222 	unsigned int head = READ_ONCE(pipe->head);  in pipe_readable()  local
226 	return !pipe_empty(head, tail) || !writers;  in pipe_readable()
253 	was_full = pipe_full(pipe->head, pipe->tail, pipe->max_usage);  in pipe_read()
256 		unsigned int head = smp_load_acquire(&pipe->head);  in pipe_read()  local
284 		if (!pipe_empty(head, tail)) {  in pipe_read()
336 			if (!pipe_empty(head, tail))	/* More to do? */  in pipe_read()
382 		was_full = pipe_full(pipe->head, pipe->tail, pipe->max_usage);  in pipe_read()
385 	if (pipe_empty(pipe->head, pipe->tail))  in pipe_read()
408 	unsigned int head = READ_ONCE(pipe->head);  in pipe_writable()  local
412 	return !pipe_full(head, tail, max_usage) ||  in pipe_writable()
421 	unsigned int head;  in pipe_write()  local
456 	head = pipe->head;  in pipe_write()
459 	if (chars && !pipe_empty(head, pipe->tail)) {  in pipe_write()
461 		struct pipe_buffer *buf = &pipe->bufs[(head - 1) & mask];  in pipe_write()
490 		head = pipe->head;  in pipe_write()
491 		if (!pipe_full(head, pipe->tail, pipe->max_usage)) {  in pipe_write()
493 			struct pipe_buffer *buf = &pipe->bufs[head & mask];  in pipe_write()
513 			head = pipe->head;  in pipe_write()
514 			if (pipe_full(head, pipe->tail, pipe->max_usage)) {  in pipe_write()
519 			pipe->head = head + 1;  in pipe_write()
523 			buf = &pipe->bufs[head & mask];  in pipe_write()
548 		if (!pipe_full(head, pipe->tail, pipe->max_usage))  in pipe_write()
576 		was_empty = pipe_empty(pipe->head, pipe->tail);  in pipe_write()
580 	if (pipe_full(pipe->head, pipe->tail, pipe->max_usage))  in pipe_write()
611 	int count, head, tail, mask;  in pipe_ioctl()  local
617 		head = pipe->head;  in pipe_ioctl()
621 		while (tail != head) {  in pipe_ioctl()
654 	unsigned int head, tail;  in pipe_poll()  local
672 	head = READ_ONCE(pipe->head);  in pipe_poll()
677 		if (!pipe_empty(head, tail))  in pipe_poll()
684 		if (!pipe_full(head, tail, pipe->max_usage))  in pipe_poll()
1254 	unsigned int head, tail, mask, n;  in pipe_resize_ring()  local
1263 	head = pipe->head;  in pipe_resize_ring()
1266 	n = pipe_occupancy(head, tail);  in pipe_resize_ring()
1278 		unsigned int h = head & mask;  in pipe_resize_ring()
1293 	head = n;  in pipe_resize_ring()
1302 	pipe->head = head;  in pipe_resize_ring()