static int ptmx_open(struct inode *inode, struct file *filp)
{
struct tty_struct *tty;
int retval;
int index;
nonseekable_open(inode, filp);
/* We refuse fsnotify events on ptmx, since it's a shared resource */
filp->f_mode |= FMODE_NONOTIFY;
retval = tty_alloc_file(filp);
if (retval)
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;
}
mutex_lock(&tty_mutex);
tty_lock();
tty = tty_init_dev(ptm_driver, index, 1);
mutex_unlock(&tty_mutex);
if (IS_ERR(tty)) {
retval = PTR_ERR(tty);
goto out;
}
set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
tty_add_file(tty, filp);
retval = devpts_pty_new(inode, tty->link);
if (retval)
goto err_release;
retval = ptm_driver->ops->open(tty, filp);
if (retval)
goto err_release;
tty_unlock();
return 0;
err_release:
tty_unlock();
tty_release(inode, filp);
return retval;
out:
devpts_kill_index(inode, index);
tty_unlock();
err_file:
tty_free_file(filp);
return retval;
}
static int ptmx_open(struct inode *inode, struct file *filp)
{
struct tty_struct *tty;
struct inode *slave_inode;
int retval;
int index;
nonseekable_open(inode, filp);
/* We refuse fsnotify events on ptmx, since it's a shared resource */
filp->f_mode |= FMODE_NONOTIFY;
retval = tty_alloc_file(filp);
if (retval)
return retval;
/* find a device that is not in use. */
mutex_lock(&devpts_mutex);
index = devpts_new_index(inode);
if (index < 0) {
retval = index;
mutex_unlock(&devpts_mutex);
goto err_file;
}
mutex_unlock(&devpts_mutex);
mutex_lock(&tty_mutex);
tty = tty_init_dev(ptm_driver, index);
if (IS_ERR(tty)) {
retval = PTR_ERR(tty);
goto out;
}
/* The tty returned here is locked so we can safely
drop the mutex */
mutex_unlock(&tty_mutex);
set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
tty->driver_data = inode;
/*
* In the case where all references to ptmx inode are dropped and we
* still have /dev/tty opened pointing to the master/slave pair (ptmx
* is closed/released before /dev/tty), we must make sure that the inode
* is still valid when we call the final pty_unix98_shutdown, thus we
* hold an additional reference to the ptmx inode. For the same /dev/tty
* last close case, we also need to make sure the super_block isn't
* destroyed (devpts instance unmounted), before /dev/tty is closed and
* on its release devpts_kill_index is called.
*/
devpts_add_ref(inode);
tty_add_file(tty, filp);
slave_inode = devpts_pty_new(inode,
MKDEV(UNIX98_PTY_SLAVE_MAJOR, index), index,
tty->link);
if (IS_ERR(slave_inode)) {
retval = PTR_ERR(slave_inode);
goto err_release;
}
tty->link->driver_data = slave_inode;
retval = ptm_driver->ops->open(tty, filp);
if (retval)
goto err_release;
tty_unlock(tty);
return 0;
err_release:
tty_unlock(tty);
tty_release(inode, filp);
return retval;
out:
mutex_unlock(&tty_mutex);
devpts_kill_index(inode, index);
err_file:
tty_free_file(filp);
return retval;
}
static int ptmx_open(struct inode *inode, struct file *filp)
{
struct tty_struct *tty;
struct inode *slave_inode;
int retval;
int index;
nonseekable_open(inode, filp);
/* We refuse fsnotify events on ptmx, since it's a shared resource */
filp->f_mode |= FMODE_NONOTIFY;
retval = tty_alloc_file(filp);
if (retval)
return retval;
/* find a device that is not in use. */
mutex_lock(&devpts_mutex);
index = devpts_new_index(inode);
if (index < 0) {
retval = index;
mutex_unlock(&devpts_mutex);
goto err_file;
}
mutex_unlock(&devpts_mutex);
mutex_lock(&tty_mutex);
tty = tty_init_dev(ptm_driver, index);
if (IS_ERR(tty)) {
retval = PTR_ERR(tty);
goto out;
}
/* The tty returned here is locked so we can safely
drop the mutex */
mutex_unlock(&tty_mutex);
set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
tty->driver_data = inode;
tty_add_file(tty, filp);
slave_inode = devpts_pty_new(inode,
MKDEV(UNIX98_PTY_SLAVE_MAJOR, index), index,
tty->link);
if (IS_ERR(slave_inode)) {
retval = PTR_ERR(slave_inode);
goto err_release;
}
tty->link->driver_data = slave_inode;
retval = ptm_driver->ops->open(tty, filp);
if (retval)
goto err_release;
tty_unlock(tty);
return 0;
err_release:
tty_unlock(tty);
tty_release(inode, filp);
return retval;
out:
mutex_unlock(&tty_mutex);
devpts_kill_index(inode, index);
err_file:
tty_free_file(filp);
return retval;
}
static int ptmx_open(struct inode *inode, struct file *filp)
{
struct pts_fs_info *fsi;
struct tty_struct *tty;
struct dentry *dentry;
int retval;
int index;
nonseekable_open(inode, filp);
/* We refuse fsnotify events on ptmx, since it's a shared resource */
filp->f_mode |= FMODE_NONOTIFY;
retval = tty_alloc_file(filp);
if (retval)
return retval;
fsi = devpts_acquire(filp);
if (IS_ERR(fsi)) {
retval = PTR_ERR(fsi);
goto out_free_file;
}
/* find a device that is not in use. */
mutex_lock(&devpts_mutex);
index = devpts_new_index(fsi);
mutex_unlock(&devpts_mutex);
retval = index;
if (index < 0)
goto out_put_fsi;
mutex_lock(&tty_mutex);
tty = tty_init_dev(ptm_driver, index);
/* The tty returned here is locked so we can safely
drop the mutex */
mutex_unlock(&tty_mutex);
retval = PTR_ERR(tty);
if (IS_ERR(tty))
goto out;
/*
* From here on out, the tty is "live", and the index and
* fsi will be killed/put by the tty_release()
*/
set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
tty->driver_data = fsi;
tty_add_file(tty, filp);
dentry = devpts_pty_new(fsi, index, tty->link);
if (IS_ERR(dentry)) {
retval = PTR_ERR(dentry);
goto err_release;
}
tty->link->driver_data = dentry;
retval = ptm_driver->ops->open(tty, filp);
if (retval)
goto err_release;
tty_debug_hangup(tty, "opening (count=%d)\n", tty->count);
tty_unlock(tty);
return 0;
err_release:
tty_unlock(tty);
// This will also put-ref the fsi
tty_release(inode, filp);
return retval;
out:
devpts_kill_index(fsi, index);
out_put_fsi:
devpts_release(fsi);
out_free_file:
tty_free_file(filp);
return retval;
}