[Sheepdog] [PATCH v4 2/6] fix a bug of deleting base vdi fail

[MORITA Kazutaka]

At Thu,  3 May 2012 18:25:45 +0800,
levin li wrote:
> 
> Take a view of the following snapshot chain:
> 
> base vdi --> snapshot vdi --> cloned vdi
> 
> when cloned vdi has its own data objects created by copy-on-write,
> we firstly delete the cloned vdi, the delete the base vdi, at last
> we delete snapshot vdi.
> 
> when deleting the snapshot vdi, it try to traverse the snapshot chain to
> cleanup all the data objects, but the copy-on-write objects has been

What does 'copy-on-write objects' mean here?  Data objects of the
cloned VDI?

> deleted by the first deletion work, so it may get failed and set the
> dw->delete_error to be true, it doesn't matter for the future deletion,

I'm not sure why dw->delete_error could be true even if there is no
problem.  The current delete process also traverse the already deleted
VDIs?  If so, it should be modified, I think.

BTW, It seems that the snapshot/clone code of the latest master is
broken, so I couldn't test your example on my environemnt at all.
Does the latest sheepdog code works on your environment correctly?

Thanks,

Kazutaka