linux-kernel - Re: [PATCH v2 6/7] cxl/region: Drop goto pattern in cxl_dax_region

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Message-ID: <d3e99ce2-b2c4-42d5-95da-3711b27fd5de@intel.com>
Date: Wed, 19 Feb 2025 10:23:11 -0700
From: Dave Jiang <dave.jiang@...el.com>
To: Li Ming <ming.li@...omail.com>, dave@...olabs.net,
 jonathan.cameron@...wei.com, alison.schofield@...el.com,
 vishal.l.verma@...el.com, ira.weiny@...el.com, dan.j.williams@...el.com
Cc: linux-cxl@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 6/7] cxl/region: Drop goto pattern in
 cxl_dax_region_alloc()



On 2/17/25 7:48 AM, Li Ming wrote:
> In cxl_dax_region_alloc(), there is a goto pattern to release the rwsem
> cxl_region_rwsem when the function returns, the down_read() and up_read
> can be replaced by a guard(rwsem_read) then the goto pattern can be
> removed.
> 
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@...wei.com>
> Signed-off-by: Li Ming <ming.li@...omail.com>

Reviewed-by: Dave Jiang <dave.jiang@...el.com>

> ---
>  drivers/cxl/core/region.c | 16 +++++-----------
>  1 file changed, 5 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index d8a71f9f9fa5..320a3f218131 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -3038,17 +3038,13 @@ static struct cxl_dax_region *cxl_dax_region_alloc(struct cxl_region *cxlr)
>  	struct cxl_dax_region *cxlr_dax;
>  	struct device *dev;
>  
> -	down_read(&cxl_region_rwsem);
> -	if (p->state != CXL_CONFIG_COMMIT) {
> -		cxlr_dax = ERR_PTR(-ENXIO);
> -		goto out;
> -	}
> +	guard(rwsem_read)(&cxl_region_rwsem);
> +	if (p->state != CXL_CONFIG_COMMIT)
> +		return ERR_PTR(-ENXIO);
>  
>  	cxlr_dax = kzalloc(sizeof(*cxlr_dax), GFP_KERNEL);
> -	if (!cxlr_dax) {
> -		cxlr_dax = ERR_PTR(-ENOMEM);
> -		goto out;
> -	}
> +	if (!cxlr_dax)
> +		return ERR_PTR(-ENOMEM);
>  
>  	cxlr_dax->hpa_range.start = p->res->start;
>  	cxlr_dax->hpa_range.end = p->res->end;
> @@ -3061,8 +3057,6 @@ static struct cxl_dax_region *cxl_dax_region_alloc(struct cxl_region *cxlr)
>  	dev->parent = &cxlr->dev;
>  	dev->bus = &cxl_bus_type;
>  	dev->type = &cxl_dax_region_type;
> -out:
> -	up_read(&cxl_region_rwsem);
>  
>  	return cxlr_dax;
>  }