[PATCH 53/76] tty: Finish fixing up the init_dev interface to use ERR_PTR

Alan Cox
2008-10-05T16:24:18Z

Original suggestion and proposal from Sukadev Bhattiprolu.

Signed-off-by: Alan Cox <alan@redhat.com>
---

drivers/char/pty.c | 6 ++++--
drivers/char/tty_io.c | 52 ++++++++++++++++++++-----------------------------
include/linux/tty.h | 4 ++--
3 files changed, 27 insertions(+), 35 deletions(-)

diff --git a/drivers/char/pty.c b/drivers/char/pty.c
index 4e6490b..c984500 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 888380f..b0ad488 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 6cc7ccc..54523a3 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;