Started to enforce a one to one relationship between struct tty_struct and...

Started to enforce a one to one relationship between struct tty_struct and struct vc_data. It will make it easier to handle things.

drivers/char/console.c

@@ -2382,6 +2382,7 @@ static int con_open(struct tty_struct *tty, struct file * filp)
 
 	vt_cons[currcons]->vc_num = currcons;
 	tty->driver_data = vt_cons[currcons];
+	vc_cons[currcons].d->vc_tty = tty;
 
 	if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
 		tty->winsize.ws_row = video_num_lines;

include/linux/console_struct.h

@@ -33,6 +33,7 @@ struct vc_data {
 	unsigned int	vc_top, vc_bottom;	/* Scrolling region */
 	unsigned int	vc_state;		/* Escape sequence parser state */
 	unsigned int	vc_npar,vc_par[NPAR];	/* Parameters of current escape sequence */
+	struct tty_struct *vc_tty;		/* TTY we are attached to */
 	unsigned long	vc_origin;		/* [!] Start of real screen */
 	unsigned long	vc_scr_end;		/* [!] End of real screen */
 	unsigned long	vc_visible_origin;	/* [!] Top of visible window */