[Qemu-devel] [PATCH 0/3] block: prohibit migrations during tasks

[John Snow <jsnow@redhat.com>]

requires:
[PATCH v2] migration: disallow migrate_add_blocker during migration

We don't want to allow migrations during sensitive
operations such as snapshots or mirroring. In conjunction
with the previous patch, we will also prohibit the
user from starting any block jobs while migrations
are active.

Questions:
 - Are there other actions that need to be guarded?
 - Are there actions here that are guarded, but
   should not be?
 - Is this worth doing at all? libvirt saves us
   in most cases.
 - What other cases besides a fully synchronized
   mirror might be valid in a migration workflow?

Known open issues:
 - Does not guard against incoming migrations,
   only outgoing ones. Is this a problem? Are
   there valid use cases for running jobs on
   a machine before or during an incoming migration?

John Snow (3):
  block: prohibit migration during BlockJobs
  block/mirror: allow migration after sync
  block: prohibit migration during transactions

 block/mirror.c           |  2 ++
 blockdev.c               | 12 ++++++++++++
 blockjob.c               | 16 ++++++++++++++++
 include/block/blockjob.h |  8 ++++++++
 4 files changed, 38 insertions(+)

-- 
2.4.3