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>
This commit is contained in:
Alan Cox 2012-07-17 17:06:57 +01:00 committed by Greg Kroah-Hartman
parent 3db1ddb725
commit 36b3c070d2
6 changed files with 34 additions and 50 deletions

View file

@ -527,12 +527,6 @@ static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
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 @@ static const struct tty_operations ptm_unix98_ops = {
.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 @@ static const struct tty_operations pty_unix98_ops = {
.chars_in_buffer = pty_chars_in_buffer,
.unthrottle = pty_unthrottle,
.set_termios = pty_set_termios,
.shutdown = pty_unix98_shutdown,
.cleanup = pty_cleanup,
};

View file

@ -1249,16 +1249,16 @@ int tty_init_termios(struct tty_struct *tty)
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 @@ void tty_free_termios(struct tty_struct *tty)
{
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 @@ static void queue_release_one_tty(struct kref *kref)
{
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 @@ static void release_tty(struct tty_struct *tty, int idx)
/* 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);

View file

@ -2850,7 +2850,6 @@ static void con_shutdown(struct tty_struct *tty)
console_lock();
vc->port.tty = NULL;
console_unlock();
tty_shutdown(tty);
}
static int default_italic_color = 2; // green (ASCII)

View file

@ -305,8 +305,7 @@ static void serial_close(struct tty_struct *tty, struct file *filp)
* 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)
{

View file

@ -423,7 +423,6 @@ extern void tty_unthrottle(struct tty_struct *tty);
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);

View file

@ -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);
*