mirror of
https://github.com/virt-manager/virt-manager.git
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580 lines
18 KiB
Python
580 lines
18 KiB
Python
#
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# Storage lookup/creation helpers
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#
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# Copyright 2013 Red Hat, Inc.
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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# MA 02110-1301 USA.
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import logging
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import os
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import re
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import statvfs
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import libvirt
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from . import util
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from .storage import StoragePool, StorageVolume
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def _lookup_pool_by_dirname(conn, path):
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"""
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Try to find the parent pool for the passed path.
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If found, and the pool isn't running, attempt to start it up.
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return pool, or None if not found
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"""
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pool = StoragePool.lookup_pool_by_path(conn, os.path.dirname(path))
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if not pool:
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return None
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# Ensure pool is running
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if pool.info()[0] != libvirt.VIR_STORAGE_POOL_RUNNING:
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pool.create(0)
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return pool
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def _lookup_vol_by_path(conn, path):
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"""
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Try to find a volume matching the full passed path. Call info() on
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it to ensure the volume wasn't removed behind libvirt's back
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"""
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try:
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vol = conn.storageVolLookupByPath(path)
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vol.info()
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return vol, None
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except libvirt.libvirtError, e:
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if (hasattr(libvirt, "VIR_ERR_NO_STORAGE_VOL")
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and e.get_error_code() != libvirt.VIR_ERR_NO_STORAGE_VOL):
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raise
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return None, e
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def _lookup_vol_by_basename(pool, path):
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"""
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Try to lookup a volume for 'path' in parent 'pool' by it's filename.
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This sometimes works in cases where full volume path lookup doesn't,
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since not all libvirt storage backends implement path lookup.
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"""
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name = os.path.basename(path)
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if name in pool.listVolumes():
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return pool.lookupByName(name)
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def check_if_path_managed(conn, path):
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"""
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Try to lookup storage objects for the passed path.
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Returns (volume, parent pool). Only one is returned at a time.
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"""
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vol, ignore = _lookup_vol_by_path(conn, path)
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if vol:
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return vol, vol.storagePoolLookupByVolume()
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pool = _lookup_pool_by_dirname(conn, path)
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if not pool:
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return None, None
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# We have the parent pool, but didn't find a volume on first lookup
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# attempt. Refresh the pool and try again, incase we were just out
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# of date.
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try:
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pool.refresh(0)
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vol, verr = _lookup_vol_by_path(conn, path)
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if verr:
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try:
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vol = _lookup_vol_by_basename(pool, path)
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except:
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pass
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except Exception, e:
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vol = None
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pool = None
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verr = str(e)
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if not vol and not pool and verr:
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raise ValueError(_("Cannot use storage %(path)s: %(err)s") %
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{'path' : path, 'err' : verr})
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return vol, pool
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def _can_auto_manage(path):
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path = path or ""
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skip_prefixes = ["/dev", "/sys", "/proc"]
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if path_is_url(path):
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return False
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for prefix in skip_prefixes:
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if path.startswith(prefix + "/") or path == prefix:
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return False
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return True
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def manage_path(conn, path):
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"""
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If path is not managed, try to create a storage pool to probe the path
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"""
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if not conn.check_support(conn.SUPPORT_CONN_STORAGE):
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return None, None
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if not path:
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return None, None
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if not path_is_url(path):
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path = os.path.abspath(path)
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vol, pool = check_if_path_managed(conn, path)
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if vol or pool or not _can_auto_manage(path):
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return vol, pool
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dirname = os.path.dirname(path)
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poolname = os.path.basename(dirname).replace(" ", "_")
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if not poolname:
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poolname = "dirpool"
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poolname = StoragePool.find_free_name(conn, poolname)
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logging.debug("Attempting to build pool=%s target=%s", poolname, dirname)
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poolxml = StoragePool(conn)
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poolxml.name = poolname
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poolxml.type = poolxml.TYPE_DIR
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poolxml.target_path = dirname
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pool = poolxml.install(build=False, create=True, autostart=True)
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conn.clear_cache(pools=True)
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vol = _lookup_vol_by_basename(pool, path)
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return vol, pool
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def path_is_url(path):
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"""
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Detect if path is a URL
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"""
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if not path:
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return False
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return bool(re.match("[a-zA-Z]+(\+[a-zA-Z]+)?://.*", path))
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##############################################
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# Classes for tracking storage media details #
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##############################################
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class _StorageBase(object):
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"""
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Storage base class, defining the API used by VirtualDisk
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"""
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def __init__(self, conn):
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self._conn = conn
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self._parent_pool_xml = None
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def get_size(self):
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raise NotImplementedError()
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def get_dev_type(self):
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raise NotImplementedError()
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def get_driver_type(self):
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raise NotImplementedError()
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def get_vol_install(self):
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raise NotImplementedError()
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def get_vol_object(self):
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raise NotImplementedError()
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def get_parent_pool(self):
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raise NotImplementedError()
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def get_parent_pool_xml(self):
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if not self._parent_pool_xml and self.get_parent_pool():
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self._parent_pool_xml = StoragePool(self._conn,
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parsexml=self.get_parent_pool().XMLDesc(0))
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return self._parent_pool_xml
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def validate(self, disk):
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raise NotImplementedError()
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def get_path(self):
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raise NotImplementedError()
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# Storage creation routines
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def is_size_conflict(self):
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raise NotImplementedError()
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def create(self, progresscb):
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raise NotImplementedError()
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def will_create_storage(self):
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raise NotImplementedError()
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class _StorageCreator(_StorageBase):
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"""
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Base object for classes that will actually create storage on disk
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"""
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def __init__(self, conn):
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_StorageBase.__init__(self, conn)
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self._pool = None
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self._vol_install = None
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self._path = None
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self._size = None
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self._dev_type = None
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##############
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# Public API #
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##############
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def create(self, progresscb):
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raise NotImplementedError()
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def get_path(self):
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if self._vol_install and not self._path:
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xmlobj = StoragePool(self._conn,
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parsexml=self._vol_install.pool.XMLDesc(0))
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if self.get_dev_type() == "network":
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self._path = self._vol_install.name
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else:
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self._path = (xmlobj.target_path + "/" +
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self._vol_install.name)
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return self._path
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def get_vol_install(self):
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return self._vol_install
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def get_vol_xml(self):
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return self._vol_install
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def get_size(self):
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if self._size is None:
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self._size = (float(self._vol_install.capacity) /
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1024.0 / 1024.0 / 1024.0)
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return self._size
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def get_dev_type(self):
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if not self._dev_type:
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if self._vol_install:
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if self._vol_install.file_type == libvirt.VIR_STORAGE_VOL_FILE:
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self._dev_type = "file"
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elif (self._vol_install.file_type ==
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libvirt.VIR_STORAGE_VOL_NETWORK):
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self._dev_type = "network"
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else:
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self._dev_type = "block"
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else:
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self._dev_type = "file"
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return self._dev_type
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def get_driver_type(self):
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if self._vol_install:
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if self._vol_install.supports_property("format"):
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return self._vol_install.format
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return "raw"
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def validate(self, disk):
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if disk.device in ["floppy", "cdrom"]:
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raise ValueError(_("Cannot create storage for %s device.") %
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disk.device)
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if self._vol_install:
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self._vol_install.validate()
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else:
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if disk.type == "block":
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raise ValueError(_("Local block device path '%s' must "
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"exist.") % self.get_path())
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if self._size is None:
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raise ValueError(_("size is required for non-existent disk "
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"'%s'" % self.get_path()))
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err, msg = self.is_size_conflict()
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if err:
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raise ValueError(msg)
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if msg:
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logging.warn(msg)
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def will_create_storage(self):
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return True
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def get_vol_object(self):
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return None
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def get_parent_pool(self):
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if self._vol_install:
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return self._vol_install.pool
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return None
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def exists(self):
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return False
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class CloneStorageCreator(_StorageCreator):
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"""
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Handles manually copying local files for Cloner
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Many clone scenarios will use libvirt storage APIs, which will use
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the ManagedStorageCreator
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"""
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def __init__(self, conn, output_path, input_path, size, sparse):
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_StorageCreator.__init__(self, conn)
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self._path = output_path
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self._output_path = output_path
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self._input_path = input_path
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self._size = size
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self._sparse = sparse
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def is_size_conflict(self):
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ret = False
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msg = None
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vfs = os.statvfs(os.path.dirname(self._path))
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avail = vfs[statvfs.F_FRSIZE] * vfs[statvfs.F_BAVAIL]
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need = long(self._size * 1024L * 1024L * 1024L)
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if need > avail:
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if self._sparse:
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msg = _("The filesystem will not have enough free space"
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" to fully allocate the sparse file when the guest"
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" is running.")
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else:
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ret = True
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msg = _("There is not enough free space to create the disk.")
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if msg:
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msg += (_(" %d M requested > %d M available") %
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((need / (1024 * 1024)), (avail / (1024 * 1024))))
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return (ret, msg)
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def create(self, progresscb):
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text = (_("Cloning %(srcfile)s") %
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{'srcfile' : os.path.basename(self._input_path)})
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size_bytes = long(self.get_size() * 1024L * 1024L * 1024L)
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progresscb.start(filename=self._output_path, size=long(size_bytes),
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text=text)
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# Plain file clone
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self._clone_local(progresscb, size_bytes)
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def _clone_local(self, meter, size_bytes):
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if self._input_path == "/dev/null":
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# Not really sure why this check is here,
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# but keeping for compat
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logging.debug("Source dev was /dev/null. Skipping")
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return
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if self._input_path == self._output_path:
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logging.debug("Source and destination are the same. Skipping.")
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return
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# If a destination file exists and sparse flag is True,
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# this priority takes an existing file.
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if (not os.path.exists(self._output_path) and self._sparse):
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clone_block_size = 4096
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sparse = True
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fd = None
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try:
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fd = os.open(self._output_path, os.O_WRONLY | os.O_CREAT, 0640)
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os.ftruncate(fd, size_bytes)
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finally:
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if fd:
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os.close(fd)
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else:
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clone_block_size = 1024 * 1024 * 10
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sparse = False
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logging.debug("Local Cloning %s to %s, sparse=%s, block_size=%s",
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self._input_path, self._output_path,
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sparse, clone_block_size)
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zeros = '\0' * 4096
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src_fd, dst_fd = None, None
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try:
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try:
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src_fd = os.open(self._input_path, os.O_RDONLY)
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dst_fd = os.open(self._output_path,
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os.O_WRONLY | os.O_CREAT, 0640)
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i = 0
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while 1:
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l = os.read(src_fd, clone_block_size)
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s = len(l)
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if s == 0:
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meter.end(size_bytes)
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break
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# check sequence of zeros
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if sparse and zeros == l:
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os.lseek(dst_fd, s, 1)
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else:
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b = os.write(dst_fd, l)
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if s != b:
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meter.end(i)
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break
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i += s
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if i < size_bytes:
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meter.update(i)
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except OSError, e:
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raise RuntimeError(_("Error cloning diskimage %s to %s: %s") %
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(self._input_path, self._output_path, str(e)))
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finally:
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if src_fd is not None:
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os.close(src_fd)
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if dst_fd is not None:
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os.close(dst_fd)
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class ManagedStorageCreator(_StorageCreator):
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"""
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Handles storage creation via libvirt APIs. All the actual creation
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logic lives in StorageVolume, this is mostly about pulling out bits
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from that class and mapping them to VirtualDisk elements
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"""
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def __init__(self, conn, vol_install):
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_StorageCreator.__init__(self, conn)
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self._pool = vol_install.pool
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self._vol_install = vol_install
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def create(self, progresscb):
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return self._vol_install.install(meter=progresscb)
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def is_size_conflict(self):
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return self._vol_install.is_size_conflict()
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class StorageBackend(_StorageBase):
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"""
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Class that carries all the info about any existing storage that
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the disk references
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"""
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def __init__(self, conn, path, vol_object, parent_pool):
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_StorageBase.__init__(self, conn)
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self._vol_object = vol_object
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self._parent_pool = parent_pool
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self._path = path
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if self._vol_object is not None:
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self._path = None
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if self._vol_object and not self._parent_pool:
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raise RuntimeError(
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"programming error: parent_pool must be specified")
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# Cached bits
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self._vol_xml = None
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self._parent_pool_xml = None
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self._exists = None
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self._size = None
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self._dev_type = None
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##############
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# Public API #
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##############
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def get_path(self):
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if self._vol_object:
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return self.get_vol_xml().target_path
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return self._path
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def get_vol_object(self):
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return self._vol_object
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def get_vol_xml(self):
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if self._vol_xml is None:
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self._vol_xml = StorageVolume(self._conn,
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parsexml=self._vol_object.XMLDesc(0))
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return self._vol_xml
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def get_parent_pool(self):
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return self._parent_pool
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def get_size(self):
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"""
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Return size of existing storage
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"""
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if self._size is None:
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ret = 0
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if self._vol_object:
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ret = self.get_vol_xml().capacity
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elif self._path:
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ignore, ret = util.stat_disk(self._path)
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self._size = (float(ret) / 1024.0 / 1024.0 / 1024.0)
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return self._size
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def exists(self):
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if self._exists is None:
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if self._path is None:
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self._exists = True
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elif self._vol_object:
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self._exists = True
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elif (not self.get_dev_type() == "network" and
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not self._conn.is_remote() and
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os.path.exists(self._path)):
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self._exists = True
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elif self._parent_pool:
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self._exists = False
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elif self.get_dev_type() == "network":
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self._exists = True
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elif (self._conn.is_remote() and
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not _can_auto_manage(self._path)):
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# This allows users to pass /dev/sdX and we don't try to
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# validate it exists on the remote connection, since
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# autopooling /dev is perilous. Libvirt will error if
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# the device doesn't exist.
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self._exists = True
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else:
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self._exists = False
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return self._exists
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def get_dev_type(self):
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"""
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Return disk 'type' value per storage settings
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"""
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if self._dev_type is None:
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if self._vol_object:
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if self.get_vol_xml().type:
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self._dev_type = self.get_vol_xml().type
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else:
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t = self._vol_object.info()[0]
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if t == StorageVolume.TYPE_FILE:
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self._dev_type = "file"
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elif t == StorageVolume.TYPE_BLOCK:
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self._dev_type = "block"
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elif t == StorageVolume.TYPE_NETWORK:
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self._dev_type = "network"
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else:
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self._dev_type = "file"
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elif self._path and path_is_url(self._path):
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self._dev_type = "network"
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elif self._path and not self._conn.is_remote():
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if os.path.isdir(self._path):
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self._dev_type = "dir"
|
|
elif util.stat_disk(self._path)[0]:
|
|
self._dev_type = "file"
|
|
else:
|
|
self._dev_type = "block"
|
|
|
|
if not self._dev_type:
|
|
self._dev_type = "block"
|
|
return self._dev_type
|
|
|
|
def get_driver_type(self):
|
|
if self._vol_object:
|
|
ret = self.get_vol_xml().format
|
|
if ret != "unknown":
|
|
return ret
|
|
return None
|
|
|
|
def validate(self, disk):
|
|
ignore = disk
|
|
return
|
|
def get_vol_install(self):
|
|
return None
|
|
def is_size_conflict(self):
|
|
return (False, None)
|
|
def will_create_storage(self):
|
|
return False
|
|
def create(self, progresscb):
|
|
ignore = progresscb
|
|
raise RuntimeError("programming error: %s can't create storage" %
|
|
self.__class__.__name__)
|