lockdep: annotate journal_start()

On Fri, 2007-07-13 at 02:05 -0700, Andrew Morton wrote:

> Except lockdep doesn't know about journal_start(), which has ranking
> requirements similar to a semaphore.  

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/jbd.h b/include/linux/jbd.h
index 4527375..700a93b 100644
--- a/include/linux/jbd.h
+++ b/include/linux/jbd.h
@@ -30,6 +30,7 @@
 #include <linux/bit_spinlock.h>
 #include <linux/mutex.h>
 #include <linux/timer.h>
+#include <linux/lockdep.h>
 
 #include <asm/semaphore.h>
 #endif
@@ -396,6 +397,10 @@
 	unsigned int	h_sync:		1;	/* sync-on-close */
 	unsigned int	h_jdata:	1;	/* force data journaling */
 	unsigned int	h_aborted:	1;	/* fatal error on handle */
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map	h_lockdep_map;
+#endif
 };