119 	size_t read_tail;  member
133 	return ldata->read_head - ldata->read_tail;  in read_cnt()
214 		n = ldata->commit_head - ldata->read_tail;  in chars_in_buffer()
216 		n = ldata->canon_head - ldata->read_tail;  in chars_in_buffer()
244 	if (ldata->icanon && ldata->canon_head == ldata->read_tail)  in n_tty_check_throttle()
324 	ldata->read_head = ldata->canon_head = ldata->read_tail = 0;  in reset_buffer_flags()
1728 		size_t tail = smp_load_acquire(&ldata->read_tail);  in n_tty_receive_buf_common()
1813 		ldata->line_start = ldata->read_tail;  in n_tty_set_termios()
1815 			ldata->canon_head = ldata->read_tail;  in n_tty_set_termios()
1960 		return ldata->canon_head != ldata->read_tail;  in input_available_p()
1962 		return ldata->commit_head - ldata->read_tail >= amt;  in input_available_p()
1995 	size_t tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1);  in copy_from_read_buf()
1998 	n = min(head - ldata->read_tail, N_TTY_BUF_SIZE - tail);  in copy_from_read_buf()
2006 		smp_store_release(&ldata->read_tail, ldata->read_tail + n);  in copy_from_read_buf()
2009 		    (head == ldata->read_tail))  in copy_from_read_buf()
2052 	n = min(*nr, smp_load_acquire(&ldata->canon_head) - ldata->read_tail);  in canon_copy_from_read_buf()
2056 	tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1);  in canon_copy_from_read_buf()
2081 		eof_push = !n && ldata->read_tail != ldata->line_start;  in canon_copy_from_read_buf()
2102 	smp_store_release(&ldata->read_tail, ldata->read_tail + c);  in canon_copy_from_read_buf()
2106 			ldata->line_start = ldata->read_tail;  in canon_copy_from_read_buf()
2225 	tail = ldata->read_tail;  in n_tty_read()
2317 	if (tail != ldata->read_tail)  in n_tty_read()
2494 	if (ldata->canon_head == ldata->read_tail)  in inq_canon()
2497 	tail = ldata->read_tail;  in inq_canon()