dlm: delayed reply message warning

Add an option (disabled by default) to print a warning message
when a lock has been waiting a configurable amount of time for
a reply message from another node.  This is mainly for debugging.

Signed-off-by: David Teigland <teigland@redhat.com>
diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
index b942049..6a92478 100644
--- a/fs/dlm/dlm_internal.h
+++ b/fs/dlm/dlm_internal.h
@@ -245,6 +245,7 @@
 
 	int8_t			lkb_wait_type;	/* type of reply waiting for */
 	int8_t			lkb_wait_count;
+	int			lkb_wait_nodeid; /* for debugging */
 
 	struct list_head	lkb_idtbl_list;	/* lockspace lkbtbl */
 	struct list_head	lkb_statequeue;	/* rsb g/c/w list */
@@ -254,6 +255,7 @@
 	struct list_head	lkb_ownqueue;	/* list of locks for a process */
 	struct list_head	lkb_time_list;
 	ktime_t			lkb_timestamp;
+	ktime_t			lkb_wait_time;
 	unsigned long		lkb_timeout_cs;
 
 	struct dlm_callback	lkb_callbacks[DLM_CALLBACKS_SIZE];