guest_device_name found duplicate device name error occurs when shared volume is detached.

[unakatsuo]

Assume we have two instances, instance A and instance B, and we tried to swap a volume on shared disk from instance A to B. The attach succeeds on instance B side but detaching failed.

API call to reproduce the issue:

$ MUSSEL_LOGLEVEL=debug /opt/axsh/wakame-vdc/client/mussel/mussel.sh instance create --host-node-id=hn-psv0011temp --image-id=wmi-centos1d64nfs --ssh-key_id=ssh-een2k7jq --hypervisor=kvm --cpu-cores=1 --memory-size=128 --volumes[0][size]=10 --volumes[0][volume_type]=shared --vifs=./vif

$ MUSSEL_LOGLEVEL=debug /opt/axsh/wakame-vdc/client/mussel/mussel.sh volume detach vol-ngv0m908 --instance_id=i-zrhbz8yt
$ MUSSEL_LOGLEVEL=debug /opt/axsh/wakame-vdc/client/mussel/mussel.sh volume attach vol-ngv0m908 --instance_id=i-5nfdkxei
$ MUSSEL_LOGLEVEL=debug /opt/axsh/wakame-vdc/client/mussel/mussel.sh volume detach vol-ngv0m908 --instance_id=i-5nfdkxei

hva.log

2015-02-23 20:00:15 JobContext thr=JobWorker[0/1] [INFO]: Job start d3180f65877bad018dab00e74246cd1e9f7ed7e0 (Local ID: d3180f65877bad01
8dab00e74246cd1e9f7ed7e0)[ attach ]
I, [2015-02-23T20:00:15.311102 #14168]  INFO -- HvaHandler: Session ID: d3180f65877bad018dab00e74246cd1e9f7ed7e0: Instance UUID: i-5hlyh
5vw: Attaching vol-c8zosntq on i-5hlyh5vw
D, [2015-02-23T20:00:15.324356 #14168] DEBUG -- Kvm: Session ID: d3180f65877bad018dab00e74246cd1e9f7ed7e0: monitor port number: 29888
I, [2015-02-23T20:00:15.807223 #14168]  INFO -- HvaHandler: Session ID: d3180f65877bad018dab00e74246cd1e9f7ed7e0: Instance UUID: i-5hlyh5vw: Attached vol-c8zosntq on i-5hlyh5vw
2015-02-23 20:00:15 JobContext thr=JobWorker[0/1] [INFO]: Job complete d3180f65877bad018dab00e74246cd1e9f7ed7e0 (Local ID: d3180f65877bad018dab00e74246cd1e9f7ed7e0)[ attach ]: 0.636517838 sec
2015-02-23 20:00:56 JobContext thr=JobWorker[0/1] [INFO]: Job start 6aaf28e01220e0e65bbd797af400fa829c5d7d96 (Local ID: 6aaf28e01220e0e65bbd797af400fa829c5d7d96)[ detach ]
I, [2015-02-23T20:00:57.055175 #14168]  INFO -- HvaHandler: Session ID: 6aaf28e01220e0e65bbd797af400fa829c5d7d96: Instance UUID: i-5hlyh5vw: Detaching vol-c8zosntq on i-5hlyh5vw
2015-02-23 20:00:57 JobContext thr=JobWorker[0/1] [ERROR]: Job failed 6aaf28e01220e0e65bbd797af400fa829c5d7d96 [ detach ]: {:message=>"guest_device_name found duplicate device name (vda, vdc, vdc) for i-5hlyh5vw", :error_type=>"Sequel::ValidationFailed"}
2015-02-23 20:00:57 JobContext thr=JobWorker[0/1] [ERROR]: Caught Isono::NodeModules::RpcChannel::RpcError: {:message=>"guest_device_name found duplicate device name (vda, vdc, vdc) for i-5hlyh5vw", :error_type=>"Sequel::ValidationFailed"}
        /opt/axsh/wakame-vdc/dcmgr/vendor/bundle/ruby/2.0.0/gems/isono-0.2.19/lib/isono/node_modules/rpc_channel.rb:459:in `wait'
        /opt/axsh/wakame-vdc/dcmgr/vendor/bundle/ruby/2.0.0/gems/isono-0.2.19/lib/isono/node_modules/rpc_channel.rb:153:in `request'
        /opt/axsh/wakame-vdc/dcmgr/lib/dcmgr/rpc/hva_handler.rb:498:in `block in <class:HvaHandler>'
        /opt/axsh/wakame-vdc/dcmgr/vendor/bundle/ruby/2.0.0/gems/isono-0.2.19/lib/isono/rack/proc.rb:25:in `instance_eval'
        /opt/axsh/wakame-vdc/dcmgr/vendor/bundle/ruby/2.0.0/gems/isono-0.2.19/lib/isono/rack/proc.rb:25:in `call'
        /opt/axsh/wakame-vdc/dcmgr/vendor/bundle/ruby/2.0.0/gems/isono-0.2.19/lib/isono/rack/map.rb:52:in `call'
        /opt/axsh/wakame-vdc/dcmgr/vendor/bundle/ruby/2.0.0/gems/isono-0.2.19/lib/isono/rack/map.rb:52:in `call'
        /opt/axsh/wakame-vdc/dcmgr/vendor/bundle/ruby/2.0.0/gems/isono-0.2.19/lib/isono/rack/builder.rb:36:in `call'
        /opt/axsh/wakame-vdc/dcmgr/vendor/bundle/ruby/2.0.0/gems/isono-0.2.19/lib/isono/rack/job.rb:59:in `block (2 levels) in call'
        /opt/axsh/wakame-vdc/dcmgr/vendor/bundle/ruby/2.0.0/gems/isono-0.2.19/lib/isono/node_modules/job_worker.rb:67:in `call'
        /opt/axsh/wakame-vdc/dcmgr/vendor/bundle/ruby/2.0.0/gems/isono-0.2.19/lib/isono/node_modules/job_worker.rb:67:in `block in start'
        /opt/axsh/wakame-vdc/dcmgr/vendor/bundle/ruby/2.0.0/gems/isono-0.2.19/lib/isono/thread_pool.rb:32:in `call'
        /opt/axsh/wakame-vdc/dcmgr/vendor/bundle/ruby/2.0.0/gems/isono-0.2.19/lib/isono/thread_pool.rb:32:in `block (2 levels) in initialize'