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From: Terry Lambert <terry@lambert.org>
Message-Id: <199608141744.KAA29411@phaeton.artisoft.com>
Subject: Re: Nightmare.
To: jgreco@brasil.moneng.mei.com (Joe Greco)
Date: Wed, 14 Aug 1996 10:44:14 -0700 (MST)
Cc: terry@lambert.org, jgreco@brasil.moneng.mei.com, ulf@lamb.net,
        jkh@time.cdrom.com, hackers@freebsd.org
In-Reply-To: <199608141721.MAA12196@brasil.moneng.mei.com> from "Joe Greco" at Aug 14, 96 12:21:10 pm
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> > > Consider all the programs that could clobber a mounted file system.  Would
> > > it make more sense if we somehow protected a mounted disk device from
> > > being clobbered?
> > 
> > Yes.  Disable the raw device for mounted disks.  The stacking
> > architecture disallows (since it internall references the vnodes) a
> > device level soloution that does anything to the non-raw device.
> > 
> > If we can get past the point where devfs is a mandatory item, then we
> > can fix all of this without breaking FS stacking.  There is no soloution
> > otherwise that could not be broken by a clever idiot.
> 
> Would it make more sense to just disable _writes_ to raw devices for mounted
> disks?  (probably writes to both devices, for that matter)
> 
> I am thinking specifically of using dump,dd,etc to read a mounted file
> system for some useful purpose.

Doesn't dump take the mount point name, not the device, as an argument?

It doesn't document which device it needs in the man page very well, but
the exmaple clear shows "/usr/src" as the "[filesystem]" reference.


					Terry Lambert
					terry@lambert.org
---
Any opinions in this posting are my own and not those of my present
or previous employers.