118 	size_t read_tail;  member
134 	return ldata->read_head - ldata->read_tail;  in read_cnt()
226 		n = ldata->commit_head - ldata->read_tail;  in chars_in_buffer()
228 		n = ldata->canon_head - ldata->read_tail;  in chars_in_buffer()
256 	if (ldata->icanon && ldata->canon_head == ldata->read_tail)  in n_tty_check_throttle()
332 	ldata->read_head = ldata->canon_head = ldata->read_tail = 0;  in reset_buffer_flags()
1653 		size_t tail = smp_load_acquire(&ldata->read_tail);  in n_tty_receive_buf_common()
1732 		ldata->line_start = ldata->read_tail;  in n_tty_set_termios()
1734 			ldata->canon_head = ldata->read_tail;  in n_tty_set_termios()
1871 		return ldata->canon_head != ldata->read_tail;  in input_available_p()
1873 		return ldata->commit_head - ldata->read_tail >= amt;  in input_available_p()
1904 	size_t tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1);  in copy_from_read_buf()
1906 	n = min(head - ldata->read_tail, N_TTY_BUF_SIZE - tail);  in copy_from_read_buf()
1914 		smp_store_release(&ldata->read_tail, ldata->read_tail + n);  in copy_from_read_buf()
1917 		    (head == ldata->read_tail))  in copy_from_read_buf()
1923 		return head != ldata->read_tail;  in copy_from_read_buf()
1966 	n = min(*nr + 1, canon_head - ldata->read_tail);  in canon_copy_from_read_buf()
1968 	tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1);  in canon_copy_from_read_buf()
2002 	smp_store_release(&ldata->read_tail, ldata->read_tail + c);  in canon_copy_from_read_buf()
2006 			ldata->line_start = ldata->read_tail;  in canon_copy_from_read_buf()
2014 	return ldata->read_tail != canon_head;  in canon_copy_from_read_buf()
2132 	tail = ldata->read_tail;  in n_tty_read()
2221 	if (tail != ldata->read_tail)  in n_tty_read()
2388 	if (ldata->canon_head == ldata->read_tail)  in inq_canon()
2391 	tail = ldata->read_tail;  in inq_canon()