Coda File System

Re: venus-kernel interface

From: Jan Harkes <jaharkes_at_cs.cmu.edu>
Date: Wed, 29 Sep 2004 09:37:17 -0400
On Wed, Sep 29, 2004 at 11:26:37AM +0200, Ivan Popov wrote:
> to save some "Read The Source" time, if somebody would tell me,
> how much the same is the Coda userspace/kernel protocol
> on differnet OS and architectures.

Some small differences, mostly in the OPEN upcall. BSD's want a
device/inode number pair, Linux expects an open filedescriptor, while
Windows needs the pathname to access the container file.

I think all three of these variants actually use their own upcall, so
we don't need to have #if defined(__BSD__) #elif defined(__linux__) ...
type construction.

> The client does not. Clog could not talk to (native) Venus on FreeBSD,
> and (linux-abi) Venus can not mount /coda.

Clog uses ioctls on a special file in /coda, so I don't expect it to
work until you can at least mount the tree, but there shouldn't be many
OS specific differences (Windows is another story). The mount process is
quite different between the BSDs and Linux.

> At any rate, we should have a binary definition of the protocol - imho.

Or a text based protocol. It might be less efficient, but a lot more
portable (and easier to debug). In any case, I'm not yet sure of the
real value of a 32-bit userspace on a 64-bit kernel, it is probably
better to get userspace cleaned up so that we can build a working 64-bit
binary.

Jan
Received on 2004-09-29 09:38:33