Re: [PATCH next] mm/mempolicy: Fix error code in sysfs_wi_node_add()

[Honggyu Kim <honggyu.kim@sk.com>]

Hi Dan,

On 4/23/2025 5:24 PM, Dan Carpenter wrote:
> Return -EEXIST if the node already exists.  Don't return success.
> 
> Fixes: 1bf270ac1b0a ("mm/mempolicy: support memory hotplug in weighted interleave")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
> Potentially returning success was intentional?  This is from static
> analysis and I can't be totally sure.
> 
>   mm/mempolicy.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index f43951668c41..0538a994440a 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -3539,7 +3539,7 @@ static const struct kobj_type wi_ktype = {
>   
>   static int sysfs_wi_node_add(int nid)
>   {
> -	int ret = 0;
> +	int ret;
>   	char *name;
>   	struct iw_node_attr *new_attr;
>   
> @@ -3569,6 +3569,7 @@ static int sysfs_wi_node_add(int nid)
>   	if (wi_group->nattrs[nid]) {
>   		mutex_unlock(&wi_group->kobj_lock);
>   		pr_info("node%d already exists\n", nid);
> +		ret = -EEXIST;

Returning -EEXIST here looks good to me, but could you remove the above pr_info
as well?  I mean the following change is needed.

-		pr_info("node%d already exists\n", nid)
+		ret = -EEXIST;

We don't need the above pr_info here because we delegate a warning message to
its caller wi_node_notifier().

This can close another warning report below.
https://lore.kernel.org/all/202505020458.yLHRAaW9-lkp@intel.com

If you apply my suggestion then please add

	Reviewed-by: Honggyu Kim <honggyu.kim@sk.com>

Thanks,
Honggyu

>   		goto out;
>   	}
>