615 lines
18 KiB
Python
615 lines
18 KiB
Python
#
|
|
# Storage lookup/creation helpers
|
|
#
|
|
# Copyright 2013 Red Hat, Inc.
|
|
#
|
|
# This work is licensed under the GNU GPLv2 or later.
|
|
# See the COPYING file in the top-level directory.
|
|
|
|
import logging
|
|
import os
|
|
import re
|
|
import stat
|
|
|
|
import libvirt
|
|
|
|
from .storage import StoragePool, StorageVolume
|
|
|
|
|
|
def _lookup_pool_by_dirname(conn, path):
|
|
"""
|
|
Try to find the parent pool for the passed path.
|
|
If found, and the pool isn't running, attempt to start it up.
|
|
|
|
return pool, or None if not found
|
|
"""
|
|
pool = StoragePool.lookup_pool_by_path(conn, os.path.dirname(path))
|
|
if not pool:
|
|
return None
|
|
|
|
# Ensure pool is running
|
|
if pool.info()[0] != libvirt.VIR_STORAGE_POOL_RUNNING:
|
|
pool.create(0)
|
|
return pool
|
|
|
|
|
|
def _lookup_vol_by_path(conn, path):
|
|
"""
|
|
Try to find a volume matching the full passed path. Call info() on
|
|
it to ensure the volume wasn't removed behind libvirt's back
|
|
"""
|
|
try:
|
|
vol = conn.storageVolLookupByPath(path)
|
|
vol.info()
|
|
return vol, None
|
|
except libvirt.libvirtError as e:
|
|
if (hasattr(libvirt, "VIR_ERR_NO_STORAGE_VOL") and
|
|
e.get_error_code() != libvirt.VIR_ERR_NO_STORAGE_VOL):
|
|
raise
|
|
return None, e
|
|
|
|
|
|
def _lookup_vol_by_basename(pool, path):
|
|
"""
|
|
Try to lookup a volume for 'path' in parent 'pool' by it's filename.
|
|
This sometimes works in cases where full volume path lookup doesn't,
|
|
since not all libvirt storage backends implement path lookup.
|
|
"""
|
|
name = os.path.basename(path)
|
|
if name in pool.listVolumes():
|
|
return pool.storageVolLookupByName(name)
|
|
|
|
|
|
def _stat_disk(path):
|
|
"""
|
|
Returns the tuple (isreg, size)
|
|
"""
|
|
if not os.path.exists(path):
|
|
return True, 0
|
|
|
|
mode = os.stat(path)[stat.ST_MODE]
|
|
|
|
# os.path.getsize('/dev/..') can be zero on some platforms
|
|
if stat.S_ISBLK(mode):
|
|
try:
|
|
fd = os.open(path, os.O_RDONLY)
|
|
# os.SEEK_END is not present on all systems
|
|
size = os.lseek(fd, 0, 2)
|
|
os.close(fd)
|
|
except Exception:
|
|
size = 0
|
|
return False, size
|
|
elif stat.S_ISREG(mode):
|
|
return True, os.path.getsize(path)
|
|
|
|
return True, 0
|
|
|
|
|
|
def check_if_path_managed(conn, path):
|
|
"""
|
|
Try to lookup storage objects for the passed path.
|
|
|
|
Returns (volume, parent pool). Only one is returned at a time.
|
|
"""
|
|
vol, ignore = _lookup_vol_by_path(conn, path)
|
|
if vol:
|
|
return vol, vol.storagePoolLookupByVolume()
|
|
|
|
pool = _lookup_pool_by_dirname(conn, path)
|
|
if not pool:
|
|
return None, None
|
|
|
|
# We have the parent pool, but didn't find a volume on first lookup
|
|
# attempt. Refresh the pool and try again, incase we were just out
|
|
# of date.
|
|
try:
|
|
pool.refresh(0)
|
|
vol, verr = _lookup_vol_by_path(conn, path)
|
|
if verr:
|
|
try:
|
|
vol = _lookup_vol_by_basename(pool, path)
|
|
except Exception:
|
|
pass
|
|
except Exception as e:
|
|
vol = None
|
|
pool = None
|
|
verr = str(e)
|
|
|
|
if not vol and not pool and verr:
|
|
raise ValueError(_("Cannot use storage %(path)s: %(err)s") %
|
|
{'path': path, 'err': verr})
|
|
|
|
return vol, pool
|
|
|
|
|
|
def _can_auto_manage(path):
|
|
path = path or ""
|
|
skip_prefixes = ["/dev", "/sys", "/proc"]
|
|
|
|
if path_is_url(path):
|
|
return False
|
|
|
|
for prefix in skip_prefixes:
|
|
if path.startswith(prefix + "/") or path == prefix:
|
|
return False
|
|
return True
|
|
|
|
|
|
def manage_path(conn, path):
|
|
"""
|
|
If path is not managed, try to create a storage pool to probe the path
|
|
"""
|
|
if not conn.check_support(conn.SUPPORT_CONN_STORAGE):
|
|
return None, None
|
|
if not path:
|
|
return None, None
|
|
|
|
if not path_is_url(path):
|
|
path = os.path.abspath(path)
|
|
vol, pool = check_if_path_managed(conn, path)
|
|
if vol or pool or not _can_auto_manage(path):
|
|
return vol, pool
|
|
|
|
dirname = os.path.dirname(path)
|
|
poolname = os.path.basename(dirname).replace(" ", "_")
|
|
if not poolname:
|
|
poolname = "dirpool"
|
|
poolname = StoragePool.find_free_name(conn, poolname)
|
|
logging.debug("Attempting to build pool=%s target=%s", poolname, dirname)
|
|
|
|
poolxml = StoragePool(conn)
|
|
poolxml.name = poolname
|
|
poolxml.type = poolxml.TYPE_DIR
|
|
poolxml.target_path = dirname
|
|
pool = poolxml.install(build=False, create=True, autostart=True)
|
|
|
|
vol = _lookup_vol_by_basename(pool, path)
|
|
return vol, pool
|
|
|
|
|
|
def path_is_url(path):
|
|
"""
|
|
Detect if path is a URL
|
|
"""
|
|
if not path:
|
|
return False
|
|
return bool(re.match("[a-zA-Z]+(\+[a-zA-Z]+)?://.*", path))
|
|
|
|
|
|
def _get_dev_type(path, vol_xml, vol_object, pool_xml, remote):
|
|
"""
|
|
Try to get device type for volume.
|
|
"""
|
|
if vol_xml:
|
|
if vol_xml.type:
|
|
return vol_xml.type
|
|
|
|
# If vol_xml.type is None the vol_xml.file_type can return only
|
|
# these types: block, network or file
|
|
if vol_xml.file_type == libvirt.VIR_STORAGE_VOL_BLOCK:
|
|
return "block"
|
|
elif vol_xml.file_type == libvirt.VIR_STORAGE_VOL_NETWORK:
|
|
return "network"
|
|
|
|
if vol_object:
|
|
t = vol_object.info()[0]
|
|
if t == StorageVolume.TYPE_FILE:
|
|
return "file"
|
|
elif t == StorageVolume.TYPE_BLOCK:
|
|
return "block"
|
|
elif t == StorageVolume.TYPE_NETWORK:
|
|
return "network"
|
|
|
|
if pool_xml:
|
|
t = pool_xml.get_disk_type()
|
|
if t == StorageVolume.TYPE_BLOCK:
|
|
return "block"
|
|
elif t == StorageVolume.TYPE_NETWORK:
|
|
return "network"
|
|
|
|
if path:
|
|
if path_is_url(path):
|
|
return "network"
|
|
|
|
if not remote:
|
|
if os.path.isdir(path):
|
|
return "dir"
|
|
elif _stat_disk(path)[0]:
|
|
return "file"
|
|
else:
|
|
return "block"
|
|
|
|
return "file"
|
|
|
|
|
|
##############################################
|
|
# Classes for tracking storage media details #
|
|
##############################################
|
|
|
|
class _StorageBase(object):
|
|
"""
|
|
Storage base class, defining the API used by DeviceDisk
|
|
"""
|
|
def __init__(self, conn):
|
|
self._conn = conn
|
|
self._parent_pool_xml = None
|
|
|
|
def get_size(self):
|
|
raise NotImplementedError()
|
|
def get_dev_type(self):
|
|
raise NotImplementedError()
|
|
def get_driver_type(self):
|
|
raise NotImplementedError()
|
|
def get_vol_install(self):
|
|
raise NotImplementedError()
|
|
def get_vol_object(self):
|
|
raise NotImplementedError()
|
|
def get_parent_pool(self):
|
|
raise NotImplementedError()
|
|
def get_parent_pool_xml(self):
|
|
if not self._parent_pool_xml and self.get_parent_pool():
|
|
self._parent_pool_xml = StoragePool(self._conn,
|
|
parsexml=self.get_parent_pool().XMLDesc(0))
|
|
return self._parent_pool_xml
|
|
def validate(self, disk):
|
|
raise NotImplementedError()
|
|
def get_path(self):
|
|
raise NotImplementedError()
|
|
|
|
# Storage creation routines
|
|
def is_size_conflict(self):
|
|
raise NotImplementedError()
|
|
def create(self, progresscb):
|
|
raise NotImplementedError()
|
|
def will_create_storage(self):
|
|
raise NotImplementedError()
|
|
|
|
|
|
class _StorageCreator(_StorageBase):
|
|
"""
|
|
Base object for classes that will actually create storage on disk
|
|
"""
|
|
def __init__(self, conn):
|
|
_StorageBase.__init__(self, conn)
|
|
|
|
self._pool = None
|
|
self._vol_install = None
|
|
self._path = None
|
|
self._size = None
|
|
self._dev_type = None
|
|
|
|
|
|
##############
|
|
# Public API #
|
|
##############
|
|
|
|
def create(self, progresscb):
|
|
raise NotImplementedError()
|
|
|
|
def get_path(self):
|
|
if self._vol_install and not self._path:
|
|
xmlobj = StoragePool(self._conn,
|
|
parsexml=self._vol_install.pool.XMLDesc(0))
|
|
if self.get_dev_type() == "network":
|
|
self._path = self._vol_install.name
|
|
else:
|
|
sep = "/"
|
|
if xmlobj.target_path == "" or xmlobj.target_path[-1] == '/':
|
|
sep = ""
|
|
self._path = (xmlobj.target_path + sep +
|
|
self._vol_install.name)
|
|
return self._path
|
|
|
|
def get_vol_install(self):
|
|
return self._vol_install
|
|
def get_vol_xml(self):
|
|
return self._vol_install
|
|
|
|
def get_size(self):
|
|
if self._size is None:
|
|
self._size = (float(self._vol_install.capacity) /
|
|
1024.0 / 1024.0 / 1024.0)
|
|
return self._size
|
|
|
|
def get_dev_type(self):
|
|
if not self._dev_type:
|
|
self._dev_type = _get_dev_type(self._path, self._vol_install, None,
|
|
self.get_parent_pool_xml(),
|
|
self._conn.is_remote())
|
|
return self._dev_type
|
|
|
|
def get_driver_type(self):
|
|
if self._vol_install:
|
|
if self._vol_install.supports_property("format"):
|
|
return self._vol_install.format
|
|
return "raw"
|
|
|
|
def validate(self, disk):
|
|
if disk.device in ["floppy", "cdrom"]:
|
|
raise ValueError(_("Cannot create storage for %s device.") %
|
|
disk.device)
|
|
|
|
if self._vol_install:
|
|
self._vol_install.validate()
|
|
return
|
|
|
|
if self._size is None:
|
|
raise ValueError(_("size is required for non-existent disk "
|
|
"'%s'" % self.get_path()))
|
|
|
|
err, msg = self.is_size_conflict()
|
|
if err:
|
|
raise ValueError(msg)
|
|
if msg:
|
|
logging.warning(msg)
|
|
|
|
def will_create_storage(self):
|
|
return True
|
|
def get_vol_object(self):
|
|
return None
|
|
def get_parent_pool(self):
|
|
if self._vol_install:
|
|
return self._vol_install.pool
|
|
return None
|
|
def exists(self):
|
|
return False
|
|
|
|
|
|
class CloneStorageCreator(_StorageCreator):
|
|
"""
|
|
Handles manually copying local files for Cloner
|
|
|
|
Many clone scenarios will use libvirt storage APIs, which will use
|
|
the ManagedStorageCreator
|
|
"""
|
|
def __init__(self, conn, output_path, input_path, size, sparse):
|
|
_StorageCreator.__init__(self, conn)
|
|
|
|
self._path = output_path
|
|
self._output_path = output_path
|
|
self._input_path = input_path
|
|
self._size = size
|
|
self._sparse = sparse
|
|
|
|
def is_size_conflict(self):
|
|
ret = False
|
|
msg = None
|
|
if self.get_dev_type() == "block":
|
|
avail = _stat_disk(self._path)[1]
|
|
else:
|
|
vfs = os.statvfs(os.path.dirname(self._path))
|
|
avail = vfs.f_frsize * vfs.f_bavail
|
|
need = int(self._size) * 1024 * 1024 * 1024
|
|
if need > avail:
|
|
if self._sparse:
|
|
msg = _("The filesystem will not have enough free space"
|
|
" to fully allocate the sparse file when the guest"
|
|
" is running.")
|
|
else:
|
|
ret = True
|
|
msg = _("There is not enough free space to create the disk.")
|
|
|
|
|
|
if msg:
|
|
msg += (_(" %d M requested > %d M available") %
|
|
((need // (1024 * 1024)), (avail // (1024 * 1024))))
|
|
return (ret, msg)
|
|
|
|
def create(self, progresscb):
|
|
text = (_("Cloning %(srcfile)s") %
|
|
{'srcfile': os.path.basename(self._input_path)})
|
|
|
|
size_bytes = int(self.get_size()) * 1024 * 1024 * 1024
|
|
progresscb.start(filename=self._output_path, size=size_bytes,
|
|
text=text)
|
|
|
|
# Plain file clone
|
|
self._clone_local(progresscb, size_bytes)
|
|
|
|
def _clone_local(self, meter, size_bytes):
|
|
if self._input_path == "/dev/null":
|
|
# Not really sure why this check is here,
|
|
# but keeping for compat
|
|
logging.debug("Source dev was /dev/null. Skipping")
|
|
return
|
|
if self._input_path == self._output_path:
|
|
logging.debug("Source and destination are the same. Skipping.")
|
|
return
|
|
|
|
# If a destination file exists and sparse flag is True,
|
|
# this priority takes an existing file.
|
|
|
|
if (not os.path.exists(self._output_path) and self._sparse):
|
|
clone_block_size = 4096
|
|
sparse = True
|
|
fd = None
|
|
try:
|
|
fd = os.open(self._output_path, os.O_WRONLY | os.O_CREAT,
|
|
0o640)
|
|
os.ftruncate(fd, size_bytes)
|
|
finally:
|
|
if fd:
|
|
os.close(fd)
|
|
else:
|
|
clone_block_size = 1024 * 1024 * 10
|
|
sparse = False
|
|
|
|
logging.debug("Local Cloning %s to %s, sparse=%s, block_size=%s",
|
|
self._input_path, self._output_path,
|
|
sparse, clone_block_size)
|
|
|
|
zeros = '\0' * 4096
|
|
|
|
src_fd, dst_fd = None, None
|
|
try:
|
|
try:
|
|
src_fd = os.open(self._input_path, os.O_RDONLY)
|
|
dst_fd = os.open(self._output_path,
|
|
os.O_WRONLY | os.O_CREAT, 0o640)
|
|
|
|
i = 0
|
|
while 1:
|
|
l = os.read(src_fd, clone_block_size)
|
|
s = len(l)
|
|
if s == 0:
|
|
meter.end(size_bytes)
|
|
break
|
|
# check sequence of zeros
|
|
if sparse and zeros == l:
|
|
os.lseek(dst_fd, s, 1)
|
|
else:
|
|
b = os.write(dst_fd, l)
|
|
if s != b:
|
|
meter.end(i)
|
|
break
|
|
i += s
|
|
if i < size_bytes:
|
|
meter.update(i)
|
|
except OSError as e:
|
|
raise RuntimeError(_("Error cloning diskimage %s to %s: %s") %
|
|
(self._input_path, self._output_path, str(e)))
|
|
finally:
|
|
if src_fd is not None:
|
|
os.close(src_fd)
|
|
if dst_fd is not None:
|
|
os.close(dst_fd)
|
|
|
|
|
|
class ManagedStorageCreator(_StorageCreator):
|
|
"""
|
|
Handles storage creation via libvirt APIs. All the actual creation
|
|
logic lives in StorageVolume, this is mostly about pulling out bits
|
|
from that class and mapping them to DeviceDisk elements
|
|
"""
|
|
def __init__(self, conn, vol_install):
|
|
_StorageCreator.__init__(self, conn)
|
|
|
|
self._pool = vol_install.pool
|
|
self._vol_install = vol_install
|
|
|
|
def create(self, progresscb):
|
|
return self._vol_install.install(meter=progresscb)
|
|
def is_size_conflict(self):
|
|
return self._vol_install.is_size_conflict()
|
|
|
|
|
|
class StorageBackend(_StorageBase):
|
|
"""
|
|
Class that carries all the info about any existing storage that
|
|
the disk references
|
|
"""
|
|
def __init__(self, conn, path, vol_object, parent_pool):
|
|
_StorageBase.__init__(self, conn)
|
|
|
|
self._vol_object = vol_object
|
|
self._parent_pool = parent_pool
|
|
self._path = path
|
|
|
|
if self._vol_object is not None:
|
|
self._path = None
|
|
|
|
if self._vol_object and not self._parent_pool:
|
|
raise RuntimeError(
|
|
"programming error: parent_pool must be specified")
|
|
|
|
# Cached bits
|
|
self._vol_xml = None
|
|
self._parent_pool_xml = None
|
|
self._exists = None
|
|
self._size = None
|
|
self._dev_type = None
|
|
|
|
|
|
##############
|
|
# Public API #
|
|
##############
|
|
|
|
def get_path(self):
|
|
if self._vol_object:
|
|
return self.get_vol_xml().target_path
|
|
return self._path
|
|
|
|
def get_vol_object(self):
|
|
return self._vol_object
|
|
def get_vol_xml(self):
|
|
if self._vol_xml is None:
|
|
self._vol_xml = StorageVolume(self._conn,
|
|
parsexml=self._vol_object.XMLDesc(0))
|
|
self._vol_xml.pool = self._parent_pool
|
|
return self._vol_xml
|
|
|
|
def get_parent_pool(self):
|
|
return self._parent_pool
|
|
|
|
def get_size(self):
|
|
"""
|
|
Return size of existing storage
|
|
"""
|
|
if self._size is None:
|
|
ret = 0
|
|
if self._vol_object:
|
|
ret = self.get_vol_xml().capacity
|
|
elif self._path:
|
|
ret = _stat_disk(self._path)[1]
|
|
self._size = (float(ret) / 1024.0 / 1024.0 / 1024.0)
|
|
return self._size
|
|
|
|
def exists(self):
|
|
if self._exists is None:
|
|
if self._path is None:
|
|
self._exists = True
|
|
elif self._vol_object:
|
|
self._exists = True
|
|
elif (not self.get_dev_type() == "network" and
|
|
not self._conn.is_remote() and
|
|
os.path.exists(self._path)):
|
|
self._exists = True
|
|
elif self._parent_pool:
|
|
self._exists = False
|
|
elif self.get_dev_type() == "network":
|
|
self._exists = True
|
|
elif (self._conn.is_remote() and
|
|
not _can_auto_manage(self._path)):
|
|
# This allows users to pass /dev/sdX and we don't try to
|
|
# validate it exists on the remote connection, since
|
|
# autopooling /dev is perilous. Libvirt will error if
|
|
# the device doesn't exist.
|
|
self._exists = True
|
|
else:
|
|
self._exists = False
|
|
return self._exists
|
|
|
|
def get_dev_type(self):
|
|
"""
|
|
Return disk 'type' value per storage settings
|
|
"""
|
|
if self._dev_type is None:
|
|
vol_xml = None
|
|
if self._vol_object:
|
|
vol_xml = self.get_vol_xml()
|
|
self._dev_type = _get_dev_type(self._path, vol_xml, self._vol_object,
|
|
self.get_parent_pool_xml(),
|
|
self._conn.is_remote())
|
|
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__)
|