openstack/swift
Code Issues Proposed changes
swift/swift/obj/diskfile.py
Tim Burke 396380f340 Better handle missing files in _construct_from_data_file 
There's a window between when we list the files on disk and when we actually
try to open the .data file where another process could delete it. That should
raise a DiskFileNotExist error, not an IOError.

Change-Id: I1b43fef35949cb6f71997874e4e6b7646eeec8fe
Closes-Bug: 1712662
2017-11-13 16:04:49 -08:00

3435 lines
141 KiB
Python
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# Copyright (c) 2010-2013 OpenStack Foundation
#
# 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.
"""
Disk File Interface for the Swift Object Server
The `DiskFile`, `DiskFileWriter` and `DiskFileReader` classes combined define
the on-disk abstraction layer for supporting the object server REST API
interfaces (excluding `REPLICATE`). Other implementations wishing to provide
an alternative backend for the object server must implement the three
classes. An example alternative implementation can be found in the
`mem_server.py` and `mem_diskfile.py` modules along size this one.
The `DiskFileManager` is a reference implemenation specific class and is not
part of the backend API.
The remaining methods in this module are considered implementation specific and
are also not considered part of the backend API.
"""
import six.moves.cPickle as pickle
import copy
import errno
import fcntl
import json
import os
import re
import time
import uuid
import hashlib
import logging
import traceback
import xattr
from os.path import basename, dirname, exists, join, splitext
from random import shuffle
from tempfile import mkstemp
from contextlib import contextmanager
from collections import defaultdict
from datetime import timedelta
from eventlet import Timeout
from eventlet.hubs import trampoline
import six
from pyeclib.ec_iface import ECDriverError, ECInvalidFragmentMetadata, \
ECBadFragmentChecksum, ECInvalidParameter
from swift import gettext_ as _
from swift.common.constraints import check_drive
from swift.common.request_helpers import is_sys_meta
from swift.common.utils import mkdirs, Timestamp, \
storage_directory, hash_path, renamer, fallocate, fsync, fdatasync, \
fsync_dir, drop_buffer_cache, lock_path, write_pickle, \
config_true_value, listdir, split_path, remove_file, \
get_md5_socket, F_SETPIPE_SZ, decode_timestamps, encode_timestamps, \
tpool_reraise, MD5_OF_EMPTY_STRING, link_fd_to_path, o_tmpfile_supported, \
O_TMPFILE, makedirs_count, replace_partition_in_path
from swift.common.splice import splice, tee
from swift.common.exceptions import DiskFileQuarantined, DiskFileNotExist, \
DiskFileCollision, DiskFileNoSpace, DiskFileDeviceUnavailable, \
DiskFileDeleted, DiskFileError, DiskFileNotOpen, PathNotDir, \
ReplicationLockTimeout, DiskFileExpired, DiskFileXattrNotSupported, \
DiskFileBadMetadataChecksum
from swift.common.swob import multi_range_iterator
from swift.common.storage_policy import (
get_policy_string, split_policy_string, PolicyError, POLICIES,
REPL_POLICY, EC_POLICY)
from functools import partial
PICKLE_PROTOCOL = 2
DEFAULT_RECLAIM_AGE = timedelta(weeks=1).total_seconds()
HASH_FILE = 'hashes.pkl'
HASH_INVALIDATIONS_FILE = 'hashes.invalid'
METADATA_KEY = 'user.swift.metadata'
METADATA_CHECKSUM_KEY = 'user.swift.metadata_checksum'
DROP_CACHE_WINDOW = 1024 * 1024
# These are system-set metadata keys that cannot be changed with a POST.
# They should be lowercase.
RESERVED_DATAFILE_META = {'content-length', 'deleted', 'etag'}
DATAFILE_SYSTEM_META = {'x-static-large-object'}
DATADIR_BASE = 'objects'
ASYNCDIR_BASE = 'async_pending'
TMP_BASE = 'tmp'
get_data_dir = partial(get_policy_string, DATADIR_BASE)
get_async_dir = partial(get_policy_string, ASYNCDIR_BASE)
get_tmp_dir = partial(get_policy_string, TMP_BASE)
MIN_TIME_UPDATE_AUDITOR_STATUS = 60
# This matches rsync tempfiles, like ".<timestamp>.data.Xy095a"
RE_RSYNC_TEMPFILE = re.compile(r'^\..*\.([a-zA-Z0-9_]){6}$')
def _get_filename(fd):
"""
Helper function to get to file name from a file descriptor or filename.
:param fd: file descriptor or filename.
:returns: the filename.
"""
if hasattr(fd, 'name'):
# fd object
return fd.name
# fd is a filename
return fd
def _encode_metadata(metadata):
"""
UTF8 encode any unicode keys or values in given metadata dict.
:param metadata: a dict
"""
def encode_str(item):
if isinstance(item, six.text_type):
return item.encode('utf8')
return item
return dict(((encode_str(k), encode_str(v)) for k, v in metadata.items()))
def read_metadata(fd, add_missing_checksum=False):
"""
Helper function to read the pickled metadata from an object file.
:param fd: file descriptor or filename to load the metadata from
:param add_missing_checksum: if set and checksum is missing, add it
:returns: dictionary of metadata
"""
metadata = b''
key = 0
try:
while True:
metadata += xattr.getxattr(fd, '%s%s' % (METADATA_KEY,
(key or '')))
key += 1
except (IOError, OSError) as e:
if errno.errorcode.get(e.errno) in ('ENOTSUP', 'EOPNOTSUPP'):
msg = "Filesystem at %s does not support xattr"
logging.exception(msg, _get_filename(fd))
raise DiskFileXattrNotSupported(e)
if e.errno == errno.ENOENT:
raise DiskFileNotExist()
# TODO: we might want to re-raise errors that don't denote a missing
# xattr here. Seems to be ENODATA on linux and ENOATTR on BSD/OSX.
metadata_checksum = None
try:
metadata_checksum = xattr.getxattr(fd, METADATA_CHECKSUM_KEY)
except (IOError, OSError):
# All the interesting errors were handled above; the only thing left
# here is ENODATA / ENOATTR to indicate that this attribute doesn't
# exist. This is fine; it just means that this object predates the
# introduction of metadata checksums.
if add_missing_checksum:
new_checksum = hashlib.md5(metadata).hexdigest()
try:
xattr.setxattr(fd, METADATA_CHECKSUM_KEY, new_checksum)
except (IOError, OSError) as e:
logging.error("Error adding metadata: %s" % e)
if metadata_checksum:
computed_checksum = hashlib.md5(metadata).hexdigest()
if metadata_checksum != computed_checksum:
raise DiskFileBadMetadataChecksum(
"Metadata checksum mismatch for %s: "
"stored checksum='%s', computed='%s'" % (
fd, metadata_checksum, computed_checksum))
# strings are utf-8 encoded when written, but have not always been
# (see https://bugs.launchpad.net/swift/+bug/1678018) so encode them again
# when read
return _encode_metadata(pickle.loads(metadata))
def write_metadata(fd, metadata, xattr_size=65536):
"""
Helper function to write pickled metadata for an object file.
:param fd: file descriptor or filename to write the metadata
:param metadata: metadata to write
"""
metastr = pickle.dumps(_encode_metadata(metadata), PICKLE_PROTOCOL)
metastr_md5 = hashlib.md5(metastr).hexdigest()
key = 0
try:
while metastr:
xattr.setxattr(fd, '%s%s' % (METADATA_KEY, key or ''),
metastr[:xattr_size])
metastr = metastr[xattr_size:]
key += 1
xattr.setxattr(fd, METADATA_CHECKSUM_KEY, metastr_md5)
except IOError as e:
# errno module doesn't always have both of these, hence the ugly
# check
if errno.errorcode.get(e.errno) in ('ENOTSUP', 'EOPNOTSUPP'):
msg = "Filesystem at %s does not support xattr"
logging.exception(msg, _get_filename(fd))
raise DiskFileXattrNotSupported(e)
elif e.errno in (errno.ENOSPC, errno.EDQUOT):
msg = "No space left on device for %s" % _get_filename(fd)
logging.exception(msg)
raise DiskFileNoSpace()
raise
def extract_policy(obj_path):
"""
Extracts the policy for an object (based on the name of the objects
directory) given the device-relative path to the object. Returns None in
the event that the path is malformed in some way.
The device-relative path is everything after the mount point; for example:
/srv/node/d42/objects-5/30/179/
485dc017205a81df3af616d917c90179/1401811134.873649.data
would have device-relative path:
objects-5/30/179/485dc017205a81df3af616d917c90179/1401811134.873649.data
:param obj_path: device-relative path of an object, or the full path
:returns: a :class:`~swift.common.storage_policy.BaseStoragePolicy` or None
"""
try:
obj_portion = obj_path[obj_path.rindex(DATADIR_BASE):]
obj_dirname = obj_portion[:obj_portion.index('/')]
except Exception:
return None
try:
base, policy = split_policy_string(obj_dirname)
except PolicyError:
return None
return policy
def quarantine_renamer(device_path, corrupted_file_path):
"""
In the case that a file is corrupted, move it to a quarantined
area to allow replication to fix it.
:params device_path: The path to the device the corrupted file is on.
:params corrupted_file_path: The path to the file you want quarantined.
:returns: path (str) of directory the file was moved to
:raises OSError: re-raises non errno.EEXIST / errno.ENOTEMPTY
exceptions from rename
"""
policy = extract_policy(corrupted_file_path)
if policy is None:
# TODO: support a quarantine-unknown location
policy = POLICIES.legacy
from_dir = dirname(corrupted_file_path)
to_dir = join(device_path, 'quarantined',
get_data_dir(policy),
basename(from_dir))
invalidate_hash(dirname(from_dir))
try:
renamer(from_dir, to_dir, fsync=False)
except OSError as e:
if e.errno not in (errno.EEXIST, errno.ENOTEMPTY):
raise
to_dir = "%s-%s" % (to_dir, uuid.uuid4().hex)
renamer(from_dir, to_dir, fsync=False)
return to_dir
def read_hashes(partition_dir):
"""
Read the existing hashes.pkl
:returns: a dict, the suffix hashes (if any), the key 'valid' will be False
if hashes.pkl is corrupt, cannot be read or does not exist
"""
hashes_file = join(partition_dir, HASH_FILE)
hashes = {'valid': False}
try:
with open(hashes_file, 'rb') as hashes_fp:
pickled_hashes = hashes_fp.read()
except (IOError, OSError):
pass
else:
try:
hashes = pickle.loads(pickled_hashes)
except Exception:
# pickle.loads() can raise a wide variety of exceptions when
# given invalid input depending on the way in which the
# input is invalid.
pass
# hashes.pkl w/o valid updated key is "valid" but "forever old"
hashes.setdefault('valid', True)
hashes.setdefault('updated', -1)
return hashes
def write_hashes(partition_dir, hashes):
"""
Write hashes to hashes.pkl
The updated key is added to hashes before it is written.
"""
hashes_file = join(partition_dir, HASH_FILE)
# 'valid' key should always be set by the caller; however, if there's a bug
# setting invalid is most safe
hashes.setdefault('valid', False)
hashes['updated'] = time.time()
write_pickle(hashes, hashes_file, partition_dir, PICKLE_PROTOCOL)
def consolidate_hashes(partition_dir):
"""
Take what's in hashes.pkl and hashes.invalid, combine them, write the
result back to hashes.pkl, and clear out hashes.invalid.
:param partition_dir: absolute path to partition dir containing hashes.pkl
and hashes.invalid
:returns: a dict, the suffix hashes (if any), the key 'valid' will be False
if hashes.pkl is corrupt, cannot be read or does not exist
"""
invalidations_file = join(partition_dir, HASH_INVALIDATIONS_FILE)
with lock_path(partition_dir):
hashes = read_hashes(partition_dir)
found_invalidation_entry = False
try:
with open(invalidations_file, 'rb') as inv_fh:
for line in inv_fh:
found_invalidation_entry = True
suffix = line.strip()
hashes[suffix] = None
except (IOError, OSError) as e:
if e.errno != errno.ENOENT:
raise
if found_invalidation_entry:
write_hashes(partition_dir, hashes)
# Now that all the invalidations are reflected in hashes.pkl, it's
# safe to clear out the invalidations file.
with open(invalidations_file, 'wb') as inv_fh:
pass
return hashes
def invalidate_hash(suffix_dir):
"""
Invalidates the hash for a suffix_dir in the partition's hashes file.
:param suffix_dir: absolute path to suffix dir whose hash needs
invalidating
"""
suffix = basename(suffix_dir)
partition_dir = dirname(suffix_dir)
invalidations_file = join(partition_dir, HASH_INVALIDATIONS_FILE)
with lock_path(partition_dir):
with open(invalidations_file, 'ab') as inv_fh:
inv_fh.write(suffix + "\n")
def relink_paths(target_path, new_target_path, check_existing=False):
"""
Hard-links a file located in target_path using the second path
new_target_path. Creates intermediate directories if required.
:param target_path: current absolute filename
:param new_target_path: new absolute filename for the hardlink
:param check_existing: if True, check whether the link is already present
before attempting to create a new one
"""
if target_path != new_target_path:
logging.debug('Relinking %s to %s due to next_part_power set',
target_path, new_target_path)
new_target_dir = os.path.dirname(new_target_path)
if not os.path.isdir(new_target_dir):
os.makedirs(new_target_dir)
link_exists = False
if check_existing:
try:
new_stat = os.stat(new_target_path)
orig_stat = os.stat(target_path)
link_exists = (new_stat.st_ino == orig_stat.st_ino)
except OSError:
pass # if anything goes wrong, try anyway
if not link_exists:
os.link(target_path, new_target_path)
def get_part_path(dev_path, policy, partition):
"""
Given the device path, policy, and partition, returns the full
path to the partition
"""
return os.path.join(dev_path, get_data_dir(policy), str(partition))
class AuditLocation(object):
"""
Represents an object location to be audited.
Other than being a bucket of data, the only useful thing this does is
stringify to a filesystem path so the auditor's logs look okay.
"""
def __init__(self, path, device, partition, policy):
self.path, self.device, self.partition, self.policy = (
path, device, partition, policy)
def __str__(self):
return str(self.path)
def object_audit_location_generator(devices, mount_check=True, logger=None,
device_dirs=None, auditor_type="ALL"):
"""
Given a devices path (e.g. "/srv/node"), yield an AuditLocation for all
objects stored under that directory if device_dirs isn't set. If
device_dirs is set, only yield AuditLocation for the objects under the
entries in device_dirs. The AuditLocation only knows the path to the hash
directory, not to the .data file therein (if any). This is to avoid a
double listdir(hash_dir); the DiskFile object will always do one, so
we don't.
:param devices: parent directory of the devices to be audited
:param mount_check: flag to check if a mount check should be performed
on devices
:param logger: a logger object
:param device_dirs: a list of directories under devices to traverse
:param auditor_type: either ALL or ZBF
"""
if not device_dirs:
device_dirs = listdir(devices)
else:
# remove bogus devices and duplicates from device_dirs
device_dirs = list(
set(listdir(devices)).intersection(set(device_dirs)))
# randomize devices in case of process restart before sweep completed
shuffle(device_dirs)
for device in device_dirs:
if not check_drive(devices, device, mount_check):
if logger:
logger.debug(
'Skipping %s as it is not %s', device,
'mounted' if mount_check else 'a dir')
continue
# loop through object dirs for all policies
device_dir = os.path.join(devices, device)
try:
dirs = os.listdir(device_dir)
except OSError as e:
if logger:
logger.debug(
_('Skipping %(dir)s: %(err)s') % {'dir': device_dir,
'err': e.strerror})
continue
for dir_ in dirs:
if not dir_.startswith(DATADIR_BASE):
continue
try:
base, policy = split_policy_string(dir_)
except PolicyError as e:
if logger:
logger.warning(_('Directory %(directory)r does not map '
'to a valid policy (%(error)s)') % {
'directory': dir_, 'error': e})
continue
datadir_path = os.path.join(devices, device, dir_)
partitions = get_auditor_status(datadir_path, logger, auditor_type)
for pos, partition in enumerate(partitions):
update_auditor_status(datadir_path, logger,
partitions[pos:], auditor_type)
part_path = os.path.join(datadir_path, partition)
try:
suffixes = listdir(part_path)
except OSError as e:
if e.errno != errno.ENOTDIR:
raise
continue
for asuffix in suffixes:
suff_path = os.path.join(part_path, asuffix)
try:
hashes = listdir(suff_path)
except OSError as e:
if e.errno != errno.ENOTDIR:
raise
continue
for hsh in hashes:
hsh_path = os.path.join(suff_path, hsh)
yield AuditLocation(hsh_path, device, partition,
policy)
update_auditor_status(datadir_path, logger, [], auditor_type)
def get_auditor_status(datadir_path, logger, auditor_type):
auditor_status = os.path.join(
datadir_path, "auditor_status_%s.json" % auditor_type)
status = {}
try:
if six.PY3:
statusfile = open(auditor_status, encoding='utf8')
else:
statusfile = open(auditor_status, 'rb')
with statusfile:
status = statusfile.read()
except (OSError, IOError) as e:
if e.errno != errno.ENOENT and logger:
logger.warning(_('Cannot read %(auditor_status)s (%(err)s)') %
{'auditor_status': auditor_status, 'err': e})
return listdir(datadir_path)
try:
status = json.loads(status)
except ValueError as e:
logger.warning(_('Loading JSON from %(auditor_status)s failed'
' (%(err)s)') %
{'auditor_status': auditor_status, 'err': e})
return listdir(datadir_path)
return status['partitions']
def update_auditor_status(datadir_path, logger, partitions, auditor_type):
status = json.dumps({'partitions': partitions})
if six.PY3:
status = status.encode('utf8')
auditor_status = os.path.join(
datadir_path, "auditor_status_%s.json" % auditor_type)
try:
mtime = os.stat(auditor_status).st_mtime
except OSError:
mtime = 0
recently_updated = (mtime + MIN_TIME_UPDATE_AUDITOR_STATUS) > time.time()
if recently_updated and len(partitions) > 0:
if logger:
logger.debug(
'Skipping the update of recently changed %s' % auditor_status)
return
try:
with open(auditor_status, "wb") as statusfile:
statusfile.write(status)
except (OSError, IOError) as e:
if logger:
logger.warning(_('Cannot write %(auditor_status)s (%(err)s)') %
{'auditor_status': auditor_status, 'err': e})
def clear_auditor_status(devices, auditor_type="ALL"):
for device in os.listdir(devices):
for dir_ in os.listdir(os.path.join(devices, device)):
if not dir_.startswith("objects"):
continue
datadir_path = os.path.join(devices, device, dir_)
auditor_status = os.path.join(
datadir_path, "auditor_status_%s.json" % auditor_type)
remove_file(auditor_status)
def strip_self(f):
"""
Wrapper to attach module level functions to base class.
"""
def wrapper(self, *args, **kwargs):
return f(*args, **kwargs)
return wrapper
class DiskFileRouter(object):
policy_type_to_manager_cls = {}
@classmethod
def register(cls, policy_type):
"""
Decorator for Storage Policy implementations to register
their DiskFile implementation.
"""
def register_wrapper(diskfile_cls):
if policy_type in cls.policy_type_to_manager_cls:
raise PolicyError(
'%r is already registered for the policy_type %r' % (
cls.policy_type_to_manager_cls[policy_type],
policy_type))
cls.policy_type_to_manager_cls[policy_type] = diskfile_cls
return diskfile_cls
return register_wrapper
def __init__(self, *args, **kwargs):
self.policy_to_manager = {}
for policy in POLICIES:
manager_cls = self.policy_type_to_manager_cls[policy.policy_type]
self.policy_to_manager[policy] = manager_cls(*args, **kwargs)
def __getitem__(self, policy):
return self.policy_to_manager[policy]
class BaseDiskFileManager(object):
"""
Management class for devices, providing common place for shared parameters
and methods not provided by the DiskFile class (which primarily services
the object server REST API layer).
The `get_diskfile()` method is how this implementation creates a `DiskFile`
object.
.. note::
This class is reference implementation specific and not part of the
pluggable on-disk backend API.
.. note::
TODO(portante): Not sure what the right name to recommend here, as
"manager" seemed generic enough, though suggestions are welcome.
:param conf: caller provided configuration object
:param logger: caller provided logger
"""
diskfile_cls = None # must be set by subclasses
invalidate_hash = strip_self(invalidate_hash)
consolidate_hashes = strip_self(consolidate_hashes)
quarantine_renamer = strip_self(quarantine_renamer)
def __init__(self, conf, logger):
self.logger = logger
self.devices = conf.get('devices', '/srv/node')
self.disk_chunk_size = int(conf.get('disk_chunk_size', 65536))
self.keep_cache_size = int(conf.get('keep_cache_size', 5242880))
self.bytes_per_sync = int(conf.get('mb_per_sync', 512)) * 1024 * 1024
self.mount_check = config_true_value(conf.get('mount_check', 'true'))
self.reclaim_age = int(conf.get('reclaim_age', DEFAULT_RECLAIM_AGE))
replication_concurrency_per_device = conf.get(
'replication_concurrency_per_device')
replication_one_per_device = conf.get('replication_one_per_device')
if replication_concurrency_per_device is None \
and replication_one_per_device is not None:
self.logger.warning('Option replication_one_per_device is '
'deprecated and will be removed in a future '
'version. Update your configuration to use '
'option replication_concurrency_per_device.')
if config_true_value(replication_one_per_device):
replication_concurrency_per_device = 1
else:
replication_concurrency_per_device = 0
elif replication_one_per_device is not None:
self.logger.warning('Option replication_one_per_device ignored as '
'replication_concurrency_per_device is '
'defined.')
if replication_concurrency_per_device is None:
self.replication_concurrency_per_device = 1
else:
self.replication_concurrency_per_device = int(
replication_concurrency_per_device)
self.replication_lock_timeout = int(conf.get(
'replication_lock_timeout', 15))
self.use_splice = False
self.pipe_size = None
conf_wants_splice = config_true_value(conf.get('splice', 'no'))
# If the operator wants zero-copy with splice() but we don't have the
# requisite kernel support, complain so they can go fix it.
if conf_wants_splice and not splice.available:
self.logger.warning(
"Use of splice() requested (config says \"splice = %s\"), "
"but the system does not support it. "
"splice() will not be used." % conf.get('splice'))
elif conf_wants_splice and splice.available:
try:
sockfd = get_md5_socket()
os.close(sockfd)
except IOError as err:
# AF_ALG socket support was introduced in kernel 2.6.38; on
# systems with older kernels (or custom-built kernels lacking
# AF_ALG support), we can't use zero-copy.
if err.errno != errno.EAFNOSUPPORT:
raise
self.logger.warning("MD5 sockets not supported. "
"splice() will not be used.")
else:
self.use_splice = True
with open('/proc/sys/fs/pipe-max-size') as f:
max_pipe_size = int(f.read())
self.pipe_size = min(max_pipe_size, self.disk_chunk_size)
self.use_linkat = o_tmpfile_supported()
def make_on_disk_filename(self, timestamp, ext=None,
ctype_timestamp=None, *a, **kw):
"""
Returns filename for given timestamp.
:param timestamp: the object timestamp, an instance of
:class:`~swift.common.utils.Timestamp`
:param ext: an optional string representing a file extension to be
appended to the returned file name
:param ctype_timestamp: an optional content-type timestamp, an instance
of :class:`~swift.common.utils.Timestamp`
:returns: a file name
"""
rv = timestamp.internal
if ext == '.meta' and ctype_timestamp:
# If ctype_timestamp is None then the filename is simply the
# internal form of the timestamp. If ctype_timestamp is not None
# then the difference between the raw values of the two timestamps
# is appended as a hex number, with its sign.
#
# There are two reasons for encoding the content-type timestamp
# in the filename in this way. First, it means that two .meta files
# having the same timestamp but different content-type timestamps
# (and potentially different content-type values) will be distinct
# and therefore will be independently replicated when rsync
# replication is used. That ensures that all nodes end up having
# all content-type values after replication (with the most recent
# value being selected when the diskfile is opened). Second, having
# the content-type encoded in timestamp in the filename makes it
# possible for the on disk file search code to determine that
# timestamp by inspecting only the filename, and not needing to
# open the file and read its xattrs.
rv = encode_timestamps(timestamp, ctype_timestamp, explicit=True)
if ext:
rv = '%s%s' % (rv, ext)
return rv
def parse_on_disk_filename(self, filename):
"""
Parse an on disk file name.
:param filename: the file name including extension
:returns: a dict, with keys for timestamp, ext and ctype_timestamp:
* timestamp is a :class:`~swift.common.utils.Timestamp`
* ctype_timestamp is a :class:`~swift.common.utils.Timestamp` or
None for .meta files, otherwise None
* ext is a string, the file extension including the leading dot or
the empty string if the filename has no extension.
Subclasses may override this method to add further keys to the
returned dict.
:raises DiskFileError: if any part of the filename is not able to be
validated.
"""
ts_ctype = None
fname, ext = splitext(filename)
try:
if ext == '.meta':
timestamp, ts_ctype = decode_timestamps(
fname, explicit=True)[:2]
else:
timestamp = Timestamp(fname)
except ValueError:
raise DiskFileError('Invalid Timestamp value in filename %r'
% filename)
return {
'timestamp': timestamp,
'ext': ext,
'ctype_timestamp': ts_ctype
}
def _process_ondisk_files(self, exts, results, **kwargs):
"""
Called by get_ondisk_files(). Should be over-ridden to implement
subclass specific handling of files.
:param exts: dict of lists of file info, keyed by extension
:param results: a dict that may be updated with results
"""
raise NotImplementedError
def _verify_ondisk_files(self, results, **kwargs):
"""
Verify that the final combination of on disk files complies with the
diskfile contract.
:param results: files that have been found and accepted
:returns: True if the file combination is compliant, False otherwise
"""
data_file, meta_file, ts_file = tuple(
[results[key]
for key in ('data_file', 'meta_file', 'ts_file')])
return ((data_file is None and meta_file is None and ts_file is None)
or (ts_file is not None and data_file is None
and meta_file is None)
or (data_file is not None and ts_file is None))
def _split_list(self, original_list, condition):
"""
Split a list into two lists. The first list contains the first N items
of the original list, in their original order, where 0 < N <=
len(original list). The second list contains the remaining items of the
original list, in their original order.
The index, N, at which the original list is split is the index of the
first item in the list that does not satisfy the given condition. Note
that the original list should be appropriately sorted if the second
list is to contain no items that satisfy the given condition.
:param original_list: the list to be split.
:param condition: a single argument function that will be used to test
for the list item to split on.
:return: a tuple of two lists.
"""
for i, item in enumerate(original_list):
if not condition(item):
return original_list[:i], original_list[i:]
return original_list, []
def _split_gt_timestamp(self, file_info_list, timestamp):
"""
Given a list of file info dicts, reverse sorted by timestamp, split the
list into two: items newer than timestamp, and items at same time or
older than timestamp.
:param file_info_list: a list of file_info dicts.
:param timestamp: a Timestamp.
:return: a tuple of two lists.
"""
return self._split_list(
file_info_list, lambda x: x['timestamp'] > timestamp)
def _split_gte_timestamp(self, file_info_list, timestamp):
"""
Given a list of file info dicts, reverse sorted by timestamp, split the
list into two: items newer than or at same time as the timestamp, and
items older than timestamp.
:param file_info_list: a list of file_info dicts.
:param timestamp: a Timestamp.
:return: a tuple of two lists.
"""
return self._split_list(
file_info_list, lambda x: x['timestamp'] >= timestamp)
def get_ondisk_files(self, files, datadir, verify=True, **kwargs):
"""
Given a simple list of files names, determine the files that constitute
a valid fileset i.e. a set of files that defines the state of an
object, and determine the files that are obsolete and could be deleted.
Note that some files may fall into neither category.
If a file is considered part of a valid fileset then its info dict will
be added to the results dict, keyed by <extension>_info. Any files that
are no longer required will have their info dicts added to a list
stored under the key 'obsolete'.
The results dict will always contain entries with keys 'ts_file',
'data_file' and 'meta_file'. Their values will be the fully qualified
path to a file of the corresponding type if there is such a file in the
valid fileset, or None.
:param files: a list of file names.
:param datadir: directory name files are from.
:param verify: if True verify that the ondisk file contract has not
been violated, otherwise do not verify.
:returns: a dict that will contain keys:
ts_file -> path to a .ts file or None
data_file -> path to a .data file or None
meta_file -> path to a .meta file or None
ctype_file -> path to a .meta file or None
and may contain keys:
ts_info -> a file info dict for a .ts file
data_info -> a file info dict for a .data file
meta_info -> a file info dict for a .meta file
ctype_info -> a file info dict for a .meta file which
contains the content-type value
unexpected -> a list of file paths for unexpected
files
possible_reclaim -> a list of file info dicts for possible
reclaimable files
obsolete -> a list of file info dicts for obsolete files
"""
# Build the exts data structure:
# exts is a dict that maps file extensions to a list of file_info
# dicts for the files having that extension. The file_info dicts are of
# the form returned by parse_on_disk_filename, with the filename added.
# Each list is sorted in reverse timestamp order.
# the results dict is used to collect results of file filtering
results = {}
# The exts dict will be modified during subsequent processing as files
# are removed to be discarded or ignored.
exts = defaultdict(list)
for afile in files:
# Categorize files by extension
try:
file_info = self.parse_on_disk_filename(afile)
file_info['filename'] = afile
exts[file_info['ext']].append(file_info)
except DiskFileError as e:
file_path = os.path.join(datadir or '', afile)
results.setdefault('unexpected', []).append(file_path)
# log warnings if it's not a rsync temp file
if RE_RSYNC_TEMPFILE.match(afile):
self.logger.debug('Rsync tempfile: %s', file_path)
else:
self.logger.warning('Unexpected file %s: %s',
file_path, e)
for ext in exts:
# For each extension sort files into reverse chronological order.
exts[ext] = sorted(
exts[ext], key=lambda info: info['timestamp'], reverse=True)
if exts.get('.ts'):
# non-tombstones older than or equal to latest tombstone are
# obsolete
for ext in filter(lambda ext: ext != '.ts', exts.keys()):
exts[ext], older = self._split_gt_timestamp(
exts[ext], exts['.ts'][0]['timestamp'])
results.setdefault('obsolete', []).extend(older)
# all but most recent .ts are obsolete
results.setdefault('obsolete', []).extend(exts['.ts'][1:])
exts['.ts'] = exts['.ts'][:1]
if exts.get('.meta'):
# retain the newest meta file
retain = 1
if exts['.meta'][1:]:
# there are other meta files so find the one with newest
# ctype_timestamp...
exts['.meta'][1:] = sorted(
exts['.meta'][1:],
key=lambda info: info['ctype_timestamp'],
reverse=True)
# ...and retain this IFF its ctype_timestamp is greater than
# newest meta file
if (exts['.meta'][1]['ctype_timestamp'] >
exts['.meta'][0]['ctype_timestamp']):
if (exts['.meta'][1]['timestamp'] ==
exts['.meta'][0]['timestamp']):
# both at same timestamp so retain only the one with
# newest ctype
exts['.meta'][:2] = [exts['.meta'][1],
exts['.meta'][0]]
retain = 1
else:
# retain both - first has newest metadata, second has
# newest ctype
retain = 2
# discard all meta files not being retained...
results.setdefault('obsolete', []).extend(exts['.meta'][retain:])
exts['.meta'] = exts['.meta'][:retain]
# delegate to subclass handler
self._process_ondisk_files(exts, results, **kwargs)
# set final choice of files
if 'data_info' in results:
if exts.get('.meta'):
# only report a meta file if a data file has been chosen
results['meta_info'] = exts['.meta'][0]
ctype_info = exts['.meta'].pop()
if (ctype_info['ctype_timestamp']
> results['data_info']['timestamp']):
results['ctype_info'] = ctype_info
elif exts.get('.ts'):
# only report a ts file if a data file has not been chosen
# (ts files will commonly already have been removed from exts if
# a data file was chosen, but that may not be the case if
# non-durable EC fragment(s) were chosen, hence the elif here)
results['ts_info'] = exts['.ts'][0]
# set ts_file, data_file, meta_file and ctype_file with path to
# chosen file or None
for info_key in ('data_info', 'meta_info', 'ts_info', 'ctype_info'):
info = results.get(info_key)
key = info_key[:-5] + '_file'
results[key] = join(datadir, info['filename']) if info else None
if verify:
assert self._verify_ondisk_files(
results, **kwargs), \
"On-disk file search algorithm contract is broken: %s" \
% str(results)
return results
def cleanup_ondisk_files(self, hsh_path, **kwargs):
"""
Clean up on-disk files that are obsolete and gather the set of valid
on-disk files for an object.
:param hsh_path: object hash path
:param frag_index: if set, search for a specific fragment index .data
file, otherwise accept the first valid .data file
:returns: a dict that may contain: valid on disk files keyed by their
filename extension; a list of obsolete files stored under the
key 'obsolete'; a list of files remaining in the directory,
reverse sorted, stored under the key 'files'.
"""
def is_reclaimable(timestamp):
return (time.time() - float(timestamp)) > self.reclaim_age
files = listdir(hsh_path)
files.sort(reverse=True)
results = self.get_ondisk_files(
files, hsh_path, verify=False, **kwargs)
if 'ts_info' in results and is_reclaimable(
results['ts_info']['timestamp']):
remove_file(join(hsh_path, results['ts_info']['filename']))
files.remove(results.pop('ts_info')['filename'])
for file_info in results.get('possible_reclaim', []):
# stray files are not deleted until reclaim-age
if is_reclaimable(file_info['timestamp']):
results.setdefault('obsolete', []).append(file_info)
for file_info in results.get('obsolete', []):
remove_file(join(hsh_path, file_info['filename']))
files.remove(file_info['filename'])
results['files'] = files
return results
def _update_suffix_hashes(self, hashes, ondisk_info):
"""
Applies policy specific updates to the given dict of md5 hashes for
the given ondisk_info.
:param hashes: a dict of md5 hashes to be updated
:param ondisk_info: a dict describing the state of ondisk files, as
returned by get_ondisk_files
"""
raise NotImplementedError
def _hash_suffix_dir(self, path):
"""
:param path: full path to directory
"""
hashes = defaultdict(hashlib.md5)
try:
path_contents = sorted(os.listdir(path))
except OSError as err:
if err.errno in (errno.ENOTDIR, errno.ENOENT):
raise PathNotDir()
raise
for hsh in path_contents:
hsh_path = join(path, hsh)
try:
ondisk_info = self.cleanup_ondisk_files(hsh_path)
except OSError as err:
if err.errno == errno.ENOTDIR:
partition_path = dirname(path)
objects_path = dirname(partition_path)
device_path = dirname(objects_path)
quar_path = quarantine_renamer(device_path, hsh_path)
logging.exception(
_('Quarantined %(hsh_path)s to %(quar_path)s because '
'it is not a directory'), {'hsh_path': hsh_path,
'quar_path': quar_path})
continue
raise
if not ondisk_info['files']:
try:
os.rmdir(hsh_path)
except OSError:
pass
continue
# ondisk_info has info dicts containing timestamps for those
# files that could determine the state of the diskfile if it were
# to be opened. We update the suffix hash with the concatenation of
# each file's timestamp and extension. The extension is added to
# guarantee distinct hash values from two object dirs that have
# different file types at the same timestamp(s).
#
# Files that may be in the object dir but would have no effect on
# the state of the diskfile are not used to update the hash.
for key in (k for k in ('meta_info', 'ts_info')
if k in ondisk_info):
info = ondisk_info[key]
hashes[None].update(info['timestamp'].internal + info['ext'])
# delegate to subclass for data file related updates...
self._update_suffix_hashes(hashes, ondisk_info)
if 'ctype_info' in ondisk_info:
# We have a distinct content-type timestamp so update the
# hash. As a precaution, append '_ctype' to differentiate this
# value from any other timestamp value that might included in
# the hash in future. There is no .ctype file so use _ctype to
# avoid any confusion.
info = ondisk_info['ctype_info']
hashes[None].update(info['ctype_timestamp'].internal
+ '_ctype')
try:
os.rmdir(path)
except OSError as e:
if e.errno == errno.ENOENT:
raise PathNotDir()
else:
# if we remove it, pretend like it wasn't there to begin with so
# that the suffix key gets removed
raise PathNotDir()
return hashes
def _hash_suffix(self, path):
"""
Performs reclamation and returns an md5 of all (remaining) files.
:param path: full path to directory
:raises PathNotDir: if given path is not a valid directory
:raises OSError: for non-ENOTDIR errors
"""
raise NotImplementedError
def _get_hashes(self, *args, **kwargs):
hashed, hashes = self.__get_hashes(*args, **kwargs)
hashes.pop('updated', None)
hashes.pop('valid', None)
return hashed, hashes
def __get_hashes(self, device, partition, policy, recalculate=None,
do_listdir=False):
"""
Get hashes for each suffix dir in a partition. do_listdir causes it to
mistrust the hash cache for suffix existence at the (unexpectedly high)
cost of a listdir.
:param device: name of target device
:param partition: partition on the device in which the object lives
:param policy: the StoragePolicy instance
:param recalculate: list of suffixes which should be recalculated when
got
:param do_listdir: force existence check for all hashes in the
partition
:returns: tuple of (number of suffix dirs hashed, dictionary of hashes)
"""
hashed = 0
dev_path = self.get_dev_path(device)
partition_path = get_part_path(dev_path, policy, partition)
hashes_file = join(partition_path, HASH_FILE)
modified = False
orig_hashes = {'valid': False}
if recalculate is None:
recalculate = []
try:
orig_hashes = self.consolidate_hashes(partition_path)
except Exception:
self.logger.warning('Unable to read %r', hashes_file,
exc_info=True)
if not orig_hashes['valid']:
# This is the only path to a valid hashes from invalid read (e.g.
# does not exist, corrupt, etc.). Moreover, in order to write this
# valid hashes we must read *the exact same* invalid state or we'll
# trigger race detection.
do_listdir = True
hashes = {'valid': True}
# If the exception handling around consolidate_hashes fired we're
# going to do a full rehash regardless; but we need to avoid
# needless recursion if the on-disk hashes.pkl is actually readable
# (worst case is consolidate_hashes keeps raising exceptions and we
# eventually run out of stack).
# N.B. orig_hashes invalid only effects new parts and error/edge
# conditions - so try not to get overly caught up trying to
# optimize it out unless you manage to convince yourself there's a
# bad behavior.
orig_hashes = read_hashes(partition_path)
else:
hashes = copy.deepcopy(orig_hashes)
if do_listdir:
for suff in os.listdir(partition_path):
if len(suff) == 3:
hashes.setdefault(suff, None)
modified = True
self.logger.debug('Run listdir on %s', partition_path)
hashes.update((suffix, None) for suffix in recalculate)
for suffix, hash_ in hashes.items():
if not hash_:
suffix_dir = join(partition_path, suffix)
try:
hashes[suffix] = self._hash_suffix(suffix_dir)
hashed += 1
except PathNotDir:
del hashes[suffix]
except OSError:
logging.exception(_('Error hashing suffix'))
modified = True
if modified:
with lock_path(partition_path):
if read_hashes(partition_path) == orig_hashes:
write_hashes(partition_path, hashes)
return hashed, hashes
return self.__get_hashes(device, partition, policy,
recalculate=recalculate,
do_listdir=do_listdir)
else:
return hashed, hashes
def construct_dev_path(self, device):
"""
Construct the path to a device without checking if it is mounted.
:param device: name of target device
:returns: full path to the device
"""
return os.path.join(self.devices, device)
def get_dev_path(self, device, mount_check=None):
"""
Return the path to a device, first checking to see if either it
is a proper mount point, or at least a directory depending on
the mount_check configuration option.
:param device: name of target device
:param mount_check: whether or not to check mountedness of device.
Defaults to bool(self.mount_check).
:returns: full path to the device, None if the path to the device is
not a proper mount point or directory.
"""
if mount_check is False:
# explicitly forbidden from syscall, just return path
return join(self.devices, device)
# we'll do some kind of check if not explicitly forbidden
if mount_check or self.mount_check:
mount_check = True
else:
mount_check = False
return check_drive(self.devices, device, mount_check)
@contextmanager
def replication_lock(self, device):
"""
A context manager that will lock on the device given, if
configured to do so.
:param device: name of target device
:raises ReplicationLockTimeout: If the lock on the device
cannot be granted within the configured timeout.
"""
if self.replication_concurrency_per_device:
dev_path = self.get_dev_path(device)
with lock_path(
dev_path,
timeout=self.replication_lock_timeout,
timeout_class=ReplicationLockTimeout,
limit=self.replication_concurrency_per_device):
yield True
else:
yield True
def pickle_async_update(self, device, account, container, obj, data,
timestamp, policy):
"""
Write data describing a container update notification to a pickle file
in the async_pending directory.
:param device: name of target device
:param account: account name for the object
:param container: container name for the object
:param obj: object name for the object
:param data: update data to be written to pickle file
:param timestamp: a Timestamp
:param policy: the StoragePolicy instance
"""
device_path = self.construct_dev_path(device)
async_dir = os.path.join(device_path, get_async_dir(policy))
tmp_dir = os.path.join(device_path, get_tmp_dir(policy))
mkdirs(tmp_dir)
ohash = hash_path(account, container, obj)
write_pickle(
data,
os.path.join(async_dir, ohash[-3:], ohash + '-' +
Timestamp(timestamp).internal),
tmp_dir)
self.logger.increment('async_pendings')
def get_diskfile(self, device, partition, account, container, obj,
policy, **kwargs):
"""
Returns a BaseDiskFile instance for an object based on the object's
partition, path parts and policy.
:param device: name of target device
:param partition: partition on device in which the object lives
:param account: account name for the object
:param container: container name for the object
:param obj: object name for the object
:param policy: the StoragePolicy instance
"""
dev_path = self.get_dev_path(device)
if not dev_path:
raise DiskFileDeviceUnavailable()
return self.diskfile_cls(self, dev_path,
partition, account, container, obj,
policy=policy, use_splice=self.use_splice,
pipe_size=self.pipe_size,
use_linkat=self.use_linkat, **kwargs)
def object_audit_location_generator(self, device_dirs=None,
auditor_type="ALL"):
"""
Yield an AuditLocation for all objects stored under device_dirs.
:param device_dirs: directory of target device
:param auditor_type: either ALL or ZBF
"""
return object_audit_location_generator(self.devices, self.mount_check,
self.logger, device_dirs,
auditor_type)
def get_diskfile_from_audit_location(self, audit_location):
"""
Returns a BaseDiskFile instance for an object at the given
AuditLocation.
:param audit_location: object location to be audited
"""
dev_path = self.get_dev_path(audit_location.device, mount_check=False)
return self.diskfile_cls.from_hash_dir(
self, audit_location.path, dev_path,
audit_location.partition, policy=audit_location.policy)
def get_diskfile_from_hash(self, device, partition, object_hash,
policy, **kwargs):
"""
Returns a DiskFile instance for an object at the given
object_hash. Just in case someone thinks of refactoring, be
sure DiskFileDeleted is *not* raised, but the DiskFile
instance representing the tombstoned object is returned
instead.
:param device: name of target device
:param partition: partition on the device in which the object lives
:param object_hash: the hash of an object path
:param policy: the StoragePolicy instance
:raises DiskFileNotExist: if the object does not exist
:returns: an instance of BaseDiskFile
"""
dev_path = self.get_dev_path(device)
if not dev_path:
raise DiskFileDeviceUnavailable()
object_path = os.path.join(
dev_path, get_data_dir(policy), str(partition), object_hash[-3:],
object_hash)
try:
filenames = self.cleanup_ondisk_files(object_path)['files']
except OSError as err:
if err.errno == errno.ENOTDIR:
quar_path = self.quarantine_renamer(dev_path, object_path)
logging.exception(
_('Quarantined %(object_path)s to %(quar_path)s because '
'it is not a directory'), {'object_path': object_path,
'quar_path': quar_path})
raise DiskFileNotExist()
if err.errno != errno.ENOENT:
raise
raise DiskFileNotExist()
if not filenames:
raise DiskFileNotExist()
try:
metadata = read_metadata(os.path.join(object_path, filenames[-1]))
except EOFError:
raise DiskFileNotExist()
try:
account, container, obj = split_path(
metadata.get('name', ''), 3, 3, True)
except ValueError:
raise DiskFileNotExist()
return self.diskfile_cls(self, dev_path,
partition, account, container, obj,
policy=policy, **kwargs)
def get_hashes(self, device, partition, suffixes, policy):
"""
:param device: name of target device
:param partition: partition name
:param suffixes: a list of suffix directories to be recalculated
:param policy: the StoragePolicy instance
:returns: a dictionary that maps suffix directories
"""
dev_path = self.get_dev_path(device)
if not dev_path:
raise DiskFileDeviceUnavailable()
partition_path = get_part_path(dev_path, policy, partition)
if not os.path.exists(partition_path):
mkdirs(partition_path)
_junk, hashes = tpool_reraise(
self._get_hashes, device, partition, policy, recalculate=suffixes)
return hashes
def _listdir(self, path):
"""
:param path: full path to directory
"""
try:
return os.listdir(path)
except OSError as err:
if err.errno != errno.ENOENT:
self.logger.error(
'ERROR: Skipping %r due to error with listdir attempt: %s',
path, err)
return []
def yield_suffixes(self, device, partition, policy):
"""
Yields tuples of (full_path, suffix_only) for suffixes stored
on the given device and partition.
:param device: name of target device
:param partition: partition name
:param policy: the StoragePolicy instance
"""
dev_path = self.get_dev_path(device)
if not dev_path:
raise DiskFileDeviceUnavailable()
partition_path = get_part_path(dev_path, policy, partition)
for suffix in self._listdir(partition_path):
if len(suffix) != 3:
continue
try:
int(suffix, 16)
except ValueError:
continue
yield (os.path.join(partition_path, suffix), suffix)
def yield_hashes(self, device, partition, policy,
suffixes=None, **kwargs):
"""
Yields tuples of (hash_only, timestamps) for object
information stored for the given device, partition, and
(optionally) suffixes. If suffixes is None, all stored
suffixes will be searched for object hashes. Note that if
suffixes is not None but empty, such as [], then nothing will
be yielded.
timestamps is a dict which may contain items mapping:
- ts_data -> timestamp of data or tombstone file,
- ts_meta -> timestamp of meta file, if one exists
- ts_ctype -> timestamp of meta file containing most recent
content-type value, if one exists
where timestamps are instances of
:class:`~swift.common.utils.Timestamp`
:param device: name of target device
:param partition: partition name
:param policy: the StoragePolicy instance
:param suffixes: optional list of suffix directories to be searched
"""
dev_path = self.get_dev_path(device)
if not dev_path:
raise DiskFileDeviceUnavailable()
if suffixes is None:
suffixes = self.yield_suffixes(device, partition, policy)
else:
partition_path = get_part_path(dev_path, policy, partition)
suffixes = (
(os.path.join(partition_path, suffix), suffix)
for suffix in suffixes)
key_preference = (
('ts_meta', 'meta_info', 'timestamp'),
('ts_data', 'data_info', 'timestamp'),
('ts_data', 'ts_info', 'timestamp'),
('ts_ctype', 'ctype_info', 'ctype_timestamp'),
)
for suffix_path, suffix in suffixes:
for object_hash in self._listdir(suffix_path):
object_path = os.path.join(suffix_path, object_hash)
try:
results = self.cleanup_ondisk_files(
object_path, **kwargs)
timestamps = {}
for ts_key, info_key, info_ts_key in key_preference:
if info_key not in results:
continue
timestamps[ts_key] = results[info_key][info_ts_key]
if 'ts_data' not in timestamps:
# file sets that do not include a .data or .ts
# file cannot be opened and therefore cannot
# be ssync'd
continue
yield (object_hash, timestamps)
except AssertionError as err:
self.logger.debug('Invalid file set in %s (%s)' % (
object_path, err))
except DiskFileError as err:
self.logger.debug(
'Invalid diskfile filename in %r (%s)' % (
object_path, err))
class BaseDiskFileWriter(object):
"""
Encapsulation of the write context for servicing PUT REST API
requests. Serves as the context manager object for the
:class:`swift.obj.diskfile.DiskFile` class's
:func:`swift.obj.diskfile.DiskFile.create` method.
.. note::
It is the responsibility of the
:func:`swift.obj.diskfile.DiskFile.create` method context manager to
close the open file descriptor.
.. note::
The arguments to the constructor are considered implementation
specific. The API does not define the constructor arguments.
:param name: name of object from REST API
:param datadir: on-disk directory object will end up in on
:func:`swift.obj.diskfile.DiskFileWriter.put`
:param fd: open file descriptor of temporary file to receive data
:param tmppath: full path name of the opened file descriptor
:param bytes_per_sync: number bytes written between sync calls
:param diskfile: the diskfile creating this DiskFileWriter instance
:param next_part_power: the next partition power to be used
"""
def __init__(self, name, datadir, fd, tmppath, bytes_per_sync, diskfile,
next_part_power):
# Parameter tracking
self._name = name
self._datadir = datadir
self._fd = fd
self._tmppath = tmppath
self._bytes_per_sync = bytes_per_sync
self._diskfile = diskfile
self.next_part_power = next_part_power
# Internal attributes
self._upload_size = 0
self._last_sync = 0
self._extension = '.data'
self._put_succeeded = False
@property
def manager(self):
return self._diskfile.manager
@property
def put_succeeded(self):
return self._put_succeeded
def write(self, chunk):
"""
Write a chunk of data to disk. All invocations of this method must
come before invoking the :func:
For this implementation, the data is written into a temporary file.
:param chunk: the chunk of data to write as a string object
:returns: the total number of bytes written to an object
"""
while chunk:
written = os.write(self._fd, chunk)
self._upload_size += written
chunk = chunk[written:]
# For large files sync every 512MB (by default) written
diff = self._upload_size - self._last_sync
if diff >= self._bytes_per_sync:
tpool_reraise(fdatasync, self._fd)
drop_buffer_cache(self._fd, self._last_sync, diff)
self._last_sync = self._upload_size
return self._upload_size
def _finalize_put(self, metadata, target_path, cleanup):
# Write the metadata before calling fsync() so that both data and
# metadata are flushed to disk.
write_metadata(self._fd, metadata)
# We call fsync() before calling drop_cache() to lower the amount of
# redundant work the drop cache code will perform on the pages (now
# that after fsync the pages will be all clean).
fsync(self._fd)
# From the Department of the Redundancy Department, make sure we call
# drop_cache() after fsync() to avoid redundant work (pages all
# clean).
drop_buffer_cache(self._fd, 0, self._upload_size)
self.manager.invalidate_hash(dirname(self._datadir))
# After the rename/linkat completes, this object will be available for
# requests to reference.
if self._tmppath:
# It was a named temp file created by mkstemp()
renamer(self._tmppath, target_path)
else:
# It was an unnamed temp file created by open() with O_TMPFILE
link_fd_to_path(self._fd, target_path,
self._diskfile._dirs_created)
# Check if the partition power will/has been increased
new_target_path = None
if self.next_part_power:
new_target_path = replace_partition_in_path(
target_path, self.next_part_power)
if target_path != new_target_path:
try:
fsync_dir(os.path.dirname(target_path))
relink_paths(target_path, new_target_path)
except OSError as exc:
self.manager.logger.exception(
'Relinking %s to %s failed: %s',
target_path, new_target_path, exc)
# If rename is successful, flag put as succeeded. This is done to avoid
# unnecessary os.unlink() of tempfile later. As renamer() has
# succeeded, the tempfile would no longer exist at its original path.
self._put_succeeded = True
if cleanup:
try:
self.manager.cleanup_ondisk_files(self._datadir)
except OSError:
logging.exception(_('Problem cleaning up %s'), self._datadir)
self._part_power_cleanup(target_path, new_target_path)
def _put(self, metadata, cleanup=True, *a, **kw):
"""
Helper method for subclasses.
For this implementation, this method is responsible for renaming the
temporary file to the final name and directory location. This method
should be called after the final call to
:func:`swift.obj.diskfile.DiskFileWriter.write`.
:param metadata: dictionary of metadata to be associated with the
object
:param cleanup: a Boolean. If True then obsolete files will be removed
from the object dir after the put completes, otherwise
obsolete files are left in place.
"""
timestamp = Timestamp(metadata['X-Timestamp'])
ctype_timestamp = metadata.get('Content-Type-Timestamp')
if ctype_timestamp:
ctype_timestamp = Timestamp(ctype_timestamp)
filename = self.manager.make_on_disk_filename(
timestamp, self._extension, ctype_timestamp=ctype_timestamp,
*a, **kw)
metadata['name'] = self._name
target_path = join(self._datadir, filename)
tpool_reraise(self._finalize_put, metadata, target_path, cleanup)
def put(self, metadata):
"""
Finalize writing the file on disk.
:param metadata: dictionary of metadata to be associated with the
object
"""
raise NotImplementedError
def commit(self, timestamp):
"""
Perform any operations necessary to mark the object as durable. For
replication policy type this is a no-op.
:param timestamp: object put timestamp, an instance of
:class:`~swift.common.utils.Timestamp`
"""
pass
def _part_power_cleanup(self, cur_path, new_path):
"""
Cleanup relative DiskFile directories.
If the partition power is increased soon or has just been increased but
the relinker didn't yet cleanup the old files, an additional cleanup of
the relative dirs has to be done. Otherwise there might be some unused
files left if a PUT or DELETE is done in the meantime
:param cur_path: current full path to an object file
:param new_path: recomputed path to an object file, based on the
next_part_power set in the ring
"""
if new_path is None:
return
# Partition power will be increased soon
if new_path != cur_path:
new_target_dir = os.path.dirname(new_path)
try:
self.manager.cleanup_ondisk_files(new_target_dir)
except OSError:
logging.exception(
_('Problem cleaning up %s'), new_target_dir)
# Partition power has been increased, cleanup not yet finished
else:
prev_part_power = int(self.next_part_power) - 1
old_target_path = replace_partition_in_path(
cur_path, prev_part_power)
old_target_dir = os.path.dirname(old_target_path)
try:
self.manager.cleanup_ondisk_files(old_target_dir)
except OSError:
logging.exception(
_('Problem cleaning up %s'), old_target_dir)
class BaseDiskFileReader(object):
"""
Encapsulation of the WSGI read context for servicing GET REST API
requests. Serves as the context manager object for the
:class:`swift.obj.diskfile.DiskFile` class's
:func:`swift.obj.diskfile.DiskFile.reader` method.
.. note::
The quarantining behavior of this method is considered implementation
specific, and is not required of the API.
.. note::
The arguments to the constructor are considered implementation
specific. The API does not define the constructor arguments.
:param fp: open file object pointer reference
:param data_file: on-disk data file name for the object
:param obj_size: verified on-disk size of the object
:param etag: expected metadata etag value for entire file
:param disk_chunk_size: size of reads from disk in bytes
:param keep_cache_size: maximum object size that will be kept in cache
:param device_path: on-disk device path, used when quarantining an obj
:param logger: logger caller wants this object to use
:param quarantine_hook: 1-arg callable called w/reason when quarantined
:param use_splice: if true, use zero-copy splice() to send data
:param pipe_size: size of pipe buffer used in zero-copy operations
:param diskfile: the diskfile creating this DiskFileReader instance
:param keep_cache: should resulting reads be kept in the buffer cache
"""
def __init__(self, fp, data_file, obj_size, etag,
disk_chunk_size, keep_cache_size, device_path, logger,
quarantine_hook, use_splice, pipe_size, diskfile,
keep_cache=False):
# Parameter tracking
self._fp = fp
self._data_file = data_file
self._obj_size = obj_size
self._etag = etag
self._diskfile = diskfile
self._disk_chunk_size = disk_chunk_size
self._device_path = device_path
self._logger = logger
self._quarantine_hook = quarantine_hook
self._use_splice = use_splice
self._pipe_size = pipe_size
if keep_cache:
# Caller suggests we keep this in cache, only do it if the
# object's size is less than the maximum.
self._keep_cache = obj_size < keep_cache_size
else:
self._keep_cache = False
# Internal Attributes
self._iter_etag = None
self._bytes_read = 0
self._started_at_0 = False
self._read_to_eof = False
self._md5_of_sent_bytes = None
self._suppress_file_closing = False
self._quarantined_dir = None
@property
def manager(self):
return self._diskfile.manager
def _init_checks(self):
if self._fp.tell() == 0:
self._started_at_0 = True
self._iter_etag = hashlib.md5()
def _update_checks(self, chunk):
if self._iter_etag:
self._iter_etag.update(chunk)
def __iter__(self):
"""Returns an iterator over the data file."""
try:
dropped_cache = 0
self._bytes_read = 0
self._started_at_0 = False
self._read_to_eof = False
self._init_checks()
while True:
chunk = self._fp.read(self._disk_chunk_size)
if chunk:
self._update_checks(chunk)
self._bytes_read += len(chunk)
if self._bytes_read - dropped_cache > DROP_CACHE_WINDOW:
self._drop_cache(self._fp.fileno(), dropped_cache,
self._bytes_read - dropped_cache)
dropped_cache = self._bytes_read
yield chunk
else:
self._read_to_eof = True
self._drop_cache(self._fp.fileno(), dropped_cache,
self._bytes_read - dropped_cache)
break
finally:
if not self._suppress_file_closing:
self.close()
def can_zero_copy_send(self):
return self._use_splice
def zero_copy_send(self, wsockfd):
"""
Does some magic with splice() and tee() to move stuff from disk to
network without ever touching userspace.
:param wsockfd: file descriptor (integer) of the socket out which to
send data
"""
# Note: if we ever add support for zero-copy ranged GET responses,
# we'll have to make this conditional.
self._started_at_0 = True
rfd = self._fp.fileno()
client_rpipe, client_wpipe = os.pipe()
hash_rpipe, hash_wpipe = os.pipe()
md5_sockfd = get_md5_socket()
# The actual amount allocated to the pipe may be rounded up to the
# nearest multiple of the page size. If we have the memory allocated,
# we may as well use it.
#
# Note: this will raise IOError on failure, so we don't bother
# checking the return value.
pipe_size = fcntl.fcntl(client_rpipe, F_SETPIPE_SZ, self._pipe_size)
fcntl.fcntl(hash_rpipe, F_SETPIPE_SZ, pipe_size)
dropped_cache = 0
self._bytes_read = 0
try:
while True:
# Read data from disk to pipe
(bytes_in_pipe, _1, _2) = splice(
rfd, None, client_wpipe, None, pipe_size, 0)
if bytes_in_pipe == 0:
self._read_to_eof = True
self._drop_cache(rfd, dropped_cache,
self._bytes_read - dropped_cache)
break
self._bytes_read += bytes_in_pipe
# "Copy" data from pipe A to pipe B (really just some pointer
# manipulation in the kernel, not actual copying).
bytes_copied = tee(client_rpipe, hash_wpipe, bytes_in_pipe, 0)
if bytes_copied != bytes_in_pipe:
# We teed data between two pipes of equal size, and the
# destination pipe was empty. If, somehow, the destination
# pipe was full before all the data was teed, we should
# fail here. If we don't raise an exception, then we will
# have the incorrect MD5 hash once the object has been
# sent out, causing a false-positive quarantine.
raise Exception("tee() failed: tried to move %d bytes, "
"but only moved %d" %
(bytes_in_pipe, bytes_copied))
# Take the data and feed it into an in-kernel MD5 socket. The
# MD5 socket hashes data that is written to it. Reading from
# it yields the MD5 checksum of the written data.
#
# Note that we don't have to worry about splice() returning
# None here (which happens on EWOULDBLOCK); we're splicing
# $bytes_in_pipe bytes from a pipe with exactly that many
# bytes in it, so read won't block, and we're splicing it into
# an MD5 socket, which synchronously hashes any data sent to
# it, so writing won't block either.
(hashed, _1, _2) = splice(hash_rpipe, None, md5_sockfd, None,
bytes_in_pipe, splice.SPLICE_F_MORE)
if hashed != bytes_in_pipe:
raise Exception("md5 socket didn't take all the data? "
"(tried to write %d, but wrote %d)" %
(bytes_in_pipe, hashed))
while bytes_in_pipe > 0:
try:
res = splice(client_rpipe, None, wsockfd, None,
bytes_in_pipe, 0)
bytes_in_pipe -= res[0]
except IOError as exc:
if exc.errno == errno.EWOULDBLOCK:
trampoline(wsockfd, write=True)
else:
raise
if self._bytes_read - dropped_cache > DROP_CACHE_WINDOW:
self._drop_cache(rfd, dropped_cache,
self._bytes_read - dropped_cache)
dropped_cache = self._bytes_read
finally:
# Linux MD5 sockets return '00000000000000000000000000000000' for
# the checksum if you didn't write any bytes to them, instead of
# returning the correct value.
if self._bytes_read > 0:
bin_checksum = os.read(md5_sockfd, 16)
hex_checksum = ''.join("%02x" % ord(c) for c in bin_checksum)
else:
hex_checksum = MD5_OF_EMPTY_STRING
self._md5_of_sent_bytes = hex_checksum
os.close(client_rpipe)
os.close(client_wpipe)
os.close(hash_rpipe)
os.close(hash_wpipe)
os.close(md5_sockfd)
self.close()
def app_iter_range(self, start, stop):
"""
Returns an iterator over the data file for range (start, stop)
"""
if start or start == 0:
self._fp.seek(start)
if stop is not None:
length = stop - start
else:
length = None
try:
for chunk in self:
if length is not None:
length -= len(chunk)
if length < 0:
# Chop off the extra:
yield chunk[:length]
break
yield chunk
finally:
if not self._suppress_file_closing:
self.close()
def app_iter_ranges(self, ranges, content_type, boundary, size):
"""
Returns an iterator over the data file for a set of ranges
"""
if not ranges:
yield ''
else:
try:
self._suppress_file_closing = True
for chunk in multi_range_iterator(
ranges, content_type, boundary, size,
self.app_iter_range):
yield chunk
finally:
self._suppress_file_closing = False
self.close()
def _drop_cache(self, fd, offset, length):
"""
Method for no-oping buffer cache drop method.
:param fd: file descriptor or filename
"""
if not self._keep_cache:
drop_buffer_cache(fd, offset, length)
def _quarantine(self, msg):
self._quarantined_dir = self.manager.quarantine_renamer(
self._device_path, self._data_file)
self._logger.warning("Quarantined object %s: %s" % (
self._data_file, msg))
self._logger.increment('quarantines')
self._quarantine_hook(msg)
def _handle_close_quarantine(self):
"""Check if file needs to be quarantined"""
if self._iter_etag and not self._md5_of_sent_bytes:
self._md5_of_sent_bytes = self._iter_etag.hexdigest()
if self._bytes_read != self._obj_size:
self._quarantine(
"Bytes read: %s, does not match metadata: %s" % (
self._bytes_read, self._obj_size))
elif self._md5_of_sent_bytes and \
self._etag != self._md5_of_sent_bytes:
self._quarantine(
"ETag %s and file's md5 %s do not match" % (
self._etag, self._md5_of_sent_bytes))
def close(self):
"""
Close the open file handle if present.
For this specific implementation, this method will handle quarantining
the file if necessary.
"""
if self._fp:
try:
if self._started_at_0 and self._read_to_eof:
self._handle_close_quarantine()
except DiskFileQuarantined:
raise
except (Exception, Timeout) as e:
self._logger.error(_(
'ERROR DiskFile %(data_file)s'
' close failure: %(exc)s : %(stack)s'),
{'exc': e, 'stack': ''.join(traceback.format_stack()),
'data_file': self._data_file})
finally:
fp, self._fp = self._fp, None
fp.close()
class BaseDiskFile(object):
"""
Manage object files.
This specific implementation manages object files on a disk formatted with
a POSIX-compliant file system that supports extended attributes as
metadata on a file or directory.
.. note::
The arguments to the constructor are considered implementation
specific. The API does not define the constructor arguments.
The following path format is used for data file locations:
<devices_path/<device_dir>/<datadir>/<partdir>/<suffixdir>/<hashdir>/
<datafile>.<ext>
:param mgr: associated DiskFileManager instance
:param device_path: path to the target device or drive
:param partition: partition on the device in which the object lives
:param account: account name for the object
:param container: container name for the object
:param obj: object name for the object
:param _datadir: override the full datadir otherwise constructed here
:param policy: the StoragePolicy instance
:param use_splice: if true, use zero-copy splice() to send data
:param pipe_size: size of pipe buffer used in zero-copy operations
:param use_linkat: if True, use open() with linkat() to create obj file
:param open_expired: if True, open() will not raise a DiskFileExpired if
object is expired
:param next_part_power: the next partition power to be used
"""
reader_cls = None # must be set by subclasses
writer_cls = None # must be set by subclasses
def __init__(self, mgr, device_path, partition,
account=None, container=None, obj=None, _datadir=None,
policy=None, use_splice=False, pipe_size=None,
use_linkat=False, open_expired=False, next_part_power=None,
**kwargs):
self._manager = mgr
self._device_path = device_path
self._logger = mgr.logger
self._disk_chunk_size = mgr.disk_chunk_size
self._bytes_per_sync = mgr.bytes_per_sync
self._use_splice = use_splice
self._pipe_size = pipe_size
self._use_linkat = use_linkat
self._open_expired = open_expired
# This might look a lttle hacky i.e tracking number of newly created
# dirs to fsync only those many later. If there is a better way,
# please suggest.
# Or one could consider getting rid of doing fsyncs on dirs altogether
# and mounting XFS with the 'dirsync' mount option which should result
# in all entry fops being carried out synchronously.
self._dirs_created = 0
self.policy = policy
self.next_part_power = next_part_power
if account and container and obj:
self._name = '/' + '/'.join((account, container, obj))
self._account = account
self._container = container
self._obj = obj
else:
# gets populated when we read the metadata
self._name = None
self._account = None
self._container = None
self._obj = None
self._tmpdir = join(device_path, get_tmp_dir(policy))
self._ondisk_info = None
self._metadata = None
self._datafile_metadata = None
self._metafile_metadata = None
self._data_file = None
self._fp = None
self._quarantined_dir = None
self._content_length = None
if _datadir:
self._datadir = _datadir
else:
name_hash = hash_path(account, container, obj)
self._datadir = join(
device_path, storage_directory(get_data_dir(policy),
partition, name_hash))
@property
def manager(self):
return self._manager
@property
def account(self):
return self._account
@property
def container(self):
return self._container
@property
def obj(self):
return self._obj
@property
def content_length(self):
if self._metadata is None:
raise DiskFileNotOpen()
return self._content_length
@property
def timestamp(self):
if self._metadata is None:
raise DiskFileNotOpen()
return Timestamp(self._metadata.get('X-Timestamp'))
@property
def data_timestamp(self):
if self._datafile_metadata is None:
raise DiskFileNotOpen()
return Timestamp(self._datafile_metadata.get('X-Timestamp'))
@property
def durable_timestamp(self):
"""
Provides the timestamp of the newest data file found in the object
directory.
:return: A Timestamp instance, or None if no data file was found.
:raises DiskFileNotOpen: if the open() method has not been previously
called on this instance.
"""
if self._ondisk_info is None:
raise DiskFileNotOpen()
if self._datafile_metadata:
return Timestamp(self._datafile_metadata.get('X-Timestamp'))
return None
@property
def fragments(self):
return None
@property
def content_type(self):
if self._metadata is None:
raise DiskFileNotOpen()
return self._metadata.get('Content-Type')
@property
def content_type_timestamp(self):
if self._metadata is None:
raise DiskFileNotOpen()
t = self._metadata.get('Content-Type-Timestamp',
self._datafile_metadata.get('X-Timestamp'))
return Timestamp(t)
@classmethod
def from_hash_dir(cls, mgr, hash_dir_path, device_path, partition, policy):
return cls(mgr, device_path, None, partition, _datadir=hash_dir_path,
policy=policy)
def open(self, modernize=False):
"""
Open the object.
This implementation opens the data file representing the object, reads
the associated metadata in the extended attributes, additionally
combining metadata from fast-POST `.meta` files.
:param modernize: if set, update this diskfile to the latest format.
Currently, this means adding metadata checksums if none are
present.
.. note::
An implementation is allowed to raise any of the following
exceptions, but is only required to raise `DiskFileNotExist` when
the object representation does not exist.
:raises DiskFileCollision: on name mis-match with metadata
:raises DiskFileNotExist: if the object does not exist
:raises DiskFileDeleted: if the object was previously deleted
:raises DiskFileQuarantined: if while reading metadata of the file
some data did pass cross checks
:returns: itself for use as a context manager
"""
# First figure out if the data directory exists
try:
files = os.listdir(self._datadir)
except OSError as err:
if err.errno == errno.ENOTDIR:
# If there's a file here instead of a directory, quarantine
# it; something's gone wrong somewhere.
raise self._quarantine(
# hack: quarantine_renamer actually renames the directory
# enclosing the filename you give it, but here we just
# want this one file and not its parent.
os.path.join(self._datadir, "made-up-filename"),
"Expected directory, found file at %s" % self._datadir)
elif err.errno != errno.ENOENT:
raise DiskFileError(
"Error listing directory %s: %s" % (self._datadir, err))
# The data directory does not exist, so the object cannot exist.
files = []
# gather info about the valid files to use to open the DiskFile
file_info = self._get_ondisk_files(files)
self._data_file = file_info.get('data_file')
if not self._data_file:
raise self._construct_exception_from_ts_file(**file_info)
self._fp = self._construct_from_data_file(
modernize=modernize, **file_info)
# This method must populate the internal _metadata attribute.
self._metadata = self._metadata or {}
return self
def __enter__(self):
"""
Context enter.
.. note::
An implementation shall raise `DiskFileNotOpen` when has not
previously invoked the :func:`swift.obj.diskfile.DiskFile.open`
method.
"""
if self._metadata is None:
raise DiskFileNotOpen()
return self
def __exit__(self, t, v, tb):
"""
Context exit.
.. note::
This method will be invoked by the object server while servicing
the REST API *before* the object has actually been read. It is the
responsibility of the implementation to properly handle that.
"""
if self._fp is not None:
fp, self._fp = self._fp, None
fp.close()
def _quarantine(self, data_file, msg):
"""
Quarantine a file; responsible for incrementing the associated logger's
count of quarantines.
:param data_file: full path of data file to quarantine
:param msg: reason for quarantining to be included in the exception
:returns: DiskFileQuarantined exception object
"""
self._quarantined_dir = self.manager.quarantine_renamer(
self._device_path, data_file)
self._logger.warning("Quarantined object %s: %s" % (
data_file, msg))
self._logger.increment('quarantines')
return DiskFileQuarantined(msg)
def _get_ondisk_files(self, files):
"""
Determine the on-disk files to use.
:param files: a list of files in the object's dir
:returns: dict of files to use having keys 'data_file', 'ts_file',
'meta_file'
"""
raise NotImplementedError
def _construct_exception_from_ts_file(self, ts_file, **kwargs):
"""
If a tombstone is present it means the object is considered
deleted. We just need to pull the metadata from the tombstone file
which has the timestamp to construct the deleted exception. If there
was no tombstone, just report it does not exist.
:param ts_file: the tombstone file name found on disk
:returns: DiskFileDeleted if the ts_file was provided, else
DiskFileNotExist
"""
if not ts_file:
exc = DiskFileNotExist()
else:
try:
metadata = self._failsafe_read_metadata(ts_file, ts_file)
except DiskFileQuarantined:
# If the tombstone's corrupted, quarantine it and pretend it
# wasn't there
exc = DiskFileNotExist()
else:
# All well and good that we have found a tombstone file, but
# we don't have a data file so we are just going to raise an
# exception that we could not find the object, providing the
# tombstone's timestamp.
exc = DiskFileDeleted(metadata=metadata)
return exc
def _verify_name_matches_hash(self, data_file):
"""
:param data_file: data file name, used when quarantines occur
"""
hash_from_fs = os.path.basename(self._datadir)
hash_from_name = hash_path(self._name.lstrip('/'))
if hash_from_fs != hash_from_name:
raise self._quarantine(
data_file,
"Hash of name in metadata does not match directory name")
def _verify_data_file(self, data_file, fp):
"""
Verify the metadata's name value matches what we think the object is
named.
:param data_file: data file name being consider, used when quarantines
occur
:param fp: open file pointer so that we can `fstat()` the file to
verify the on-disk size with Content-Length metadata value
:raises DiskFileCollision: if the metadata stored name does not match
the referenced name of the file
:raises DiskFileExpired: if the object has expired
:raises DiskFileQuarantined: if data inconsistencies were detected
between the metadata and the file-system
metadata
"""
try:
mname = self._metadata['name']
except KeyError:
raise self._quarantine(data_file, "missing name metadata")
else:
if mname != self._name:
self._logger.error(
_('Client path %(client)s does not match '
'path stored in object metadata %(meta)s'),
{'client': self._name, 'meta': mname})
raise DiskFileCollision('Client path does not match path '
'stored in object metadata')
try:
x_delete_at = int(self._metadata['X-Delete-At'])
except KeyError:
pass
except ValueError:
# Quarantine, the x-delete-at key is present but not an
# integer.
raise self._quarantine(
data_file, "bad metadata x-delete-at value %s" % (
self._metadata['X-Delete-At']))
else:
if x_delete_at <= time.time() and not self._open_expired:
raise DiskFileExpired(metadata=self._metadata)
try:
metadata_size = int(self._metadata['Content-Length'])
except KeyError:
raise self._quarantine(
data_file, "missing content-length in metadata")
except ValueError:
# Quarantine, the content-length key is present but not an
# integer.
raise self._quarantine(
data_file, "bad metadata content-length value %s" % (
self._metadata['Content-Length']))
fd = fp.fileno()
try:
statbuf = os.fstat(fd)
except OSError as err:
# Quarantine, we can't successfully stat the file.
raise self._quarantine(data_file, "not stat-able: %s" % err)
else:
obj_size = statbuf.st_size
if obj_size != metadata_size:
raise self._quarantine(
data_file, "metadata content-length %s does"
" not match actual object size %s" % (
metadata_size, statbuf.st_size))
self._content_length = obj_size
return obj_size
def _failsafe_read_metadata(self, source, quarantine_filename=None,
add_missing_checksum=False):
"""
Read metadata from source object file. In case of failure, quarantine
the file.
Takes source and filename separately so we can read from an open
file if we have one.
:param source: file descriptor or filename to load the metadata from
:param quarantine_filename: full path of file to load the metadata from
:param add_missing_checksum: if True and no metadata checksum is
present, generate one and write it down
"""
try:
return read_metadata(source, add_missing_checksum)
except (DiskFileXattrNotSupported, DiskFileNotExist):
raise
except DiskFileBadMetadataChecksum as err:
raise self._quarantine(quarantine_filename, str(err))
except Exception as err:
raise self._quarantine(
quarantine_filename,
"Exception reading metadata: %s" % err)
def _merge_content_type_metadata(self, ctype_file):
"""
When a second .meta file is providing the most recent Content-Type
metadata then merge it into the metafile_metadata.
:param ctype_file: An on-disk .meta file
"""
ctypefile_metadata = self._failsafe_read_metadata(
ctype_file, ctype_file)
if ('Content-Type' in ctypefile_metadata
and (ctypefile_metadata.get('Content-Type-Timestamp') >
self._metafile_metadata.get('Content-Type-Timestamp'))
and (ctypefile_metadata.get('Content-Type-Timestamp') >
self.data_timestamp)):
self._metafile_metadata['Content-Type'] = \
ctypefile_metadata['Content-Type']
self._metafile_metadata['Content-Type-Timestamp'] = \
ctypefile_metadata.get('Content-Type-Timestamp')
def _construct_from_data_file(self, data_file, meta_file, ctype_file,
modernize=False,
**kwargs):
"""
Open the `.data` file to fetch its metadata, and fetch the metadata
from fast-POST `.meta` files as well if any exist, merging them
properly.
:param data_file: on-disk `.data` file being considered
:param meta_file: on-disk fast-POST `.meta` file being considered
:param ctype_file: on-disk fast-POST `.meta` file being considered that
contains content-type and content-type timestamp
:param modernize: whether to update the on-disk files to the newest
format
:returns: an opened data file pointer
:raises DiskFileError: various exceptions from
:func:`swift.obj.diskfile.DiskFile._verify_data_file`
"""
try:
fp = open(data_file, 'rb')
except IOError as e:
if e.errno == errno.ENOENT:
raise DiskFileNotExist()
raise
self._datafile_metadata = self._failsafe_read_metadata(
fp, data_file,
add_missing_checksum=modernize)
self._metadata = {}
if meta_file:
self._metafile_metadata = self._failsafe_read_metadata(
meta_file, meta_file,
add_missing_checksum=modernize)
if ctype_file and ctype_file != meta_file:
self._merge_content_type_metadata(ctype_file)
sys_metadata = dict(
[(key, val) for key, val in self._datafile_metadata.items()
if key.lower() in (RESERVED_DATAFILE_META |
DATAFILE_SYSTEM_META)
or is_sys_meta('object', key)])
self._metadata.update(self._metafile_metadata)
self._metadata.update(sys_metadata)
# diskfile writer added 'name' to metafile, so remove it here
self._metafile_metadata.pop('name', None)
# TODO: the check for Content-Type is only here for tests that
# create .data files without Content-Type
if ('Content-Type' in self._datafile_metadata and
(self.data_timestamp >
self._metafile_metadata.get('Content-Type-Timestamp'))):
self._metadata['Content-Type'] = \
self._datafile_metadata['Content-Type']
self._metadata.pop('Content-Type-Timestamp', None)
else:
self._metadata.update(self._datafile_metadata)
if self._name is None:
# If we don't know our name, we were just given a hash dir at
# instantiation, so we'd better validate that the name hashes back
# to us
self._name = self._metadata['name']
self._verify_name_matches_hash(data_file)
self._verify_data_file(data_file, fp)
return fp
def get_metafile_metadata(self):
"""
Provide the metafile metadata for a previously opened object as a
dictionary. This is metadata that was written by a POST and does not
include any persistent metadata that was set by the original PUT.
:returns: object's .meta file metadata dictionary, or None if there is
no .meta file
:raises DiskFileNotOpen: if the
:func:`swift.obj.diskfile.DiskFile.open` method was not previously
invoked
"""
if self._metadata is None:
raise DiskFileNotOpen()
return self._metafile_metadata
def get_datafile_metadata(self):
"""
Provide the datafile metadata for a previously opened object as a
dictionary. This is metadata that was included when the object was
first PUT, and does not include metadata set by any subsequent POST.
:returns: object's datafile metadata dictionary
:raises DiskFileNotOpen: if the
:func:`swift.obj.diskfile.DiskFile.open` method was not previously
invoked
"""
if self._datafile_metadata is None:
raise DiskFileNotOpen()
return self._datafile_metadata
def get_metadata(self):
"""
Provide the metadata for a previously opened object as a dictionary.
:returns: object's metadata dictionary
:raises DiskFileNotOpen: if the
:func:`swift.obj.diskfile.DiskFile.open` method was not previously
invoked
"""
if self._metadata is None:
raise DiskFileNotOpen()
return self._metadata
def read_metadata(self):
"""
Return the metadata for an object without requiring the caller to open
the object first.
:returns: metadata dictionary for an object
:raises DiskFileError: this implementation will raise the same
errors as the `open()` method.
"""
with self.open():
return self.get_metadata()
def reader(self, keep_cache=False,
_quarantine_hook=lambda m: None):
"""
Return a :class:`swift.common.swob.Response` class compatible
"`app_iter`" object as defined by
:class:`swift.obj.diskfile.DiskFileReader`.
For this implementation, the responsibility of closing the open file
is passed to the :class:`swift.obj.diskfile.DiskFileReader` object.
:param keep_cache: caller's preference for keeping data read in the
OS buffer cache
:param _quarantine_hook: 1-arg callable called when obj quarantined;
the arg is the reason for quarantine.
Default is to ignore it.
Not needed by the REST layer.
:returns: a :class:`swift.obj.diskfile.DiskFileReader` object
"""
dr = self.reader_cls(
self._fp, self._data_file, int(self._metadata['Content-Length']),
self._metadata['ETag'], self._disk_chunk_size,
self._manager.keep_cache_size, self._device_path, self._logger,
use_splice=self._use_splice, quarantine_hook=_quarantine_hook,
pipe_size=self._pipe_size, diskfile=self, keep_cache=keep_cache)
# At this point the reader object is now responsible for closing
# the file pointer.
self._fp = None
return dr
def _get_tempfile(self):
fallback_to_mkstemp = False
tmppath = None
if self._use_linkat:
self._dirs_created = makedirs_count(self._datadir)
try:
fd = os.open(self._datadir, O_TMPFILE | os.O_WRONLY)
except OSError as err:
if err.errno in (errno.EOPNOTSUPP, errno.EISDIR, errno.EINVAL):
msg = 'open(%s, O_TMPFILE | O_WRONLY) failed: %s \
Falling back to using mkstemp()' \
% (self._datadir, os.strerror(err.errno))
self._logger.warning(msg)
fallback_to_mkstemp = True
else:
raise
if not self._use_linkat or fallback_to_mkstemp:
if not exists(self._tmpdir):
mkdirs(self._tmpdir)
fd, tmppath = mkstemp(dir=self._tmpdir)
return fd, tmppath
@contextmanager
def create(self, size=None):
"""
Context manager to create a file. We create a temporary file first, and
then return a DiskFileWriter object to encapsulate the state.
.. note::
An implementation is not required to perform on-disk
preallocations even if the parameter is specified. But if it does
and it fails, it must raise a `DiskFileNoSpace` exception.
:param size: optional initial size of file to explicitly allocate on
disk
:raises DiskFileNoSpace: if a size is specified and allocation fails
"""
try:
fd, tmppath = self._get_tempfile()
except OSError as err:
if err.errno in (errno.ENOSPC, errno.EDQUOT):
# No more inodes in filesystem
raise DiskFileNoSpace()
raise
dfw = None
try:
if size is not None and size > 0:
try:
fallocate(fd, size)
except OSError as err:
if err.errno in (errno.ENOSPC, errno.EDQUOT):
raise DiskFileNoSpace()
raise
dfw = self.writer_cls(self._name, self._datadir, fd, tmppath,
bytes_per_sync=self._bytes_per_sync,
diskfile=self,
next_part_power=self.next_part_power)
yield dfw
finally:
try:
os.close(fd)
except OSError:
pass
if (dfw is None) or (not dfw.put_succeeded):
# Try removing the temp file only if put did NOT succeed.
#
# dfw.put_succeeded is set to True after renamer() succeeds in
# DiskFileWriter._finalize_put()
try:
if tmppath:
# when mkstemp() was used
os.unlink(tmppath)
except OSError:
self._logger.exception('Error removing tempfile: %s' %
tmppath)
def write_metadata(self, metadata):
"""
Write a block of metadata to an object without requiring the caller to
create the object first. Supports fast-POST behavior semantics.
:param metadata: dictionary of metadata to be associated with the
object
:raises DiskFileError: this implementation will raise the same
errors as the `create()` method.
"""
with self.create() as writer:
writer._extension = '.meta'
writer.put(metadata)
def delete(self, timestamp):
"""
Delete the object.
This implementation creates a tombstone file using the given
timestamp, and removes any older versions of the object file. Any
file that has an older timestamp than timestamp will be deleted.
.. note::
An implementation is free to use or ignore the timestamp
parameter.
:param timestamp: timestamp to compare with each file
:raises DiskFileError: this implementation will raise the same
errors as the `create()` method.
"""
# this is dumb, only tests send in strings
timestamp = Timestamp(timestamp)
with self.create() as deleter:
deleter._extension = '.ts'
deleter.put({'X-Timestamp': timestamp.internal})
class DiskFileReader(BaseDiskFileReader):
pass
class DiskFileWriter(BaseDiskFileWriter):
def put(self, metadata):
"""
Finalize writing the file on disk.
:param metadata: dictionary of metadata to be associated with the
object
"""
super(DiskFileWriter, self)._put(metadata, True)
class DiskFile(BaseDiskFile):
reader_cls = DiskFileReader
writer_cls = DiskFileWriter
def _get_ondisk_files(self, files):
self._ondisk_info = self.manager.get_ondisk_files(files, self._datadir)
return self._ondisk_info
@DiskFileRouter.register(REPL_POLICY)
class DiskFileManager(BaseDiskFileManager):
diskfile_cls = DiskFile
def _process_ondisk_files(self, exts, results, **kwargs):
"""
Implement replication policy specific handling of .data files.
:param exts: dict of lists of file info, keyed by extension
:param results: a dict that may be updated with results
"""
if exts.get('.data'):
for ext in exts.keys():
if ext == '.data':
# older .data's are obsolete
exts[ext], obsolete = self._split_gte_timestamp(
exts[ext], exts['.data'][0]['timestamp'])
else:
# other files at same or older timestamp as most recent
# data are obsolete
exts[ext], obsolete = self._split_gt_timestamp(
exts[ext], exts['.data'][0]['timestamp'])
results.setdefault('obsolete', []).extend(obsolete)
# set results
results['data_info'] = exts['.data'][0]
# .meta files *may* be ready for reclaim if there is no data
if exts.get('.meta') and not exts.get('.data'):
results.setdefault('possible_reclaim', []).extend(
exts.get('.meta'))
def _update_suffix_hashes(self, hashes, ondisk_info):
"""
Applies policy specific updates to the given dict of md5 hashes for
the given ondisk_info.
:param hashes: a dict of md5 hashes to be updated
:param ondisk_info: a dict describing the state of ondisk files, as
returned by get_ondisk_files
"""
if 'data_info' in ondisk_info:
file_info = ondisk_info['data_info']
hashes[None].update(
file_info['timestamp'].internal + file_info['ext'])
def _hash_suffix(self, path):
"""
Performs reclamation and returns an md5 of all (remaining) files.
:param path: full path to directory
:raises PathNotDir: if given path is not a valid directory
:raises OSError: for non-ENOTDIR errors
:returns: md5 of files in suffix
"""
hashes = self._hash_suffix_dir(path)
return hashes[None].hexdigest()
class ECDiskFileReader(BaseDiskFileReader):
def __init__(self, fp, data_file, obj_size, etag,
disk_chunk_size, keep_cache_size, device_path, logger,
quarantine_hook, use_splice, pipe_size, diskfile,
keep_cache=False):
super(ECDiskFileReader, self).__init__(
fp, data_file, obj_size, etag,
disk_chunk_size, keep_cache_size, device_path, logger,
quarantine_hook, use_splice, pipe_size, diskfile, keep_cache)
self.frag_buf = None
self.frag_offset = 0
self.frag_size = self._diskfile.policy.fragment_size
def _init_checks(self):
super(ECDiskFileReader, self)._init_checks()
# for a multi-range GET this will be called at the start of each range;
# only initialise the frag_buf for reads starting at 0.
# TODO: reset frag buf to '' if tell() shows that start is on a frag
# boundary so that we check frags selected by a range not starting at 0
if self._started_at_0:
self.frag_buf = ''
else:
self.frag_buf = None
def _check_frag(self, frag):
if not frag:
return
if not isinstance(frag, six.binary_type):
# ECInvalidParameter can be returned if the frag violates the input
# format so for safety, check the input chunk if it's binary to
# avoid quarantining a valid fragment archive.
self._diskfile._logger.warn(
_('Unexpected fragment data type (not quarantined)'
'%(datadir)s: %(type)s at offset 0x%(offset)x'),
{'datadir': self._diskfile._datadir,
'type': type(frag),
'offset': self.frag_offset})
return
try:
self._diskfile.policy.pyeclib_driver.get_metadata(frag)
except (ECInvalidFragmentMetadata, ECBadFragmentChecksum,
ECInvalidParameter):
# Any of these exceptions may be returned from ECDriver with a
# corrupted fragment.
msg = 'Invalid EC metadata at offset 0x%x' % self.frag_offset
self._quarantine(msg)
# We have to terminate the response iter with an exception but it
# can't be StopIteration, this will produce a STDERR traceback in
# eventlet.wsgi if you have eventlet_debug turned on; but any
# attempt to finish the iterator cleanly won't trigger the needful
# error handling cleanup - failing to do so, and yet still failing
# to deliver all promised bytes will hang the HTTP connection
raise DiskFileQuarantined(msg)
except ECDriverError as err:
self._diskfile._logger.warn(
_('Problem checking EC fragment %(datadir)s: %(err)s'),
{'datadir': self._diskfile._datadir, 'err': err})
def _update_checks(self, chunk):
super(ECDiskFileReader, self)._update_checks(chunk)
if self.frag_buf is not None:
self.frag_buf += chunk
cursor = 0
while len(self.frag_buf) >= cursor + self.frag_size:
self._check_frag(self.frag_buf[cursor:cursor + self.frag_size])
cursor += self.frag_size
self.frag_offset += self.frag_size
if cursor:
self.frag_buf = self.frag_buf[cursor:]
def _handle_close_quarantine(self):
super(ECDiskFileReader, self)._handle_close_quarantine()
self._check_frag(self.frag_buf)
class ECDiskFileWriter(BaseDiskFileWriter):
def _finalize_durable(self, data_file_path, durable_data_file_path):
exc = None
new_data_file_path = new_durable_data_file_path = None
if self.next_part_power:
new_data_file_path = replace_partition_in_path(
data_file_path, self.next_part_power)
new_durable_data_file_path = replace_partition_in_path(
durable_data_file_path, self.next_part_power)
try:
try:
os.rename(data_file_path, durable_data_file_path)
fsync_dir(self._datadir)
if self.next_part_power and \
data_file_path != new_data_file_path:
try:
os.rename(new_data_file_path,
new_durable_data_file_path)
except OSError as exc:
self.manager.logger.exception(
'Renaming new path %s to %s failed: %s',
new_data_file_path, new_durable_data_file_path,
exc)
except (OSError, IOError) as err:
if err.errno not in (errno.ENOSPC, errno.EDQUOT):
# re-raise to catch all handler
raise
params = {'file': durable_data_file_path, 'err': err}
self.manager.logger.exception(
_('No space left on device for %(file)s (%(err)s)'),
params)
exc = DiskFileNoSpace(
'No space left on device for %(file)s (%(err)s)' % params)
else:
try:
self.manager.cleanup_ondisk_files(self._datadir)
except OSError as os_err:
self.manager.logger.exception(
_('Problem cleaning up %(datadir)s (%(err)s)'),
{'datadir': self._datadir, 'err': os_err})
self._part_power_cleanup(
durable_data_file_path, new_durable_data_file_path)
except Exception as err:
params = {'file': durable_data_file_path, 'err': err}
self.manager.logger.exception(
_('Problem making data file durable %(file)s (%(err)s)'),
params)
exc = DiskFileError(
'Problem making data file durable %(file)s (%(err)s)' % params)
if exc:
raise exc
def commit(self, timestamp):
"""
Finalize put by renaming the object data file to include a durable
marker. We do this for EC policy because it requires a 2-phase put
commit confirmation.
:param timestamp: object put timestamp, an instance of
:class:`~swift.common.utils.Timestamp`
:raises DiskFileError: if the diskfile frag_index has not been set
(either during initialisation or a call to put())
"""
data_file_path = join(
self._datadir, self.manager.make_on_disk_filename(
timestamp, '.data', self._diskfile._frag_index))
durable_data_file_path = os.path.join(
self._datadir, self.manager.make_on_disk_filename(
timestamp, '.data', self._diskfile._frag_index, durable=True))
tpool_reraise(
self._finalize_durable, data_file_path, durable_data_file_path)
def put(self, metadata):
"""
The only difference between this method and the replication policy
DiskFileWriter method is adding the frag index to the metadata.
:param metadata: dictionary of metadata to be associated with object
"""
fi = None
cleanup = True
if self._extension == '.data':
# generally we treat the fragment index provided in metadata as
# canon, but if it's unavailable (e.g. tests) it's reasonable to
# use the frag_index provided at instantiation. Either way make
# sure that the fragment index is included in object sysmeta.
fi = metadata.setdefault('X-Object-Sysmeta-Ec-Frag-Index',
self._diskfile._frag_index)
fi = self.manager.validate_fragment_index(fi)
self._diskfile._frag_index = fi
# defer cleanup until commit() writes makes diskfile durable
cleanup = False
super(ECDiskFileWriter, self)._put(metadata, cleanup, frag_index=fi)
class ECDiskFile(BaseDiskFile):
reader_cls = ECDiskFileReader
writer_cls = ECDiskFileWriter
def __init__(self, *args, **kwargs):
super(ECDiskFile, self).__init__(*args, **kwargs)
frag_index = kwargs.get('frag_index')
self._frag_index = None
if frag_index is not None:
self._frag_index = self.manager.validate_fragment_index(frag_index)
self._frag_prefs = self._validate_frag_prefs(kwargs.get('frag_prefs'))
self._durable_frag_set = None
def _validate_frag_prefs(self, frag_prefs):
"""
Validate that frag_prefs is a list of dicts containing expected keys
'timestamp' and 'exclude'. Convert timestamp values to Timestamp
instances and validate that exclude values are valid fragment indexes.
:param frag_prefs: data to validate, should be a list of dicts.
:raise DiskFileError: if the frag_prefs data is invalid.
:return: a list of dicts with converted and validated values.
"""
# We *do* want to preserve an empty frag_prefs list because it
# indicates that a durable file is not required.
if frag_prefs is None:
return None
try:
return [
{'timestamp': Timestamp(pref['timestamp']),
'exclude': [self.manager.validate_fragment_index(fi)
for fi in pref['exclude']]}
for pref in frag_prefs]
except ValueError as e:
raise DiskFileError(
'Bad timestamp in frag_prefs: %r: %s'
% (frag_prefs, e))
except DiskFileError as e:
raise DiskFileError(
'Bad fragment index in frag_prefs: %r: %s'
% (frag_prefs, e))
except (KeyError, TypeError) as e:
raise DiskFileError(
'Bad frag_prefs: %r: %s' % (frag_prefs, e))
@property
def durable_timestamp(self):
"""
Provides the timestamp of the newest durable file found in the object
directory.
:return: A Timestamp instance, or None if no durable file was found.
:raises DiskFileNotOpen: if the open() method has not been previously
called on this instance.
"""
if self._ondisk_info is None:
raise DiskFileNotOpen()
if self._ondisk_info.get('durable_frag_set'):
return self._ondisk_info['durable_frag_set'][0]['timestamp']
return None
@property
def fragments(self):
"""
Provides information about all fragments that were found in the object
directory, including fragments without a matching durable file, and
including any fragment chosen to construct the opened diskfile.
:return: A dict mapping <Timestamp instance> -> <list of frag indexes>,
or None if the diskfile has not been opened or no fragments
were found.
"""
if self._ondisk_info:
frag_sets = self._ondisk_info['frag_sets']
return dict([(ts, [info['frag_index'] for info in frag_set])
for ts, frag_set in frag_sets.items()])
def _get_ondisk_files(self, files):
"""
The only difference between this method and the replication policy
DiskFile method is passing in the frag_index and frag_prefs kwargs to
our manager's get_ondisk_files method.
:param files: list of file names
"""
self._ondisk_info = self.manager.get_ondisk_files(
files, self._datadir, frag_index=self._frag_index,
frag_prefs=self._frag_prefs)
return self._ondisk_info
def purge(self, timestamp, frag_index):
"""
Remove a tombstone file matching the specified timestamp or
datafile matching the specified timestamp and fragment index
from the object directory.
This provides the EC reconstructor/ssync process with a way to
remove a tombstone or fragment from a handoff node after
reverting it to its primary node.
The hash will be invalidated, and if empty or invalid the
hsh_path will be removed on next cleanup_ondisk_files.
:param timestamp: the object timestamp, an instance of
:class:`~swift.common.utils.Timestamp`
:param frag_index: fragment archive index, must be
a whole number or None.
"""
purge_file = self.manager.make_on_disk_filename(
timestamp, ext='.ts')
remove_file(os.path.join(self._datadir, purge_file))
if frag_index is not None:
# data file may or may not be durable so try removing both filename
# possibilities
purge_file = self.manager.make_on_disk_filename(
timestamp, ext='.data', frag_index=frag_index)
remove_file(os.path.join(self._datadir, purge_file))
purge_file = self.manager.make_on_disk_filename(
timestamp, ext='.data', frag_index=frag_index, durable=True)
remove_file(os.path.join(self._datadir, purge_file))
self.manager.invalidate_hash(dirname(self._datadir))
@DiskFileRouter.register(EC_POLICY)
class ECDiskFileManager(BaseDiskFileManager):
diskfile_cls = ECDiskFile
def validate_fragment_index(self, frag_index):
"""
Return int representation of frag_index, or raise a DiskFileError if
frag_index is not a whole number.
:param frag_index: a fragment archive index
"""
try:
frag_index = int(str(frag_index))
except (ValueError, TypeError) as e:
raise DiskFileError(
'Bad fragment index: %s: %s' % (frag_index, e))
if frag_index < 0:
raise DiskFileError(
'Fragment index must not be negative: %s' % frag_index)
return frag_index
def make_on_disk_filename(self, timestamp, ext=None, frag_index=None,
ctype_timestamp=None, durable=False, *a, **kw):
"""
Returns the EC specific filename for given timestamp.
:param timestamp: the object timestamp, an instance of
:class:`~swift.common.utils.Timestamp`
:param ext: an optional string representing a file extension to be
appended to the returned file name
:param frag_index: a fragment archive index, used with .data extension
only, must be a whole number.
:param ctype_timestamp: an optional content-type timestamp, an instance
of :class:`~swift.common.utils.Timestamp`
:param durable: if True then include a durable marker in data filename.
:returns: a file name
:raises DiskFileError: if ext=='.data' and the kwarg frag_index is not
a whole number
"""
if ext == '.data':
# for datafiles only we encode the fragment index in the filename
# to allow archives of different indexes to temporarily be stored
# on the same node in certain situations
frag_index = self.validate_fragment_index(frag_index)
rv = timestamp.internal + '#' + str(frag_index)
if durable:
rv += '#d'
return '%s%s' % (rv, ext)
return super(ECDiskFileManager, self).make_on_disk_filename(
timestamp, ext, ctype_timestamp, *a, **kw)
def parse_on_disk_filename(self, filename):
"""
Returns timestamp(s) and other info extracted from a policy specific
file name. For EC policy the data file name includes a fragment index
and possibly a durable marker, both of which which must be stripped off
to retrieve the timestamp.
:param filename: the file name including extension
:returns: a dict, with keys for timestamp, frag_index, durable, ext and
ctype_timestamp:
* timestamp is a :class:`~swift.common.utils.Timestamp`
* frag_index is an int or None
* ctype_timestamp is a :class:`~swift.common.utils.Timestamp` or
None for .meta files, otherwise None
* ext is a string, the file extension including the leading dot or
the empty string if the filename has no extension
* durable is a boolean that is True if the filename is a data file
that includes a durable marker
:raises DiskFileError: if any part of the filename is not able to be
validated.
"""
frag_index = None
float_frag, ext = splitext(filename)
if ext == '.data':
parts = float_frag.split('#')
try:
timestamp = Timestamp(parts[0])
except ValueError:
raise DiskFileError('Invalid Timestamp value in filename %r'
% filename)
# it is an error for an EC data file to not have a valid
# fragment index
try:
frag_index = parts[1]
except IndexError:
# expect validate_fragment_index raise DiskFileError
pass
frag_index = self.validate_fragment_index(frag_index)
try:
durable = parts[2] == 'd'
except IndexError:
durable = False
return {
'timestamp': timestamp,
'frag_index': frag_index,
'ext': ext,
'ctype_timestamp': None,
'durable': durable
}
rv = super(ECDiskFileManager, self).parse_on_disk_filename(filename)
rv['frag_index'] = None
return rv
def _process_ondisk_files(self, exts, results, frag_index=None,
frag_prefs=None, **kwargs):
"""
Implement EC policy specific handling of .data and legacy .durable
files.
If a frag_prefs keyword arg is provided then its value may determine
which fragment index at which timestamp is used to construct the
diskfile. The value of frag_prefs should be a list. Each item in the
frag_prefs list should be a dict that describes per-timestamp
preferences using the following items:
* timestamp: An instance of :class:`~swift.common.utils.Timestamp`.
* exclude: A list of valid fragment indexes (i.e. whole numbers)
that should be EXCLUDED when choosing a fragment at the
timestamp. This list may be empty.
For example::
[
{'timestamp': <Timestamp instance>, 'exclude': [1,3]},
{'timestamp': <Timestamp instance>, 'exclude': []}
]
The order of per-timestamp dicts in the frag_prefs list is significant
and indicates descending preference for fragments from each timestamp
i.e. a fragment that satisfies the first per-timestamp preference in
the frag_prefs will be preferred over a fragment that satisfies a
subsequent per-timestamp preferred, and so on.
If a timestamp is not cited in any per-timestamp preference dict then
it is assumed that any fragment index at that timestamp may be used to
construct the diskfile.
When a frag_prefs arg is provided, including an empty list, there is no
requirement for there to be a durable file at the same timestamp as a
data file that is chosen to construct the disk file
:param exts: dict of lists of file info, keyed by extension
:param results: a dict that may be updated with results
:param frag_index: if set, search for a specific fragment index .data
file, otherwise accept the first valid .data file.
:param frag_prefs: if set, search for any fragment index .data file
that satisfies the frag_prefs.
"""
durable_info = None
if exts.get('.durable'):
# in older versions, separate .durable files were used to indicate
# the durability of data files having the same timestamp
durable_info = exts['.durable'][0]
# Split the list of .data files into sets of frags having the same
# timestamp, identifying the durable and newest sets (if any) as we go.
# To do this we can take advantage of the list of .data files being
# reverse-time ordered. Keep the resulting per-timestamp frag sets in
# a frag_sets dict mapping a Timestamp instance -> frag_set.
all_frags = exts.get('.data')
frag_sets = {}
durable_frag_set = None
while all_frags:
frag_set, all_frags = self._split_gte_timestamp(
all_frags, all_frags[0]['timestamp'])
# sort the frag set into ascending frag_index order
frag_set.sort(key=lambda info: info['frag_index'])
timestamp = frag_set[0]['timestamp']
frag_sets[timestamp] = frag_set
for frag in frag_set:
# a data file marked as durable may supersede a legacy durable
# file if it is newer
if frag['durable']:
if (not durable_info or
durable_info['timestamp'] < timestamp):
# this frag defines the durable timestamp
durable_info = frag
break
if durable_info and durable_info['timestamp'] == timestamp:
durable_frag_set = frag_set
break # ignore frags that are older than durable timestamp
# Choose which frag set to use
chosen_frag_set = None
if frag_prefs is not None:
candidate_frag_sets = dict(frag_sets)
# For each per-timestamp frag preference dict, do we have any frag
# indexes at that timestamp that are not in the exclusion list for
# that timestamp? If so choose the highest of those frag_indexes.
for ts, exclude_indexes in [
(ts_pref['timestamp'], ts_pref['exclude'])
for ts_pref in frag_prefs
if ts_pref['timestamp'] in candidate_frag_sets]:
available_indexes = [info['frag_index']
for info in candidate_frag_sets[ts]]
acceptable_indexes = list(set(available_indexes) -
set(exclude_indexes))
if acceptable_indexes:
chosen_frag_set = candidate_frag_sets[ts]
# override any frag_index passed in as method param with
# the last (highest) acceptable_index
frag_index = acceptable_indexes[-1]
break
else:
# this frag_set has no acceptable frag index so
# remove it from the candidate frag_sets
candidate_frag_sets.pop(ts)
else:
# No acceptable frag index was found at any timestamp mentioned
# in the frag_prefs. Choose the newest remaining candidate
# frag_set - the proxy can decide if it wants the returned
# fragment with that time.
if candidate_frag_sets:
ts_newest = sorted(candidate_frag_sets.keys())[-1]
chosen_frag_set = candidate_frag_sets[ts_newest]
else:
chosen_frag_set = durable_frag_set
# Select a single chosen frag from the chosen frag_set, by either
# matching against a specified frag_index or taking the highest index.
chosen_frag = None
if chosen_frag_set:
if frag_index is not None:
# search the frag set to find the exact frag_index
for info in chosen_frag_set:
if info['frag_index'] == frag_index:
chosen_frag = info
break
else:
chosen_frag = chosen_frag_set[-1]
# If we successfully found a frag then set results
if chosen_frag:
results['data_info'] = chosen_frag
results['durable_frag_set'] = durable_frag_set
results['chosen_frag_set'] = chosen_frag_set
if chosen_frag_set != durable_frag_set:
# hide meta files older than data file but newer than durable
# file so they don't get marked as obsolete (we already threw
# out .meta's that are older than a .durable)
exts['.meta'], _older = self._split_gt_timestamp(
exts['.meta'], chosen_frag['timestamp'])
results['frag_sets'] = frag_sets
# Mark everything older than most recent durable data as obsolete
# and remove from the exts dict.
if durable_info:
for ext in exts.keys():
exts[ext], older = self._split_gte_timestamp(
exts[ext], durable_info['timestamp'])
results.setdefault('obsolete', []).extend(older)
# Mark any isolated legacy .durable as obsolete
if exts.get('.durable') and not durable_frag_set:
results.setdefault('obsolete', []).extend(exts['.durable'])
exts.pop('.durable')
# Fragments *may* be ready for reclaim, unless they are durable
for frag_set in frag_sets.values():
if frag_set in (durable_frag_set, chosen_frag_set):
continue
results.setdefault('possible_reclaim', []).extend(frag_set)
# .meta files *may* be ready for reclaim if there is no durable data
if exts.get('.meta') and not durable_frag_set:
results.setdefault('possible_reclaim', []).extend(
exts.get('.meta'))
def _verify_ondisk_files(self, results, frag_index=None,
frag_prefs=None, **kwargs):
"""
Verify that the final combination of on disk files complies with the
erasure-coded diskfile contract.
:param results: files that have been found and accepted
:param frag_index: specifies a specific fragment index .data file
:param frag_prefs: if set, indicates that fragment preferences have
been specified and therefore that a selected fragment is not
required to be durable.
:returns: True if the file combination is compliant, False otherwise
"""
if super(ECDiskFileManager, self)._verify_ondisk_files(
results, **kwargs):
have_data_file = results['data_file'] is not None
have_durable = (results.get('durable_frag_set') is not None or
(have_data_file and frag_prefs is not None))
return have_data_file == have_durable
return False
def _update_suffix_hashes(self, hashes, ondisk_info):
"""
Applies policy specific updates to the given dict of md5 hashes for
the given ondisk_info.
The only difference between this method and the replication policy
function is the way that data files update hashes dict. Instead of all
filenames hashed into a single hasher, each data file name will fall
into a bucket keyed by its fragment index.
:param hashes: a dict of md5 hashes to be updated
:param ondisk_info: a dict describing the state of ondisk files, as
returned by get_ondisk_files
"""
for frag_set in ondisk_info['frag_sets'].values():
for file_info in frag_set:
fi = file_info['frag_index']
hashes[fi].update(file_info['timestamp'].internal)
if 'durable_frag_set' in ondisk_info:
# The durable_frag_set may be indicated by a legacy
# <timestamp>.durable file or by a durable <timestamp>#fi#d.data
# file. Either way we update hashes[None] with the string
# <timestamp>.durable which is a consistent representation of the
# abstract state of the object regardless of the actual file set.
# That way if we use a local combination of a legacy t1.durable and
# t1#0.data to reconstruct a remote t1#0#d.data then, when next
# hashed, the local and remote will make identical updates to their
# suffix hashes.
file_info = ondisk_info['durable_frag_set'][0]
hashes[None].update(file_info['timestamp'].internal + '.durable')
def _hash_suffix(self, path):
"""
Performs reclamation and returns an md5 of all (remaining) files.
:param path: full path to directory
:raises PathNotDir: if given path is not a valid directory
:raises OSError: for non-ENOTDIR errors
:returns: dict of md5 hex digests
"""
# hash_per_fi instead of single hash for whole suffix
# here we flatten out the hashers hexdigest into a dictionary instead
# of just returning the one hexdigest for the whole suffix
hash_per_fi = self._hash_suffix_dir(path)
return dict((fi, md5.hexdigest()) for fi, md5 in hash_per_fi.items())
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