tty: BKL pushdown

- Push the BKL down into the line disciplines
- Switch the tty layer to unlocked_ioctl
- Introduce a new ctrl_lock spin lock for the control bits
- Eliminate much of the lock_kernel use in n_tty
- Prepare to (but don't yet) call the drivers with the lock dropped
  on the paths that historically held the lock

BKL now primarily protects open/close/ldisc change in the tty layer

[jirislaby@gmail.com: a couple of fixes]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index c6e72aebd16b..9663e8776724 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -1046,7 +1046,7 @@ static int vt_check(struct file *file)
         struct inode *inode = file->f_path.dentry->d_inode;
         struct vc_data *vc;
         
-        if (file->f_op->ioctl != tty_ioctl)
+        if (file->f_op->unlocked_ioctl != tty_ioctl)
                 return -EINVAL;
                         
         tty = (struct tty_struct *)file->private_data;