[PATCH] prepare for 32-bit dev_t: tty usage

	tty->device had been used only in a couple of places and can be
calculated by tty->index and tty->driver.  Field removed, its users switched
to static inline dev_t tty_devnum(tty).

arch/x86_64/ia32/ia32_ioctl.c

@@ -35,7 +35,7 @@ static int tiocgdev(unsigned fd, unsigned cmd,  unsigned int *ptr)
 	real_tty = (struct tty_struct *)file->private_data;
 	if (!real_tty) 	
 		return -EINVAL; 
-	return put_user(real_tty->device, ptr); 
+	return put_user(tty_devnum(real_tty), ptr); 
 } 
 
 

drivers/char/tty_io.c

@@ -826,7 +826,6 @@ static int init_dev(struct tty_driver *driver, int idx,
 	if(!tty)
 		goto fail_no_mem;
 	initialize_tty_struct(tty);
-	tty->device = MKDEV(driver->major, driver->minor_start) + idx;
 	tty->driver = driver;
 	tty->index = idx;
 	tty_line_name(driver, idx, tty->name);
@@ -854,8 +853,6 @@ static int init_dev(struct tty_driver *driver, int idx,
 		if (!o_tty)
 			goto free_mem_out;
 		initialize_tty_struct(o_tty);
-		o_tty->device = MKDEV(driver->other->major,
-					driver->other->minor_start) + idx;
 		o_tty->driver = driver->other;
 		o_tty->index = idx;
 		tty_line_name(driver->other, idx, o_tty->name);

drivers/net/slip.c

@@ -869,12 +869,12 @@ slip_open(struct tty_struct *tty)
 
 	/* OK.  Find a free SLIP channel to use. */
 	err = -ENFILE;
-	if ((sl = sl_alloc(tty->device)) == NULL)
+	if ((sl = sl_alloc(tty_devnum(tty))) == NULL)
 		goto err_exit;
 
 	sl->tty = tty;
 	tty->disc_data = sl;
-	sl->line = tty->device;
+	sl->line = tty_devnum(tty);
 	sl->pid = current->pid;
 	if (tty->driver->flush_buffer)
 		tty->driver->flush_buffer(tty);

fs/proc/array.c

@@ -306,7 +306,7 @@ int proc_pid_stat(struct task_struct *task, char * buffer)
 		mm = mmgrab(mm);
 	if (task->tty) {
 		tty_pgrp = task->tty->pgrp;
-		tty_nr = task->tty->device;
+		tty_nr = tty_devnum(task->tty);
 	}
 	task_unlock(task);
 	if (mm) {

include/linux/tty.h

@@ -264,7 +264,6 @@ struct tty_struct {
 	char name[64];
 	int pgrp;
 	int session;
-	dev_t	device;
 	unsigned long flags;
 	int count;
 	struct winsize winsize;
@@ -419,5 +418,10 @@ extern void console_print(const char *);
 extern int vt_ioctl(struct tty_struct *tty, struct file * file,
 		    unsigned int cmd, unsigned long arg);
 
+static inline dev_t tty_devnum(struct tty_struct *tty)
+{
+	return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index;
+}
+
 #endif /* __KERNEL__ */
 #endif

kernel/acct.c

@@ -342,7 +342,7 @@ static void do_acct_process(long exitcode, struct file *file)
 	ac.ac_stime = encode_comp_t(current->stime);
 	ac.ac_uid = current->uid;
 	ac.ac_gid = current->gid;
-	ac.ac_tty = current->tty ? current->tty->device : 0;
+	ac.ac_tty = current->tty ? tty_devnum(current->tty) : 0;
 
 	ac.ac_flag = 0;
 	if (current->flags & PF_FORKNOEXEC)