From owner-freebsd-hackers Thu Nov 12 09:18:07 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id JAA29410 for freebsd-hackers-outgoing; Thu, 12 Nov 1998 09:18:07 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from bingsun1.cc.binghamton.edu (bingsun1.cc.binghamton.edu [128.226.1.2]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id JAA29397 for ; Thu, 12 Nov 1998 09:18:05 -0800 (PST) (envelope-from bf20761@binghamton.edu) Received: from localhost (bf20761@localhost) by bingsun1.cc.binghamton.edu (8.8.7/8.6.9) with SMTP id MAA10392; Thu, 12 Nov 1998 12:17:19 -0500 (EST) Date: Thu, 12 Nov 1998 12:17:18 -0500 (EST) From: zhihuizhang X-Sender: bf20761@bingsun1 Reply-To: zhihuizhang To: Julian Elischer cc: hackers Subject: More questions on DEVFS Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG I have a couple of questions on DEVFS which is hard to figure out from the source code: (1) As I understand it, special files can be created only by superuser via mknod and file systems can only be mounted by superuser. I do not see any reason why the superuser will mount the device file system multiple times and possibly at different mount points. (2) Both the block and character switch table have a major number at its end (d_maj) which is often set to be -1 (see mem_cdevsw[] in file i386/mem.c for an example). This makes devfs_add_devswf() return without adding a device entry. Is this the way that is used to circuit the DEVFS code on purpose? Thanks for your help. -------------------------------------------------- | Zhihui Zhang, http://cs.binghamton.edu/~zzhang | | Dept. of Computer Science, SUNY at Binghamton | -------------------------------------------------- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message