diff options
| -rw-r--r-- | drivers/tty/tty_io.c | 93 |
1 files changed, 55 insertions, 38 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 1b90c986b1b..00b84984308 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1824,6 +1824,53 @@ static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) } /** + * tty_lookup_driver - lookup a tty driver for a given device file + * @device: device number + * @filp: file pointer to tty + * @noctty: set if the device should not become a controlling tty + * @index: index for the device in the @return driver + * @return: driver for this inode (with increased refcount) + * + * If @return is not erroneous, the caller is responsible to decrement the + * refcount by tty_driver_kref_put. + * + * Locking: tty_mutex protects get_tty_driver + */ +static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, + int *noctty, int *index) +{ + struct tty_driver *driver; + +#ifdef CONFIG_VT + if (device == MKDEV(TTY_MAJOR, 0)) { + extern struct tty_driver *console_driver; + driver = tty_driver_kref_get(console_driver); + *index = fg_console; + *noctty = 1; + return driver; + } +#endif + if (device == MKDEV(TTYAUX_MAJOR, 1)) { + struct tty_driver *console_driver = console_device(index); + if (console_driver) { + driver = tty_driver_kref_get(console_driver); + if (driver) { + /* Don't let /dev/console block */ + filp->f_flags |= O_NONBLOCK; + *noctty = 1; + return driver; + } + } + return ERR_PTR(-ENODEV); + } + + driver = get_tty_driver(device, index); + if (!driver) + return ERR_PTR(-ENODEV); + return driver; +} + +/** * tty_open - open a tty device * @inode: inode of device file * @filp: file pointer to tty @@ -1839,7 +1886,7 @@ static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) * The termios state of a pty is reset on first open so that * settings don't persist across reuse. * - * Locking: tty_mutex protects tty, get_tty_driver and tty_init_dev work. + * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. * tty->count should protect the rest. * ->siglock protects ->signal/->sighand */ @@ -1873,47 +1920,17 @@ retry_open: mutex_unlock(&tty_mutex); tty_free_file(filp); return PTR_ERR(tty); - } else if (tty) - goto got_driver; - -#ifdef CONFIG_VT - if (device == MKDEV(TTY_MAJOR, 0)) { - extern struct tty_driver *console_driver; - driver = tty_driver_kref_get(console_driver); - index = fg_console; - noctty = 1; - goto got_driver; - } -#endif - if (device == MKDEV(TTYAUX_MAJOR, 1)) { - struct tty_driver *console_driver = console_device(&index); - if (console_driver) { - driver = tty_driver_kref_get(console_driver); - if (driver) { - /* Don't let /dev/console block */ - filp->f_flags |= O_NONBLOCK; - noctty = 1; - goto got_driver; - } + } else if (!tty) { + driver = tty_lookup_driver(device, filp, &noctty, &index); + if (IS_ERR(driver)) { + tty_unlock(); + mutex_unlock(&tty_mutex); + tty_free_file(filp); + return PTR_ERR(driver); } - tty_unlock(); - mutex_unlock(&tty_mutex); - tty_free_file(filp); - return -ENODEV; - } - driver = get_tty_driver(device, &index); - if (!driver) { - tty_unlock(); - mutex_unlock(&tty_mutex); - tty_free_file(filp); - return -ENODEV; - } -got_driver: - if (!tty) { /* check whether we're reopening an existing tty */ tty = tty_driver_lookup_tty(driver, inode, index); - if (IS_ERR(tty)) { tty_unlock(); mutex_unlock(&tty_mutex); |