Extent File System for Linux 2.2
================================

This package is an implementation of the SGI's extent filesystem (efs).
EFS was widely used on IRIX 5.3 systems and is still found on most
SGI distribution CDs. Since the advent of IRIX 6.x, most people have
migrated to xfs.

The filesystem is implemented as a loadable module which allows you to
mount your efs-format CDs onto your Linux system. Support for efs hard
drive media is in this release (see README.PARTITIONS). The filesystem
support is read-only in this release.

REQUIREMENTS
------------

You need to be running at least Linux 2.2.0 to compile this code.
Your CD-ROM must also be able to read 512-byte blocks.

COMPILATION
-----------

To build the efs.o module just type "make".

You can insert the module into a running kernel with "insmod efs.o"
An efs CD can then be mounted using "mount /dev/cd-device /mount/point".

To remove the module, unmount all efs filesystems and enter "rmmod efs".

USING HARD-DISK PARTITIONS
--------------------------

This module also contains support for hard-drive partitions.

If you are not running Linux/MIPS then you will need to patch your kernel.
In the Makefile, set KERNEL_TOP appropriately and enter "make genhd".
Note that the second patch will fail if you have a 2.2.5-ac2 or later kernel.

Once your kernel has been rebuilt and you have reinserted efs.o, you will
be able to access devices on your irix drive as normal.

KERNEL PATCH
------------

This version of efs contains a kernel patch. To apply the patch and copy
the relevant files into your linux kernel tree, edit the Makefile to set
KERNEL_TOP correctly and enter "make kernel".

Enabling the "experimental code" configuration option will allow you to
see the CONFIG_FS_EFS option and compile the code either into your kernel,
or as a module. Note that if you are not running on an SGI (ie CONFIG_SGI
is not defined) and you wish your kernel to recognise SGI disk labels then
you must answer Y to CONFIG_SGI_DISKLABEL.

LOCATION
--------

http://aeschi.ch.eu.org/efs/

WARRANTY
--------

THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS"
WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE
OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

COPYRIGHT
---------

This software is released under the terms of the GNU General Public
License version 2 and is (c) Al Smith 1999.

Portions of the code were inspired by Christian Vogelgsang's efsmod-0.6
and by Mike Shaver's work on efs support for Linux/MIPS.

THANKS
------

Thanks go to (in no particular order):

   Ralf Baechle     <ralf@uni-koblenz.de>
   Tore Bergen     <torel@bergen.sgi.com>
  Ariel Faigon     <ariel@sgi.com>
   Mike Shaver    <shaver@netscape.com>
    Ian Wells    <I.Wells@tarragon-et.co.uk>
Matthew Wilcox     <willy@bofh.ai>

--
Al Smith <Al.Smith@aeschi.ch.eu.org> - May 1999
 
