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OpenStack Study: linuxscsi.py**** CubicPower OpenStack Study ****
# (c) Copyright 2013 Hewlett-Packard Development Company, L.P. # # Licensed under the Apache License, Version 2.0 (the "License"); you may # not use this file except in compliance with the License. You may obtain # a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the # License for the specific language governing permissions and limitations # under the License. """Generic linux scsi subsystem and Multipath utilities. Note, this is not iSCSI. """ import os from cinder.brick import executor from cinder.openstack.common.gettextutils import _ from cinder.openstack.common import log as logging from cinder.openstack.common import processutils as putils LOG = logging.getLogger(__name__)
**** CubicPower OpenStack Study **** class LinuxSCSI(executor.Executor):
**** CubicPower OpenStack Study **** def __init__(self, root_helper, execute=putils.execute, *args, **kwargs): super(LinuxSCSI, self).__init__(root_helper, execute, *args, **kwargs)
**** CubicPower OpenStack Study **** def echo_scsi_command(self, path, content): """Used to echo strings to scsi subsystem.""" args = ["-a", path] kwargs = dict(process_input=content, run_as_root=True, root_helper=self._root_helper) self._execute('tee', *args, **kwargs)
**** CubicPower OpenStack Study **** def get_name_from_path(self, path): """Translates /dev/disk/by-path/ entry to /dev/sdX.""" name = os.path.realpath(path) if name.startswith("/dev/"): return name else: return None
**** CubicPower OpenStack Study **** def remove_scsi_device(self, device): """Removes a scsi device based upon /dev/sdX name.""" path = "/sys/block/%s/device/delete" % device.replace("/dev/", "") if os.path.exists(path): LOG.debug("Remove SCSI device(%s) with %s" % (device, path)) self.echo_scsi_command(path, "1")
**** CubicPower OpenStack Study **** def get_device_info(self, device): (out, err) = self._execute('sg_scan', device, run_as_root=True, root_helper=self._root_helper) dev_info = {'device': device, 'host': None, 'channel': None, 'id': None, 'lun': None} if out: line = out.strip() line = line.replace(device + ": ", "") info = line.split(" ") for item in info: if '=' in item: pair = item.split('=') dev_info[pair[0]] = pair[1] elif 'scsi' in item: dev_info['host'] = item.replace('scsi', '') return dev_info
**** CubicPower OpenStack Study **** def remove_multipath_device(self, multipath_name): """This removes LUNs associated with a multipath device and the multipath device itself. """ LOG.debug("remove multipath device %s" % multipath_name) mpath_dev = self.find_multipath_device(multipath_name) if mpath_dev: devices = mpath_dev['devices'] LOG.debug("multipath LUNs to remove %s" % devices) for device in devices: self.remove_scsi_device(device['device']) self.flush_multipath_device(mpath_dev['id'])
**** CubicPower OpenStack Study **** def flush_multipath_device(self, device): try: self._execute('multipath', '-f', device, run_as_root=True, root_helper=self._root_helper) except putils.ProcessExecutionError as exc: LOG.warn(_("multipath call failed exit (%(code)s)") % {'code': exc.exit_code})
**** CubicPower OpenStack Study **** def flush_multipath_devices(self): try: self._execute('multipath', '-F', run_as_root=True, root_helper=self._root_helper) except putils.ProcessExecutionError as exc: LOG.warn(_("multipath call failed exit (%(code)s)") % {'code': exc.exit_code})
**** CubicPower OpenStack Study **** def find_multipath_device(self, device): """Find a multipath device associated with a LUN device name. device can be either a /dev/sdX entry or a multipath id. """ mdev = None devices = [] out = None try: (out, err) = self._execute('multipath', '-l', device, run_as_root=True, root_helper=self._root_helper) except putils.ProcessExecutionError as exc: LOG.warn(_("multipath call failed exit (%(code)s)") % {'code': exc.exit_code}) return None if out: lines = out.strip() lines = lines.split("\n") if lines: line = lines[0] info = line.split(" ") # device line output is different depending # on /etc/multipath.conf settings. if info[1][:2] == "dm": mdev = "/dev/%s" % info[1] mdev_id = info[0] elif info[2][:2] == "dm": mdev = "/dev/%s" % info[2] mdev_id = info[1].replace('(', '') mdev_id = mdev_id.replace(')', '') if mdev is None: LOG.warn(_("Couldn't find multipath device %(line)s") % {'line': line}) return None LOG.debug(_("Found multipath device = %(mdev)s") % {'mdev': mdev}) device_lines = lines[3:] for dev_line in device_lines: if dev_line.find("policy") != -1: continue dev_line = dev_line.lstrip(' |-`') dev_info = dev_line.split() address = dev_info[0].split(":") dev = {'device': '/dev/%s' % dev_info[1], 'host': address[0], 'channel': address[1], 'id': address[2], 'lun': address[3] } devices.append(dev) if mdev is not None: info = {"device": mdev, "id": mdev_id, "devices": devices} return info return None
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