Move tty lookup/reopen to caller

Move tty_driver_lookup_tty() and tty_reopen() from tty_init_dev()
into tty_open() (one of the two callers of tty_init_dev()).  These
calls are not really required in ptmx_open(), the other caller,
since ptmx_open() would be setting up a new tty.

Changelog[v2]:
	- remove the lookup and reopen calls from ptmx_open
	- merge with recent changes to ttydev tree

Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 16 insertions, 15 deletions

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index e881e9ed08de..36098ee8fe65 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -1376,19 +1376,6 @@ struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx,
         struct tty_struct *tty;
         int retval;
 
-        /* check whether we're reopening an existing tty */
-        tty = tty_driver_lookup_tty(driver, idx);
-
-        if (IS_ERR(tty))
-                return tty;
-
-        if (tty) {
-                retval = tty_reopen(tty);
-                if (retval)
-                        return ERR_PTR(retval);
-                return tty;
-        }
-
         /* Check if pty master is being opened multiple times */
         if (driver->subtype == PTY_TYPE_MASTER &&
                 (driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok)
@@ -1790,7 +1777,7 @@ void tty_release_dev(struct file *filp)
 
 static int __tty_open(struct inode *inode, struct file *filp)
 {
-        struct tty_struct *tty;
+        struct tty_struct *tty = NULL;
         int noctty, retval;
         struct tty_driver *driver;
         int index;
@@ -1847,7 +1834,21 @@ retry_open:
                 return -ENODEV;
         }
 got_driver:
-        tty = tty_init_dev(driver, index, 0);
+        if (!tty) {
+                /* check whether we're reopening an existing tty */
+                tty = tty_driver_lookup_tty(driver, index);
+
+                if (IS_ERR(tty))
+                        return PTR_ERR(tty);
+        }
+
+        if (tty) {
+                retval = tty_reopen(tty);
+                if (retval)
+                        tty = ERR_PTR(retval);
+        } else
+                tty = tty_init_dev(driver, index, 0);
+
         mutex_unlock(&tty_mutex);
         tty_driver_kref_put(driver);
         if (IS_ERR(tty))