On Sat, 21 Jul 2007 20:44:13 -0600 (MDT)
"M. Warner Losh" <[EMAIL PROTECTED]> wrote:
> In message: <[EMAIL PROTECTED]>
> Norberto Meijome <[EMAIL PROTECTED]> writes:
> : On Thu, 19 Jul 2007 09:02:50 -0600 (MDT)
> : "M. Warner Losh" <[EMAIL PROTECTED]> wrote:
> :
> : > In message: <[EMAIL PROTECTED]>
> : > Momchil Ivanov <[EMAIL PROTECTED]> 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 :)
>
> src/sys/fs/..., src/sys/kern/... and src/sys/vm/... are your best bets.
>
> : 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 ?
>
> Check, sure, it can check. But what does a simple check accomplish if
> the filesystem panics if the underlying media returns an error? The
> problem isn't as simple as just looking in one place or another, but
> rather systemic in nature.
>
thanks Warner. What do you estimate is the cost (time, at least) to investigate
and fix this issue? SoC project? 4 mth project?
cheers,
B
_________________________
{Beto|Norberto|Numard} Meijome
Anyone who isn't confused here doesn't really understand what's going on.
I speak for myself, not my employer. Contents may be hot. Slippery when wet.
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Warned.
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