aboutsummaryrefslogtreecommitdiff
path: root/drivers/tty
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/tty_io.c93
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);