diff --git a/fs/pnode.h b/fs/pnode.h
index 9b88ba0..b59f0e9 100644
--- a/fs/pnode.h
+++ b/fs/pnode.h
@@ -12,10 +12,12 @@
 #include <linux/mount.h>
 
 #define IS_MNT_SHARED(mnt) (mnt->mnt_flags & MNT_SHARED)
+#define IS_MNT_SLAVE(mnt) (mnt->mnt_master)
 #define IS_MNT_NEW(mnt)  (!mnt->mnt_namespace)
 #define CLEAR_MNT_SHARED(mnt) (mnt->mnt_flags &= ~MNT_SHARED)
 
 #define CL_EXPIRE    		0x01
+#define CL_SLAVE     		0x02
 #define CL_COPY_ALL 		0x04
 #define CL_MAKE_SHARED 		0x08
 #define CL_PROPAGATION 		0x10