Date: Sat, 21 Jul 2007 11:06:03 +1000 From: Norberto Meijome <freebsd@meijome.net> To: "M. Warner Losh" <imp@bsdimp.com> 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? 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>
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On Thu, 19 Jul 2007 09:02:50 -0600 (MDT)
"M. Warner Losh" <imp@bsdimp.com> wrote:
> In message: <200707190943.55428.idiotbg@gmail.com>
> Momchil Ivanov <idiotbg@gmail.com> 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.
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