Ext2fs on a MPC850 running BusyBox Linux and a 2.4.27 kernel

Ext2fs on a MPC850 running BusyBox Linux and a 2.4.27 kernel

[Wouter Thielen]

Hello,

I am trying to get a 128K read/write partition on the 4M NAND flash chip 
to store configuration data for the system in ext2 format. mke2fs and 
mounting works fine. The problem starts when I write to the partition: I 
can write to it fine, but without proper umounting the data written 
won't be saved. I tried the following things:
- mounting with -o sync
- checking the fs/ext2/* code and trying to get fs update operations to 
call the functions that umount calls (ext2_put_super and 
ext2_sync_super), but that only results in kernel oopses and no saved 
data either.

I have been suggested to use a flash filesystem like jffs2, but the 
problem is that I have only 1 block to work with. Flash filesystems 
require more, jffs2 requires 6 blocks for 1 usable block and that would 
be an inacceptable overhead of 83%. So I'd like to try to use ext2 (or 
minixfs which is slimmer than ext2, but still has the same problem) for 
that small read/write partition. Anyone got any ideas/suggestions on how 
to make ext2 sync to disk after write operations in the buffer?

Wouter Thielen
MuLogic B.V. Netherlands