223 	unsigned int tail = READ_ONCE(pipe->tail);  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()
257 		unsigned int tail = pipe->tail;  in pipe_read()  local
284 		if (!pipe_empty(head, tail)) {  in pipe_read()
285 			struct pipe_buffer *buf = &pipe->bufs[tail & mask];  in pipe_read()
329 				tail++;  in pipe_read()
330 				pipe->tail = 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()
409 	unsigned int tail = READ_ONCE(pipe->tail);  in pipe_writable()  local
412 	return !pipe_full(head, tail, max_usage) ||  in pipe_writable()
459 	if (chars && !pipe_empty(head, pipe->tail)) {  in pipe_write()
491 		if (!pipe_full(head, pipe->tail, pipe->max_usage)) {  in pipe_write()
514 			if (pipe_full(head, pipe->tail, pipe->max_usage)) {  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
618 		tail = pipe->tail;  in pipe_ioctl()
621 		while (tail != head) {  in pipe_ioctl()
622 			count += pipe->bufs[tail & mask].len;  in pipe_ioctl()
623 			tail++;  in pipe_ioctl()
654 	unsigned int head, tail;  in pipe_poll()  local
673 	tail = READ_ONCE(pipe->tail);  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
1264 	tail = pipe->tail;  in pipe_resize_ring()
1266 	n = pipe_occupancy(head, tail);  in pipe_resize_ring()
1279 		unsigned int t = tail & mask;  in pipe_resize_ring()
1294 	tail = 0;  in pipe_resize_ring()
1301 	pipe->tail = tail;  in pipe_resize_ring()