From ad776537cc6b4b936cfd11893e7b698dfa072666 Mon Sep 17 00:00:00 2001
From: "Liam R. Howlett" <howlett@gmail.com>
Date: Thu, 6 Dec 2007 17:37:59 -0500
Subject: [PATCH] Add mutex_lock_killable
Similar to mutex_lock_interruptible, it can be interrupted by a fatal
signal only.
Signed-off-by: Liam R. Howlett <howlett@gmail.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
---
include/linux/mutex.h | 5 +++++
kernel/mutex.c | 36 +++++++++++++++++++++++++++++++++---
2 files changed, 38 insertions(+), 3 deletions(-)
diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index 601479772b98..05c590352dd7 100644
--- a/include/linux/mutex.h
+++ b/include/linux/mutex.h
@@ -125,15 +125,20 @@ static inline int fastcall mutex_is_locked(struct mutex *lock)
extern void mutex_lock_nested(struct mutex *lock, unsigned int subclass);
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,
+ unsigned int subclass);
#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)
#else
extern void fastcall mutex_lock(struct mutex *lock);
extern int __must_check fastcall mutex_lock_interruptible(struct mutex *lock);
+extern int __must_check fastcall 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)
#endif
/*
diff --git a/kernel/mutex.c b/kernel/mutex.c
index d7fe50cc556f..d9ec9b666250 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -166,9 +166,12 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
* got a signal? (This code gets eliminated in the
* TASK_UNINTERRUPTIBLE case.)
*/
- if (unlikely(state == TASK_INTERRUPTIBLE &&
- signal_pending(task))) {
- mutex_remove_waiter(lock, &waiter, task_thread_info(task));
+ if (unlikely((state == TASK_INTERRUPTIBLE &&
+ signal_pending(task)) ||
+ (state == TASK_KILLABLE &&
+ fatal_signal_pending(task)))) {
+ mutex_remove_waiter(lock, &waiter,
+ task_thread_info(task));
mutex_release(&lock->dep_map, 1, ip);
spin_unlock_mutex(&lock->wait_lock, flags);
@@ -210,6 +213,14 @@ mutex_lock_nested(struct mutex *lock, unsigned int subclass)
EXPORT_SYMBOL_GPL(mutex_lock_nested);
+int __sched
+mutex_lock_killable_nested(struct mutex *lock, unsigned int subclass)
+{
+ might_sleep();
+ return __mutex_lock_common(lock, TASK_KILLABLE, subclass, _RET_IP_);
+}
+EXPORT_SYMBOL_GPL(mutex_lock_killable_nested);
+
int __sched
mutex_lock_interruptible_nested(struct mutex *lock, unsigned int subclass)
{
@@ -272,6 +283,9 @@ __mutex_unlock_slowpath(atomic_t *lock_count)
* mutex_lock_interruptible() and mutex_trylock().
*/
static int fastcall noinline __sched
+__mutex_lock_killable_slowpath(atomic_t *lock_count);
+
+static noinline int fastcall __sched
__mutex_lock_interruptible_slowpath(atomic_t *lock_count);
/***
@@ -294,6 +308,14 @@ int fastcall __sched mutex_lock_interruptible(struct mutex *lock)
EXPORT_SYMBOL(mutex_lock_interruptible);
+int fastcall __sched mutex_lock_killable(struct mutex *lock)
+{
+ might_sleep();
+ return __mutex_fastpath_lock_retval
+ (&lock->count, __mutex_lock_killable_slowpath);
+}
+EXPORT_SYMBOL(mutex_lock_killable);
+
static void fastcall noinline __sched
__mutex_lock_slowpath(atomic_t *lock_count)
{
@@ -303,6 +325,14 @@ __mutex_lock_slowpath(atomic_t *lock_count)
}
static int fastcall noinline __sched
+__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_);
+}
+
+static noinline int fastcall __sched
__mutex_lock_interruptible_slowpath(atomic_t *lock_count)
{
struct mutex *lock = container_of(lock_count, struct mutex, count);
--
2.34.1