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tty_lock: Localise the lock

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In each remaining case the tty_lock is associated with a specific tty. This
means we can now lock on a per tty basis. We do need tty_lock_pair() for
the pty case. Uglier but still a step in the right direction.

[fixed up calls in 3 missing drivers - gregkh]

Signed-off-by: Alan Cox <alan@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alan Cox
2012-05-03 22:24:08 +01:00
committed by Greg Kroah-Hartman
parent d739e65bb2
commit d29f3ef39b
15 changed files with 155 additions and 103 deletions
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23
include/linux/tty.h
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@@ -268,6 +268,7 @@ struct tty_struct {
struct mutex ldisc_mutex;
struct tty_ldisc *ldisc;
struct mutex legacy_mutex;
struct mutex termios_mutex;
spinlock_t ctrl_lock;
/* Termios values are protected by the termios mutex */
@@ -605,8 +606,12 @@ extern long vt_compat_ioctl(struct tty_struct *tty,
/* tty_mutex.c */
/* functions for preparation of BKL removal */
extern void __lockfunc tty_lock(void) __acquires(tty_lock);
extern void __lockfunc tty_unlock(void) __releases(tty_lock);
extern void __lockfunc tty_lock(struct tty_struct *tty);
extern void __lockfunc tty_unlock(struct tty_struct *tty);
extern void __lockfunc tty_lock_pair(struct tty_struct *tty,
struct tty_struct *tty2);
extern void __lockfunc tty_unlock_pair(struct tty_struct *tty,
struct tty_struct *tty2);
/*
* this shall be called only from where BTM is held (like close)
@@ -621,9 +626,9 @@ extern void __lockfunc tty_unlock(void) __releases(tty_lock);
static inline void tty_wait_until_sent_from_close(struct tty_struct *tty,
long timeout)
{
tty_unlock(); /* tty->ops->close holds the BTM, drop it while waiting */
tty_unlock(tty); /* tty->ops->close holds the BTM, drop it while waiting */
tty_wait_until_sent(tty, timeout);
tty_lock();
tty_lock(tty);
}
/*
@@ -638,16 +643,16 @@ static inline void tty_wait_until_sent_from_close(struct tty_struct *tty,
*
* Do not use in new code.
*/
#define wait_event_interruptible_tty(wq, condition) \
#define wait_event_interruptible_tty(tty, wq, condition) \
({ \
int __ret = 0; \
if (!(condition)) { \
__wait_event_interruptible_tty(wq, condition, __ret); \
__wait_event_interruptible_tty(tty, wq, condition, __ret); \
} \
__ret; \
})
#define __wait_event_interruptible_tty(wq, condition, ret) \
#define __wait_event_interruptible_tty(tty, wq, condition, ret) \
do { \
DEFINE_WAIT(__wait); \
\
@@ -656,9 +661,9 @@ do { \
if (condition) \
break; \
if (!signal_pending(current)) { \
tty_unlock(); \
tty_unlock(tty); \
schedule(); \
tty_lock(); \
tty_lock(tty); \
continue; \
} \
ret = -ERESTARTSYS; \