FreeLists / openbeos / [openbeos] Re: About filesystems

["Bruno G. Albuquerque" <bga@xxxxxxxxxxxxx>]

Marcus Petersson disse:

> Just wondering if there's some sort of middle-layer, or common stub
> source for various filesystems? It seems more like they are all separate
> from each other. Not that it matters much. I suppose dos and iso9600
> covers most of the cases where foreign filesystems are concerned.

All filesystems implement a specific API that is required by the BeOS VFS
(Virtual File System) layer. Of course the internal implementation varies
from FS to FS as they do thigs differently.

> It would be good to have some documentation about the dos filesystem.

Well, the source is avaiable. :) Also, Dominic's "Practical File System
Design With The Be File System" is available for download and is the bes
reference there is for writting a filesystem for BeOS.

> I'd like to modify it for personal use. The idea is to add attribute
> emulation by relaying attribute calls to the boot disk, similar to my
> attribute library (http://www.bebits.com/app/3683) but transparent.

A cool thing to do would be something like what the SkyOS guys are doing.
Basically that is an extra layer that allows attributes to be read and
written from a specific location (a file, for instance) and that would
allow adding attribute support to filesystems that do not nativelly
support it. It is moe or less what HPFS does with FAT partitions in OS/2.

I guess a cool approach would be to create a link that would be linked to
the FS add-on and would provide all the abstraction for this so the code
required in the FS itself for this to work would be minimal.

-Bruno