539 	struct bio *head;  member
545 	return bl->head == NULL;  in bio_list_empty()
550 	bl->head = bl->tail = NULL;  in bio_list_init()
556 	for (bio = (bl)->head; bio; bio = bio->bi_next)
576 		bl->head = bio;  in bio_list_add()
583 	bio->bi_next = bl->head;  in bio_list_add_head()
585 	bl->head = bio;  in bio_list_add_head()
593 	if (!bl2->head)  in bio_list_merge()
597 		bl->tail->bi_next = bl2->head;  in bio_list_merge()
599 		bl->head = bl2->head;  in bio_list_merge()
607 	if (!bl2->head)  in bio_list_merge_head()
610 	if (bl->head)  in bio_list_merge_head()
611 		bl2->tail->bi_next = bl->head;  in bio_list_merge_head()
615 	bl->head = bl2->head;  in bio_list_merge_head()
620 	return bl->head;  in bio_list_peek()
625 	struct bio *bio = bl->head;  in bio_list_pop()
628 		bl->head = bl->head->bi_next;  in bio_list_pop()
629 		if (!bl->head)  in bio_list_pop()
640 	struct bio *bio = bl->head;  in bio_list_get()
642 	bl->head = bl->tail = NULL;  in bio_list_get()