Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/Documentation/filesystems/ext4/index.rst b/Documentation/filesystems/ext4/index.rst
index 7112160..705d813 100644
--- a/Documentation/filesystems/ext4/index.rst
+++ b/Documentation/filesystems/ext4/index.rst
@@ -1,17 +1,14 @@
 .. SPDX-License-Identifier: GPL-2.0
 
-===============
-ext4 Filesystem
-===============
-
-General usage and on-disk artifacts writen by ext4.  More documentation may
-be ported from the wiki as time permits.  This should be considered the
-canonical source of information as the details here have been reviewed by
-the ext4 community.
+===================================
+ext4 Data Structures and Algorithms
+===================================
 
 .. toctree::
-   :maxdepth: 5
+   :maxdepth: 6
    :numbered:
 
-   ext4
-   ondisk/index
+   about
+   overview
+   globals
+   dynamic