[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH] Add a --force option to detach operations

On Thu, 2006-12-14 at 13:29 +0000, Keir Fraser wrote:
> On 14/12/06 12:52, "Glauber de Oliveira Costa" <glommer@xxxxxxxxx> wrote:
> > How can we be more brutal than that ? The only non-brutal thing I've put 
> > there
> > is denying disconnection when still in Connected state. But if for
> > some reason the frontend does not want to disconnect, then the tools
> > have no power over it. It can simply crash guest.
> > 
> > Example: attach a device, mount it at guest, and try to detach it
> > using --force. It should not force it, as it crashes the guest.
> Don't use --force if you don't know what you're doing is a reasonable
> caveat. You're on flakey ground if you have to use it in any case as
> something is obviously screwed.

These kind of things can happen by accident. And in case an accident
happens, it does not seems a good idea to crash the guest.

Moreover, the lack of any kind of timeout can lead netfront to leak
memory. If the stores are released too early, backend may be unable to
release the references, and frontend will leak. I see no way of having
any guarantee of being in a termination state, so we will not be able to
to be sure it is safe to remove the entries anyway. But tests I made
with that timeout value lead to no leaks. 

Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.