From owner-freebsd-current Tue Jun 2 12:56:18 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id MAA28440 for freebsd-current-outgoing; Tue, 2 Jun 1998 12:56:18 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from smtp02.primenet.com (daemon@smtp02.primenet.com [206.165.6.132]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id MAA28434 for ; Tue, 2 Jun 1998 12:56:14 -0700 (PDT) (envelope-from tlambert@usr06.primenet.com) Received: (from daemon@localhost) by smtp02.primenet.com (8.8.8/8.8.8) id MAA28485; Tue, 2 Jun 1998 12:56:09 -0700 (MST) Received: from usr06.primenet.com(206.165.6.206) via SMTP by smtp02.primenet.com, id smtpd028403; Tue Jun 2 12:56:04 1998 Received: (from tlambert@localhost) by usr06.primenet.com (8.8.5/8.8.5) id MAA03610; Tue, 2 Jun 1998 12:55:50 -0700 (MST) From: Terry Lambert Message-Id: <199806021955.MAA03610@usr06.primenet.com> Subject: Re: I see one major problem with DEVFS... To: mike@smith.net.au (Mike Smith) Date: Tue, 2 Jun 1998 19:55:49 +0000 (GMT) Cc: tlambert@primenet.com, mike@smith.net.au, bag@sinbin.demos.su, eivind@yes.no, sepotvin@videotron.ca, current@FreeBSD.ORG In-Reply-To: <199806020042.RAA02307@dingo.cdrom.com> from "Mike Smith" at Jun 1, 98 05:42:07 pm X-Mailer: ELM [version 2.4 PL25] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > > Since it's the same space, you could hard link from your devfs into > > the empty one to create the nodes. > > > > This is even better, since it allows a chroot in a chroot to never > > inherit more than the parent. 8-). > > However it is problematic to link outside of a chroot, and it may not > always be desirable to be so fancy (eg. when using chroot for > engineering rather than security reasons). Not the same thing. I'm talking about: -----------+---+-------------------+-----------+------- chroot 2 | | | | -------+---+---+-----------+-------+-----------+------- chroot 1 | | | | | | ---+---+---+---+---+---+---+---+---+---+---+---+---+--- system | | | | | | | | | | | | | ---+---+---+---+---+---+---+---+---+---+---+---+---+--- template chroot 1 and chroot 2 were populated from system using the link(2) call, which worked "across" devfs instances. > > > DEVFS is per-system. You cannot export a DEVFS via NFS (it makes no > > > sense to do so - devices there are only relevant to the host system). > > No, it's a direct feature of DEVFS, or more particularly to achieve the > results desired by the original poster you cannot use an NFS-mounted > devfs. ??? You'd have to restate your understanding of the results; from mine, I was under the impression they were talking about remote mounts of NFS roots. There is also the problem of non-devfs capable kernels remote NFS root mounting from FreeBSD -- this one requires the ability referesent device node for remote use, even if they locally have no meaning. > > For normal devices that are only operated on via open/close/read/write, > > it makes sens to export a devfs. > > No, it does not. There is no identifying information exported with a > DEVFS node that allows the local system to correctly connect a node > from a remote DEVFS (which may not map to a local driver) to a local > device. The vnode *is* the device. No connection is necessary. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message