From owner-freebsd-current Fri May 11 7:16: 1 2001 Delivered-To: freebsd-current@freebsd.org Received: from fledge.watson.org (fledge.watson.org [204.156.12.50]) by hub.freebsd.org (Postfix) with ESMTP id 422F737B422; Fri, 11 May 2001 07:15:58 -0700 (PDT) (envelope-from robert@fledge.watson.org) Received: from fledge.watson.org (robert@fledge.pr.watson.org [192.0.2.3]) by fledge.watson.org (8.11.3/8.11.3) with SMTP id f4BEF7f23294; Fri, 11 May 2001 10:15:07 -0400 (EDT) (envelope-from robert@fledge.watson.org) Date: Fri, 11 May 2001 10:15:06 -0400 (EDT) From: Robert Watson X-Sender: robert@fledge.watson.org To: Poul-Henning Kamp Cc: Bruce Evans , mjacob@feral.com, Ruslan Ermilov , current@FreeBSD.ORG Subject: Re: DEVFS In-Reply-To: <81920.989570646@critter> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Fri, 11 May 2001, Poul-Henning Kamp wrote: > In message , Bruce Evan > s writes: > > >> Blame the poor design of mount(2) (and ask Adrian when he fixes > >> it :-) > > > >It must be the excellent design of mount(2) that makes it so easy to > >do things with it where it can be used :-). > > Just too bad it wasn't designed so that it can be used from kernel > processes as well :-( I've made this observation before, of course, but it is my general opionion that, leaving aside uio structures, awareness of "userland" data pointers should generall be limited to the system call code rather than the service implementation. The existence of userland points in VFS calls (and I've introduced one myself in the vfs_extattrctl call) is generally evil. It makes it much harder to initiate a service from within a kernel thread or process, and do ABI wrapping. Robert N M Watson FreeBSD Core Team, TrustedBSD Project robert@fledge.watson.org NAI Labs, Safeport Network Services To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message