tty: Extract various bits of ldisc code

Before trying to tackle the ldisc bugs the code needs to be a good deal
more readable, so do the simple extractions of routines first.

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

1 files changed, 19 insertions, 5 deletions

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 6c817398232e..be49d0730bb9 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -2481,6 +2481,24 @@ static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int
         return tty->ops->tiocmset(tty, file, set, clear);
 }
 
+struct tty_struct *tty_pair_get_tty(struct tty_struct *tty)
+{
+        if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+            tty->driver->subtype == PTY_TYPE_MASTER)
+                tty = tty->link;
+        return tty;
+}
+EXPORT_SYMBOL(tty_pair_get_tty);
+
+struct tty_struct *tty_pair_get_pty(struct tty_struct *tty)
+{
+        if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
+            tty->driver->subtype == PTY_TYPE_MASTER)
+            return tty;
+        return tty->link;
+}
+EXPORT_SYMBOL(tty_pair_get_pty);
+
 /*
  * Split this up, as gcc can choke on it otherwise..
  */
@@ -2496,11 +2514,7 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
         if (tty_paranoia_check(tty, inode, "tty_ioctl"))
                 return -EINVAL;
 
-        real_tty = tty;
-        if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
-            tty->driver->subtype == PTY_TYPE_MASTER)
-                real_tty = tty->link;
-
+        real_tty = tty_pair_get_tty(tty);
 
         /*
          * Factor out some common prep work