locking/rwsem: Provide down_write_killable()

[cascardo/linux.git] / kernel / locking / rwsem.c

diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
index 205be0c..c817216 100644 (file)
--- a/kernel/locking/rwsem.c
+++ b/kernel/locking/rwsem.c
@@ -54,6 +54,25 @@ void __sched down_write(struct rw_semaphore *sem)
 
 EXPORT_SYMBOL(down_write);
 
+/*
+ * lock for writing
+ */
+int __sched down_write_killable(struct rw_semaphore *sem)
+{
+       might_sleep();
+       rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_);
+
+       if (LOCK_CONTENDED_RETURN(sem, __down_write_trylock, __down_write_killable)) {
+               rwsem_release(&sem->dep_map, 1, _RET_IP_);
+               return -EINTR;
+       }
+
+       rwsem_set_owner(sem);
+       return 0;
+}
+
+EXPORT_SYMBOL(down_write_killable);
+
 /*
  * trylock for writing -- returns 1 if successful, 0 if contention
  */