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. Reading disclaimers makes you go blind. Writing them is worse. You have been Warned. _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"