tty: shutdown method

[linux-2.6-omap-h63xx.git] / drivers / char / vt.c

diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index 60359c360912c7d4dddee8e76a6a4ffb2c576e7e..37a45db5bae080a376c37902643b9d44fcc3fbd9 100644 (file)
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -2136,27 +2136,9 @@ static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int co
            release_console_sem();
            return 0;
        }
-       release_console_sem();
-
        orig_buf = buf;
        orig_count = count;
 
-       /* At this point 'buf' is guaranteed to be a kernel buffer
-        * and therefore no access to userspace (and therefore sleeping)
-        * will be needed.  The con_buf_mtx serializes all tty based
-        * console rendering and vcs write/read operations.  We hold
-        * the console spinlock during the entire write.
-        */
-
-       acquire_console_sem();
-
-       vc = tty->driver_data;
-       if (vc == NULL) {
-               printk(KERN_ERR "vt: argh, driver_data _became_ NULL !\n");
-               release_console_sem();
-               goto out;
-       }
-
        himask = vc->vc_hi_font_mask;
        charmask = himask ? 0x1ff : 0xff;
 
@@ -2583,8 +2565,6 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
        int lines;
        int ret;
 
-       if (tty->driver->type != TTY_DRIVER_TYPE_CONSOLE)
-               return -EINVAL;
        if (current->signal->tty != tty && !capable(CAP_SYS_ADMIN))
                return -EPERM;
        if (get_user(type, p))
@@ -2778,6 +2758,12 @@ static int con_open(struct tty_struct *tty, struct file *filp)
                ret = vc_allocate(currcons);
                if (ret == 0) {
                        struct vc_data *vc = vc_cons[currcons].d;
+
+                       /* Still being freed */
+                       if (vc->vc_tty) {
+                               release_console_sem();
+                               return -ERESTARTSYS;
+                       }
                        tty->driver_data = vc;
                        vc->vc_tty = tty;
 
@@ -2807,25 +2793,18 @@ static int con_open(struct tty_struct *tty, struct file *filp)
  */
 static void con_close(struct tty_struct *tty, struct file *filp)
 {
-       mutex_lock(&tty_mutex);
-       acquire_console_sem();
-       if (tty && tty->count == 1) {
-               struct vc_data *vc = tty->driver_data;
+       /* Nothing to do - we defer to shutdown */
+}
 
-               if (vc)
-                       vc->vc_tty = NULL;
-               tty->driver_data = NULL;
-               vcs_remove_sysfs(tty);
-               release_console_sem();
-               mutex_unlock(&tty_mutex);
-               /*
-                * tty_mutex is released, but we still hold BKL, so there is
-                * still exclusion against init_dev()
-                */
-               return;
-       }
+static void con_shutdown(struct tty_struct *tty)
+{
+       struct vc_data *vc = tty->driver_data;
+       BUG_ON(vc == NULL);
+       acquire_console_sem();
+       vc->vc_tty = NULL;
+       vcs_remove_sysfs(tty);
        release_console_sem();
-       mutex_unlock(&tty_mutex);
+       tty_shutdown(tty);
 }
 
 static int default_italic_color    = 2; // green (ASCII)
@@ -2950,6 +2929,7 @@ static const struct tty_operations con_ops = {
        .throttle = con_throttle,
        .unthrottle = con_unthrottle,
        .resize = vt_resize,
+       .shutdown = con_shutdown
 };
 
 int __init vty_init(void)