Re: [Libvir] PATCH: Fix crash in cleanup when VM creation fails

["Daniel P. Berrange" <berrange redhat com>]

On Tue, Jul 24, 2007 at 03:23:42AM -0400, Daniel Veillard wrote:
> On Mon, Jul 23, 2007 at 08:55:52PM +0100, Daniel P. Berrange wrote:
> > If using the 'virDomainCreateLinux' call to create a VM, a so called 
> > 'transient' domain will be created - ie one without any config file.
> > There is special code in the qemudShutdownVMDaemon method to cleanup
> > the resources associated with such domains, in particuarly free'ing 
> > the struct qemud_vm  object. Unfortunately in the virDomainCreateLinux
> > codepath this is a problem, because we still need the 'struct qemud_vm'
> > object in certain edge cases, and so the caller has to free it. We
> > currently have a double free() in that scenario. This patch removes
> > the call to qemudFreeVMDaemon from qemudShutdownVMDaemon. Instead it
> > is now always the caller's responsibility to cleanup after transient
> > domains.
> 
>   I think a bit weird that a routine which may still fail in some
> way can be switched back from returning an int to void and still
> generate an improvement. The way we used the return value of Shutdown
> is not needed anymore but I wonder about the possibility of other error
> case.

The return value in the original code was more or less useless already as
there was nothing that could be failing & the function was always returning
success, so we were checking for a failure which would never occur.

Dan.
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