# Copyright 2017 Red Hat, Inc. # # 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. import logging from diskimage_builder.block_device.exception \ import BlockDeviceSetupException from diskimage_builder.block_device.plugin import NodeBase from diskimage_builder.block_device.plugin import PluginBase from diskimage_builder.block_device.utils import exec_sudo from diskimage_builder.block_device.utils import parse_abs_size_spec PHYSICAL_EXTENT_BYTES = parse_abs_size_spec('4MiB') LVS_TYPES = ['thin', 'thin-pool'] logger = logging.getLogger(__name__) # # LVM # --- # # The LVM config has three required keys; pvs, vgs and lvs # # lvm: -> LVSNode # pvs: -> PvsNode # lvs: -> LvsNode # vgs: -> VgsNode # # The LVMPlugin will verify this and build nodes into the # configuration graph. # # As described below, a LVSNode is created for synchronisation # purposes. Thus if you had something like two partitions that became # two physical-volumes (pv1 & pv2), that you then combine into a # single volume group (vg) and then create several logical volumes # (lv1, lv2, lv3) your graph would end up looking like: # # partition1 partition2 # | | # ---> LVSNode <--+ # | # +------+------+ # v v # pv1 pv2 # | | # +--> vg <---+ # | # +-----+-----+ # v v v # lv1 lv2 lv3 # # After the create() call on the LVSNode object, the entire LVM setup # would actually be complete. The other nodes are all just # place-holders, and are used for further ordering (for example, the # fs creation & mounting should depend on the logical volume nodes). # For this reason, their create() calls are blank. However, for code # organisational purposes they have a private _create() and _cleanup() # call that is driven by the LVSNode object. def lvremove(device_name): logger.debug('Removing logical volume %s', device_name) try: exec_sudo(["lvchange", "--activate", "n", device_name]) exec_sudo(["lvremove", "--yes", "/dev/%s" % device_name]) except BlockDeviceSetupException as e: # Do not raise an error - maybe other cleanup methods # can at least do some more work. logger.warning("Removing logical volume failed (%s)", e.returncode) def vgremove(vg_name): logger.debug('Removing volume group %s', vg_name) try: exec_sudo(["vgremove", "--yes", "--force", vg_name]) except BlockDeviceSetupException as e: # Do not raise an error - maybe other cleanup methods # can at least do some more work. logger.warning("Removing volume group failed (%s)", e.returncode) class PvsNode(NodeBase): def __init__(self, name, state, base, options): """Physical volume This is a placeholder node for the LVM physical volumes. Arguments: :param name: Name of this node :param state: global state pointer :param base: Parent partition :param options: config options """ super(PvsNode, self).__init__(name, state) self.base = base self.options = options def _create(self): # the underlying device path of our parent was previously # recorded into the state during blockdev creation; look it # up. phys_dev = self.state['blockdev'][self.base]['device'] cmd = ["pvcreate"] cmd.append(phys_dev) if self.options: cmd.extend(self.options) logger.debug("Creating pv command [%s]", cmd) exec_sudo(cmd) # save state if 'pvs' not in self.state: self.state['pvs'] = {} self.state['pvs'][self.name] = { 'opts': self.options, 'device': phys_dev } def get_edges(self): # See LVMNode.get_edges() for how this gets connected return ([], []) def create(self): # see notes in LVMNode object pass class VgsNode(NodeBase): def __init__(self, name, state, base, options): """Volume Group This is a placeholder node for a volume group Arguments: :param name: Name of this node :param state: global state pointer :param base: Parent :class:`PvsNodes` this volume group exists on :param options: extra options passed to the `vgcreate` command """ super(VgsNode, self).__init__(name, state) self.base = base self.options = options def _create(self): # The PV's have saved their actual device name into the state # during their _create(). Look at our base elements and thus # find the underlying device paths in the state. pvs_devs = [] for pv in self.base: pvs_dev = self.state['pvs'][pv]['device'] pvs_devs.append(pvs_dev) cmd = ["vgcreate", ] cmd.append(self.name) cmd.extend(pvs_devs) if self.options: cmd.extend(self.options) logger.debug("Creating vg command [%s]", cmd) exec_sudo(cmd) self.add_rollback(vgremove, self.name) # save state if 'vgs' not in self.state: self.state['vgs'] = {} self.state['vgs'][self.name] = { 'opts': self.options, 'devices': self.base, } def _umount(self): exec_sudo(['vgchange', '-an', self.name]) def get_edges(self): # self.base is already a list, per the config. There might be # multiple pv parents here. edge_from = self.base edge_to = [] return (edge_from, edge_to) def create(self): # see notes in LVMNode object pass class LvsNode(NodeBase): def __init__(self, name, state, base, options, size, extents, segtype, thin_pool): """Logical Volume This is a placeholder node for a logical volume Arguments: :param name: Name of this node :param state: global state pointer :param base: the parent volume group :param options: options passed to lvcreate :param size: size of the LV, using the supported unit types (MB, MiB, etc) :param extents: size of the LV in extents :param segtype: value passed to segment type, supports thin and thin-pool :param thin_pool: name of the thin pool to create this volume from """ super(LvsNode, self).__init__(name, state) self.base = base self.options = options self.size = size self.extents = extents self.type = segtype self.thin_pool = thin_pool def _create(self): cmd = ["lvcreate", ] cmd.extend(['--name', self.name]) if self.type: cmd.extend(['--type', self.type]) if self.thin_pool: cmd.extend(['--thin-pool', self.thin_pool]) if self.size: size = parse_abs_size_spec(self.size) # ensuire size aligns with physical extents size = size - size % PHYSICAL_EXTENT_BYTES size_arg = '-V' if self.type == 'thin' else '-L' cmd.extend([size_arg, '%dB' % size]) elif self.extents: cmd.extend(['-l', self.extents]) if self.options: cmd.extend(self.options) cmd.append(self.base) logger.debug("Creating lv command [%s]", cmd) exec_sudo(cmd) # save state device_name = '%s-%s' % (self.base, self.name) self.state['blockdev'][self.name] = { 'vgs': self.base, 'size': self.size, 'extents': self.extents, 'opts': self.options, 'device': '/dev/mapper/%s' % device_name } self.add_rollback(lvremove, "%s/%s" % (self.base, self.name)) def _umount(self): exec_sudo(['lvchange', '-an', '/dev/%s/%s' % (self.base, self.name)]) def get_edges(self): edge_from = [self.base] edge_to = [] return (edge_from, edge_to) def create(self): # see notes in LVMNode object pass class LVMNode(NodeBase): def __init__(self, name, state, pvs, lvs, vgs): """LVM Driver Node This is the "global" node where all LVM operations are driven from. In the node graph, the LVM physical-volumes depend on this node. This node then depends on the devices that the PV's require. This node incorporates *all* LVM setup; i.e. after the create() call here we have created all pv's, lv's and vg. The Node objects in the graph are therefore just dependency place holders whose create() call does nothing. Arguments: :param name: name of this node :param state: global state pointer :param pvs: A list of :class:`PvsNode` objects :param lvs: A list of :class:`LvsNode` objects :param vgs: A list of :class:`VgsNode` objects """ super(LVMNode, self).__init__(name, state) self.pvs = pvs self.lvs = lvs self.vgs = vgs def get_edges(self): # This node requires the physical device(s), which is # recorded in the "base" argument of the PV nodes. pvs = [] for pv in self.pvs: pvs.append(pv.base) edge_from = set(pvs) # The PV nodes should then depend on us. i.e., we just made # this node a synchronisation point edge_to = [pv.name for pv in self.pvs] return (edge_from, edge_to) def create(self): # Run through pvs->vgs->lvs and create them # XXX: we could theoretically get this same info from walking # the graph of our children nodes? Would that be helpful in # any way? for pvs in self.pvs: pvs._create() for vgs in self.vgs: vgs._create() for lvs in self.lvs: lvs._create() def umount(self): for lvs in self.lvs: lvs._umount() for vgs in self.vgs: vgs._umount() exec_sudo(['udevadm', 'settle']) def cleanup(self): # Information about the PV, VG and LV is typically # cached in lvmetad. Even after removing PV device and # partitions this data is not automatically updated # which leads to a couple of problems. # the 'pvscan --cache' scans the available disks # and updates the cache. # This is in cleanup because it must be called after the # umount of the containing block device is done, (which should # all be done in umount phase). try: exec_sudo(['pvscan', '--cache']) except BlockDeviceSetupException as e: logger.info("pvscan call failed [%s]", e.returncode) class LVMPlugin(PluginBase): def _config_error(self, msg): raise BlockDeviceSetupException(msg) def __init__(self, config, defaults, state): """Build LVM nodes This reads the "lvm:" config stanza, validates it and produces the PV, VG and LV nodes. These are all synchronised via a LVMNode as described above. Arguments: :param config: "lvm" configuration dictionary :param defaults: global defaults dictionary :param state: global state reference """ super(LVMPlugin, self).__init__() # note lvm: doesn't require a base ... the base is the # physical devices the "pvs" nodes are made on. if 'name' not in config: self._config_error("Lvm config requires 'name'") if 'pvs' not in config: self._config_error("Lvm config requires a 'pvs'") if 'vgs' not in config: self._config_error("Lvm config needs 'vgs'") if 'lvs' not in config: self._config_error("Lvm config needs 'lvs'") # create physical volume nodes self.pvs = [] self.pvs_keys = [] for pvs_cfg in config['pvs']: if 'name' not in pvs_cfg: self._config_error("Missing 'name' in pvs config") if 'base' not in pvs_cfg: self._config_error("Missing 'base' in pvs_config") pvs_item = PvsNode(pvs_cfg['name'], state, pvs_cfg['base'], pvs_cfg.get('options')) self.pvs.append(pvs_item) # create volume group nodes self.vgs = [] self.vgs_keys = [] for vgs_cfg in config['vgs']: if 'name' not in vgs_cfg: self._config_error("Missing 'name' in vgs config") if 'base' not in vgs_cfg: self._config_error("Missing 'base' in vgs config") # Ensure we have a valid PVs backing this VG for pvs in vgs_cfg['base']: if not any(pv.name == pvs for pv in self.pvs): self._config_error("base:%s in vgs does not " "match a valid pvs" % pvs) vgs_item = VgsNode(vgs_cfg['name'], state, vgs_cfg['base'], vgs_cfg.get('options', None)) self.vgs.append(vgs_item) # create logical volume nodes self.lvs = [] for lvs_cfg in config['lvs']: if 'name' not in lvs_cfg: self._config_error("Missing 'name' in lvs config") if 'base' not in lvs_cfg: self._config_error("Missing 'base' in lvs config") if 'size' not in lvs_cfg and 'extents' not in lvs_cfg: self._config_error("Missing 'size' or 'extents' in lvs config") # ensure this logical volume has a valid volume group base if not any(vg.name == lvs_cfg['base'] for vg in self.vgs): self._config_error("base:%s in lvs does not match a valid vg" % lvs_cfg['base']) if 'type' in lvs_cfg: if lvs_cfg['type'] not in LVS_TYPES: self._config_error( "Unsupported type:%s, supported types: %s" % (lvs_cfg['type'], ', '.join(LVS_TYPES))) lvs_item = LvsNode(lvs_cfg['name'], state, lvs_cfg['base'], lvs_cfg.get('options', None), lvs_cfg.get('size', None), lvs_cfg.get('extents', None), lvs_cfg.get('type', None), lvs_cfg.get('thin-pool', None)) self.lvs.append(lvs_item) # create the "driver" node self.lvm_node = LVMNode(config['name'], state, self.pvs, self.lvs, self.vgs) def get_nodes(self): # the nodes for insertion into the graph are all of the pvs, # vgs and lvs nodes we have created above and the root node and # the cleanup node. return self.pvs + self.vgs + self.lvs \ + [self.lvm_node]