Re: [PATCH 5/6] mm/hugetlb: fix sysfs group leak in hugetlb_unregister_node()

[Yin, Fengwei]

On 8/17/2022 5:41 PM, Yin, Fengwei wrote:
> Hi Miaohe,
> 
> On 8/16/2022 9:05 PM, Miaohe Lin wrote:
>> }
>>  
>>  	if (h->demote_order) {
>> -		if (sysfs_create_group(hstate_kobjs[hi],
>> -					&hstate_demote_attr_group))
>> +		retval = sysfs_create_group(hstate_kobjs[hi],
>> +					    &hstate_demote_attr_group);
> What about add one more:
>    just return if hstate_attr_group creating failed:
> 
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 0aee2f3ae15c..a67ef4b4eb3f 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -3845,6 +3845,7 @@ static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent,
>         if (retval) {
>                 kobject_put(hstate_kobjs[hi]);
>                 hstate_kobjs[hi] = NULL;
> +               return retval;
>         }
Please ignore this. Just saw the patch 2 made this change.

Regards
Yin, Fengwei

> 
> Once hstate_kobjs[hi] is set to NULL, hstate_demote_attr_group creating will
> fail as well. Thanks.
> 
> 
> Regards
> Yin, Fengwei
> 
>> +		if (retval) {
>>  			pr_warn("HugeTLB unable to create demote interfaces for %s\n", h->name);
>> +			sysfs_remove_group(hstate_kobjs[hi], hstate_attr_group);
>> +			kobject_put(hstate_kobjs[hi]);
>> +			hstate_kobjs[hi] = NULL;
>> +			return retval;
>> +		}
>>  	}
>