diff options
Diffstat (limited to 'drivers/tty/pty.c')
| -rw-r--r-- | drivers/tty/pty.c | 79 |
1 files changed, 37 insertions, 42 deletions
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index e16a49b507ef..cf0dc51a2690 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -626,7 +626,7 @@ static int pty_unix98_ioctl(struct tty_struct *tty, */ static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, - struct inode *ptm_inode, int idx) + struct file *file, int idx) { /* Master must be open via /dev/ptmx */ return ERR_PTR(-EIO); @@ -642,12 +642,12 @@ static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, */ static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, - struct inode *pts_inode, int idx) + struct file *file, int idx) { struct tty_struct *tty; mutex_lock(&devpts_mutex); - tty = devpts_get_priv(pts_inode); + tty = devpts_get_priv(file->f_path.dentry); mutex_unlock(&devpts_mutex); /* Master must be open before slave */ if (!tty) @@ -663,14 +663,14 @@ static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty) /* this is called once with whichever end is closed last */ static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) { - struct inode *ptmx_inode; + struct pts_fs_info *fsi; if (tty->driver->subtype == PTY_TYPE_MASTER) - ptmx_inode = tty->driver_data; + fsi = tty->driver_data; else - ptmx_inode = tty->link->driver_data; - devpts_kill_index(ptmx_inode, tty->index); - devpts_del_ref(ptmx_inode); + fsi = tty->link->driver_data; + devpts_kill_index(fsi, tty->index); + devpts_put_ref(fsi); } static const struct tty_operations ptm_unix98_ops = { @@ -720,8 +720,9 @@ static const struct tty_operations pty_unix98_ops = { static int ptmx_open(struct inode *inode, struct file *filp) { + struct pts_fs_info *fsi; struct tty_struct *tty; - struct inode *slave_inode; + struct dentry *dentry; int retval; int index; @@ -734,54 +735,46 @@ static int ptmx_open(struct inode *inode, struct file *filp) if (retval) return retval; + fsi = devpts_get_ref(inode, filp); + retval = -ENODEV; + if (!fsi) + goto out_free_file; + /* 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; - } - + index = devpts_new_index(fsi); mutex_unlock(&devpts_mutex); - mutex_lock(&tty_mutex); - tty = tty_init_dev(ptm_driver, index); + retval = index; + if (index < 0) + goto out_put_ref; - if (IS_ERR(tty)) { - retval = PTR_ERR(tty); - goto out; - } + 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); - set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ - tty->driver_data = inode; + retval = PTR_ERR(tty); + if (IS_ERR(tty)) + goto out; /* - * 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. + * From here on out, the tty is "live", and the index and + * fsi will be killed/put by the tty_release() */ - devpts_add_ref(inode); + set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ + tty->driver_data = fsi; 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); + dentry = devpts_pty_new(fsi, index, tty->link); + if (IS_ERR(dentry)) { + retval = PTR_ERR(dentry); goto err_release; } - tty->link->driver_data = slave_inode; + tty->link->driver_data = dentry; retval = ptm_driver->ops->open(tty, filp); if (retval) @@ -793,12 +786,14 @@ static int ptmx_open(struct inode *inode, struct file *filp) return 0; err_release: tty_unlock(tty); + // This will also put-ref the fsi tty_release(inode, filp); return retval; out: - mutex_unlock(&tty_mutex); - devpts_kill_index(inode, index); -err_file: + devpts_kill_index(fsi, index); +out_put_ref: + devpts_put_ref(fsi); +out_free_file: tty_free_file(filp); return retval; } |