Commit 4ea3cd65 authored by Uwe Kleine-König's avatar Uwe Kleine-König Committed by Greg Kroah-Hartman
Browse files

tty: rename tty_kopen() and add new function tty_kopen_shared() 



Introduce a new function tty_kopen_shared() that yields a struct
tty_struct. The semantic difference to tty_kopen() is that the tty is
expected to be used already. So rename tty_kopen() to
tty_kopen_exclusive() for clearness, adapt the single user and put the
common code in a new static helper function.

tty_kopen_shared is to be used to implement an LED trigger for tty
devices in one of the next patches.

Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20201218104246.591315-2-u.kleine-koenig@pengutronix.de


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 5c8fe583

drivers/accessibility/speakup/spk_ttyio.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -152,7 +152,7 @@ static int spk_ttyio_initialise_ldisc(struct spk_synth *synth) 
	if (ret)

	if (ret)

		return ret;

		return ret;





	tty = tty_kopen(dev);

	tty = tty_kopen_exclusive(dev);

	if (IS_ERR(tty))

	if (IS_ERR(tty))

		return PTR_ERR(tty);

		return PTR_ERR(tty);

drivers/tty/tty_io.c

+38 −18
Original line number Original line Diff line number Diff line
@@ -1875,22 +1875,7 @@ static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, 
	return driver;

	return driver;

}

}





/**

static struct tty_struct *tty_kopen(dev_t device, int shared)

 *	tty_kopen	-	open a tty device for kernel

 *	@device: dev_t of device to open

 *

 *	Opens tty exclusively for kernel. Performs the driver lookup,

 *	makes sure it's not already opened and performs the first-time

 *	tty initialization.

 *

 *	Returns the locked initialized &tty_struct

 *

 *	Claims the global tty_mutex to serialize:

 *	  - concurrent first-time tty initialization

 *	  - concurrent tty driver removal w/ lookup

 *	  - concurrent tty removal from driver table

 */

struct tty_struct *tty_kopen(dev_t device)

{

{

	struct tty_struct *tty;

	struct tty_struct *tty;

	struct tty_driver *driver;

	struct tty_driver *driver;
@@ -1905,7 +1890,7 @@ struct tty_struct *tty_kopen(dev_t device) 




	/* check whether we're reopening an existing tty */

	/* check whether we're reopening an existing tty */

	tty = tty_driver_lookup_tty(driver, NULL, index);

	tty = tty_driver_lookup_tty(driver, NULL, index);

	if (IS_ERR(tty))

	if (IS_ERR(tty) || shared)

		goto out;

		goto out;





	if (tty) {

	if (tty) {
@@ -1923,7 +1908,42 @@ struct tty_struct *tty_kopen(dev_t device) 
	tty_driver_kref_put(driver);

	tty_driver_kref_put(driver);

	return tty;

	return tty;

}

}

EXPORT_SYMBOL_GPL(tty_kopen);



/**

 *	tty_kopen_exclusive	-	open a tty device for kernel

 *	@device: dev_t of device to open

 *

 *	Opens tty exclusively for kernel. Performs the driver lookup,

 *	makes sure it's not already opened and performs the first-time

 *	tty initialization.

 *

 *	Returns the locked initialized &tty_struct

 *

 *	Claims the global tty_mutex to serialize:

 *	  - concurrent first-time tty initialization

 *	  - concurrent tty driver removal w/ lookup

 *	  - concurrent tty removal from driver table

 */

struct tty_struct *tty_kopen_exclusive(dev_t device)

{

	return tty_kopen(device, 0);

}

EXPORT_SYMBOL_GPL(tty_kopen_exclusive);



/**

 *	tty_kopen_shared	-	open a tty device for shared in-kernel use

 *	@device: dev_t of device to open

 *

 *	Opens an already existing tty for in-kernel use. Compared to

 *	tty_kopen_exclusive() above it doesn't ensure to be the only user.

 *

 *	Locking is identical to tty_kopen() above.

 */

struct tty_struct *tty_kopen_shared(dev_t device)

{

	return tty_kopen(device, 1);

}

EXPORT_SYMBOL_GPL(tty_kopen_shared);





/**

/**

 *	tty_open_by_driver	-	open a tty device

 *	tty_open_by_driver	-	open a tty device

include/linux/tty.h

+3 −2
Original line number Original line Diff line number Diff line
@@ -416,7 +416,8 @@ extern struct tty_struct *get_current_tty(void); 
/* tty_io.c */

/* tty_io.c */

extern int __init tty_init(void);

extern int __init tty_init(void);

extern const char *tty_name(const struct tty_struct *tty);

extern const char *tty_name(const struct tty_struct *tty);

extern struct tty_struct *tty_kopen(dev_t device);

extern struct tty_struct *tty_kopen_exclusive(dev_t device);

extern struct tty_struct *tty_kopen_shared(dev_t device);

extern void tty_kclose(struct tty_struct *tty);

extern void tty_kclose(struct tty_struct *tty);

extern int tty_dev_name_to_number(const char *name, dev_t *number);

extern int tty_dev_name_to_number(const char *name, dev_t *number);

extern int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout);

extern int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout);
@@ -441,7 +442,7 @@ static inline int __init tty_init(void) 
{ return 0; }

{ return 0; }

static inline const char *tty_name(const struct tty_struct *tty)

static inline const char *tty_name(const struct tty_struct *tty)

{ return "(none)"; }

{ return "(none)"; }

static inline struct tty_struct *tty_kopen(dev_t device)

static inline struct tty_struct *tty_kopen_exclusive(dev_t device)

{ return ERR_PTR(-ENODEV); }

{ return ERR_PTR(-ENODEV); }

static inline void tty_kclose(struct tty_struct *tty)

static inline void tty_kclose(struct tty_struct *tty)

{ }

{ }