[Sheepdog] Bug: snapshot causes vdi attributes to be lost

[Chris Webb]

With current git HEAD and the sheepdog driver in qemu-kvm 0.14.1:

  # qemu-img create sheepdog:foo 100
  Formatting 'sheepdog:foo', fmt=raw size=100 
  # collie vdi setattr foo wibble wobble
  # collie vdi getattr foo wibble; echo
  wobble

All good so far. However, after I take a snapshot,

  # qemu-img snapshot -c '' sheepdog:foo
  # collie vdi list foo                
    name        id    size    used  shared    creation time   vdi id
  ------------------------------------------------------------------
  s foo          1  0.0 MB  0.0 MB  0.0 MB 2011-07-28 11:05   d9d577
    foo          2  0.0 MB  0.0 MB  0.0 MB 2011-07-28 11:07   d9d578
  # collie vdi getattr foo wibble
  no such attribute, wibble
  # collie vdi getattr -s 1 foo wibble
  no such attribute, wibble
  # collie vdi getattr -s 2 foo wibble
  no such attribute, wibble

So it seems to have vanished, neither being attached to the snapshot nor the
head of the vdi.

Cheers,

Chris.