From owner-freebsd-stable@FreeBSD.ORG Sat Jul 21 01:06:15 2007 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A1FF716A417 for ; Sat, 21 Jul 2007 01:06:15 +0000 (UTC) (envelope-from freebsd@meijome.net) Received: from sigma.octantis.com.au (ns2.octantis.com.au [207.44.189.124]) by mx1.freebsd.org (Postfix) with ESMTP id 5641713C46A for ; Sat, 21 Jul 2007 01:06:15 +0000 (UTC) (envelope-from freebsd@meijome.net) Received: (qmail 22335 invoked from network); 20 Jul 2007 20:06:13 -0500 Received: from 203-206-233-219.dyn.iinet.net.au (HELO localhost) (203.206.233.219) by sigma.octantis.com.au with (DHE-RSA-AES256-SHA encrypted) SMTP; 20 Jul 2007 20:06:12 -0500 Date: Sat, 21 Jul 2007 11:06:03 +1000 From: Norberto Meijome To: "M. Warner Losh" Message-ID: <20070721110603.3878d933@localhost> In-Reply-To: <20070719.090250.1387160138.imp@bsdimp.com> References: <20070719130252.6880b967@localhost> <469F101C.5060906@gmx.de> <200707190943.55428.idiotbg@gmail.com> <20070719.090250.1387160138.imp@bsdimp.com> X-Mailer: Claws Mail 2.10.0 (GTK+ 2.10.14; i386-portbld-freebsd6.2) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: LoN_Kamikaze@gmx.de, olli@lurza.secnetix.de, freebsd-stable@freebsd.org, idiotbg@gmail.com, josh@tcbug.org Subject: Re: removing external usb hdd without unmounting causes reboot? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 21 Jul 2007 01:06:15 -0000 On Thu, 19 Jul 2007 09:02:50 -0600 (MDT) "M. Warner Losh" wrote: > In message: <200707190943.55428.idiotbg@gmail.com> > Momchil Ivanov writes: > : What is then the reason for the kernel not being able to unmount a > : filesystem whose provider is no longer present? > > The problem is that the device driver has wound down, deallocated > memory, etc. Now the kernel comes along with stale references to the > device and panic ensues. It is really just that simple. There's no > replacement of the now-dead device with dead calls. > > And even if you fixed that, most of the file systems in the tree today > do not tolerate errors on writes at all and that also leads to > panics. This is why firewire freezes the I/Os rather than failing > them (and why umount -f on a firewire drive hangs). Please point me to the correct RTFM, because I feel this worth it :) Is there a reason why the kernel cannot check 'upwards' if a device is being used, ie mounted ? and prevent the unloading of the device driver ? thanks for your time illuminating this ignoramus :) _________________________ {Beto|Norberto|Numard} Meijome "Egotism is the anesthetic that dulls the pain of stupidity." Frank Leahy I speak for myself, not my employer. Contents may be hot. Slippery when wet. Reading disclaimers makes you go blind. Writing them is worse. You have been Warned.