[Sheepdog] [PATCH 0/2] fix vdi operation bugs

[Chris Webb]

Hi Kazutaka. I pulled these fixes (your devel branch is master + these fixes
at the moment) and rebuilt. However, I'm afraid I'm still seeing flaky
operation.

I do a successful

  collie vdi create 7fa6adbe-2551-4a60-ab50-c901c972d11d 539545600

then a bunch of successful setattr, getattr and writes, but after a few
blocks of writing, end up with

collie vdi write 7fa6adbe-2551-4a60-ab50-c901c972d11d 16777216
failed to write object, 2eb90900000004 No object found
failed to write vdi
exit 1

I've put the corresponding sheep.logs at

  http://cdw.me.uk/tmp/sheep-00.log
  http://cdw.me.uk/tmp/sheep-01.log
  http://cdw.me.uk/tmp/sheep-02.log

After a couple more repeats of the create-and-upload operation, it gets this
bad:

0026# collie vdi list
  name        id    size    used  shared    creation time   vdi id
------------------------------------------------------------------
  7fa6adbe-2551-4a60-ab50-c901c972d11d     1  515 MB   16 MB  0.0 MB 2011-10-26 16:56   2eb909
failed to read object, 809a7d7500000000 No object found
failed to read a inode header
  9fbb9334-fc73-406d-8641-2cbaedf61d10     1  515 MB  4.0 MB  0.0 MB 2011-10-26 17:00   e7f8bc

In the case that caused this, collie create worked then setattr -x failed:

collie vdi create c4053f86-11bf-4a75-808f-37d80ac7b92d 539545600
exit 0

collie vdi setattr -x c4053f86-11bf-4a75-808f-37d80ac7b92d lock
failed to set attr, I/O error
exit 1

sheep.logs for this more extended test at

  http://cdw.me.uk/tmp/sheep2-00.log
  http://cdw.me.uk/tmp/sheep2-01.log
  http://cdw.me.uk/tmp/sheep2-02.log

Sorry to be so regularly the bearer of problem reports! I think the big
difference with automated users of sheepdog like our management system is that
collie calls are executed quite rapidly in close succession, so we create and
immediate setattr and so on, which might be why we are turning up so many
timing problems.

Best wishes,

Chris.