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

[Gregory Price <gourry@gourry.net>]

On Wed, Apr 23, 2025 at 11:24:58AM +0300, 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.

I think this was intentional to allow hotplug callbacks to continue
executing.  I will let the SK folks who wrote the patch confirm/deny.

If it is intentional, then we need to add a comment here to explain.

~Gregory

> 
>  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;
>  		goto out;
>  	}
>  
> -- 
> 2.47.2
>