def _getRoots(self):
for (header, buf) in self._walkTree(BTRFS_ROOT_TREE_OBJECTID):
if header.type == objectTypeKeys['BTRFS_ROOT_BACKREF_KEY']:
data = Structure(
(btrfs_root_ref, 'ref'),
(t.char, 'name', header.len - btrfs_root_ref.size),
).read(buf)
info = data.ref
name = data.name
directory = self.INO_LOOKUP(treeid=header.offset,
objectid=info.dirid)
logger.debug("%s: %s %s", name, pretty(info),
pretty(directory))
self.volumes[header.objectid]._addLink(
header.offset,
info.dirid,
info.sequence,
directory.name,
name,
)
elif header.type == objectTypeKeys['BTRFS_ROOT_ITEM_KEY']:
if header.len == btrfs_root_item.size:
info = btrfs_root_item.read(buf)
elif header.len == btrfs_root_item_v0.size:
info = btrfs_root_item_v0.read(buf)
else:
assert False, header.len
if ((header.objectid >= BTRFS_FIRST_FREE_OBJECTID
and header.objectid <= BTRFS_LAST_FREE_OBJECTID)
or header.objectid == BTRFS_FS_TREE_OBJECTID):
assert header.objectid not in self.volumes, header.objectid
self.volumes[header.objectid] = _Volume(
self,
header.objectid,
header.offset,
info,
)
# import crc32c # This provides *slow* btrfs crc32c
import crcmod.predefined # This provides fast compiled extension
crc32c = crcmod.predefined.mkPredefinedCrcFun("crc-32c")
import logging
import struct
logger = logging.getLogger(__name__)
# logger.setLevel('DEBUG')
BTRFS_SEND_STREAM_MAGIC = "btrfs-stream\0"
BTRFS_SEND_STREAM_VERSION = 1
btrfs_stream_header = Structure(
(t.char, 'magic', len(BTRFS_SEND_STREAM_MAGIC)),
(t.le32, 'version'),
packed=True
)
btrfs_cmd_header = Structure(
# /* len excluding the header */
(t.le32, 'len'),
(t.le16, 'cmd'),
# /* crc including the header with zero crc field */
(t.le32, 'crc'),
packed=True
)
btrfs_tlv_header = Structure(
(t.le16, 'tlv_type'),
# /* len excluding the header */
class FileSystem(ioctl.Device):
""" Mounted file system descriptor for ioctl actions. """
def __init__(self, path):
""" Initialize. """
super(FileSystem, self).__init__(path)
self.defaultID = None
self.devices = []
self.volumes = {}
self.mounts = {}
@property
def subvolumes(self):
""" Subvolumes contained in this mount. """
self.SYNC()
self._getDevices()
self._getRoots()
self._getMounts()
self._getUsage()
volumes = self.volumes.values()
volumes.sort(key=(lambda v: v.fullPath))
return volumes
def _rescanSizes(self, force=True):
""" Zero and recalculate quota sizes to subvolume sizes will be correct. """
status = self.QUOTA_CTL(cmd=BTRFS_QUOTA_CTL_ENABLE).status
logger.debug("CTL Status: %s", hex(status))
status = self.QUOTA_RESCAN_STATUS()
logger.debug("RESCAN Status: %s", status)
if not status.flags:
if not force:
return
self.QUOTA_RESCAN()
logger.warn("Waiting for btrfs quota usage scan...")
self.QUOTA_RESCAN_WAIT()
def _getDevices(self):
if self.devices:
return
fs = self.FS_INFO()
for i in xrange(1, fs.max_id + 1):
try:
dev = self.DEV_INFO(devid=i)
except IOError as error:
if error.errno == 19:
continue
raise
self.devices.append(dev.path)
def _getMounts(self):
# This is a "fake" device, created separately for each subvol
# See https://bugzilla.redhat.com/show_bug.cgi?id=711881
# myDevice = os.stat(self.path).st_dev
# myDevice = (os.major(myDevice), os.minor(myDevice))
if self.mounts:
return
if self.defaultID is None:
logger.warn("Default subvolume not identified")
defaultSubvol = ""
else:
defaultSubvol = self.volumes[self.defaultID].fullPath.rstrip("/")
logger.debug("Default subvolume: %s", defaultSubvol)
with open("/proc/self/mountinfo") as mtab:
for line in mtab:
# (dev, path, fs, opts, freq, passNum) = line.split() # /etc/mtab
(left, _, right) = line.partition(" - ")
(mountID, parentID, devIDs, subvol, path,
mountOpts) = left.split()[:6]
(fs, dev, superOpts) = right.split()
if fs != "btrfs":
continue
if dev not in self.devices:
logger.debug(
"%s device (%s) not in %s devices (%s)",
path,
dev,
self.path,
self.devices,
)
continue
self.mounts[subvol] = path
logger.debug("%s: %s", subvol, path)
Key = collections.namedtuple('Key', ('objectid', 'type', 'offset'))
Key.first = Key(
objectid=0,
type=0,
offset=0,
)
Key.last = Key(
objectid=BTRFS_LAST_FREE_OBJECTID,
type=t.max_u32,
offset=t.max_u64,
)
Key.next = (
lambda key: FileSystem.Key(key.objectid, key.type, key.offset + 1))
def _walkTree(self, treeid):
key = FileSystem.Key.first
while True:
# Returned objects seem to be monotonically increasing in (objectid, type, offset)
# min and max values are *not* filters.
result = self.TREE_SEARCH(key=dict(
tree_id=treeid,
min_type=key.type,
max_type=FileSystem.Key.last.type,
min_objectid=key.objectid,
max_objectid=FileSystem.Key.last.objectid,
min_offset=key.offset,
max_offset=FileSystem.Key.last.offset,
min_transid=0,
max_transid=t.max_u64,
nr_items=4096,
), )
# logger.debug("Search key result: \n%s", pretty(result.key))
buf = ioctl.Buffer(result.buf)
results = result.key.nr_items
# logger.debug("Reading %d nodes from %d bytes", results, buf.len)
if results == 0:
break
for _ in xrange(results):
# assert buf.len >= btrfs_ioctl_search_header.size, buf.len
data = buf.read(btrfs_ioctl_search_header)
# logger.debug("Object %d: %s", i, pretty(data))
# assert buf.len >= data.len, (buf.len, data.len)
yield (data, buf.readBuffer(data.len))
key = FileSystem.Key(data.objectid, data.type,
data.offset).next()
def _getRoots(self):
for (header, buf) in self._walkTree(BTRFS_ROOT_TREE_OBJECTID):
if header.type == objectTypeKeys['BTRFS_ROOT_BACKREF_KEY']:
info = buf.read(btrfs_root_ref)
name = buf.readView(info.name_len).tobytes()
directory = self.INO_LOOKUP(treeid=header.offset,
objectid=info.dirid)
logger.debug("%s: %s %s", name, pretty(info),
pretty(directory))
self.volumes[header.objectid]._addLink(
header.offset,
info.dirid,
info.sequence,
directory.name,
name,
)
elif header.type == objectTypeKeys['BTRFS_ROOT_ITEM_KEY']:
if header.len == btrfs_root_item.size:
info = buf.read(btrfs_root_item)
elif header.len == btrfs_root_item_v0.size:
info = buf.read(btrfs_root_item_v0)
else:
assert False, header.len
if ((header.objectid >= BTRFS_FIRST_FREE_OBJECTID
and header.objectid <= BTRFS_LAST_FREE_OBJECTID)
or header.objectid == BTRFS_FS_TREE_OBJECTID):
assert header.objectid not in self.volumes, header.objectid
self.volumes[header.objectid] = _Volume(
self,
header.objectid,
header.offset,
info,
)
elif header.type == objectTypeKeys['BTRFS_DIR_ITEM_KEY']:
info = buf.read(btrfs_dir_item)
name = buf.readView(info.name_len).tobytes()
if name == "default":
self.defaultID = info.location.objectid
logger.debug("Found dir '%s' is %d", name, self.defaultID)
def _getUsage(self):
try:
self._rescanSizes(False)
self._unsafeGetUsage()
except (IOError, _BtrfsError) as error:
logger.warn("%s", error)
self._rescanSizes()
self._unsafeGetUsage()
def _unsafeGetUsage(self):
for (header, buf) in self._walkTree(BTRFS_QUOTA_TREE_OBJECTID):
# logger.debug("%s %s", objectTypeNames[header.type], header)
if header.type == objectTypeKeys['BTRFS_QGROUP_INFO_KEY']:
data = btrfs_qgroup_info_item.read(buf)
try:
vol = self.volumes[header.offset]
vol.totalSize = data.referenced
vol.exclusiveSize = data.exclusive
if (data.referenced < 0 or data.exclusive < 0
or data.referenced < data.exclusive):
raise _BtrfsError(
"Btrfs returned corrupt size of %s (%s exclusive) for %s"
% (
humanize(vol.totalSize or -1),
humanize(vol.exclusiveSize or -1),
vol.fullPath,
))
except KeyError:
pass
elif header.type == objectTypeKeys['BTRFS_QGROUP_LIMIT_KEY']:
data = btrfs_qgroup_limit_item.read(buf)
elif header.type == objectTypeKeys['BTRFS_QGROUP_RELATION_KEY']:
data = None
else:
data = None
# logger.debug('%s', pretty(data))
def _getDevInfo(self):
return self.DEV_INFO(devid=1, uuid="")
def _getFSInfo(self):
return self.FS_INFO()
volid_struct = Structure((t.u64, 'id'))
SYNC = Control.IO(8)
TREE_SEARCH = Control.IOWR(17, btrfs_ioctl_search_args)
INO_LOOKUP = Control.IOWR(18, btrfs_ioctl_ino_lookup_args)
DEFAULT_SUBVOL = Control.IOW(19, volid_struct)
DEV_INFO = Control.IOWR(30, btrfs_ioctl_dev_info_args)
FS_INFO = Control.IOR(31, btrfs_ioctl_fs_info_args)
QUOTA_CTL = Control.IOWR(40, btrfs_ioctl_quota_ctl_args)
QUOTA_RESCAN = Control.IOW(44, btrfs_ioctl_quota_rescan_args)
QUOTA_RESCAN_STATUS = Control.IOR(45, btrfs_ioctl_quota_rescan_args)
QUOTA_RESCAN_WAIT = Control.IO(46)
if u is None:
return ''
return "".join(u.split('-')).decode('hex')
BTRFS_DEVICE_PATH_NAME_MAX = 1024
BTRFS_SUBVOL_CREATE_ASYNC = (1 << 0)
BTRFS_SUBVOL_RDONLY = (1 << 1)
BTRFS_SUBVOL_QGROUP_INHERIT = (1 << 2)
BTRFS_FSID_SIZE = 16
BTRFS_UUID_SIZE = 16
BTRFS_INO_LOOKUP_PATH_MAX = 4080
btrfs_ioctl_ino_lookup_args = Structure(
(t.u64, 'treeid'), (t.u64, 'objectid'),
(t.char, 'name', BTRFS_INO_LOOKUP_PATH_MAX, t.readString, t.writeString),
packed=True)
btrfs_ioctl_search_key = Structure(
(t.u64, 'tree_id'), (t.u64, 'min_objectid'), (t.u64, 'max_objectid'),
(t.u64, 'min_offset'), (t.u64, 'max_offset'), (t.u64, 'min_transid'),
(t.u64, 'max_transid'), (t.u32, 'min_type'), (t.u32, 'max_type'),
(t.u32, 'nr_items'), (t.u32, 'unused'), (t.u64, 'unused1'),
(t.u64, 'unused2'), (t.u64, 'unused3'), (t.u64, 'unused4'),
packed=True)
btrfs_ioctl_search_header = Structure((t.u64, 'transid'), (t.u64, 'objectid'),
(t.u64, 'offset'), (t.u32, 'type'),
(t.u32, 'len'),
packed=True)