After failover the Secondary side of replication shouldn't change state, because
it now functions as our primary disk.
In replication_start, replication_do_checkpoint, replication_stop, ignore
the request if current state is BLOCK_REPLICATION_DONE (sucessful failover) or
BLOCK_REPLICATION_FAILOVER (failover in progres i.e. currently merging active
and hidden images into the base image).
Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Reviewed-by: Zhang Chen <chen.zhang@intel.com>
Acked-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>