[sheepdog] [PATCH] sheep: fix a dead-lock bug in screen_object_list()

[Liu Yuan]

On 11/26/2012 01:48 PM, levin li wrote:
> screen_object_list() is called in recovery, if a VDI creation is in progress,
> then the VDI creation operation is blocked by gateway to wait for completion of
> recovery, and if we make screen_object_list() to retry infinitely to wait the
> nr_objs to be not zero, which also means it waits for VDI creation to complete,
> so, both VDI creation and recovery can not finish, it's a dead-lock.

Hi Levin,
  can you add a test for this case as tests/050? This will exclude the
chance that others step in this problem again accidentally.

  This is indeed a catastrophic bug that already destroyed a running
cluster.

Thanks,
Yuan