TTY: devpts, do not set driver_data

The goal is to stop setting and using tty->driver_data in devpts code.
It should be used solely by the driver's code, pty in this case.

Now driver_data are managed only in the pty driver. devpts_pty_new is
switched to accept what we used to dig out of tty_struct, i.e. device
node number and index.

This also removes a note about driver_data being set outside of the
driver.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 5 insertions, 5 deletions

diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index 9985b451e937..559e5b27941a 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -4,9 +4,6 @@
  *  Added support for a Unix98-style ptmx device.
  *    -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
  *
- *  When reading this code see also fs/devpts. In particular note that the
- *  driver_data field is used by the devpts side as a binding to the devpts
- *  inode.
  */
 
 #include <linux/module.h>
@@ -59,7 +56,7 @@ static void pty_close(struct tty_struct *tty, struct file *filp)
 #ifdef CONFIG_UNIX98_PTYS
                 if (tty->driver == ptm_driver) {
                         mutex_lock(&devpts_mutex);
-                        devpts_pty_kill(tty->link);
+                        devpts_pty_kill(tty->link->driver_data);
                         mutex_unlock(&devpts_mutex);
                 }
 #endif
@@ -651,7 +648,9 @@ static int ptmx_open(struct inode *inode, struct file *filp)
 
         tty_add_file(tty, filp);
 
-        slave_inode = devpts_pty_new(inode, tty->link);
+        slave_inode = devpts_pty_new(inode,
+                        MKDEV(UNIX98_PTY_SLAVE_MAJOR, index), index,
+                        tty->link);
         if (IS_ERR(slave_inode)) {
                 retval = PTR_ERR(slave_inode);
                 goto err_release;
@@ -662,6 +661,7 @@ static int ptmx_open(struct inode *inode, struct file *filp)
                 goto err_release;
 
         tty_unlock(tty);
+        tty->link->driver_data = slave_inode;
         return 0;
 err_release:
         tty_unlock(tty);