lockdep: Fix lockdep annotation for pipe_double_lock()
The presumed use of the pipe_double_lock() routine is to lock 2 locks in
a deadlock free way by ordering the locks by their address. However it
fails to keep the specified lock classes in order and explicitly
annotates a deadlock.
Rectify this.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Miklos Szeredi <mszeredi@suse.cz>
LKML-Reference: <1248163763.15751.11098.camel@twins>
diff --git a/fs/pipe.c b/fs/pipe.c
index f7dd21a..52c4151 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -68,8 +68,8 @@
pipe_lock_nested(pipe1, I_MUTEX_PARENT);
pipe_lock_nested(pipe2, I_MUTEX_CHILD);
} else {
- pipe_lock_nested(pipe2, I_MUTEX_CHILD);
- pipe_lock_nested(pipe1, I_MUTEX_PARENT);
+ pipe_lock_nested(pipe2, I_MUTEX_PARENT);
+ pipe_lock_nested(pipe1, I_MUTEX_CHILD);
}
}