25 	queue->stub.next = NULL;  in vdo_make_funnel_queue()
41 	 * Barrier requirements: We need a read barrier between reading a "next" field pointer  in get_oldest()
46 	struct funnel_queue_entry *next = READ_ONCE(oldest->next);  in get_oldest()  local
53 		if (next == NULL)  in get_oldest()
59 		oldest = next;  in get_oldest()
61 		next = READ_ONCE(oldest->next);  in get_oldest()
68 	if (next == NULL) {  in get_oldest()
74 			 * assigned previous->next. The queue is really still empty.  in get_oldest()
86 		next = READ_ONCE(oldest->next);  in get_oldest()
87 		if (next == NULL) {  in get_oldest()
90 			 * but who hasn't yet updated previous->next. Try again later.  in get_oldest()
113 	 * consumer and oldest->next is never used by a producer thread after it is swung from NULL  in vdo_funnel_queue_poll()
116 	queue->oldest = READ_ONCE(oldest->next);  in vdo_funnel_queue_poll()
120 	 * to the next call we'll properly see the dependent data.  in vdo_funnel_queue_poll()
124 	 * If "oldest" is a very light-weight work item, we'll be looking for the next one very  in vdo_funnel_queue_poll()
128 	WRITE_ONCE(oldest->next, NULL);  in vdo_funnel_queue_poll()
151 	 * Oldest is not the stub, so there's another entry, though if next is NULL we can't  in vdo_is_funnel_queue_idle()
162 	 * Whether anything is retrievable depends on whether stub.next has been updated and become  in vdo_is_funnel_queue_idle()