Skip to content

Commit

Permalink
Add an instance parameter devpts interfaces
Browse files Browse the repository at this point in the history 
Pass-in 'inode' or 'tty' parameter to devpts interfaces.  With multiple
devpts instances, these parameters will be used in subsequent patches
to identify the instance of devpts mounted. The parameters also help
simplify devpts implementation.

Changelog[v3]:
	- minor changes due to merge with ttydev updates
	- rename parameters to emphasize they are ptmx or pts inodes
	- pass-in tty_struct * to devpts_pty_kill() (this will help
	  cleanup the get_node() call in a subsequent patch)

Signed-off-by: Sukadev Bhattiprolu <[email protected]>
Signed-off-by: Alan Cox <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
  • Loading branch information
@torvalds
Sukadev Bhattiprolu authored and torvalds committed Oct 13, 2008
1 parent 4a2b5fd commit 15f1a63
Show file tree
Hide file tree
Showing 5 changed files with 47 additions and 30 deletions.
18 changes: 10 additions & 8 deletions drivers/char/pty.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -60,7 +60,7 @@ static void pty_close(struct tty_struct * tty, struct file * filp)
set_bit(TTY_OTHER_CLOSED, &tty->flags);
#ifdef CONFIG_UNIX98_PTYS
if (tty->driver == ptm_driver)
devpts_pty_kill(tty->index);
devpts_pty_kill(tty->link);
#endif
tty_vhangup(tty->link);
}
Expand Down Expand Up @@ -453,9 +453,10 @@ static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file,
* This provides our locking.
*/

static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, int idx)
static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
struct inode *ptm_inode, int idx)
{
struct tty_struct *tty = devpts_get_tty(idx);
struct tty_struct *tty = devpts_get_tty(ptm_inode, idx);
if (tty)
tty = tty->link;
return tty;
Expand All @@ -470,9 +471,10 @@ static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, int idx)
* This provides our locking.
*/

static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, int idx)
static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
struct inode *pts_inode, int idx)
{
struct tty_struct *tty = devpts_get_tty(idx);
struct tty_struct *tty = devpts_get_tty(pts_inode, idx);
/* Master must be open before slave */
if (!tty)
return ERR_PTR(-EIO);
Expand Down Expand Up @@ -602,7 +604,7 @@ static int __ptmx_open(struct inode *inode, struct file *filp)
nonseekable_open(inode, filp);

/* find a device that is not in use. */
index = devpts_new_index();
index = devpts_new_index(inode);
if (index < 0)
return index;

Expand All @@ -619,7 +621,7 @@ static int __ptmx_open(struct inode *inode, struct file *filp)
filp->private_data = tty;
file_move(filp, &tty->tty_files);

retval = devpts_pty_new(tty->link);
retval = devpts_pty_new(inode, tty->link);
if (retval)
goto out1;

Expand All @@ -630,7 +632,7 @@ static int __ptmx_open(struct inode *inode, struct file *filp)
tty_release_dev(filp);
return retval;
out:
devpts_kill_index(index);
devpts_kill_index(inode, index);
return retval;
}

Expand Down
14 changes: 8 additions & 6 deletions drivers/char/tty_io.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1213,12 +1213,13 @@ static void tty_line_name(struct tty_driver *driver, int index, char *p)
* be held until the 'fast-open' is also done. Will change once we
* have refcounting in the driver and per driver locking
*/
struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, int idx)
struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver,
struct inode *inode, int idx)
{
struct tty_struct *tty;

if (driver->ops->lookup)
return driver->ops->lookup(driver, idx);
return driver->ops->lookup(driver, inode, idx);

tty = driver->ttys[idx];
return tty;
Expand Down Expand Up @@ -1539,10 +1540,11 @@ void tty_release_dev(struct file *filp)
int devpts;
int idx;
char buf[64];
struct inode *inode;

inode = filp->f_path.dentry->d_inode;
tty = (struct tty_struct *)filp->private_data;
if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode,
"tty_release_dev"))
if (tty_paranoia_check(tty, inode, "tty_release_dev"))
return;

check_tty_count(tty, "tty_release_dev");
Expand Down Expand Up @@ -1751,7 +1753,7 @@ void tty_release_dev(struct file *filp)

/* Make this pty number available for reallocation */
if (devpts)
devpts_kill_index(idx);
devpts_kill_index(inode, idx);
}

/**
Expand Down Expand Up @@ -1836,7 +1838,7 @@ static int __tty_open(struct inode *inode, struct file *filp)
got_driver:
if (!tty) {
/* check whether we're reopening an existing tty */
tty = tty_driver_lookup_tty(driver, index);
tty = tty_driver_lookup_tty(driver, inode, index);

if (IS_ERR(tty))
return PTR_ERR(tty);
Expand Down
11 changes: 6 additions & 5 deletions fs/devpts/inode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -177,7 +177,7 @@ static struct dentry *get_node(int num)
return lookup_one_len(s, root, sprintf(s, "%d", num));
}

int devpts_new_index(void)
int devpts_new_index(struct inode *ptmx_inode)
{
int index;
int ida_ret;
Expand Down Expand Up @@ -205,14 +205,14 @@ int devpts_new_index(void)
return index;
}

void devpts_kill_index(int idx)
void devpts_kill_index(struct inode *ptmx_inode, int idx)
{
mutex_lock(&allocated_ptys_lock);
ida_remove(&allocated_ptys, idx);
mutex_unlock(&allocated_ptys_lock);
}

int devpts_pty_new(struct tty_struct *tty)
int devpts_pty_new(struct inode *ptmx_inode, struct tty_struct *tty)
{
int number = tty->index; /* tty layer puts index from devpts_new_index() in here */
struct tty_driver *driver = tty->driver;
Expand Down Expand Up @@ -245,7 +245,7 @@ int devpts_pty_new(struct tty_struct *tty)
return 0;
}

struct tty_struct *devpts_get_tty(int number)
struct tty_struct *devpts_get_tty(struct inode *pts_inode, int number)
{
struct dentry *dentry = get_node(number);
struct tty_struct *tty;
Expand All @@ -262,8 +262,9 @@ struct tty_struct *devpts_get_tty(int number)
return tty;
}

void devpts_pty_kill(int number)
void devpts_pty_kill(struct tty_struct *tty)
{
int number = tty->index;
struct dentry *dentry = get_node(number);

if (!IS_ERR(dentry)) {
Expand Down
31 changes: 21 additions & 10 deletions include/linux/devpts_fs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -17,20 +17,31 @@

#ifdef CONFIG_UNIX98_PTYS

int devpts_new_index(void);
void devpts_kill_index(int idx);
int devpts_pty_new(struct tty_struct *tty); /* mknod in devpts */
struct tty_struct *devpts_get_tty(int number); /* get tty structure */
void devpts_pty_kill(int number); /* unlink */
int devpts_new_index(struct inode *ptmx_inode);
void devpts_kill_index(struct inode *ptmx_inode, int idx);
/* mknod in devpts */
int devpts_pty_new(struct inode *ptmx_inode, struct tty_struct *tty);
/* get tty structure */
struct tty_struct *devpts_get_tty(struct inode *pts_inode, int number);
/* unlink */
void devpts_pty_kill(struct tty_struct *tty);

#else

/* Dummy stubs in the no-pty case */
static inline int devpts_new_index(void) { return -EINVAL; }
static inline void devpts_kill_index(int idx) { }
static inline int devpts_pty_new(struct tty_struct *tty) { return -EINVAL; }
static inline struct tty_struct *devpts_get_tty(int number) { return NULL; }
static inline void devpts_pty_kill(int number) { }
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 int devpts_pty_new(struct inode *ptmx_inode,
struct tty_struct *tty)
{
return -EINVAL;
}
static inline struct tty_struct *devpts_get_tty(struct inode *pts_inode,
int number)
{
return NULL;
}
static inline void devpts_pty_kill(struct tty_struct *tty) { }

#endif

Expand Down
3 changes: 2 additions & 1 deletion include/linux/tty_driver.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -225,7 +225,8 @@ struct tty_struct;
struct tty_driver;

struct tty_operations {
struct tty_struct * (*lookup)(struct tty_driver *driver, int idx);
struct tty_struct * (*lookup)(struct tty_driver *driver,
struct inode *inode, int idx);
int (*install)(struct tty_driver *driver, struct tty_struct *tty);
void (*remove)(struct tty_driver *driver, struct tty_struct *tty);
int (*open)(struct tty_struct * tty, struct file * filp);
Expand Down

0 comments on commit 15f1a63

Please sign in to comment.