diff --git a/fs/namespace.c b/fs/namespace.c
index 25c1dcf..d25d460 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1538,7 +1538,7 @@
 		err = do_remount_sb(sb, flags, data, 0);
 	if (!err) {
 		spin_lock(&vfsmount_lock);
-		mnt_flags |= path->mnt->mnt_flags & MNT_PNODE_MASK;
+		mnt_flags |= path->mnt->mnt_flags & MNT_PROPAGATION_MASK;
 		path->mnt->mnt_flags = mnt_flags;
 		spin_unlock(&vfsmount_lock);
 	}
diff --git a/fs/pnode.h b/fs/pnode.h
index 6c7ef32..1ea4ae1e 100644
--- a/fs/pnode.h
+++ b/fs/pnode.h
@@ -25,7 +25,7 @@
 
 static inline void set_mnt_shared(struct vfsmount *mnt)
 {
-	mnt->mnt_flags &= ~MNT_PNODE_MASK;
+	mnt->mnt_flags &= ~MNT_SHARED_MASK;
 	mnt->mnt_flags |= MNT_SHARED;
 }
 
diff --git a/include/linux/mount.h b/include/linux/mount.h
index 5d52753..375d43a 100644
--- a/include/linux/mount.h
+++ b/include/linux/mount.h
@@ -34,7 +34,16 @@
 
 #define MNT_SHARED	0x1000	/* if the vfsmount is a shared mount */
 #define MNT_UNBINDABLE	0x2000	/* if the vfsmount is a unbindable mount */
-#define MNT_PNODE_MASK	0x3000	/* propagation flag mask */
+/*
+ * MNT_SHARED_MASK is the set of flags that should be cleared when a
+ * mount becomes shared.  Currently, this is only the flag that says a
+ * mount cannot be bind mounted, since this is how we create a mount
+ * that shares events with another mount.  If you add a new MNT_*
+ * flag, consider how it interacts with shared mounts.
+ */
+#define MNT_SHARED_MASK	(MNT_UNBINDABLE)
+#define MNT_PROPAGATION_MASK	(MNT_SHARED | MNT_UNBINDABLE)
+
 
 struct vfsmount {
 	struct list_head mnt_hash;