From owner-freebsd-fs Mon Jun 3 9:26:56 2002 Delivered-To: freebsd-fs@freebsd.org Received: from cs.columbia.edu (cs.columbia.edu [128.59.16.20]) by hub.freebsd.org (Postfix) with ESMTP id 6213237B401 for ; Mon, 3 Jun 2002 09:26:53 -0700 (PDT) Received: from shekel.mcl.cs.columbia.edu (shekel.mcl.cs.columbia.edu [128.59.18.15]) by cs.columbia.edu (8.12.1/8.12.1) with ESMTP id g53GQqMk026919; Mon, 3 Jun 2002 12:26:52 -0400 (EDT) Received: from shekel.mcl.cs.columbia.edu ([127.0.0.1]) by shekel.mcl.cs.columbia.edu (8.12.1/8.12.1) with ESMTP id g53GQpbT028133; Mon, 3 Jun 2002 12:26:51 -0400 (EDT) Received: (from ezk@localhost) by shekel.mcl.cs.columbia.edu (8.12.1/8.12.1/Submit) id g53GQoMl028130; Mon, 3 Jun 2002 12:26:50 -0400 (EDT) Date: Mon, 3 Jun 2002 12:26:50 -0400 (EDT) Message-Id: <200206031626.g53GQoMl028130@shekel.mcl.cs.columbia.edu> From: Erez Zadok To: Terry Lambert Cc: dak , freebsd-fs@FreeBSD.ORG Subject: Re: Implementing a new FS with loadable modules In-reply-to: Your message of "Sun, 05 May 2002 12:05:20 PDT." <3CD58270.DF9B8F06@mindspring.com> Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org Sorry for the late reply. In message <3CD58270.DF9B8F06@mindspring.com>, Terry Lambert writes: > dak wrote: > 2) Stacking VFS layer > > Examples: nullfs; there are no other working examples. Dak, you might want to check my FiST system: http://www.cs.columbia.edu/~ezk/research/fist/ I have working examples for fbsd 3.x for some time, including an encryption file system called Cryptfs. It uses "wrapfs" templates that include more functionality than nullfs. However, it will be easier to understand nullfs first, as Terry suggests. My students and I have been updating the stackable templates we have (yes, *templates*! :-) for fbsd 4.5 recently. We discovered and fixed a bunch of bugs found using FSX and other custom f/s exercisers we wrote. Right now we're trying to deal with some odd interaction b/t read+write and page ops. (Yes, we're working around the VFS, not fixing it; the VFS problems are well known and hopefully are/will be fixed in 5.x.) We hope to release a fully-working template for fbsd 4.5 this month. An announcement will be made on this list. Testers will be more than welcome at that time. Erez. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message