From owner-freebsd-current  Tue May 30 10:49:26 2000
Delivered-To: freebsd-current@freebsd.org
Received: from almso1.proxy.att.com (almso1.att.com [192.128.167.69])
	by hub.freebsd.org (Postfix) with ESMTP
	id 20C3237B589; Tue, 30 May 2000 10:49:19 -0700 (PDT)
	(envelope-from myevmenkin@att.com)
Received: from flf960r1.ems.att.com ([135.71.244.37])
	by almso1.proxy.att.com (AT&T IPNS/MSO-2.2) with ESMTP id NAA17677;
	Tue, 30 May 2000 13:49:17 -0400 (EDT)
Received: from njb140bh3.ems.att.com by flf960r1.ems.att.com (8.8.8+Sun/ATTEMS-1.4.1 sol2)
	id NAA01596; Tue, 30 May 2000 13:46:53 -0400 (EDT)
Received: by njb140bh3.ems.att.com with Internet Mail Service (5.5.2650.21)
	id <L9N0NVYM>; Tue, 30 May 2000 13:49:16 -0400
Message-ID: <E598F159668DD311B9C700902799EAF447340E@njb140po01.ems.att.com>
From: "Yevmenkin, Maksim N, CSCIO" <myevmenkin@att.com>
To: "'freebsd-hackers@freebsd.org'" <freebsd-hackers@freebsd.org>
Cc: "'freebsd-current@freebsd.org'" <freebsd-current@freebsd.org>
Subject: stupid FS questions
Date: Tue, 30 May 2000 13:49:15 -0400
MIME-Version: 1.0
X-Mailer: Internet Mail Service (5.5.2650.21)
Content-Type: text/plain;
	charset="koi8-r"
Sender: owner-freebsd-current@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.ORG

Hello All,

i've been looking at ``mount_xxx'' code and have noticed "strange" thing.
all ``mount_xxx'' utilities have common part of code, like

 	error = getvfsbyname("xxx", &vfc);
	if (error && vfsisloadable("xxx")) {
                   if (vfsload("xxx"))
                           err(EX_OSERR, "vfsload(xxx)");
                   endvfsent();    /* flush cache */
                   error = getvfsbyname("xxx", &vfc);
	}
	if (error)
                   errx(1, "xxx filesystem is not available");

           if (mount(vfc.vfc_name, dir, mntflags, &args) < 0)
                   err(1, NULL);

1) what is the reason for this? why can't move this code to ``mount''?
2) what is the purpose of the following code in
``/sys/kern/vfs_syscalls.c''?

...
  for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
                if (!strcmp(vfsp->vfc_name, fstypename))
                        break;
        if (vfsp == NULL) {
                linker_file_t lf;

                /* Refuse to load modules if securelevel raised */
                if (securelevel > 0) {
                        vput(vp);
                        return EPERM; 
                }
                /* Only load modules for root (very important!) */
                if ((error = suser(p)) != 0) {
                        vput(vp);
                        return error;
                }
                error = linker_load_file(fstypename, &lf);
                if (error || lf == NULL) {
                        vput(vp);
                        if (lf == NULL)
                                error = ENODEV;
                        return error;
                }
...

from my understanding this is done to load FS module.
or did i miss someting?

thanks,
emax


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message