On 8/16/2022 9:05 PM, Miaohe Lin wrote:
> The sysfs group per_node_hstate_attr_group and hstate_demote_attr_group
> when h->demote_order != 0 are created in hugetlb_register_node(). But
> these sysfs groups are not removed when unregister the node, thus sysfs
> group is leaked. Using sysfs_remove_group() to fix this issue.
>
> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Reviewed-by: Fengwei Yin <fengwei.yin@xxxxxxxxx>
Regards
Yin, Fengwei
> ---
> mm/hugetlb.c | 25 ++++++++++++++++++-------
> 1 file changed, 18 insertions(+), 7 deletions(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index b69d7808f457..e1356ad57087 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -3850,12 +3850,18 @@ static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent,
> }
>
> 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);
> + 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;
> + }
> }
>
> - return retval;
> + return 0;
> }
>
> static void __init hugetlb_sysfs_init(void)
> @@ -3941,10 +3947,15 @@ static void hugetlb_unregister_node(struct node *node)
>
> for_each_hstate(h) {
> int idx = hstate_index(h);
> - if (nhs->hstate_kobjs[idx]) {
> - kobject_put(nhs->hstate_kobjs[idx]);
> - nhs->hstate_kobjs[idx] = NULL;
> - }
> + struct kobject *hstate_kobj = nhs->hstate_kobjs[idx];
> +
> + if (!hstate_kobj)
> + continue;
> + if (h->demote_order)
> + sysfs_remove_group(hstate_kobj, &hstate_demote_attr_group);
> + sysfs_remove_group(hstate_kobj, &per_node_hstate_attr_group);
> + kobject_put(hstate_kobj);
> + nhs->hstate_kobjs[idx] = NULL;
> }
>
> kobject_put(nhs->hugepages_kobj);
