Re: [PATCH v5 02/13] mm: Introduce memfile_notifier

[Hillf Danton <hdanton@sina.com>]

On Thu, 10 Mar 2022 22:09:00 +0800 Chao Peng wrote:
> +
> +void memfile_register_backing_store(struct memfile_backing_store *bs)
> +{
> +	BUG_ON(!bs || !bs->get_notifier_list);
> +
> +	list_add_tail(&bs->list, &backing_store_list);
> +}
> +
> +void memfile_unregister_backing_store(struct memfile_backing_store *bs)
> +{
> +	list_del(&bs->list);
> +}
> +
> +static int memfile_get_notifier_info(struct inode *inode,

Nit, s/get/lookup/

> +				     struct memfile_notifier_list **list,
> +				     struct memfile_pfn_ops **ops)
> +{
> +	struct memfile_backing_store *bs, *iter;
> +	struct memfile_notifier_list *tmp;
> +
> +	list_for_each_entry_safe(bs, iter, &backing_store_list, list) {

Wonder what serializes list walk with list del and add above.

> +		tmp = bs->get_notifier_list(inode);
> +		if (tmp) {
> +			*list = tmp;
> +			if (ops)
> +				*ops = &bs->pfn_ops;
> +			return 0;
> +		}
> +	}
> +	return -EOPNOTSUPP;
> +}