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Commit 023d43c7 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Peter Zijlstra
Browse files

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: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
LKML-Reference: <1248163763.15751.11098.camel@twins>
parent aea1f796

fs/pipe.c

+2 −2
Original line number Diff line number Diff line
@@ -68,8 +68,8 @@ void pipe_double_lock(struct pipe_inode_info *pipe1, 
		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);

	}

}