Revert "TTY: get rid of BTM around devpts_*"

This reverts commit d3bda5298aad98c7a27678bdd0dd9d008ab9e685.

Sasha reported that this causes problems, so revert it.

Cc: Sasha Levin <levinsasha928@gmail.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 5 insertions, 3 deletions

diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index 39afd045f8ef..ddec9f3c3396 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -54,8 +54,8 @@ static void pty_close(struct tty_struct *tty, struct file *filp)
         wake_up_interruptible(&tty->link->write_wait);
         if (tty->driver->subtype == PTY_TYPE_MASTER) {
                 set_bit(TTY_OTHER_CLOSED, &tty->flags);
-                tty_unlock();
                 devpts_pty_kill(tty->link);
+                tty_unlock();
                 tty_vhangup(tty->link);
                 tty_lock();
         }
@@ -613,7 +613,9 @@ static int ptmx_open(struct inode *inode, struct file *filp)
                 return retval;
 
         /* find a device that is not in use. */
+        tty_lock();
         index = devpts_new_index(inode);
+        tty_unlock();
         if (index < 0) {
                 retval = index;
                 goto err_file;
@@ -648,8 +650,8 @@ err_release:
         tty_release(inode, filp);
         return retval;
 out:
-        tty_unlock();
         devpts_kill_index(inode, index);
+        tty_unlock();
 err_file:
         tty_free_file(filp);
         return retval;
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index ea7ebe22a16c..44736f9e61d7 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1789,11 +1789,11 @@ int tty_release(struct inode *inode, struct file *filp)
          * the slots and preserving the termios structure.
          */
         release_tty(tty, idx);
-        tty_unlock();
 
         /* Make this pty number available for reallocation */
         if (devpts)
                 devpts_kill_index(inode, idx);
+        tty_unlock();
         return 0;
 }