linux-kernel - Re: [PATCH v3 01/10] maple_tree: Rework mtree_alloc_{range,rrange}()

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Message-ID: <20230523175247.7pbduzhlsc23vuo6@revolver>
Date:   Tue, 23 May 2023 13:52:47 -0400
From:   "Liam R. Howlett" <Liam.Howlett@...cle.com>
To:     Peng Zhang <zhangpeng.00@...edance.com>
Cc:     akpm@...ux-foundation.org, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, maple-tree@...ts.infradead.org
Subject: Re: [PATCH v3 01/10] maple_tree: Rework mtree_alloc_{range,rrange}()

* Peng Zhang <zhangpeng.00@...edance.com> [230522 01:07]:
> Use mas_empty_area{_rev}() to refactor mtree_alloc_{range,rrange}()

A bit of a short change log, but looks good.

Reviewed-by: Liam R. Howlett <Liam.Howlett@...cle.com>
> 
> Signed-off-by: Peng Zhang <zhangpeng.00@...edance.com>
> ---
>  lib/maple_tree.c | 57 +++++++++++++++++++++++++++---------------------
>  1 file changed, 32 insertions(+), 25 deletions(-)
> 
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index 4eb220008f72..96d102d60b4e 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -6493,31 +6493,33 @@ int mtree_alloc_range(struct maple_tree *mt, unsigned long *startp,
>  {
>  	int ret = 0;
>  
> -	MA_STATE(mas, mt, min, min);
> +	MA_STATE(mas, mt, 0, 0);
>  	if (!mt_is_alloc(mt))
>  		return -EINVAL;
>  
>  	if (WARN_ON_ONCE(mt_is_reserved(entry)))
>  		return -EINVAL;
>  
> -	if (min > max)
> -		return -EINVAL;
> -
> -	if (max < size)
> -		return -EINVAL;
> -
> -	if (!size)
> -		return -EINVAL;
> -
>  	mtree_lock(mt);
>  retry:
> -	mas.offset = 0;
> -	mas.index = min;
> -	mas.last = max - size + 1;
> -	ret = mas_alloc(&mas, entry, size, startp);
> +	ret = mas_empty_area(&mas, min, max, size);
> +	if (ret)
> +		goto unlock;
> +
> +	mas_insert(&mas, entry);
> +	/*
> +	 * mas_nomem() may release the lock, causing the allocated area
> +	 * to be unavailable, so try to allocate a free area again.
> +	 */
>  	if (mas_nomem(&mas, gfp))
>  		goto retry;
>  
> +	if (mas_is_err(&mas))
> +		ret = xa_err(mas.node);
> +	else
> +		*startp = mas.index;
> +
> +unlock:
>  	mtree_unlock(mt);
>  	return ret;
>  }
> @@ -6529,28 +6531,33 @@ int mtree_alloc_rrange(struct maple_tree *mt, unsigned long *startp,
>  {
>  	int ret = 0;
>  
> -	MA_STATE(mas, mt, min, max - size + 1);
> +	MA_STATE(mas, mt, 0, 0);
>  	if (!mt_is_alloc(mt))
>  		return -EINVAL;
>  
>  	if (WARN_ON_ONCE(mt_is_reserved(entry)))
>  		return -EINVAL;
>  
> -	if (min > max)
> -		return -EINVAL;
> -
> -	if (max < size - 1)
> -		return -EINVAL;
> -
> -	if (!size)
> -		return -EINVAL;
> -
>  	mtree_lock(mt);
>  retry:
> -	ret = mas_rev_alloc(&mas, min, max, entry, size, startp);
> +	ret = mas_empty_area_rev(&mas, min, max, size);
> +	if (ret)
> +		goto unlock;
> +
> +	mas_insert(&mas, entry);
> +	/*
> +	 * mas_nomem() may release the lock, causing the allocated area
> +	 * to be unavailable, so try to allocate a free area again.
> +	 */
>  	if (mas_nomem(&mas, gfp))
>  		goto retry;
>  
> +	if (mas_is_err(&mas))
> +		ret = xa_err(mas.node);
> +	else
> +		*startp = mas.index;
> +
> +unlock:
>  	mtree_unlock(mt);
>  	return ret;
>  }
> -- 
> 2.20.1
> 
> 
> -- 
> maple-tree mailing list
> maple-tree@...ts.infradead.org
> https://lists.infradead.org/mailman/listinfo/maple-tree

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