From e4c70a6629f9c74c4b0de258a3951890e9047c82 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 24 May 2011 17:12:03 -0700 Subject: [PATCH] lockdep, mutex: provide mutex_lock_nest_lock In order to convert i_mmap_lock to a mutex we need a mutex equivalent to spin_lock_nest_lock(), thus provide the mutex_lock_nest_lock() annotation. As with spin_lock_nest_lock(), mutex_lock_nest_lock() allows annotation of the locking pattern where an outer lock serializes the acquisition order of nested locks. That is, if every time you lock multiple locks A, say A1 and A2 you first acquire N, the order of acquiring A1 and A2 is irrelevant. Signed-off-by: Peter Zijlstra Cc: Benjamin Herrenschmidt Cc: David Miller Cc: Martin Schwidefsky Cc: Russell King Cc: Paul Mundt Cc: Jeff Dike Cc: Richard Weinberger Cc: Tony Luck Cc: KAMEZAWA Hiroyuki Cc: Hugh Dickins Cc: Mel Gorman Cc: KOSAKI Motohiro Cc: Nick Piggin Cc: Namhyung Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/lockdep.h | 3 +++ include/linux/mutex.h | 9 +++++++++ kernel/mutex.c | 25 +++++++++++++++++-------- 3 files changed, 29 insertions(+), 8 deletions(-) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 4aef1dda640..ef820a3c378 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -487,12 +487,15 @@ static inline void print_irqtrace_events(struct task_struct *curr) #ifdef CONFIG_DEBUG_LOCK_ALLOC # ifdef CONFIG_PROVE_LOCKING # define mutex_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, NULL, i) +# define mutex_acquire_nest(l, s, t, n, i) lock_acquire(l, s, t, 0, 2, n, i) # else # define mutex_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, NULL, i) +# define mutex_acquire_nest(l, s, t, n, i) lock_acquire(l, s, t, 0, 1, n, i) # endif # define mutex_release(l, n, i) lock_release(l, n, i) #else # define mutex_acquire(l, s, t, i) do { } while (0) +# define mutex_acquire_nest(l, s, t, n, i) do { } while (0) # define mutex_release(l, n, i) do { } while (0) #endif diff --git a/include/linux/mutex.h b/include/linux/mutex.h index c75471db576..a940fe435ac 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -132,6 +132,7 @@ static inline int mutex_is_locked(struct mutex *lock) */ #ifdef CONFIG_DEBUG_LOCK_ALLOC extern void mutex_lock_nested(struct mutex *lock, unsigned int subclass); +extern void _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest_lock); extern int __must_check mutex_lock_interruptible_nested(struct mutex *lock, unsigned int subclass); extern int __must_check mutex_lock_killable_nested(struct mutex *lock, @@ -140,6 +141,13 @@ extern int __must_check mutex_lock_killable_nested(struct mutex *lock, #define mutex_lock(lock) mutex_lock_nested(lock, 0) #define mutex_lock_interruptible(lock) mutex_lock_interruptible_nested(lock, 0) #define mutex_lock_killable(lock) mutex_lock_killable_nested(lock, 0) + +#define mutex_lock_nest_lock(lock, nest_lock) \ +do { \ + typecheck(struct lockdep_map *, &(nest_lock)->dep_map); \ + _mutex_lock_nest_lock(lock, &(nest_lock)->dep_map); \ +} while (0) + #else extern void mutex_lock(struct mutex *lock); extern int __must_check mutex_lock_interruptible(struct mutex *lock); @@ -148,6 +156,7 @@ extern int __must_check mutex_lock_killable(struct mutex *lock); # define mutex_lock_nested(lock, subclass) mutex_lock(lock) # define mutex_lock_interruptible_nested(lock, subclass) mutex_lock_interruptible(lock) # define mutex_lock_killable_nested(lock, subclass) mutex_lock_killable(lock) +# define mutex_lock_nest_lock(lock, nest_lock) mutex_lock(lock) #endif /* diff --git a/kernel/mutex.c b/kernel/mutex.c index 2c938e2337c..d607ed5dd44 100644 --- a/kernel/mutex.c +++ b/kernel/mutex.c @@ -131,14 +131,14 @@ EXPORT_SYMBOL(mutex_unlock); */ static inline int __sched __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, - unsigned long ip) + struct lockdep_map *nest_lock, unsigned long ip) { struct task_struct *task = current; struct mutex_waiter waiter; unsigned long flags; preempt_disable(); - mutex_acquire(&lock->dep_map, subclass, 0, ip); + mutex_acquire_nest(&lock->dep_map, subclass, 0, nest_lock, ip); #ifdef CONFIG_MUTEX_SPIN_ON_OWNER /* @@ -269,16 +269,25 @@ void __sched mutex_lock_nested(struct mutex *lock, unsigned int subclass) { might_sleep(); - __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, subclass, _RET_IP_); + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, subclass, NULL, _RET_IP_); } EXPORT_SYMBOL_GPL(mutex_lock_nested); +void __sched +_mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest) +{ + might_sleep(); + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0, nest, _RET_IP_); +} + +EXPORT_SYMBOL_GPL(_mutex_lock_nest_lock); + int __sched mutex_lock_killable_nested(struct mutex *lock, unsigned int subclass) { might_sleep(); - return __mutex_lock_common(lock, TASK_KILLABLE, subclass, _RET_IP_); + return __mutex_lock_common(lock, TASK_KILLABLE, subclass, NULL, _RET_IP_); } EXPORT_SYMBOL_GPL(mutex_lock_killable_nested); @@ -287,7 +296,7 @@ mutex_lock_interruptible_nested(struct mutex *lock, unsigned int subclass) { might_sleep(); return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, - subclass, _RET_IP_); + subclass, NULL, _RET_IP_); } EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested); @@ -393,7 +402,7 @@ __mutex_lock_slowpath(atomic_t *lock_count) { struct mutex *lock = container_of(lock_count, struct mutex, count); - __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0, _RET_IP_); + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0, NULL, _RET_IP_); } static noinline int __sched @@ -401,7 +410,7 @@ __mutex_lock_killable_slowpath(atomic_t *lock_count) { struct mutex *lock = container_of(lock_count, struct mutex, count); - return __mutex_lock_common(lock, TASK_KILLABLE, 0, _RET_IP_); + return __mutex_lock_common(lock, TASK_KILLABLE, 0, NULL, _RET_IP_); } static noinline int __sched @@ -409,7 +418,7 @@ __mutex_lock_interruptible_slowpath(atomic_t *lock_count) { struct mutex *lock = container_of(lock_count, struct mutex, count); - return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0, _RET_IP_); + return __mutex_lock_common(lock, TASK_INTERRUPTIBLE, 0, NULL, _RET_IP_); } #endif -- 2.20.1