TTY: devpts, do not set driver_data

The goal is to stop setting and using tty->driver_data in devpts code.
It should be used solely by the driver's code, pty in this case.

Now driver_data are managed only in the pty driver. devpts_pty_new is
switched to accept what we used to dig out of tty_struct, i.e. device
node number and index.

This also removes a note about driver_data being set outside of the
driver.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jiri Slaby 2012-10-18 22:26:29 +02:00 committed by Greg Kroah-Hartman
parent 162b97cfa2
commit f11afb6124
3 changed files with 16 additions and 24 deletions

View file

@ -4,9 +4,6 @@
* Added support for a Unix98-style ptmx device.
* -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
*
* When reading this code see also fs/devpts. In particular note that the
* driver_data field is used by the devpts side as a binding to the devpts
* inode.
*/
#include <linux/module.h>
@ -59,7 +56,7 @@ static void pty_close(struct tty_struct *tty, struct file *filp)
#ifdef CONFIG_UNIX98_PTYS
if (tty->driver == ptm_driver) {
mutex_lock(&devpts_mutex);
devpts_pty_kill(tty->link);
devpts_pty_kill(tty->link->driver_data);
mutex_unlock(&devpts_mutex);
}
#endif
@ -651,7 +648,9 @@ static int ptmx_open(struct inode *inode, struct file *filp)
tty_add_file(tty, filp);
slave_inode = devpts_pty_new(inode, tty->link);
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;
@ -662,6 +661,7 @@ static int ptmx_open(struct inode *inode, struct file *filp)
goto err_release;
tty_unlock(tty);
tty->link->driver_data = slave_inode;
return 0;
err_release:
tty_unlock(tty);

View file

@ -545,12 +545,9 @@ void devpts_kill_index(struct inode *ptmx_inode, int idx)
mutex_unlock(&allocated_ptys_lock);
}
struct inode *devpts_pty_new(struct inode *ptmx_inode, struct tty_struct *tty)
struct inode *devpts_pty_new(struct inode *ptmx_inode, dev_t device, int index,
void *priv)
{
/* tty layer puts index from devpts_new_index() in here */
int number = tty->index;
struct tty_driver *driver = tty->driver;
dev_t device = MKDEV(driver->major, driver->minor_start+number);
struct dentry *dentry;
struct super_block *sb = pts_sb_from_inode(ptmx_inode);
struct inode *inode;
@ -559,23 +556,18 @@ struct inode *devpts_pty_new(struct inode *ptmx_inode, struct tty_struct *tty)
struct pts_mount_opts *opts = &fsi->mount_opts;
char s[12];
/* We're supposed to be given the slave end of a pty */
BUG_ON(driver->type != TTY_DRIVER_TYPE_PTY);
BUG_ON(driver->subtype != PTY_TYPE_SLAVE);
inode = new_inode(sb);
if (!inode)
return ERR_PTR(-ENOMEM);
inode->i_ino = number + 3;
inode->i_ino = index + 3;
inode->i_uid = opts->setuid ? opts->uid : current_fsuid();
inode->i_gid = opts->setgid ? opts->gid : current_fsgid();
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
init_special_inode(inode, S_IFCHR|opts->mode, device);
inode->i_private = tty;
tty->driver_data = inode;
inode->i_private = priv;
sprintf(s, "%d", number);
sprintf(s, "%d", index);
mutex_lock(&root->d_inode->i_mutex);
@ -613,9 +605,8 @@ void *devpts_get_priv(struct inode *pts_inode)
return priv;
}
void devpts_pty_kill(struct tty_struct *tty)
void devpts_pty_kill(struct inode *inode)
{
struct inode *inode = tty->driver_data;
struct super_block *sb = pts_sb_from_inode(inode);
struct dentry *root = sb->s_root;
struct dentry *dentry;

View file

@ -20,11 +20,12 @@
int devpts_new_index(struct inode *ptmx_inode);
void devpts_kill_index(struct inode *ptmx_inode, int idx);
/* mknod in devpts */
struct inode *devpts_pty_new(struct inode *ptmx_inode, struct tty_struct *tty);
struct inode *devpts_pty_new(struct inode *ptmx_inode, dev_t device, int index,
void *priv);
/* get private structure */
void *devpts_get_priv(struct inode *pts_inode);
/* unlink */
void devpts_pty_kill(struct tty_struct *tty);
void devpts_pty_kill(struct inode *inode);
#else
@ -32,7 +33,7 @@ void devpts_pty_kill(struct tty_struct *tty);
static inline int devpts_new_index(struct inode *ptmx_inode) { return -EINVAL; }
static inline void devpts_kill_index(struct inode *ptmx_inode, int idx) { }
static inline struct inode *devpts_pty_new(struct inode *ptmx_inode,
struct tty_struct *tty)
dev_t device, int index, void *priv)
{
return ERR_PTR(-EINVAL);
}
@ -40,7 +41,7 @@ static inline void *devpts_get_priv(struct inode *pts_inode)
{
return NULL;
}
static inline void devpts_pty_kill(struct tty_struct *tty) { }
static inline void devpts_pty_kill(struct inode *inode) { }
#endif