117 	size_t read_tail;  member
133 	return ldata->read_head - ldata->read_tail;  in read_cnt()
225 		n = ldata->commit_head - ldata->read_tail;  in chars_in_buffer()
227 		n = ldata->canon_head - ldata->read_tail;  in chars_in_buffer()
255 	if (ldata->icanon && ldata->canon_head == ldata->read_tail)  in n_tty_check_throttle()
331 	ldata->read_head = ldata->canon_head = ldata->read_tail = 0;  in reset_buffer_flags()
1716 		size_t tail = smp_load_acquire(&ldata->read_tail);  in n_tty_receive_buf_common()
1795 		ldata->line_start = ldata->read_tail;  in n_tty_set_termios()
1797 			ldata->canon_head = ldata->read_tail;  in n_tty_set_termios()
1932 		return ldata->canon_head != ldata->read_tail;  in input_available_p()
1934 		return ldata->commit_head - ldata->read_tail >= amt;  in input_available_p()
1965 	size_t tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1);  in copy_from_read_buf()
1967 	n = min(head - ldata->read_tail, N_TTY_BUF_SIZE - tail);  in copy_from_read_buf()
1975 		smp_store_release(&ldata->read_tail, ldata->read_tail + n);  in copy_from_read_buf()
1978 		    (head == ldata->read_tail))  in copy_from_read_buf()
1984 		return head != ldata->read_tail;  in copy_from_read_buf()
2027 	n = min(*nr, canon_head - ldata->read_tail);  in canon_copy_from_read_buf()
2029 	tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1);  in canon_copy_from_read_buf()
2061 	smp_store_release(&ldata->read_tail, ldata->read_tail + c);  in canon_copy_from_read_buf()
2065 			ldata->line_start = ldata->read_tail;  in canon_copy_from_read_buf()
2073 	return ldata->read_tail != canon_head;  in canon_copy_from_read_buf()
2087 	tail = ldata->read_tail;  in canon_skip_eof()
2102 	smp_store_release(&ldata->read_tail, ldata->read_tail + 1);  in canon_skip_eof()
2227 	tail = ldata->read_tail;  in n_tty_read()
2316 	if (tail != ldata->read_tail)  in n_tty_read()
2483 	if (ldata->canon_head == ldata->read_tail)  in inq_canon()
2486 	tail = ldata->read_tail;  in inq_canon()