def _verify_cache_volume(self, context, img_meta,
img_service, cachevol_props):
"""Verify if we have a cache volume that we want.
If we don't, create one.
If we do, check if it's been updated:
* If so, delete it and recreate a new volume
* If not, we are good.
If it's out of date, delete it and create a new one.
After the function returns, there should be a cache volume available,
ready for cloning.
"""
lcfg = self.configuration
cache_dir = '%s/' % lcfg.zfssa_cache_directory
cache_vol_obj = Volume()
cache_vol_obj.provider_location = self.mount_path + '/' + cache_dir
cache_vol_obj._name_id = cachevol_props['id']
cachevol_name = cache_dir + cache_vol_obj.name
LOG.debug('Verifying cache volume %s:', cachevol_name)
try:
cache_vol = self.zfssa.get_volume(cachevol_name)
except exception.VolumeNotFound:
# There is no existing cache volume, create one:
LOG.debug('Cache volume not found. Creating one...')
return self._create_cache_volume(context,
img_meta,
img_service,
cachevol_props)
# A cache volume does exist, check if it's updated:
if ((cache_vol['updated_at'] != cachevol_props['updated_at']) or
(cache_vol['image_id'] != cachevol_props['image_id'])):
if cache_vol['numclones'] > 0:
# The cache volume is updated, but has clones
exception_msg = (_('Cannot delete '
'cache volume: %(cachevol_name)s. '
'It was updated at %(updated_at)s '
'and currently has %(numclones)d '
'volume instances.'),
{'cachevol_name': cachevol_name,
'updated_at': cachevol_props['updated_at'],
'numclones': cache_vol['numclones']})
LOG.error(exception_msg)
raise exception.VolumeBackendAPIException(data=exception_msg)
# The cache volume is updated, but has no clone, so we delete it
# and re-create a new one:
super(ZFSSANFSDriver, self).delete_volume(cache_vol_obj)
return self._create_cache_volume(context,
img_meta,
img_service,
cachevol_props)
return cachevol_name
def _create_cache_volume(self, context, img_meta, img_service,
cachevol_props):
"""Create a cache volume from an image.
Returns name of the cache volume.
"""
lcfg = self.configuration
cache_dir = '%s/' % lcfg.zfssa_cache_directory
cache_vol = Volume()
cache_vol.provider_location = self.mount_path
cache_vol._name_id = cachevol_props['id']
cache_vol.size = cachevol_props['size']
cache_vol_name = cache_dir + cache_vol.name
LOG.debug('Creating cache volume %s', cache_vol_name)
try:
self.create_volume(cache_vol)
LOG.debug('Copying image data:')
super(ZFSSANFSDriver,
self).copy_image_to_volume(context, cache_vol, img_service,
img_meta['id'])
self.zfssa.webdavclient.request(src_file=cache_vol.name,
dst_file=cache_vol_name,
method='MOVE')
except Exception as exc:
exc_msg = (_('Fail to create cache volume %(volume)s. '
'Error: %(err)s'), {
'volume': cache_vol_name,
'err': six.text_type(exc)
})
LOG.error(exc_msg)
self.zfssa.delete_file(cache_vol_name)
raise exception.VolumeBackendAPIException(data=exc_msg)
cachevol_meta = {
'updated_at': cachevol_props['updated_at'],
'image_id': cachevol_props['image_id'],
}
cachevol_meta.update({'numclones': '0'})
self.zfssa.set_file_props(cache_vol_name, cachevol_meta)
return cache_vol_name
def _create_cache_volume(self, context, img_meta,
img_service, cachevol_props):
"""Create a cache volume from an image.
Returns name of the cache volume.
"""
lcfg = self.configuration
cache_dir = '%s/' % lcfg.zfssa_cache_directory
cache_vol = Volume()
cache_vol.provider_location = self.mount_path
cache_vol._name_id = cachevol_props['id']
cache_vol.size = cachevol_props['size']
cache_vol_name = cache_dir + cache_vol.name
LOG.debug('Creating cache volume %s', cache_vol_name)
try:
self.create_volume(cache_vol)
LOG.debug('Copying image data:')
super(ZFSSANFSDriver, self).copy_image_to_volume(context,
cache_vol,
img_service,
img_meta['id'])
self.zfssa.webdavclient.request(src_file=cache_vol.name,
dst_file=cache_vol_name,
method='MOVE')
except Exception as exc:
exc_msg = (_('Fail to create cache volume %(volume)s. '
'Error: %(err)s'),
{'volume': cache_vol_name,
'err': six.text_type(exc)})
LOG.error(exc_msg)
self.zfssa.delete_file(cache_vol_name)
raise exception.VolumeBackendAPIException(data=exc_msg)
cachevol_meta = {
'updated_at': cachevol_props['updated_at'],
'image_id': cachevol_props['image_id'],
}
cachevol_meta.update({'numclones': '0'})
self.zfssa.set_file_props(cache_vol_name, cachevol_meta)
return cache_vol_name
