Re: TCFS for FreeBSD?

From: Greg Lewis (
Date: 10/17/02

Date: Fri, 18 Oct 2002 01:11:08 +0930
From: Greg Lewis <>
To: Brett Glass <>

On Thu, Oct 17, 2002 at 12:17:27AM -0600, Brett Glass wrote:
> I was under the impression that TCFS, like CFS, operated entirely
> in userspace. What parts of it work down at the kernel level?

Its a filesystem that works in the kernel much like ufs, etc. That
is, it has a standard vfsops definitions and associated functions.
All the BSD code on the TCFS site and that in OpenBSD is like this.
I don't know if maybe on Linux its implemented in user space since
I haven't looked at the Linux code.

> Also, what did you bring in from KAME? (I would think that the
> necessary crypto would be available through the OpenSSL libraries.)

Right, except OpenSSL isn't linked into the kernel :). The kernel
crypto parts that -STABLE doesn't have are the blowfish and DES
block encryption code. The code itself is originally from OpenSSL
or SSLeay by the looks of it.

> Since you've already worked heavily on the kernel stuff, I should
> probably focus on the userland utilities to avoid having to come
> up the learning curve when you're already there.

Actually, I don't know a lot about either kernel workings or
filesystems, I just wanted to try and port TCFS :). That said,
I've just checked and the user utilities aren't in my tree,
so I'll try and track them down (I must have them somewhere :).

Greg Lewis                          Email   :
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