From owner-freebsd-fs@FreeBSD.ORG Fri Feb 13 03:05:51 2004 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 09DDB16A4CE for ; Fri, 13 Feb 2004 03:05:51 -0800 (PST) Received: from mail-1.zoominternet.net (mail-1.zoominternet.net [63.67.120.5]) by mx1.FreeBSD.org (Postfix) with SMTP id A9DAA43D1F for ; Fri, 13 Feb 2004 03:05:50 -0800 (PST) (envelope-from dmmiller@cvzoom.net) Received: (qmail 8182 invoked from network); 13 Feb 2004 11:05:48 -0000 Received: from acs-24-239-218-57.zoominternet.net (HELO cvzoom.net) ([24.239.218.57]) (envelope-sender ) by mail-1.zoominternet.net (qmail-ldap-1.03) with SMTP for ; 13 Feb 2004 11:05:48 -0000 Message-ID: <402CAF83.2000201@cvzoom.net> Date: Fri, 13 Feb 2004 06:05:39 -0500 From: Donn Miller User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.6) Gecko/20040204 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Tom Arnold References: In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit cc: freebsd-fs@freebsd.org Subject: Re: Upcoming filesystems? X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 13 Feb 2004 11:05:51 -0000 Tom Arnold wrote: > Are there any Journaling FS projects ongoing for FreeBSD that arn't on the > general radar? > > UFS2/Softupdates isnt working out for us so unfortunatly we are getting a > lot of push to start using the L word with ReiserFS&Friends. Not really. There is an ongoing port of XFS. Check the status report. As for UFS+softupdates, softupdates obviates (according to theory, anyways) the need for journalling. But I was wondering myself if there was some way of using softupdates and journalling together. For example, there could be some way of logging what softupdates is doing exactly so that background fsck can have better hints of which part of the filesystem needs fscked, if any. For example, there could be some "hints" stored in a journal and log that softupdates allocated a data block, but no inode was written. So fsck would know to de-allocate that particular data block, and know exactly where it is from the hints stored in the log so fsck could finish faster. But this sounds like how the typical journalling filesystem works in the first place. I did take a look at some ReiserFS code. I proceeded to do some very quick preliminary research. The first things I noted are the differences of Linux's kmalloc() vs. FreeBSD's malloc(9). Linux's kmalloc() seems to be tied down to its slab allocator, and it incorporates the filesystem buffer cache whereas FreeBSD's malloc(9) doesn't. This would be the first obstacle in porting ReiserFS to FreeBSD, as ReiserFS does call kmalloc a fair bit, and in addition, malloc(9) takes 3 arguments compared to kmalloc's 2. I'll have to take another look at kmalloc, malloc(9), and the ReiserFS code, because I'm sure I'm way off the mark. :-)