(mas, range_lo, range_hi, 1);
> @@ -4344,7 +4343,7 @@ int mas_alloc_cyclic(struct ma_state *mas, unsigned long *startp,
>   		ret = 1;
>   	}
>   	if (ret < 0 && range_lo > min) {
> -		*mas = m;
> +		mas_reset(mas);
>   		ret = mas_empty_area(mas, min, range_hi, 1);
>   		if (ret == 0)
>   			ret = 1;