From owner-freebsd-arch@FreeBSD.ORG Wed Feb 13 09:04:00 2008 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A768616A417; Wed, 13 Feb 2008 09:04:00 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [209.31.154.42]) by mx1.freebsd.org (Postfix) with ESMTP id 765A113C468; Wed, 13 Feb 2008 09:04:00 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [209.31.154.41]) by cyrus.watson.org (Postfix) with ESMTP id 7928846C53; Wed, 13 Feb 2008 04:03:59 -0500 (EST) Date: Wed, 13 Feb 2008 09:03:59 +0000 (GMT) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= In-Reply-To: <86d4r2540f.fsf@ds4.des.no> Message-ID: <20080213085903.U13849@fledge.watson.org> References: <3bbf2fe10802061700p253e68b8s704deb3e5e4ad086@mail.gmail.com> <70e8236f0802070321n9097d3fy1b39f637b3c2a06@mail.gmail.com> <867ihdc34c.fsf@ds4.des.no> <20080212190207.GB49155@beastie.creo.hu> <86d4r2540f.fsf@ds4.des.no> MIME-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="621616949-1602308289-1202893439=:13849" Cc: Csaba Henk , freebsd-fs@freebsd.org, freebsd-arch@freebsd.org Subject: Re: [RFC] Remove NTFS kernel support X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 13 Feb 2008 09:04:00 -0000 This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --621616949-1602308289-1202893439=:13849 Content-Type: TEXT/PLAIN; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE On Tue, 12 Feb 2008, Dag-Erling Sm=F8rgrav wrote: > Csaba Henk writes: >> Dag-Erling Sm=F8rgrav writes: >>> How much work would you guess it would take to reimplement the >>> userland part under a BSD license? >> Well, I just started to work on a from scratch FUSE daemon library. [...= ]=20 >> So I think: fuse4bsd (ie, the kld + the mount util) + libfolly + sysctl = fs=20 >> could go to base under BSD license. It also might make sense to rebase= =20 >> ntfs-3g atop of folly -- although it won't help ntfs-3g being GPL'd. > > That doesn't matter; ntfs-3g can still be a port. > > What does matter is that if libfolly exports the same API as libfuse, we = can=20 > have a complete BSD-licensed FUSE implementation in the base system, with= =20 > minimal effort required to port FUSE-based file systems. Has there been any work to add more mature interfaces to fuse over the last= =20 couple of years? When I looked at it previously, and that was a year or tw= o=20 ago, fuse didn't work well with our notion of "referenced" vs. "open" vnode= s,=20 and required explicit data copies from cache files into the kernel to be=20 exposed via fuse. These are both areas where nnpfs, the userspace file sys= tem=20 framework for Arla, does much better, as they offer improved handling of=20 memory mapping (which persists after file descriptor close(), as in execve(= )=20 and with shared libraries) and performance (no need to feed data for files = to=20 the kernel, you can just point the kernel at a persistent cache file, possi= bly=20 cached from a previous session, allowing normal faulting of cache data into= =20 memory rather than requiring that pages pass through user space). My=20 understanding is that the NetBSD user space fs work offers a more mature=20 back-end interface than fuse, but allows the less complex fuse API to be us= ed,=20 but I've not done any detailed reading. These are areas where I assumed th= at=20 over time we'd see functional improvements in fuse, so I guess I'm wonderin= g=20 if that has happened? Robert N M Watson Computer Laboratory University of Cambridge --621616949-1602308289-1202893439=:13849--