Re: FAT Support

[Marcus Brinkmann <Marcus.Brinkmann@ruhr-uni-bochum.de>]

On Wed, Jun 06, 2001 at 08:09:55PM -0400, Thomas A Langan wrote:
> 
> 
> I was wondering what the status is of FAT support?  Is it possible to
> mount FAT12 floppies or FAT hard drives?  I noticed Marcus had an
> implementation about a year old.  How much does it take to implement
> something like that?

It took me the ext2fs and ufs example server code, the M$ standard about FAT
filesystems and the better of three days to get a read-only implementation.

> If I've got some FAT libraries that I wrote for
> another project (that simply open the device, ie /dev/fd0, as a file and
> manipulate the FAT table and entries via stdio calls like fread/fwrite and
> fseek) would it be a good exercise to build an implementation (ie, 40-60
> hrs) to learn how to hack translators?  

The FAT format is not the problem, although I left some loose ends you are
welcome to clean up (like character tabes, long file name support etc).
Organization of the metadata is.  (The lack of inodes in FAT is contributing
to the problem).  It is unlikely that your library is matching the semantics
of the Hurd libdiskfs, so you could probably hack up an essentially single
threaded server only.

I actually have write support partially done in my development tree, at
least truncation and expansion of files.  However, there is a dead lock
involved with directories and updating the node information in the directory
record.  I always wanted to clean this up in libdiskfs, but fatfs is so low
a priority for me that I didn't come to it...
 
> Also, I've been a bit confused as to where I can find recent packages.  I
> tried using dselect and getting packages from
> alpha.gnu.org/pub/gnu/hurd/...  but there weren't too many files
> there.  I've been downloading packages now from
> ftp.us.debian.org/debian/pool/main/...  is that where the latest ones are?

debian.org has all the official stuff.  alpha.gnu.org is hackery and work
arounds.

Thanks,
Marcus

-- 
`Rhubarb is no Egyptian god.' Debian http://www.debian.org brinkmd@debian.org
Marcus Brinkmann              GNU    http://www.gnu.org    marcus@gnu.org
Marcus.Brinkmann@ruhr-uni-bochum.de
http://www.marcus-brinkmann.de