tty: Finish fixing up the init_dev interface to use ERR_PTR

Original suggestion and proposal from Sukadev Bhattiprolu.

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

3 files changed, 27 insertions, 35 deletions

diff --git a/drivers/char/pty.c b/drivers/char/pty.c
index 4e6490bda751..c98450023030 100644
--- a/drivers/char/pty.c
+++ b/drivers/char/pty.c
@@ -501,11 +501,13 @@ static int __ptmx_open(struct inode *inode, struct file *filp)
                 return index;
 
         mutex_lock(&tty_mutex);
-        retval = tty_init_dev(ptm_driver, index, &tty, 1);
+        tty = tty_init_dev(ptm_driver, index, 1);
         mutex_unlock(&tty_mutex);
 
-        if (retval)
+        if (IS_ERR(tty)) {
+                retval = PTR_ERR(tty);
                 goto out;
+        }
 
         set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
         filp->private_data = tty;
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 888380f573dc..b0ad4880c3a8 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -1324,35 +1324,32 @@ static int tty_reopen(struct tty_struct *tty)
  * relaxed for the (most common) case of reopening a tty.
  */
 
-int tty_init_dev(struct tty_driver *driver, int idx,
-        struct tty_struct **ret_tty, int first_ok)
+struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx,
+                                                                int first_ok)
 {
         struct tty_struct *tty, *o_tty;
         struct ktermios *tp, **tp_loc, *o_tp, **o_tp_loc;
         struct ktermios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc;
-        int retval = 0;
+        int retval;
 
         /* check whether we're reopening an existing tty */
         tty = tty_driver_lookup_tty(driver, idx);
-        if (IS_ERR(tty)) {
-                retval = PTR_ERR(tty);
-                goto end_init;
-        }
+
+        if (IS_ERR(tty))
+                return tty;
 
         if (tty) {
                 retval = tty_reopen(tty);
                 if (retval)
-                        return retval;
-                *ret_tty = tty;
-                return 0;
+                        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) {
-                retval = -EIO;
-                goto end_init;
-        }
+                (driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok)
+                return ERR_PTR(-EIO);
+
         /*
          * First time open is complex, especially for PTY devices.
          * This code guarantees that either everything succeeds and the
@@ -1361,10 +1358,8 @@ int tty_init_dev(struct tty_driver *driver, int idx,
          * and locked termios may be retained.)
          */
 
-        if (!try_module_get(driver->owner)) {
-                retval = -ENODEV;
-                goto end_init;
-        }
+        if (!try_module_get(driver->owner))
+                return ERR_PTR(-ENODEV);
 
         o_tty = NULL;
         tp = o_tp = NULL;
@@ -1475,7 +1470,8 @@ int tty_init_dev(struct tty_driver *driver, int idx,
         tty_driver_kref_get(driver);
         tty->count++;
 
-        if (tty_driver_install_tty(driver, tty) < 0)
+        retval = tty_driver_install_tty(driver, tty);
+        if (retval < 0)
                 goto release_mem_out;
 
         /*
@@ -1485,14 +1481,9 @@ int tty_init_dev(struct tty_driver *driver, int idx,
          */
 
         retval = tty_ldisc_setup(tty, o_tty);
-
         if (retval)
                 goto release_mem_out;
-
-        *ret_tty = tty;
-        /* All paths come through here to release the mutex */
-end_init:
-        return retval;
+        return tty;
 
         /* Release locally allocated memory ... nothing placed in slots */
 free_mem_out:
@@ -1507,8 +1498,7 @@ free_mem_out:
 
 fail_no_mem:
         module_put(driver->owner);
-        retval = -ENOMEM;
-        goto end_init;
+        return ERR_PTR(-ENOMEM);
 
         /* call the tty release_tty routine to clean out this slot */
 release_mem_out:
@@ -1516,7 +1506,7 @@ release_mem_out:
                 printk(KERN_INFO "tty_init_dev: ldisc open failed, "
                                  "clearing slot %d\n", idx);
         release_tty(tty, idx);
-        goto end_init;
+        return ERR_PTR(retval);
 }
 
 void tty_free_termios(struct tty_struct *tty)
@@ -1925,11 +1915,11 @@ retry_open:
                 return -ENODEV;
         }
 got_driver:
-        retval = tty_init_dev(driver, index, &tty, 0);
+        tty = tty_init_dev(driver, index, 0);
         mutex_unlock(&tty_mutex);
         tty_driver_kref_put(driver);
-        if (retval)
-                return retval;
+        if (IS_ERR(tty))
+                return PTR_ERR(tty);
 
         filp->private_data = tty;
         file_move(filp, &tty->tty_files);
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 6cc7ccc93c69..54523a37e956 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -401,8 +401,8 @@ extern dev_t tty_devnum(struct tty_struct *tty);
 extern void proc_clear_tty(struct task_struct *p);
 extern struct tty_struct *get_current_tty(void);
 extern void tty_default_fops(struct file_operations *fops);
-extern int tty_init_dev(struct tty_driver *driver, int idx,
-                        struct tty_struct **ret_tty, int first_ok);
+extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx,
+                                                                int first_ok);
 extern void tty_release_dev(struct file *filp);
 
 extern struct mutex tty_mutex;