docs: fix up the obviously obsolete bits in the new ext4 documentation

found at the ext4 wiki site at the URL:

http://ext4.wiki.kernel.org/index.php/Ext4_Howto

  - Compile and install the latest version of e2fsprogs (as of this

    writing version 1.41.3) from:

  - The latest version of e2fsprogs can be found at:

    http://sourceforge.net/project/showfiles.php?group_id=2406

    https://www.kernel.org/pub/linux/kernel/people/tytso/e2fsprogs/

	or

    https://www.kernel.org/pub/linux/kernel/people/tytso/e2fsprogs/

    http://sourceforge.net/project/showfiles.php?group_id=2406

	or grab the latest git repository from:

    git://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git

  - Note that it is highly important to install the mke2fs.conf file

    that comes with the e2fsprogs 1.41.x sources in /etc/mke2fs.conf. If

    you have edited the /etc/mke2fs.conf file installed on your system,

    you will need to merge your changes with the version from e2fsprogs

    1.41.x.

   https://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git

  - Create a new filesystem using the ext4 filesystem type:::

  - Create a new filesystem using the ext4 filesystem type:

        # mke2fs -t ext4 /dev/hda1

    Or to configure an existing ext3 filesystem to support extents:::

    Or to configure an existing ext3 filesystem to support extents:

	# tune2fs -O extents /dev/hda1

    If the filesystem was created with 128 byte inodes, it can be

    converted to use 256 byte for greater efficiency via:::

    converted to use 256 byte for greater efficiency via:

        # tune2fs -I 256 /dev/hda1

    (Note: we currently do not have tools to convert an ext4

    filesystem back to ext3; so please do not do try this on production

    filesystems.)

  - Mounting:::

  - Mounting:

	# mount -t ext4 /dev/hda1 /wherever

[1] Filesystems with a block size of 1k may see a limit imposed by the

directory hash tree having a maximum depth of two.

Candidate Features for Future Inclusion

---------------------------------------

* online defrag (patches available but not well tested)

* reduced mke2fs time via lazy itable initialization in conjunction with

  the uninit_bg feature (capability to do this is available in e2fsprogs

  but a kernel thread to do lazy zeroing of unused inode table blocks

  after filesystem is first mounted is required for safety)

There are several others under discussion, whether they all make it in is

partly a function of how much time everyone has to work on them. Features like

metadata checksumming have been discussed and planned for a bit but no patches

exist yet so I'm not sure they're in the near-term roadmap.

The big performance win will come with mballoc, delalloc and flex_bg

grouping of bitmaps and inode tables.  Some test results available here:

 - http://www.bullopensource.org/ext4/20080818-ffsb/ffsb-write-2.6.27-rc1.html

 - http://www.bullopensource.org/ext4/20080818-ffsb/ffsb-readwrite-2.6.27-rc1.html

Options

=======

subprojects.

.. toctree::

   :maxdepth: 4

   :maxdepth: 2

   filesystems/ext4/index