Re: [Qemu-devel] qcow2 - safe on kill? safe on power fail?

[Avi Kivity]

Anthony Liguori wrote:
> Andreas Schwab wrote:
> > Anthony Liguori <address@hidden> writes:
> >
> >  
> > > The only ways that you can cause corruption is if the QCOW2 sector
> > > allocation code is faulty (and you would be screwed no matter what 
> > > here)
> > > or if you issue a SIGTERM/SIGKILL that interrupts the code while it's
> > > allocating a new sector.
> > >     
> >
> > Blocking SIGTERM until the allocation is finished could close that hole.
> >   
>
> Seems like a band-aid to me as SIGKILL is still an issue.  Plus it 
> would involve modifying all disk formats, not just QCOW2.  I'd rather 
> see proper journal support added to QCOW2 myself.

Journalling is so out of fashion.  It's better to sequence the 
operations so that failure results in a leak instead of corruption.

--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.