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>

1 files changed, 28 insertions, 28 deletions

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index cfd12da81218..be18d60ddf4c 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -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);