[Kimchi-devel] [PATCHv3 4/5] Add volume ref_cnt: Add model and mockmodel implementation
Sheldon
shaohef at linux.vnet.ibm.com
Tue Feb 25 10:29:15 UTC 2014
volume ref_cnt is useful for storage pool integrity verification.
But we should be care for ref_cnt.
some questions about this ref_cnt.
only when all volume ref_cnt of a storage pool(all types of pool) is zero
1. we can delete this storage pool, for all types of pool, right?
2. we can deactivate this storage pool, for all types of pool, right?
when we decrease ref_cnt?
1. VM is deleted? the ref_cnt of attached volume will decrease?
2. VM is deleted outside kimchi scope, we should decrease the ref_cnt?
you increase storage volume ref_cn when a vm is created outside kimchi
scope.
3. A volume detached from a vm inside or outside kimchi scope.
and now, the kimchi can avoid the ref_cnt race right?
when a request get ref_cnt, and another request is decrease or increase
ref_cnt at the same time?
from your code:
+ vms = VMsModel(**args).get_list()
which is better ?
VMsModel(**args).get_list() or self.vms_get_list()
On 02/25/2014 04:35 PM, lvroyce at linux.vnet.ibm.com wrote:
> From: Royce Lv <lvroyce at linux.vnet.ibm.com>
>
> Set ref_cnt to 0 when new volume created,
> if the ref_cnt cannot be found,
> which means it is created outside of kimchi scope,
> report it when lookup storage volume,
> search info about storage volumes used by vms and count the ref_cnt.
>
> Signed-off-by: Royce Lv <lvroyce at linux.vnet.ibm.com>
> ---
> src/kimchi/mockmodel.py | 3 +++
> src/kimchi/model/storagevolumes.py | 31 +++++++++++++++++++++++++++++++
> 2 files changed, 34 insertions(+)
>
> diff --git a/src/kimchi/mockmodel.py b/src/kimchi/mockmodel.py
> index b50bf31..7620d38 100644
> --- a/src/kimchi/mockmodel.py
> +++ b/src/kimchi/mockmodel.py
> @@ -423,6 +423,7 @@ class MockModel(object):
> name = params['name']
> volume = MockStorageVolume(pool, name, params)
> volume.info['type'] = params['type']
> + volume.info['ref_cnt'] = params.get('ref_cnt', 0)
> volume.info['format'] = params['format']
> volume.info['path'] = os.path.join(
> pool.info['path'], name)
> @@ -884,6 +885,7 @@ class MockVMTemplate(VMTemplate):
> disk_paths = []
> for vol_info in volumes:
> vol_info['capacity'] = vol_info['capacity'] << 10
> + vol_info['ref_cnt'] = 1
> self.model.storagevolumes_create(pool.name, vol_info)
> disk_paths.append({'pool': pool.name, 'volume': vol_info['name']})
> return disk_paths
> @@ -1002,6 +1004,7 @@ class MockStorageVolume(object):
> 'capacity': capacity << 20,
> 'allocation': params.get('allocation', '512'),
> 'path': params.get('path'),
> + 'ref_cnt': params.get('ref_cnt'),
> 'format': fmt}
> if fmt == 'iso':
> self.info['allocation'] = self.info['capacity']
> diff --git a/src/kimchi/model/storagevolumes.py b/src/kimchi/model/storagevolumes.py
> index 20c65b9..9906f33 100644
> --- a/src/kimchi/model/storagevolumes.py
> +++ b/src/kimchi/model/storagevolumes.py
> @@ -29,6 +29,8 @@ from kimchi.exception import InvalidOperation, IsoFormatError
> from kimchi.exception import MissingParameter, NotFoundError, OperationFailed
> from kimchi.isoinfo import IsoImage
> from kimchi.model.storagepools import StoragePoolModel
> +from kimchi.model.vms import VMsModel
> +from kimchi.model.vmstorages import VMStoragesModel, VMStorageModel
>
>
> VOLUME_TYPE_MAP = {0: 'file',
> @@ -40,6 +42,7 @@ VOLUME_TYPE_MAP = {0: 'file',
> class StorageVolumesModel(object):
> def __init__(self, **kargs):
> self.conn = kargs['conn']
> + self.objstore = kargs['objstore']
>
> def create(self, pool, params):
> vol_xml = """
> @@ -58,6 +61,7 @@ class StorageVolumesModel(object):
> params.setdefault('format', 'qcow2')
>
> name = params['name']
> + vol_id = '%s:%s' % (pool, name)
> try:
> pool = StoragePoolModel.get_storagepool(pool, self.conn)
> xml = vol_xml % params
> @@ -71,6 +75,10 @@ class StorageVolumesModel(object):
> raise OperationFailed("KCHVOL0007E",
> {'name': name, 'pool': pool,
> 'err': e.get_error_message()})
> +
> + with self.objstore as session:
> + session.store('storagevolume', vol_id, {'ref_cnt': 0})
> +
> return name
>
> def get_list(self, pool_name):
> @@ -89,6 +97,7 @@ class StorageVolumesModel(object):
> class StorageVolumeModel(object):
> def __init__(self, **kargs):
> self.conn = kargs['conn']
> + self.objstore = kargs['objstore']
>
> def _get_storagevolume(self, pool, name):
> pool = StoragePoolModel.get_storagepool(pool, self.conn)
> @@ -103,16 +112,38 @@ class StorageVolumeModel(object):
> else:
> raise
>
> + def _get_ref_cnt(self, pool, name, path):
> + vol_id = '%s:%s' % (pool, name)
> + with self.objstore as session:
> + try:
> + ref_cnt = session.get('storagevolume', vol_id)['ref_cnt']
> + except NotFoundError:
> + # Fix storage volume created outside kimchi scope
> + ref_cnt = 0
> + args = {'conn': self.conn, 'objstore': self.objstore}
> + # try to find this volume in exsisted vm
> + vms = VMsModel(**args).get_list()
> + for vm in vms:
> + storages = VMStoragesModel(**args).get_list(vm)
> + for disk in storages:
> + if path == VMStorageModel(**args).lookup(vm, disk)['path']:
> + ref_cnt = ref_cnt + 1
> + session.store('storagevolume', vol_id, {'ref_cnt': ref_cnt})
> +
> + return ref_cnt
> +
> def lookup(self, pool, name):
> vol = self._get_storagevolume(pool, name)
> path = vol.path()
> info = vol.info()
> xml = vol.XMLDesc(0)
> fmt = xmlutils.xpath_get_text(xml, "/volume/target/format/@type")[0]
> + ref_cnt = self._get_ref_cnt(pool, name, path)
> res = dict(type=VOLUME_TYPE_MAP[info[0]],
> capacity=info[1],
> allocation=info[2],
> path=path,
> + ref_cnt=ref_cnt,
> format=fmt)
> if fmt == 'iso':
> if os.path.islink(path):
--
Thanks and best regards!
Sheldon Feng(冯少合)<shaohef at linux.vnet.ibm.com>
IBM Linux Technology Center
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