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-rw-r--r--include/linux/rwsem.h1
-rw-r--r--kernel/locking/rwsem-xadd.c33
2 files changed, 31 insertions, 3 deletions
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index dd1d14250340..0ad7318ff299 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -44,6 +44,7 @@ struct rw_semaphore {
};
extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
+extern struct rw_semaphore *rwsem_down_read_failed_killable(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_down_write_failed_killable(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *);
diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index 34e727f18e49..02f660666ab8 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -221,8 +221,8 @@ static void __rwsem_mark_wake(struct rw_semaphore *sem,
/*
* Wait for the read lock to be granted
*/
-__visible
-struct rw_semaphore __sched *rwsem_down_read_failed(struct rw_semaphore *sem)
+static inline struct rw_semaphore __sched *
+__rwsem_down_read_failed_common(struct rw_semaphore *sem, int state)
{
long count, adjustment = -RWSEM_ACTIVE_READ_BIAS;
struct rwsem_waiter waiter;
@@ -255,17 +255,44 @@ struct rw_semaphore __sched *rwsem_down_read_failed(struct rw_semaphore *sem)
/* wait to be given the lock */
while (true) {
- set_current_state(TASK_UNINTERRUPTIBLE);
+ set_current_state(state);
if (!waiter.task)
break;
+ if (signal_pending_state(state, current)) {
+ raw_spin_lock_irq(&sem->wait_lock);
+ if (waiter.task)
+ goto out_nolock;
+ raw_spin_unlock_irq(&sem->wait_lock);
+ break;
+ }
schedule();
}
__set_current_state(TASK_RUNNING);
return sem;
+out_nolock:
+ list_del(&waiter.list);
+ if (list_empty(&sem->wait_list))
+ atomic_long_add(-RWSEM_WAITING_BIAS, &sem->count);
+ raw_spin_unlock_irq(&sem->wait_lock);
+ __set_current_state(TASK_RUNNING);
+ return ERR_PTR(-EINTR);
+}
+
+__visible struct rw_semaphore * __sched
+rwsem_down_read_failed(struct rw_semaphore *sem)
+{
+ return __rwsem_down_read_failed_common(sem, TASK_UNINTERRUPTIBLE);
}
EXPORT_SYMBOL(rwsem_down_read_failed);
+__visible struct rw_semaphore * __sched
+rwsem_down_read_failed_killable(struct rw_semaphore *sem)
+{
+ return __rwsem_down_read_failed_common(sem, TASK_KILLABLE);
+}
+EXPORT_SYMBOL(rwsem_down_read_failed_killable);
+
/*
* This function must be called with the sem->wait_lock held to prevent
* race conditions between checking the rwsem wait list and setting the