cinder/cinder/brick/initiator/linuxscsi.py

173 lines
6.3 KiB
Python

# (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__)
class LinuxSCSI(executor.Executor):
def __init__(self, root_helper, execute=putils.execute,
*args, **kwargs):
super(LinuxSCSI, self).__init__(root_helper, execute,
*args, **kwargs)
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)
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
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")
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
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'])
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})
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})
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