[sheepdog] [PATCH 2/2] sheep: cleaning vdi deletion process, round 2

[Hitoshi Mitake]

At Tue, 28 Jan 2014 17:04:14 +0900,
MORITA Kazutaka wrote:
> 
> At Tue, 28 Jan 2014 15:26:52 +0900,
> Hitoshi Mitake wrote:
> > 
> > > 
> > > Only Kazutaka knows the reason. I guess it was planned to be paralle. I think
> > > deletion code is really dirty and tricky and hard to maintain, need refactor and
> > > redesign.
> > 
> > Of course I agree so I'm writing this patch.
> 
> Rather than refactoring the current code, I think we should move to
> the new delete implementation based on reference counting for the 0.9
> release.
> 
> Hitoshi, you said me before that you would take over my work to
> implement an object reclaim feature.  It looks better to me to finish
> the work first.  I guess the object reclaim code will remove this
> patch's changes.

Yes I'll work on the object reclaim, sorry for pending.

But I want to fix current code first because I need to clean up the
vdi deletion in stable-0.7 and stable-0.8. It is really hard to
maintain. e.g. we faced segfault during stress test of sheepdog and
callstack implied the bug is in the vdi deletion process. But it is
really difficult for detecting the root cause of the segfault because
of the tricky code. I don't want to see similar problems come from the
vdi deletion in the future.

For long-term maintenance of v0.7.x and v0.8.x, I want to clean up
current vdi deletion process first.

Thanks,
Hitoshi