tty: Move the handling of the tty release logic
Now that we don't have tty->termios tied to drivers->tty we can untangle
the logic here. In addition we can push the removal logic out of the
destructor path.
At that point we can think about sorting out tty_port and console and all
the other ugly hangovers.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index 5ad7ccc..60c08ce 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -527,12 +527,6 @@
return tty;
}
-static void pty_unix98_shutdown(struct tty_struct *tty)
-{
- tty_driver_remove_tty(tty->driver, tty);
- /* We have our own method as we don't use the tty index */
-}
-
/* We have no need to install and remove our tty objects as devpts does all
the work for us */
@@ -558,9 +552,8 @@
.unthrottle = pty_unthrottle,
.set_termios = pty_set_termios,
.ioctl = pty_unix98_ioctl,
- .shutdown = pty_unix98_shutdown,
- .cleanup = pty_cleanup,
- .resize = pty_resize
+ .resize = pty_resize,
+ .cleanup = pty_cleanup
};
static const struct tty_operations pty_unix98_ops = {
@@ -575,7 +568,6 @@
.chars_in_buffer = pty_chars_in_buffer,
.unthrottle = pty_unthrottle,
.set_termios = pty_set_termios,
- .shutdown = pty_unix98_shutdown,
.cleanup = pty_cleanup,
};
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index cfd12da..be18d60 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1249,16 +1249,16 @@
struct ktermios *tp;
int idx = tty->index;
- tp = tty->driver->termios[idx];
- if (tp == NULL) {
- tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL);
- if (tp == NULL)
- return -ENOMEM;
- *tp = tty->driver->init_termios;
- tty->driver->termios[idx] = tp;
+ if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS)
+ tty->termios = tty->driver->init_termios;
+ else {
+ /* Check for lazy saved data */
+ tp = tty->driver->termios[idx];
+ if (tp != NULL)
+ tty->termios = *tp;
+ else
+ tty->termios = tty->driver->init_termios;
}
- tty->termios = *tp;
-
/* Compatibility until drivers always set this */
tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios);
tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios);
@@ -1437,24 +1437,24 @@
{
struct ktermios *tp;
int idx = tty->index;
- /* Kill this flag and push into drivers for locking etc */
- if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
- /* FIXME: Locking on ->termios array */
- tp = tty->driver->termios[idx];
- tty->driver->termios[idx] = NULL;
- kfree(tp);
+
+ /* If the port is going to reset then it has no termios to save */
+ if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS)
+ return;
+
+ /* Stash the termios data */
+ tp = tty->driver->termios[idx];
+ if (tp == NULL) {
+ tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL);
+ if (tp == NULL) {
+ pr_warn("tty: no memory to save termios state.\n");
+ return;
+ }
}
- else
- *tty->driver->termios[idx] = tty->termios;
+ *tp = tty->termios;
}
EXPORT_SYMBOL(tty_free_termios);
-void tty_shutdown(struct tty_struct *tty)
-{
- tty_driver_remove_tty(tty->driver, tty);
- tty_free_termios(tty);
-}
-EXPORT_SYMBOL(tty_shutdown);
/**
* release_one_tty - release tty structure memory
@@ -1498,11 +1498,6 @@
{
struct tty_struct *tty = container_of(kref, struct tty_struct, kref);
- if (tty->ops->shutdown)
- tty->ops->shutdown(tty);
- else
- tty_shutdown(tty);
-
/* The hangup queue is now free so we can reuse it rather than
waste a chunk of memory for each port */
INIT_WORK(&tty->hangup_work, release_one_tty);
@@ -1542,6 +1537,11 @@
/* This should always be true but check for the moment */
WARN_ON(tty->index != idx);
+ if (tty->ops->shutdown)
+ tty->ops->shutdown(tty);
+ tty_free_termios(tty);
+ tty_driver_remove_tty(tty->driver, tty);
+
if (tty->link)
tty_kref_put(tty->link);
tty_kref_put(tty);
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index dbceaeb..e07ded3 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -2850,7 +2850,6 @@
console_lock();
vc->port.tty = NULL;
console_unlock();
- tty_shutdown(tty);
}
static int default_italic_color = 2; // green (ASCII)
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 5fe2135..aa4b0d7 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -305,8 +305,7 @@
* Do the resource freeing and refcount dropping for the port.
* Avoid freeing the console.
*
- * Called asynchronously after the last tty kref is dropped,
- * and the tty layer has already done the tty_shutdown(tty);
+ * Called asynchronously after the last tty kref is dropped.
*/
static void serial_cleanup(struct tty_struct *tty)
{
diff --git a/include/linux/tty.h b/include/linux/tty.h
index d5e75ee..a39e723 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -423,7 +423,6 @@
extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
extern void tty_driver_remove_tty(struct tty_driver *driver,
struct tty_struct *tty);
-extern void tty_shutdown(struct tty_struct *tty);
extern void tty_free_termios(struct tty_struct *tty);
extern int is_current_pgrp_orphaned(void);
extern struct pid *tty_get_pgrp(struct tty_struct *tty);
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index 04419c1..80e72dc 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -45,14 +45,9 @@
*
* void (*shutdown)(struct tty_struct * tty);
*
- * This routine is called synchronously when a particular tty device
- * is closed for the last time freeing up the resources.
- * Note that tty_shutdown() is not called if ops->shutdown is defined.
- * This means one is responsible to take care of calling ops->remove (e.g.
- * via tty_driver_remove_tty) and releasing tty->termios.
- * Note that this hook may be called from *all* the contexts where one
- * uses tty refcounting (e.g. tty_port_tty_get).
- *
+ * This routine is called under the tty lock when a particular tty device
+ * is closed for the last time. It executes before the tty resources
+ * are freed so may execute while another function holds a tty kref.
*
* void (*cleanup)(struct tty_struct * tty);
*