Re: [PATCH 01/12] list.h: add a list_pop helper

[Matthew Wilcox <willy@infradead.org>]

On Mon, Jun 24, 2019 at 07:52:42AM +0200, Christoph Hellwig wrote:
> +/**
> + * list_pop - delete the first entry from a list and return it
> + * @list:	the list to take the element from.
> + * @type:	the type of the struct this is embedded in.
> + * @member:	the name of the list_head within the struct.
> + *
> + * Note that if the list is empty, it returns NULL.
> + */
> +#define list_pop(list, type, member) 				\

The usual convention in list.h is that list_foo uses the list head and
list_foo_entry uses the container type.  So I think this should be
renamed to list_pop_entry() at least.  Do we also want:

static inline struct list_head *list_pop(struct list_head *head)
{
	struct list_head *first = READ_ONCE(head->next);

	if (first == head)
		return NULL;
	__list_del(head, first->next);
	return first;
}

we also seem to prefer using inline functions over #defines in this
header file.