[PATCH] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS

[Waiman Long]

It was found that the use of up_read_non_owner() in NFS was causing
the following warning when DEBUG_RWSEMS was configured.

  DEBUG_LOCKS_WARN_ON(sem->owner != ((struct task_struct *)(1UL << 0)))

Looking into the rwsem.c file, it was discovered that the corresponding
down_read_non_owner() function was not setting the owner field properly.
This is fixed now, and the warning should be gone.

Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
---
 kernel/locking/rwsem.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
index bc1e507..776308d 100644
--- a/kernel/locking/rwsem.c
+++ b/kernel/locking/rwsem.c
@@ -181,6 +181,7 @@ void down_read_non_owner(struct rw_semaphore *sem)
 	might_sleep();
 
 	__down_read(sem);
+	rwsem_set_reader_owned(sem);
 }
 
 EXPORT_SYMBOL(down_read_non_owner);
-- 
1.8.3.1