TTY: introduce deinit helpers for proper ldisc shutdown

Introduce deinitialize_tty_struct which should be called after
initialize_tty_struct and before successfull tty_ldisc_setup.

It calls tty_ldisc_deinit which is opposite of tty_ldisc_init. It only
puts a reference to ldisc and assigns NULL to tty->ldisc.

It will be used to shut down ldisc when tty_release cannot be called
yet.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Jiri Slaby 2011-03-23 10:48:35 +01:00 committed by Greg Kroah-Hartman
parent c18d77aa00
commit 6716671d8c
3 changed files with 29 additions and 0 deletions

View File

@ -2886,6 +2886,20 @@ void initialize_tty_struct(struct tty_struct *tty,
tty->dev = tty_get_device(tty); tty->dev = tty_get_device(tty);
} }
/**
* deinitialize_tty_struct
* @tty: tty to deinitialize
*
* This subroutine deinitializes a tty structure that has been newly
* allocated but tty_release cannot be called on that yet.
*
* Locking: none - tty in question must not be exposed at this point
*/
void deinitialize_tty_struct(struct tty_struct *tty)
{
tty_ldisc_deinit(tty);
}
/** /**
* tty_put_char - write one character to a tty * tty_put_char - write one character to a tty
* @tty: tty * @tty: tty

View File

@ -956,6 +956,19 @@ void tty_ldisc_init(struct tty_struct *tty)
tty_ldisc_assign(tty, ld); tty_ldisc_assign(tty, ld);
} }
/**
* tty_ldisc_init - ldisc cleanup for new tty
* @tty: tty that was allocated recently
*
* The tty structure must not becompletely set up (tty_ldisc_setup) when
* this call is made.
*/
void tty_ldisc_deinit(struct tty_struct *tty)
{
put_ldisc(tty->ldisc);
tty_ldisc_assign(tty, NULL);
}
void tty_ldisc_begin(void) void tty_ldisc_begin(void)
{ {
/* Setup the default TTY line discipline. */ /* Setup the default TTY line discipline. */

View File

@ -472,6 +472,7 @@ extern int tty_add_file(struct tty_struct *tty, struct file *file);
extern void free_tty_struct(struct tty_struct *tty); extern void free_tty_struct(struct tty_struct *tty);
extern void initialize_tty_struct(struct tty_struct *tty, extern void initialize_tty_struct(struct tty_struct *tty,
struct tty_driver *driver, int idx); struct tty_driver *driver, int idx);
extern void deinitialize_tty_struct(struct tty_struct *tty);
extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx, extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx,
int first_ok); int first_ok);
extern int tty_release(struct inode *inode, struct file *filp); extern int tty_release(struct inode *inode, struct file *filp);
@ -525,6 +526,7 @@ extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);
extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty); extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty); extern void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty);
extern void tty_ldisc_init(struct tty_struct *tty); extern void tty_ldisc_init(struct tty_struct *tty);
extern void tty_ldisc_deinit(struct tty_struct *tty);
extern void tty_ldisc_begin(void); extern void tty_ldisc_begin(void);
/* This last one is just for the tty layer internals and shouldn't be used elsewhere */ /* This last one is just for the tty layer internals and shouldn't be used elsewhere */
extern void tty_ldisc_enable(struct tty_struct *tty); extern void tty_ldisc_enable(struct tty_struct *tty);