Coda File System

Re: Dir entry XX, should be in hash bucket X

From: Ivan Popov <pin_at_medic.chalmers.se>
Date: Thu, 2 Sep 2004 21:18:03 +0200
On Thu, Sep 02, 2004 at 09:44:09AM -0400, Jan Harkes wrote:
> This is a hash that is used both on the client and the server. We can't
> really change it without making all existing directories unreadable.

Is the hash result being sent over the net? It sounds like at some time
we would need to copy all data from a realm via an old client
and then copy the data into the new realm reincarnation from a new client...

And do it on all realms and clients in the world at the same time...

If so (?), we really should fix it as soon as possible, as data amounts
present in Coda grow fast.

Could you think of a well distributing, endian/signedness independent hash,
which would be choosable as a compile option? Ideal for new installs,
not mandatory for isolated / old ones.

Then we would not need fixing the old hash either ;-)

I'd prefer to take the effort of moving all data and reinstalling all
clients NOW compared to any time later, when it is becoming harder
with each day.

Do we have other similar deeply hardwired "impossible-to-change"
things?

> The only thing we can aim for in the short term is to make it give the
> an identical result on all possible platforms (big endian/little endian,
> 32-bit/64-bit, signed chars/unsigned chars).

Jan, what would be your idea of a long-term solution?

Regards,
--
Ivan
Received on 2004-09-02 15:20:24