Introduce down_killable()
down_killable() is the functional counterpart of mutex_lock_killable.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
diff --git a/kernel/semaphore.c b/kernel/semaphore.c
index d5a7270..2da2aed 100644
--- a/kernel/semaphore.c
+++ b/kernel/semaphore.c
@@ -34,6 +34,7 @@
static noinline void __down(struct semaphore *sem);
static noinline int __down_interruptible(struct semaphore *sem);
+static noinline int __down_killable(struct semaphore *sem);
static noinline void __up(struct semaphore *sem);
void down(struct semaphore *sem)
@@ -61,6 +62,20 @@
}
EXPORT_SYMBOL(down_interruptible);
+int down_killable(struct semaphore *sem)
+{
+ unsigned long flags;
+ int result = 0;
+
+ spin_lock_irqsave(&sem->lock, flags);
+ if (unlikely(sem->count-- <= 0))
+ result = __down_killable(sem);
+ spin_unlock_irqrestore(&sem->lock, flags);
+
+ return result;
+}
+EXPORT_SYMBOL(down_killable);
+
/**
* down_trylock - try to acquire the semaphore, without waiting
* @sem: the semaphore to be acquired
@@ -143,6 +158,8 @@
for (;;) {
if (state == TASK_INTERRUPTIBLE && signal_pending(task))
goto interrupted;
+ if (state == TASK_KILLABLE && fatal_signal_pending(task))
+ goto interrupted;
__set_task_state(task, state);
spin_unlock_irq(&sem->lock);
schedule();
@@ -178,6 +195,11 @@
return __down_common(sem, TASK_INTERRUPTIBLE);
}
+static noinline int __sched __down_killable(struct semaphore *sem)
+{
+ return __down_common(sem, TASK_KILLABLE);
+}
+
static noinline void __sched __up(struct semaphore *sem)
{
if (unlikely(list_empty(&sem->wait_list)))
