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TTY: move ldisc data from tty_struct: read_* and echo_* and canon_* stuff 

All the ring-buffers...

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jiri Slaby 2012-10-18 22:26:41 +02:00 committed by Greg Kroah-Hartman
parent 3fe780b379
commit ba2e68ac61
2 changed files with 137 additions and 133 deletions
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260
drivers/tty/n_tty.c
View File

@ -83,6 +83,19 @@ struct n_tty_data {
DECLARE_BITMAP(process_char_map, 256);
DECLARE_BITMAP(read_flags, N_TTY_BUF_SIZE);
char *read_buf;
int read_head;
int read_tail;
int read_cnt;
unsigned char *echo_buf;
unsigned int echo_pos;
unsigned int echo_cnt;
int canon_data;
unsigned long canon_head;
unsigned int canon_column;
};
static inline int tty_put_user(struct tty_struct *tty, unsigned char x,
@ -110,14 +123,14 @@ static void n_tty_set_room(struct tty_struct *tty)
int left;
int old_left;
/* tty->read_cnt is not read locked ? */
/* ldata->read_cnt is not read locked ? */
if (I_PARMRK(tty)) {
/* Multiply read_cnt by 3, since each byte might take up to
* three times as many spaces when PARMRK is set (depending on
* its flags, e.g. parity error). */
left = N_TTY_BUF_SIZE - tty->read_cnt * 3 - 1;
left = N_TTY_BUF_SIZE - ldata->read_cnt * 3 - 1;
} else
left = N_TTY_BUF_SIZE - tty->read_cnt - 1;
left = N_TTY_BUF_SIZE - ldata->read_cnt - 1;
/*
* If we are doing input canonicalization, and there are no
@ -126,7 +139,7 @@ static void n_tty_set_room(struct tty_struct *tty)
* characters will be beeped.
*/
if (left <= 0)
left = ldata->icanon && !tty->canon_data;
left = ldata->icanon && !ldata->canon_data;
old_left = tty->receive_room;
tty->receive_room = left;
@ -137,10 +150,12 @@ static void n_tty_set_room(struct tty_struct *tty)
static void put_tty_queue_nolock(unsigned char c, struct tty_struct *tty)
{
if (tty->read_cnt < N_TTY_BUF_SIZE) {
tty->read_buf[tty->read_head] = c;
tty->read_head = (tty->read_head + 1) & (N_TTY_BUF_SIZE-1);
tty->read_cnt++;
struct n_tty_data *ldata = tty->disc_data;
if (ldata->read_cnt < N_TTY_BUF_SIZE) {
ldata->read_buf[ldata->read_head] = c;
ldata->read_head = (ldata->read_head + 1) & (N_TTY_BUF_SIZE-1);
ldata->read_cnt++;
}
}
@ -198,14 +213,14 @@ static void reset_buffer_flags(struct tty_struct *tty)
unsigned long flags;
spin_lock_irqsave(&tty->read_lock, flags);
tty->read_head = tty->read_tail = tty->read_cnt = 0;
ldata->read_head = ldata->read_tail = ldata->read_cnt = 0;
spin_unlock_irqrestore(&tty->read_lock, flags);
mutex_lock(&tty->echo_lock);
tty->echo_pos = tty->echo_cnt = ldata->echo_overrun = 0;
ldata->echo_pos = ldata->echo_cnt = ldata->echo_overrun = 0;
mutex_unlock(&tty->echo_lock);
tty->canon_head = tty->canon_data = ldata->erasing = 0;
ldata->canon_head = ldata->canon_data = ldata->erasing = 0;
bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE);
n_tty_set_room(tty);
}
@ -257,11 +272,11 @@ static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty)
spin_lock_irqsave(&tty->read_lock, flags);
if (!ldata->icanon) {
n = tty->read_cnt;
} else if (tty->canon_data) {
n = (tty->canon_head > tty->read_tail) ?
tty->canon_head - tty->read_tail :
tty->canon_head + (N_TTY_BUF_SIZE - tty->read_tail);
n = ldata->read_cnt;
} else if (ldata->canon_data) {
n = (ldata->canon_head > ldata->read_tail) ?
ldata->canon_head - ldata->read_tail :
ldata->canon_head + (N_TTY_BUF_SIZE - ldata->read_tail);
}
spin_unlock_irqrestore(&tty->read_lock, flags);
return n;
@ -331,11 +346,11 @@ static int do_output_char(unsigned char c, struct tty_struct *tty, int space)
if (O_ONLCR(tty)) {
if (space < 2)
return -1;
tty->canon_column = ldata->column = 0;
ldata->canon_column = ldata->column = 0;
tty->ops->write(tty, "\r\n", 2);
return 2;
}
tty->canon_column = ldata->column;
ldata->canon_column = ldata->column;
break;
case '\r':
if (O_ONOCR(tty) && ldata->column == 0)
@ -343,10 +358,10 @@ static int do_output_char(unsigned char c, struct tty_struct *tty, int space)
if (O_OCRNL(tty)) {
c = '\n';
if (O_ONLRET(tty))
tty->canon_column = ldata->column = 0;
ldata->canon_column = ldata->column = 0;
break;
}
tty->canon_column = ldata->column = 0;
ldata->canon_column = ldata->column = 0;
break;
case '\t':
spaces = 8 - (ldata->column & 7);
@ -453,14 +468,14 @@ static ssize_t process_output_block(struct tty_struct *tty,
ldata->column = 0;
if (O_ONLCR(tty))
goto break_out;
tty->canon_column = ldata->column;
ldata->canon_column = ldata->column;
break;
case '\r':
if (O_ONOCR(tty) && ldata->column == 0)
goto break_out;
if (O_OCRNL(tty))
goto break_out;
tty->canon_column = ldata->column = 0;
ldata->canon_column = ldata->column = 0;
break;
case '\t':
goto break_out;
@ -518,7 +533,7 @@ static void process_echoes(struct tty_struct *tty)
unsigned char c;
unsigned char *cp, *buf_end;
if (!tty->echo_cnt)
if (!ldata->echo_cnt)
return;
mutex_lock(&tty->output_lock);
@ -526,9 +541,9 @@ static void process_echoes(struct tty_struct *tty)
space = tty_write_room(tty);
buf_end = tty->echo_buf + N_TTY_BUF_SIZE;
cp = tty->echo_buf + tty->echo_pos;
nr = tty->echo_cnt;
buf_end = ldata->echo_buf + N_TTY_BUF_SIZE;
cp = ldata->echo_buf + ldata->echo_pos;
nr = ldata->echo_cnt;
while (nr > 0) {
c = *cp;
if (c == ECHO_OP_START) {
@ -565,7 +580,7 @@ static void process_echoes(struct tty_struct *tty)
* Otherwise, tab spacing is normal.
*/
if (!(num_chars & 0x80))
num_chars += tty->canon_column;
num_chars += ldata->canon_column;
num_bs = 8 - (num_chars & 7);
if (num_bs > space) {
@ -583,7 +598,7 @@ static void process_echoes(struct tty_struct *tty)
break;
case ECHO_OP_SET_CANON_COL:
tty->canon_column = ldata->column;
ldata->canon_column = ldata->column;
cp += 2;
nr -= 2;
break;
@ -655,14 +670,14 @@ static void process_echoes(struct tty_struct *tty)
}
if (nr == 0) {
tty->echo_pos = 0;
tty->echo_cnt = 0;
ldata->echo_pos = 0;
ldata->echo_cnt = 0;
ldata->echo_overrun = 0;
} else {
int num_processed = tty->echo_cnt - nr;
tty->echo_pos += num_processed;
tty->echo_pos &= N_TTY_BUF_SIZE - 1;
tty->echo_cnt = nr;
int num_processed = ldata->echo_cnt - nr;
ldata->echo_pos += num_processed;
ldata->echo_pos &= N_TTY_BUF_SIZE - 1;
ldata->echo_cnt = nr;
if (num_processed > 0)
ldata->echo_overrun = 0;
}
@ -689,37 +704,37 @@ static void add_echo_byte(unsigned char c, struct tty_struct *tty)
struct n_tty_data *ldata = tty->disc_data;
int new_byte_pos;
if (tty->echo_cnt == N_TTY_BUF_SIZE) {
if (ldata->echo_cnt == N_TTY_BUF_SIZE) {
/* Circular buffer is already at capacity */
new_byte_pos = tty->echo_pos;
new_byte_pos = ldata->echo_pos;
/*
* Since the buffer start position needs to be advanced,
* be sure to step by a whole operation byte group.
*/
if (tty->echo_buf[tty->echo_pos] == ECHO_OP_START) {
if (tty->echo_buf[(tty->echo_pos + 1) &
if (ldata->echo_buf[ldata->echo_pos] == ECHO_OP_START) {
if (ldata->echo_buf[(ldata->echo_pos + 1) &
(N_TTY_BUF_SIZE - 1)] ==
ECHO_OP_ERASE_TAB) {
tty->echo_pos += 3;
tty->echo_cnt -= 2;
ldata->echo_pos += 3;
ldata->echo_cnt -= 2;
} else {
tty->echo_pos += 2;
tty->echo_cnt -= 1;
ldata->echo_pos += 2;
ldata->echo_cnt -= 1;
}
} else {
tty->echo_pos++;
ldata->echo_pos++;
}
tty->echo_pos &= N_TTY_BUF_SIZE - 1;
ldata->echo_pos &= N_TTY_BUF_SIZE - 1;
ldata->echo_overrun = 1;
} else {
new_byte_pos = tty->echo_pos + tty->echo_cnt;
new_byte_pos = ldata->echo_pos + ldata->echo_cnt;
new_byte_pos &= N_TTY_BUF_SIZE - 1;
tty->echo_cnt++;
ldata->echo_cnt++;
}
tty->echo_buf[new_byte_pos] = c;
ldata->echo_buf[new_byte_pos] = c;
}
/**
@ -889,7 +904,7 @@ static void eraser(unsigned char c, struct tty_struct *tty)
unsigned long flags;
/* FIXME: locking needed ? */
if (tty->read_head == tty->canon_head) {
if (ldata->read_head == ldata->canon_head) {
/* process_output('\a', tty); */ /* what do you think? */
return;
}
@ -900,17 +915,17 @@ static void eraser(unsigned char c, struct tty_struct *tty)
else {
if (!L_ECHO(tty)) {
spin_lock_irqsave(&tty->read_lock, flags);
tty->read_cnt -= ((tty->read_head - tty->canon_head) &
ldata->read_cnt -= ((ldata->read_head - ldata->canon_head) &
(N_TTY_BUF_SIZE - 1));
tty->read_head = tty->canon_head;
ldata->read_head = ldata->canon_head;
spin_unlock_irqrestore(&tty->read_lock, flags);
return;
}
if (!L_ECHOK(tty) || !L_ECHOKE(tty) || !L_ECHOE(tty)) {
spin_lock_irqsave(&tty->read_lock, flags);
tty->read_cnt -= ((tty->read_head - tty->canon_head) &
ldata->read_cnt -= ((ldata->read_head - ldata->canon_head) &
(N_TTY_BUF_SIZE - 1));
tty->read_head = tty->canon_head;
ldata->read_head = ldata->canon_head;
spin_unlock_irqrestore(&tty->read_lock, flags);
finish_erasing(tty);
echo_char(KILL_CHAR(tty), tty);
@ -924,14 +939,14 @@ static void eraser(unsigned char c, struct tty_struct *tty)
seen_alnums = 0;
/* FIXME: Locking ?? */
while (tty->read_head != tty->canon_head) {
head = tty->read_head;
while (ldata->read_head != ldata->canon_head) {
head = ldata->read_head;
/* erase a single possibly multibyte character */
do {
head = (head - 1) & (N_TTY_BUF_SIZE-1);
c = tty->read_buf[head];
} while (is_continuation(c, tty) && head != tty->canon_head);
c = ldata->read_buf[head];
} while (is_continuation(c, tty) && head != ldata->canon_head);
/* do not partially erase */
if (is_continuation(c, tty))
@ -944,10 +959,10 @@ static void eraser(unsigned char c, struct tty_struct *tty)
else if (seen_alnums)
break;
}
cnt = (tty->read_head - head) & (N_TTY_BUF_SIZE-1);
cnt = (ldata->read_head - head) & (N_TTY_BUF_SIZE-1);
spin_lock_irqsave(&tty->read_lock, flags);
tty->read_head = head;
tty->read_cnt -= cnt;
ldata->read_head = head;
ldata->read_cnt -= cnt;
spin_unlock_irqrestore(&tty->read_lock, flags);
if (L_ECHO(tty)) {
if (L_ECHOPRT(tty)) {
@ -959,7 +974,7 @@ static void eraser(unsigned char c, struct tty_struct *tty)
echo_char(c, tty);
while (--cnt > 0) {
head = (head+1) & (N_TTY_BUF_SIZE-1);
echo_char_raw(tty->read_buf[head], tty);
echo_char_raw(ldata->read_buf[head], tty);
echo_move_back_col(tty);
}
} else if (kill_type == ERASE && !L_ECHOE(tty)) {
@ -967,7 +982,7 @@ static void eraser(unsigned char c, struct tty_struct *tty)
} else if (c == '\t') {
unsigned int num_chars = 0;
int after_tab = 0;
unsigned long tail = tty->read_head;
unsigned long tail = ldata->read_head;
/*
* Count the columns used for characters
@ -976,9 +991,9 @@ static void eraser(unsigned char c, struct tty_struct *tty)
* This info is used to go back the correct
* number of columns.
*/
while (tail != tty->canon_head) {
while (tail != ldata->canon_head) {
tail = (tail-1) & (N_TTY_BUF_SIZE-1);
c = tty->read_buf[tail];
c = ldata->read_buf[tail];
if (c == '\t') {
after_tab = 1;
break;
@ -1006,7 +1021,7 @@ static void eraser(unsigned char c, struct tty_struct *tty)
if (kill_type == ERASE)
break;
}
if (tty->read_head == tty->canon_head && L_ECHO(tty))
if (ldata->read_head == ldata->canon_head && L_ECHO(tty))
finish_erasing(tty);
}
@ -1171,7 +1186,7 @@ static inline void n_tty_receive_char(struct tty_struct *tty, unsigned char c)
if (!test_bit(c, ldata->process_char_map) || ldata->lnext) {
ldata->lnext = 0;
parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty)) ? 1 : 0;
if (tty->read_cnt >= (N_TTY_BUF_SIZE - parmrk - 1)) {
if (ldata->read_cnt >= (N_TTY_BUF_SIZE - parmrk - 1)) {
/* beep if no space */
if (L_ECHO(tty))
process_output('\a', tty);
@ -1180,7 +1195,7 @@ static inline void n_tty_receive_char(struct tty_struct *tty, unsigned char c)
if (L_ECHO(tty)) {
finish_erasing(tty);
/* Record the column of first canon char. */
if (tty->canon_head == tty->read_head)
if (ldata->canon_head == ldata->read_head)
echo_set_canon_col(tty);
echo_char(c, tty);
process_echoes(tty);
@ -1264,20 +1279,20 @@ send_signal:
}
if (c == REPRINT_CHAR(tty) && L_ECHO(tty) &&
L_IEXTEN(tty)) {
unsigned long tail = tty->canon_head;
unsigned long tail = ldata->canon_head;
finish_erasing(tty);
echo_char(c, tty);
echo_char_raw('\n', tty);
while (tail != tty->read_head) {
echo_char(tty->read_buf[tail], tty);
while (tail != ldata->read_head) {
echo_char(ldata->read_buf[tail], tty);
tail = (tail+1) & (N_TTY_BUF_SIZE-1);
}
process_echoes(tty);
return;
}
if (c == '\n') {
if (tty->read_cnt >= N_TTY_BUF_SIZE) {
if (ldata->read_cnt >= N_TTY_BUF_SIZE) {
if (L_ECHO(tty))
process_output('\a', tty);
return;
@ -1289,9 +1304,9 @@ send_signal:
goto handle_newline;
}
if (c == EOF_CHAR(tty)) {
if (tty->read_cnt >= N_TTY_BUF_SIZE)
if (ldata->read_cnt >= N_TTY_BUF_SIZE)
return;
if (tty->canon_head != tty->read_head)
if (ldata->canon_head != ldata->read_head)
set_bit(TTY_PUSH, &tty->flags);
c = __DISABLED_CHAR;
goto handle_newline;
@ -1300,7 +1315,7 @@ send_signal:
(c == EOL2_CHAR(tty) && L_IEXTEN(tty))) {
parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty))
? 1 : 0;
if (tty->read_cnt >= (N_TTY_BUF_SIZE - parmrk)) {
if (ldata->read_cnt >= (N_TTY_BUF_SIZE - parmrk)) {
if (L_ECHO(tty))
process_output('\a', tty);
return;
@ -1310,7 +1325,7 @@ send_signal:
*/
if (L_ECHO(tty)) {
/* Record the column of first canon char. */
if (tty->canon_head == tty->read_head)
if (ldata->canon_head == ldata->read_head)
echo_set_canon_col(tty);
echo_char(c, tty);
process_echoes(tty);
@ -1324,10 +1339,10 @@ send_signal:
handle_newline:
spin_lock_irqsave(&tty->read_lock, flags);
set_bit(tty->read_head, ldata->read_flags);
set_bit(ldata->read_head, ldata->read_flags);
put_tty_queue_nolock(c, tty);
tty->canon_head = tty->read_head;
tty->canon_data++;
ldata->canon_head = ldata->read_head;
ldata->canon_data++;
spin_unlock_irqrestore(&tty->read_lock, flags);
kill_fasync(&tty->fasync, SIGIO, POLL_IN);
if (waitqueue_active(&tty->read_wait))
@ -1337,7 +1352,7 @@ handle_newline:
}
parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty)) ? 1 : 0;
if (tty->read_cnt >= (N_TTY_BUF_SIZE - parmrk - 1)) {
if (ldata->read_cnt >= (N_TTY_BUF_SIZE - parmrk - 1)) {
/* beep if no space */
if (L_ECHO(tty))
process_output('\a', tty);
@ -1349,7 +1364,7 @@ handle_newline:
echo_char_raw('\n', tty);
else {
/* Record the column of first canon char. */
if (tty->canon_head == tty->read_head)
if (ldata->canon_head == ldata->read_head)
echo_set_canon_col(tty);
echo_char(c, tty);
}
@ -1403,21 +1418,21 @@ static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
if (ldata->real_raw) {
spin_lock_irqsave(&tty->read_lock, cpuflags);
i = min(N_TTY_BUF_SIZE - tty->read_cnt,
N_TTY_BUF_SIZE - tty->read_head);
i = min(N_TTY_BUF_SIZE - ldata->read_cnt,
N_TTY_BUF_SIZE - ldata->read_head);
i = min(count, i);
memcpy(tty->read_buf + tty->read_head, cp, i);
tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1);
tty->read_cnt += i;
memcpy(ldata->read_buf + ldata->read_head, cp, i);
ldata->read_head = (ldata->read_head + i) & (N_TTY_BUF_SIZE-1);
ldata->read_cnt += i;
cp += i;
count -= i;
i = min(N_TTY_BUF_SIZE - tty->read_cnt,
N_TTY_BUF_SIZE - tty->read_head);
i = min(N_TTY_BUF_SIZE - ldata->read_cnt,
N_TTY_BUF_SIZE - ldata->read_head);
i = min(count, i);
memcpy(tty->read_buf + tty->read_head, cp, i);
tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1);
tty->read_cnt += i;
memcpy(ldata->read_buf + ldata->read_head, cp, i);
ldata->read_head = (ldata->read_head + i) & (N_TTY_BUF_SIZE-1);
ldata->read_cnt += i;
spin_unlock_irqrestore(&tty->read_lock, cpuflags);
} else {
for (i = count, p = cp, f = fp; i; i--, p++) {
@ -1449,7 +1464,7 @@ static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
n_tty_set_room(tty);
if ((!ldata->icanon && (tty->read_cnt >= tty->minimum_to_wake)) ||
if ((!ldata->icanon && (ldata->read_cnt >= tty->minimum_to_wake)) ||
L_EXTPROC(tty)) {
kill_fasync(&tty->fasync, SIGIO, POLL_IN);
if (waitqueue_active(&tty->read_wait))
@ -1500,12 +1515,12 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
canon_change = (old->c_lflag ^ tty->termios.c_lflag) & ICANON;
if (canon_change) {
bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE);
tty->canon_head = tty->read_tail;
tty->canon_data = 0;
ldata->canon_head = ldata->read_tail;
ldata->canon_data = 0;
ldata->erasing = 0;
}
if (canon_change && !L_ICANON(tty) && tty->read_cnt)
if (canon_change && !L_ICANON(tty) && ldata->read_cnt)
wake_up_interruptible(&tty->read_wait);
ldata->icanon = (L_ICANON(tty) != 0);
@ -1586,11 +1601,9 @@ static void n_tty_close(struct tty_struct *tty)
struct n_tty_data *ldata = tty->disc_data;
n_tty_flush_buffer(tty);
kfree(tty->read_buf);
kfree(tty->echo_buf);
kfree(ldata->read_buf);
kfree(ldata->echo_buf);
kfree(ldata);
tty->read_buf = NULL;
tty->echo_buf = NULL;
tty->disc_data = NULL;
}
@ -1615,9 +1628,9 @@ static int n_tty_open(struct tty_struct *tty)
ldata->overrun_time = jiffies;
/* These are ugly. Currently a malloc failure here can panic */
tty->read_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
tty->echo_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
if (!tty->read_buf || !tty->echo_buf)
ldata->read_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
ldata->echo_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
if (!ldata->read_buf || !ldata->echo_buf)
goto err_free_bufs;
tty->disc_data = ldata;
@ -1630,8 +1643,8 @@ static int n_tty_open(struct tty_struct *tty)
return 0;
err_free_bufs:
kfree(tty->read_buf);
kfree(tty->echo_buf);
kfree(ldata->read_buf);
kfree(ldata->echo_buf);
kfree(ldata);
err:
return -ENOMEM;
@ -1643,9 +1656,9 @@ static inline int input_available_p(struct tty_struct *tty, int amt)
tty_flush_to_ldisc(tty);
if (ldata->icanon && !L_EXTPROC(tty)) {
if (tty->canon_data)
if (ldata->canon_data)
return 1;
} else if (tty->read_cnt >= (amt ? amt : 1))
} else if (ldata->read_cnt >= (amt ? amt : 1))
return 1;
return 0;
@ -1681,21 +1694,21 @@ static int copy_from_read_buf(struct tty_struct *tty,
retval = 0;
spin_lock_irqsave(&tty->read_lock, flags);
n = min(tty->read_cnt, N_TTY_BUF_SIZE - tty->read_tail);
n = min(ldata->read_cnt, N_TTY_BUF_SIZE - ldata->read_tail);
n = min(*nr, n);
spin_unlock_irqrestore(&tty->read_lock, flags);
if (n) {
retval = copy_to_user(*b, &tty->read_buf[tty->read_tail], n);
retval = copy_to_user(*b, &ldata->read_buf[ldata->read_tail], n);
n -= retval;
is_eof = n == 1 &&
tty->read_buf[tty->read_tail] == EOF_CHAR(tty);
tty_audit_add_data(tty, &tty->read_buf[tty->read_tail], n,
ldata->read_buf[ldata->read_tail] == EOF_CHAR(tty);
tty_audit_add_data(tty, &ldata->read_buf[ldata->read_tail], n,
ldata->icanon);
spin_lock_irqsave(&tty->read_lock, flags);
tty->read_tail = (tty->read_tail + n) & (N_TTY_BUF_SIZE-1);
tty->read_cnt -= n;
ldata->read_tail = (ldata->read_tail + n) & (N_TTY_BUF_SIZE-1);
ldata->read_cnt -= n;
/* Turn single EOF into zero-length read */
if (L_EXTPROC(tty) && ldata->icanon && is_eof && !tty->read_cnt)
if (L_EXTPROC(tty) && ldata->icanon && is_eof && !ldata->read_cnt)
n = 0;
spin_unlock_irqrestore(&tty->read_lock, flags);
*b += n;
@ -1878,22 +1891,22 @@ do_it_again:
if (ldata->icanon && !L_EXTPROC(tty)) {
/* N.B. avoid overrun if nr == 0 */
spin_lock_irqsave(&tty->read_lock, flags);
while (nr && tty->read_cnt) {
while (nr && ldata->read_cnt) {
int eol;
eol = test_and_clear_bit(tty->read_tail,
eol = test_and_clear_bit(ldata->read_tail,
ldata->read_flags);
c = tty->read_buf[tty->read_tail];
tty->read_tail = ((tty->read_tail+1) &
c = ldata->read_buf[ldata->read_tail];
ldata->read_tail = ((ldata->read_tail+1) &
(N_TTY_BUF_SIZE-1));
tty->read_cnt--;
ldata->read_cnt--;
if (eol) {
/* this test should be redundant:
* we shouldn't be reading data if
* canon_data is 0
*/
if (--tty->canon_data < 0)
tty->canon_data = 0;
if (--ldata->canon_data < 0)
ldata->canon_data = 0;
}
spin_unlock_irqrestore(&tty->read_lock, flags);
@ -2111,15 +2124,15 @@ static unsigned long inq_canon(struct tty_struct *tty)
struct n_tty_data *ldata = tty->disc_data;
int nr, head, tail;
if (!tty->canon_data)
if (!ldata->canon_data)
return 0;
head = tty->canon_head;
tail = tty->read_tail;
head = ldata->canon_head;
tail = ldata->read_tail;
nr = (head - tail) & (N_TTY_BUF_SIZE-1);
/* Skip EOF-chars.. */
while (head != tail) {
if (test_bit(tail, ldata->read_flags) &&
tty->read_buf[tail] == __DISABLED_CHAR)
ldata->read_buf[tail] == __DISABLED_CHAR)
nr--;
tail = (tail+1) & (N_TTY_BUF_SIZE-1);
}
@ -2129,6 +2142,7 @@ static unsigned long inq_canon(struct tty_struct *tty)
static int n_tty_ioctl(struct tty_struct *tty, struct file *file,
unsigned int cmd, unsigned long arg)
{
struct n_tty_data *ldata = tty->disc_data;
int retval;
switch (cmd) {
@ -2136,7 +2150,7 @@ static int n_tty_ioctl(struct tty_struct *tty, struct file *file,
return put_user(tty_chars_in_buffer(tty), (int __user *) arg);
case TIOCINQ:
/* FIXME: Locking */
retval = tty->read_cnt;
retval = ldata->read_cnt;
if (L_ICANON(tty))
retval = inq_canon(tty);
return put_user(retval, (unsigned int __user *) arg);

10
include/linux/tty.h
View File

@ -272,16 +272,6 @@ struct tty_struct {
*/
unsigned char closing:1;
unsigned short minimum_to_wake;
char *read_buf;
int read_head;
int read_tail;
int read_cnt;
unsigned char *echo_buf;
unsigned int echo_pos;
unsigned int echo_cnt;
int canon_data;
unsigned long canon_head;
unsigned int canon_column;
struct mutex atomic_read_lock;
struct mutex atomic_write_lock;
struct mutex output_lock;