ocfs2: give the dlm dirty list a reference on the lockres

Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
index 78eccd0..829cc39 100644
--- a/fs/ocfs2/dlm/dlmcommon.h
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -235,18 +235,26 @@
 	struct qstr lockname;
 	struct kref      refs;
 
-	/* please keep these next 3 in this order
-	 * some funcs want to iterate over all lists */
+	/*
+	 * Please keep granted, converting, and blocked in this order,
+	 * as some funcs want to iterate over all lists.
+	 *
+	 * All four lists are protected by the hash's reference.
+	 */
 	struct list_head granted;
 	struct list_head converting;
 	struct list_head blocked;
+	struct list_head purge;
 
+	/*
+	 * These two lists require you to hold an additional reference
+	 * while they are on the list.
+	 */
 	struct list_head dirty;
 	struct list_head recovering; // dlm_recovery_ctxt.resources list
 
 	/* unused lock resources have their last_used stamped and are
 	 * put on a list for the dlm thread to run. */
-	struct list_head purge;
 	unsigned long    last_used;
 
 	unsigned migration_pending:1;