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>

diff --git a/drivers/char/pty.c b/drivers/char/pty.c
index 4e6490bda7511eb239e5d97b6230a3faa2cbc3b0..c98450023030304611dda20532098bb4caf6bd92 100644 (file)
--- 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 888380f573dcfe622e98303dba398e63ef51c654..b0ad4880c3a822cf99a88c8a1a62772dbf05539e 100644 (file)
--- 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 6cc7ccc93c69184f5bdfa82a9f502985b475d2b3..54523a37e95646a93c9defcd8ff08cfebc8532e0 100644 (file)
--- 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;