diff --git a/[refs] b/[refs]
index b2aea5ecab41..4be9be0fd122 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 9b6e31021122babe3b3a67b102479f740928b5eb
+refs/heads/master: 8ad08d8a0c3823e9b06ef84c362c9361be323d2d
diff --git a/trunk/fs/namespace.c b/trunk/fs/namespace.c
index 7d70d63ceb29..461090a57b33 100644
--- a/trunk/fs/namespace.c
+++ b/trunk/fs/namespace.c
@@ -965,10 +965,12 @@ EXPORT_SYMBOL(may_umount_tree);
 int may_umount(struct vfsmount *mnt)
 {
 	int ret = 1;
+	down_read(&namespace_sem);
 	spin_lock(&vfsmount_lock);
 	if (propagate_mount_busy(mnt, 2))
 		ret = 0;
 	spin_unlock(&vfsmount_lock);
+	up_read(&namespace_sem);
 	return ret;
 }