tty: kref the tty driver object

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 11 insertions, 4 deletions

diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index 2c5c35c4656f..ba891dd23550 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -253,6 +253,7 @@ struct tty_operations {
 
 struct tty_driver {
         int     magic;          /* magic number for this structure */
+        struct kref kref;       /* Reference management */
         struct cdev cdev;
         struct module   *owner;
         const char      *driver_name;
@@ -266,7 +267,6 @@ struct tty_driver {
         short   subtype;        /* subtype of tty driver */
         struct ktermios init_termios; /* Initial termios */
         int     flags;          /* tty driver flags */
-        int     refcount;       /* for loadable tty drivers */
         struct proc_dir_entry *proc_entry; /* /proc fs entry */
         struct tty_driver *other; /* only used for the PTY driver */
 
@@ -288,12 +288,19 @@ struct tty_driver {
 
 extern struct list_head tty_drivers;
 
-struct tty_driver *alloc_tty_driver(int lines);
-void put_tty_driver(struct tty_driver *driver);
-void tty_set_operations(struct tty_driver *driver,
+extern struct tty_driver *alloc_tty_driver(int lines);
+extern void put_tty_driver(struct tty_driver *driver);
+extern void tty_set_operations(struct tty_driver *driver,
                         const struct tty_operations *op);
 extern struct tty_driver *tty_find_polling_driver(char *name, int *line);
 
+extern void tty_driver_kref_put(struct tty_driver *driver);
+extern inline struct tty_driver *tty_driver_kref_get(struct tty_driver *d)
+{
+        kref_get(&d->kref);
+        return d;
+}
+
 /* tty driver magic number */
 #define TTY_DRIVER_MAGIC                0x5402