[PATCH 4/5] add example of how to create a custom filesystem.

[address@hidden]

* hurd/translator/ext2fs.mdwn: explain how to create a custom
filesystem.  I had to run 'sudo chown joshua .' to create files.
Shouldn't we be able to create files without being root?  What am I
doing wrong?
---
 hurd/translator/ext2fs.mdwn | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/hurd/translator/ext2fs.mdwn b/hurd/translator/ext2fs.mdwn
index 957b9c13..5e045e51 100644
--- a/hurd/translator/ext2fs.mdwn
+++ b/hurd/translator/ext2fs.mdwn
@@ -32,6 +32,30 @@ Extend ext2fs to support 64bit time.
 
 [[!inline pagenames=faq/2_gib_partition_limit raw=yes feeds=no]]
 
+## Create your own custom ext2fs
+
+       $ dd if=/dev/zero of=silly.fs bs=1024k count=8
+       $ /sbin/mkfs.ext2 silly.fs
+       $ settrans -c silly /hurd/ext2fs `pwd`/silly.fs
+       $ ps -e | grep silly  # ext2fs has not started
+       $ ls silly
+       $ ps -e | grep silly | awk '{ print $6 " " $7 }'
+       /hurd/ext2fs /home/joshua/silly.fs
+       $ cd silly
+       $ sudo chown joshua .  # you shouldn't have to run that
+       # but I had to run it if I wanted to write files.
+       $ echo 'hello' > hello.txt
+       $ mkdir silly-dir
+       $ cd ..
+       $ fsysopts silly
+       /hurd/ext2fs --writable --relatime --no-inherit-dir-group 
/home/joshua/silly.fs
+       $ fsysopts silly --readonly  # stop writes to the filesystem
+       $ fsysopts silly --writable  # let writes again
+
+Try to make the filesystem read-only with fsysopts. Note how further
+write attempts fail now. Try to kill the active translator with
+settrans -g.
+
 ### Ognyan's Work to allow ext2 to surpass the 2 GiB limit
 
   * Ognyan Kulev, [[*Supporting Large ext2 File Systems in the
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