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Message-ID: <6b507b20-f3d1-b82d-cb20-7354c8acd20e@bytedance.com>
Date:   Wed, 26 Apr 2023 17:55:01 +0800
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Subject: Re: [PATCH 15/34] maple_tree: Return error on mte_pivots() out of
 range
To:     "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        maple-tree@lists.infradead.org,
        Andrew Morton <akpm@linux-foundation.org>
References: <20230425140955.3834476-1-Liam.Howlett@oracle.com>
 <20230425140955.3834476-16-Liam.Howlett@oracle.com>
From:   Peng Zhang <zhangpeng.00@bytedance.com>
In-Reply-To: <20230425140955.3834476-16-Liam.Howlett@oracle.com>
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在 2023/4/25 22:09, Liam R. Howlett 写道:
> Rename mte_pivots() to mas_pivots() and pass through the ma_state to set
> the error code to -EIO when the offset is out of range for the node
> type.  Change the WARN_ON() to MAS_WARN_ON() to log the maple state.
>
> Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Peng Zhang <zhangpeng.00@bytedance.com>
> ---
>   lib/maple_tree.c | 25 ++++++++++++++-----------
>   1 file changed, 14 insertions(+), 11 deletions(-)
>
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index 41873d935cfa3..89e30462f8b62 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -663,22 +663,22 @@ static inline unsigned long *ma_gaps(struct maple_node *node,
>   }
>   
>   /*
> - * mte_pivot() - Get the pivot at @piv of the maple encoded node.
> - * @mn: The maple encoded node.
> + * mas_pivot() - Get the pivot at @piv of the maple encoded node.
> + * @mas: The maple state.
>    * @piv: The pivot.
>    *
>    * Return: the pivot at @piv of @mn.
>    */
> -static inline unsigned long mte_pivot(const struct maple_enode *mn,
> -				 unsigned char piv)
> +static inline unsigned long mas_pivot(struct ma_state *mas, unsigned char piv)
>   {
> -	struct maple_node *node = mte_to_node(mn);
> -	enum maple_type type = mte_node_type(mn);
> +	struct maple_node *node = mas_mn(mas);
> +	enum maple_type type = mte_node_type(mas->node);
>   
> -	if (piv >= mt_pivots[type]) {
> -		WARN_ON(1);
> +	if (MAS_WARN_ON(mas, piv >= mt_pivots[type])) {
> +		mas_set_err(mas, -EIO);
>   		return 0;
>   	}
> +
>   	switch (type) {
>   	case maple_arange_64:
>   		return node->ma64.pivot[piv];
> @@ -5400,8 +5400,8 @@ static inline int mas_alloc(struct ma_state *mas, void *entry,
>   			return xa_err(mas->node);
>   
>   		if (!mas->index)
> -			return mte_pivot(mas->node, 0);
> -		return mte_pivot(mas->node, 1);
> +			return mas_pivot(mas, 0);
> +		return mas_pivot(mas, 1);
>   	}
>   
>   	/* Must be walking a tree. */
> @@ -5418,7 +5418,10 @@ static inline int mas_alloc(struct ma_state *mas, void *entry,
>   	 */
>   	min = mas->min;
>   	if (mas->offset)
> -		min = mte_pivot(mas->node, mas->offset - 1) + 1;
> +		min = mas_pivot(mas, mas->offset - 1) + 1;
> +
> +	if (mas_is_err(mas))
> +		return xa_err(mas->node);
>   
>   	if (mas->index < min)
>   		mas->index = min;