From bddc7152f68bc1e0ee1f55a8055e33531f384101 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Thu, 18 Oct 2012 22:26:42 +0200 Subject: [PATCH] TTY: move ldisc data from tty_struct: locks atomic_write_lock is not n_tty specific, so move it up in the tty_struct. And since these are the last ones to move, remove also the comment saying there are some ldisc' members. There are none now. Signed-off-by: Jiri Slaby Acked-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/tty/n_tty.c | 123 +++++++++++++++++++++++++------------------ drivers/tty/tty_io.c | 4 -- include/linux/tty.h | 11 +--- 3 files changed, 73 insertions(+), 65 deletions(-) diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 4794537a50ff..0a6fcda96152 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -96,6 +96,11 @@ struct n_tty_data { int canon_data; unsigned long canon_head; unsigned int canon_column; + + struct mutex atomic_read_lock; + struct mutex output_lock; + struct mutex echo_lock; + spinlock_t read_lock; }; static inline int tty_put_user(struct tty_struct *tty, unsigned char x, @@ -171,14 +176,15 @@ static void put_tty_queue_nolock(unsigned char c, struct tty_struct *tty) static void put_tty_queue(unsigned char c, struct tty_struct *tty) { + struct n_tty_data *ldata = tty->disc_data; unsigned long flags; /* * The problem of stomping on the buffers ends here. * Why didn't anyone see this one coming? --AJK */ - spin_lock_irqsave(&tty->read_lock, flags); + spin_lock_irqsave(&ldata->read_lock, flags); put_tty_queue_nolock(c, tty); - spin_unlock_irqrestore(&tty->read_lock, flags); + spin_unlock_irqrestore(&ldata->read_lock, flags); } /** @@ -212,13 +218,13 @@ static void reset_buffer_flags(struct tty_struct *tty) struct n_tty_data *ldata = tty->disc_data; unsigned long flags; - spin_lock_irqsave(&tty->read_lock, flags); + spin_lock_irqsave(&ldata->read_lock, flags); ldata->read_head = ldata->read_tail = ldata->read_cnt = 0; - spin_unlock_irqrestore(&tty->read_lock, flags); + spin_unlock_irqrestore(&ldata->read_lock, flags); - mutex_lock(&tty->echo_lock); + mutex_lock(&ldata->echo_lock); ldata->echo_pos = ldata->echo_cnt = ldata->echo_overrun = 0; - mutex_unlock(&tty->echo_lock); + mutex_unlock(&ldata->echo_lock); ldata->canon_head = ldata->canon_data = ldata->erasing = 0; bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE); @@ -270,7 +276,7 @@ static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty) unsigned long flags; ssize_t n = 0; - spin_lock_irqsave(&tty->read_lock, flags); + spin_lock_irqsave(&ldata->read_lock, flags); if (!ldata->icanon) { n = ldata->read_cnt; } else if (ldata->canon_data) { @@ -278,7 +284,7 @@ static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty) ldata->canon_head - ldata->read_tail : ldata->canon_head + (N_TTY_BUF_SIZE - ldata->read_tail); } - spin_unlock_irqrestore(&tty->read_lock, flags); + spin_unlock_irqrestore(&ldata->read_lock, flags); return n; } @@ -408,14 +414,15 @@ static int do_output_char(unsigned char c, struct tty_struct *tty, int space) static int process_output(unsigned char c, struct tty_struct *tty) { + struct n_tty_data *ldata = tty->disc_data; int space, retval; - mutex_lock(&tty->output_lock); + mutex_lock(&ldata->output_lock); space = tty_write_room(tty); retval = do_output_char(c, tty, space); - mutex_unlock(&tty->output_lock); + mutex_unlock(&ldata->output_lock); if (retval < 0) return -1; else @@ -449,11 +456,11 @@ static ssize_t process_output_block(struct tty_struct *tty, int i; const unsigned char *cp; - mutex_lock(&tty->output_lock); + mutex_lock(&ldata->output_lock); space = tty_write_room(tty); if (!space) { - mutex_unlock(&tty->output_lock); + mutex_unlock(&ldata->output_lock); return 0; } if (nr > space) @@ -496,7 +503,7 @@ static ssize_t process_output_block(struct tty_struct *tty, break_out: i = tty->ops->write(tty, buf, i); - mutex_unlock(&tty->output_lock); + mutex_unlock(&ldata->output_lock); return i; } @@ -536,8 +543,8 @@ static void process_echoes(struct tty_struct *tty) if (!ldata->echo_cnt) return; - mutex_lock(&tty->output_lock); - mutex_lock(&tty->echo_lock); + mutex_lock(&ldata->output_lock); + mutex_lock(&ldata->echo_lock); space = tty_write_room(tty); @@ -682,8 +689,8 @@ static void process_echoes(struct tty_struct *tty) ldata->echo_overrun = 0; } - mutex_unlock(&tty->echo_lock); - mutex_unlock(&tty->output_lock); + mutex_unlock(&ldata->echo_lock); + mutex_unlock(&ldata->output_lock); if (tty->ops->flush_chars) tty->ops->flush_chars(tty); @@ -748,12 +755,14 @@ static void add_echo_byte(unsigned char c, struct tty_struct *tty) static void echo_move_back_col(struct tty_struct *tty) { - mutex_lock(&tty->echo_lock); + struct n_tty_data *ldata = tty->disc_data; + + mutex_lock(&ldata->echo_lock); add_echo_byte(ECHO_OP_START, tty); add_echo_byte(ECHO_OP_MOVE_BACK_COL, tty); - mutex_unlock(&tty->echo_lock); + mutex_unlock(&ldata->echo_lock); } /** @@ -768,12 +777,14 @@ static void echo_move_back_col(struct tty_struct *tty) static void echo_set_canon_col(struct tty_struct *tty) { - mutex_lock(&tty->echo_lock); + struct n_tty_data *ldata = tty->disc_data; + + mutex_lock(&ldata->echo_lock); add_echo_byte(ECHO_OP_START, tty); add_echo_byte(ECHO_OP_SET_CANON_COL, tty); - mutex_unlock(&tty->echo_lock); + mutex_unlock(&ldata->echo_lock); } /** @@ -796,7 +807,9 @@ static void echo_set_canon_col(struct tty_struct *tty) static void echo_erase_tab(unsigned int num_chars, int after_tab, struct tty_struct *tty) { - mutex_lock(&tty->echo_lock); + struct n_tty_data *ldata = tty->disc_data; + + mutex_lock(&ldata->echo_lock); add_echo_byte(ECHO_OP_START, tty); add_echo_byte(ECHO_OP_ERASE_TAB, tty); @@ -810,7 +823,7 @@ static void echo_erase_tab(unsigned int num_chars, int after_tab, add_echo_byte(num_chars, tty); - mutex_unlock(&tty->echo_lock); + mutex_unlock(&ldata->echo_lock); } /** @@ -828,7 +841,9 @@ static void echo_erase_tab(unsigned int num_chars, int after_tab, static void echo_char_raw(unsigned char c, struct tty_struct *tty) { - mutex_lock(&tty->echo_lock); + struct n_tty_data *ldata = tty->disc_data; + + mutex_lock(&ldata->echo_lock); if (c == ECHO_OP_START) { add_echo_byte(ECHO_OP_START, tty); @@ -837,7 +852,7 @@ static void echo_char_raw(unsigned char c, struct tty_struct *tty) add_echo_byte(c, tty); } - mutex_unlock(&tty->echo_lock); + mutex_unlock(&ldata->echo_lock); } /** @@ -856,7 +871,9 @@ static void echo_char_raw(unsigned char c, struct tty_struct *tty) static void echo_char(unsigned char c, struct tty_struct *tty) { - mutex_lock(&tty->echo_lock); + struct n_tty_data *ldata = tty->disc_data; + + mutex_lock(&ldata->echo_lock); if (c == ECHO_OP_START) { add_echo_byte(ECHO_OP_START, tty); @@ -867,7 +884,7 @@ static void echo_char(unsigned char c, struct tty_struct *tty) add_echo_byte(c, tty); } - mutex_unlock(&tty->echo_lock); + mutex_unlock(&ldata->echo_lock); } /** @@ -914,19 +931,19 @@ static void eraser(unsigned char c, struct tty_struct *tty) kill_type = WERASE; else { if (!L_ECHO(tty)) { - spin_lock_irqsave(&tty->read_lock, flags); + spin_lock_irqsave(&ldata->read_lock, flags); ldata->read_cnt -= ((ldata->read_head - ldata->canon_head) & (N_TTY_BUF_SIZE - 1)); ldata->read_head = ldata->canon_head; - spin_unlock_irqrestore(&tty->read_lock, flags); + spin_unlock_irqrestore(&ldata->read_lock, flags); return; } if (!L_ECHOK(tty) || !L_ECHOKE(tty) || !L_ECHOE(tty)) { - spin_lock_irqsave(&tty->read_lock, flags); + spin_lock_irqsave(&ldata->read_lock, flags); ldata->read_cnt -= ((ldata->read_head - ldata->canon_head) & (N_TTY_BUF_SIZE - 1)); ldata->read_head = ldata->canon_head; - spin_unlock_irqrestore(&tty->read_lock, flags); + spin_unlock_irqrestore(&ldata->read_lock, flags); finish_erasing(tty); echo_char(KILL_CHAR(tty), tty); /* Add a newline if ECHOK is on and ECHOKE is off. */ @@ -960,10 +977,10 @@ static void eraser(unsigned char c, struct tty_struct *tty) break; } cnt = (ldata->read_head - head) & (N_TTY_BUF_SIZE-1); - spin_lock_irqsave(&tty->read_lock, flags); + spin_lock_irqsave(&ldata->read_lock, flags); ldata->read_head = head; ldata->read_cnt -= cnt; - spin_unlock_irqrestore(&tty->read_lock, flags); + spin_unlock_irqrestore(&ldata->read_lock, flags); if (L_ECHO(tty)) { if (L_ECHOPRT(tty)) { if (!ldata->erasing) { @@ -1338,12 +1355,12 @@ send_signal: put_tty_queue(c, tty); handle_newline: - spin_lock_irqsave(&tty->read_lock, flags); + spin_lock_irqsave(&ldata->read_lock, flags); set_bit(ldata->read_head, ldata->read_flags); put_tty_queue_nolock(c, tty); ldata->canon_head = ldata->read_head; ldata->canon_data++; - spin_unlock_irqrestore(&tty->read_lock, flags); + spin_unlock_irqrestore(&ldata->read_lock, flags); kill_fasync(&tty->fasync, SIGIO, POLL_IN); if (waitqueue_active(&tty->read_wait)) wake_up_interruptible(&tty->read_wait); @@ -1417,7 +1434,7 @@ static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp, unsigned long cpuflags; if (ldata->real_raw) { - spin_lock_irqsave(&tty->read_lock, cpuflags); + spin_lock_irqsave(&ldata->read_lock, cpuflags); i = min(N_TTY_BUF_SIZE - ldata->read_cnt, N_TTY_BUF_SIZE - ldata->read_head); i = min(count, i); @@ -1433,7 +1450,7 @@ static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp, 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); + spin_unlock_irqrestore(&ldata->read_lock, cpuflags); } else { for (i = count, p = cp, f = fp; i; i--, p++) { if (f) @@ -1626,6 +1643,10 @@ static int n_tty_open(struct tty_struct *tty) goto err; ldata->overrun_time = jiffies; + mutex_init(&ldata->atomic_read_lock); + mutex_init(&ldata->output_lock); + mutex_init(&ldata->echo_lock); + spin_lock_init(&ldata->read_lock); /* These are ugly. Currently a malloc failure here can panic */ ldata->read_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL); @@ -1677,7 +1698,7 @@ static inline int input_available_p(struct tty_struct *tty, int amt) * buffer, and once to drain the space from the (physical) beginning of * the buffer to head pointer. * - * Called under the tty->atomic_read_lock sem + * Called under the ldata->atomic_read_lock sem * */ @@ -1693,10 +1714,10 @@ static int copy_from_read_buf(struct tty_struct *tty, bool is_eof; retval = 0; - spin_lock_irqsave(&tty->read_lock, flags); + spin_lock_irqsave(&ldata->read_lock, flags); n = min(ldata->read_cnt, N_TTY_BUF_SIZE - ldata->read_tail); n = min(*nr, n); - spin_unlock_irqrestore(&tty->read_lock, flags); + spin_unlock_irqrestore(&ldata->read_lock, flags); if (n) { retval = copy_to_user(*b, &ldata->read_buf[ldata->read_tail], n); n -= retval; @@ -1704,13 +1725,13 @@ static int copy_from_read_buf(struct tty_struct *tty, 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); + spin_lock_irqsave(&ldata->read_lock, flags); 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 && !ldata->read_cnt) n = 0; - spin_unlock_irqrestore(&tty->read_lock, flags); + spin_unlock_irqrestore(&ldata->read_lock, flags); *b += n; *nr -= n; } @@ -1818,10 +1839,10 @@ do_it_again: * Internal serialization of reads. */ if (file->f_flags & O_NONBLOCK) { - if (!mutex_trylock(&tty->atomic_read_lock)) + if (!mutex_trylock(&ldata->atomic_read_lock)) return -EAGAIN; } else { - if (mutex_lock_interruptible(&tty->atomic_read_lock)) + if (mutex_lock_interruptible(&ldata->atomic_read_lock)) return -ERESTARTSYS; } packet = tty->packet; @@ -1890,7 +1911,7 @@ do_it_again: if (ldata->icanon && !L_EXTPROC(tty)) { /* N.B. avoid overrun if nr == 0 */ - spin_lock_irqsave(&tty->read_lock, flags); + spin_lock_irqsave(&ldata->read_lock, flags); while (nr && ldata->read_cnt) { int eol; @@ -1908,25 +1929,25 @@ do_it_again: if (--ldata->canon_data < 0) ldata->canon_data = 0; } - spin_unlock_irqrestore(&tty->read_lock, flags); + spin_unlock_irqrestore(&ldata->read_lock, flags); if (!eol || (c != __DISABLED_CHAR)) { if (tty_put_user(tty, c, b++)) { retval = -EFAULT; b--; - spin_lock_irqsave(&tty->read_lock, flags); + spin_lock_irqsave(&ldata->read_lock, flags); break; } nr--; } if (eol) { tty_audit_push(tty); - spin_lock_irqsave(&tty->read_lock, flags); + spin_lock_irqsave(&ldata->read_lock, flags); break; } - spin_lock_irqsave(&tty->read_lock, flags); + spin_lock_irqsave(&ldata->read_lock, flags); } - spin_unlock_irqrestore(&tty->read_lock, flags); + spin_unlock_irqrestore(&ldata->read_lock, flags); if (retval) break; } else { @@ -1958,7 +1979,7 @@ do_it_again: if (time) timeout = time; } - mutex_unlock(&tty->atomic_read_lock); + mutex_unlock(&ldata->atomic_read_lock); remove_wait_queue(&tty->read_wait, &wait); if (!waitqueue_active(&tty->read_wait)) diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 67b024ca16ec..f90b6217b3ba 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2939,11 +2939,7 @@ void initialize_tty_struct(struct tty_struct *tty, init_waitqueue_head(&tty->write_wait); init_waitqueue_head(&tty->read_wait); INIT_WORK(&tty->hangup_work, do_tty_hangup); - mutex_init(&tty->atomic_read_lock); mutex_init(&tty->atomic_write_lock); - mutex_init(&tty->output_lock); - mutex_init(&tty->echo_lock); - spin_lock_init(&tty->read_lock); spin_lock_init(&tty->ctrl_lock); INIT_LIST_HEAD(&tty->tty_files); INIT_WORK(&tty->SAK_work, do_SAK_work); diff --git a/include/linux/tty.h b/include/linux/tty.h index 226cf20e0150..08787ece3fdc 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -235,6 +235,7 @@ struct tty_struct { struct mutex ldisc_mutex; struct tty_ldisc *ldisc; + struct mutex atomic_write_lock; struct mutex legacy_mutex; struct mutex termios_mutex; spinlock_t ctrl_lock; @@ -265,20 +266,10 @@ struct tty_struct { #define N_TTY_BUF_SIZE 4096 - /* - * The following is data for the N_TTY line discipline. For - * historical reasons, this is included in the tty structure. - * Mostly locked by the BKL. - */ unsigned char closing:1; unsigned short minimum_to_wake; - struct mutex atomic_read_lock; - struct mutex atomic_write_lock; - struct mutex output_lock; - struct mutex echo_lock; unsigned char *write_buf; int write_cnt; - spinlock_t read_lock; /* If the tty has a pending do_SAK, queue it here - akpm */ struct work_struct SAK_work; struct tty_port *port;