diff --git a/[refs] b/[refs]
index c17e8d425b38..d3b8e5bdbf05 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: c809406b4f2dfac9006d7eb8dca6b9f990f10b61
+refs/heads/master: 4a0d11fae57989e24fe2ee3eff6d62d72db9716c
diff --git a/trunk/fs/namespace.c b/trunk/fs/namespace.c
index 2019899f2ab8..e5aa1eeb5748 100644
--- a/trunk/fs/namespace.c
+++ b/trunk/fs/namespace.c
@@ -1526,6 +1526,10 @@ static void chroot_fs_refs(struct nameidata *old_nd, struct nameidata *new_nd)
  * pointed to by put_old must yield the same directory as new_root. No other
  * file system may be mounted on put_old. After all, new_root is a mountpoint.
  *
+ * Also, the current root cannot be on the 'rootfs' (initial ramfs) filesystem.
+ * See Documentation/filesystems/ramfs-rootfs-initramfs.txt for alternatives
+ * in this situation.
+ *
  * Notes:
  *  - we don't move root/cwd if they are not at the root (reason: if something
  *    cared enough to change them, it's probably wrong to force them elsewhere)