Пример #1
0
	def write(self, sign=False, force=False):
		""" Write Manifest instance to disk, optionally signing it. Returns
		True if the Manifest is actually written, and False if the write
		is skipped due to existing Manifest being identical."""
		rval = False
		if not self.allow_create:
			return rval
		self.checkIntegrity()
		try:
			myentries = list(self._createManifestEntries())
			update_manifest = True
			existing_st = None
			if myentries and not force:
				try:
					f = io.open(_unicode_encode(self.getFullname(),
						encoding=_encodings['fs'], errors='strict'),
						mode='r', encoding=_encodings['repo.content'],
						errors='replace')
					oldentries = list(self._parseManifestLines(f))
					existing_st = os.fstat(f.fileno())
					f.close()
					if len(oldentries) == len(myentries):
						update_manifest = False
						for i in range(len(oldentries)):
							if oldentries[i] != myentries[i]:
								update_manifest = True
								break
				except (IOError, OSError) as e:
					if e.errno == errno.ENOENT:
						pass
					else:
						raise

			if update_manifest:
				if myentries or not (self.thin or self.allow_missing):
					# If myentries is empty, don't write an empty manifest
					# when thin or allow_missing is enabled. Except for
					# thin manifests with no DIST entries, myentries is
					# non-empty for all currently known use cases.
					write_atomic(self.getFullname(), "".join("%s\n" %
						_unicode(myentry) for myentry in myentries))
					self._apply_max_mtime(existing_st, myentries)
					rval = True
				else:
					# With thin manifest, there's no need to have
					# a Manifest file if there are no DIST entries.
					try:
						os.unlink(self.getFullname())
					except OSError as e:
						if e.errno != errno.ENOENT:
							raise
					rval = True

			if sign:
				self.sign()
		except (IOError, OSError) as e:
			if e.errno == errno.EACCES:
				raise PermissionDenied(str(e))
			raise
		return rval
	def load(self):
		""" Reload the registry data from file """
		self._data = None
		f = None
		try:
			f = open(_unicode_encode(self._filename,
					encoding=_encodings['fs'], errors='strict'), 'rb')
			if os.fstat(f.fileno()).st_size == 0:
				# ignore empty lock file
				pass
			else:
				self._data = pickle.load(f)
		except (AttributeError, EOFError, ValueError, pickle.UnpicklingError) as e:
			writemsg_level(_("!!! Error loading '%s': %s\n") % \
				(self._filename, e), level=logging.ERROR, noiselevel=-1)
		except EnvironmentError as e:
			if not hasattr(e, 'errno'):
				raise
			elif e.errno == errno.ENOENT:
				pass
			elif e.errno == PermissionDenied.errno:
				raise PermissionDenied(self._filename)
			else:
				raise
		finally:
			if f is not None:
				f.close()
		if self._data is None:
			self._data = {}
		self._data_orig = self._data.copy()
		self.pruneNonExisting()
Пример #3
0
def _fstat_nlink(fd):
	"""
	@param fd: an open file descriptor
	@type fd: Integer
	@rtype: Integer
	@return: the current number of hardlinks to the file
	"""
	try:
		return os.fstat(fd).st_nlink
	except EnvironmentError as e:
		if e.errno in (errno.ENOENT, errno.ESTALE):
			# Some filesystems such as CIFS return
			# ENOENT which means st_nlink == 0.
			return 0
		raise
Пример #4
0
def _fstat_nlink(fd):
    """
	@param fd: an open file descriptor
	@type fd: Integer
	@rtype: Integer
	@return: the current number of hardlinks to the file
	"""
    try:
        return os.fstat(fd).st_nlink
    except EnvironmentError as e:
        if e.errno in (errno.ENOENT, errno.ESTALE):
            # Some filesystems such as CIFS return
            # ENOENT which means st_nlink == 0.
            return 0
        raise
Пример #5
0
	def _getitem(self, cpv):
		d = {}
		try:
			myf = codecs.open(_unicode_encode(os.path.join(self.location, cpv),
				encoding=_encodings['fs'], errors='strict'),
				mode='r', encoding=_encodings['repo.content'],
				errors='replace')
			for k,v in zip(self.auxdbkey_order, myf):
				d[k] = v.rstrip("\n")
		except (OSError, IOError) as e:
			if errno.ENOENT == e.errno:
				raise KeyError(cpv)
			raise cache_errors.CacheCorruption(cpv, e)

		try:
			d["_mtime_"] = os.fstat(myf.fileno())[stat.ST_MTIME]
		except OSError as e:	
			myf.close()
			raise cache_errors.CacheCorruption(cpv, e)
		myf.close()
		return d
Пример #6
0
def _test_lock_fn(
    lock_fn: typing.Callable[[str, int, int], typing.Callable[[],
                                                              None]]) -> bool:
    def _test_lock(fd, lock_path):
        os.close(fd)
        try:
            with open(lock_path, "a") as f:
                lock_fn(lock_path, f.fileno(), fcntl.LOCK_EX | fcntl.LOCK_NB)
        except (TryAgain, EnvironmentError) as e:
            if isinstance(e, TryAgain) or e.errno == errno.EAGAIN:
                # Parent process holds lock, as expected.
                sys.exit(0)

        # Something went wrong.
        sys.exit(1)

    fd, lock_path = tempfile.mkstemp()
    unlock_fn = None
    try:
        try:
            unlock_fn = lock_fn(lock_path, fd, fcntl.LOCK_EX)
        except (TryAgain, EnvironmentError):
            pass
        else:
            _lock_manager(fd, os.fstat(fd), lock_path)
            proc = multiprocessing.Process(target=_test_lock,
                                           args=(fd, lock_path))
            proc.start()
            proc.join()
            if proc.exitcode == os.EX_OK:
                # the test passed
                return True
    finally:
        try:
            os.unlink(lock_path)
        except OSError:
            pass
        if unlock_fn is not None:
            unlock_fn()
    return False
Пример #7
0
def hardlink_lockfile(lockfilename, max_wait=DeprecationWarning,
	waiting_msg=None, flags=0):
	"""Does the NFS, hardlink shuffle to ensure locking on the disk.
	We create a PRIVATE hardlink to the real lockfile, that is just a
	placeholder on the disk.
	If our file can 2 references, then we have the lock. :)
	Otherwise we lather, rise, and repeat.
	"""

	if max_wait is not DeprecationWarning:
		warnings.warn("The 'max_wait' parameter of "
			"portage.locks.hardlink_lockfile() is now unused. Use "
			"flags=os.O_NONBLOCK instead.",
			DeprecationWarning, stacklevel=2)

	global _quiet
	out = None
	displayed_waiting_msg = False
	preexisting = os.path.exists(lockfilename)
	myhardlock = hardlock_name(lockfilename)

	# Since Python 3.4, chown requires int type (no proxies).
	portage_gid = int(portage.data.portage_gid)

	# myhardlock must not exist prior to our link() call, and we can
	# safely unlink it since its file name is unique to our PID
	try:
		os.unlink(myhardlock)
	except OSError as e:
		if e.errno in (errno.ENOENT, errno.ESTALE):
			pass
		else:
			func_call = "unlink('%s')" % myhardlock
			if e.errno == OperationNotPermitted.errno:
				raise OperationNotPermitted(func_call)
			elif e.errno == PermissionDenied.errno:
				raise PermissionDenied(func_call)
			else:
				raise

	while True:
		# create lockfilename if it doesn't exist yet
		try:
			myfd = os.open(lockfilename, os.O_CREAT|os.O_RDWR, 0o660)
		except OSError as e:
			func_call = "open('%s')" % lockfilename
			if e.errno == OperationNotPermitted.errno:
				raise OperationNotPermitted(func_call)
			elif e.errno == PermissionDenied.errno:
				raise PermissionDenied(func_call)
			elif e.errno == ReadOnlyFileSystem.errno:
				raise ReadOnlyFileSystem(func_call)
			else:
				raise
		else:
			myfd_st = None
			try:
				myfd_st = os.fstat(myfd)
				if not preexisting:
					# Don't chown the file if it is preexisting, since we
					# want to preserve existing permissions in that case.
					if myfd_st.st_gid != portage_gid:
						os.fchown(myfd, -1, portage_gid)
			except OSError as e:
				if e.errno not in (errno.ENOENT, errno.ESTALE):
					writemsg("%s: fchown('%s', -1, %d)\n" % \
						(e, lockfilename, portage_gid), noiselevel=-1)
					writemsg(_("Cannot chown a lockfile: '%s'\n") % \
						lockfilename, noiselevel=-1)
					writemsg(_("Group IDs of current user: %s\n") % \
						" ".join(str(n) for n in os.getgroups()),
						noiselevel=-1)
				else:
					# another process has removed the file, so we'll have
					# to create it again
					continue
			finally:
				os.close(myfd)

			# If fstat shows more than one hardlink, then it's extremely
			# unlikely that the following link call will result in a lock,
			# so optimize away the wasteful link call and sleep or raise
			# TryAgain.
			if myfd_st is not None and myfd_st.st_nlink < 2:
				try:
					os.link(lockfilename, myhardlock)
				except OSError as e:
					func_call = "link('%s', '%s')" % (lockfilename, myhardlock)
					if e.errno == OperationNotPermitted.errno:
						raise OperationNotPermitted(func_call)
					elif e.errno == PermissionDenied.errno:
						raise PermissionDenied(func_call)
					elif e.errno in (errno.ESTALE, errno.ENOENT):
						# another process has removed the file, so we'll have
						# to create it again
						continue
					else:
						raise
				else:
					if hardlink_is_mine(myhardlock, lockfilename):
						if out is not None:
							out.eend(os.EX_OK)
						break

					try:
						os.unlink(myhardlock)
					except OSError as e:
						# This should not happen, since the file name of
						# myhardlock is unique to our host and PID,
						# and the above link() call succeeded.
						if e.errno not in (errno.ENOENT, errno.ESTALE):
							raise
						raise FileNotFound(myhardlock)

		if flags & os.O_NONBLOCK:
			raise TryAgain(lockfilename)

		if out is None and not _quiet:
			out = portage.output.EOutput()
		if out is not None and not displayed_waiting_msg:
			displayed_waiting_msg = True
			if waiting_msg is None:
				waiting_msg = _("waiting for lock on %s\n") % lockfilename
			out.ebegin(waiting_msg)

		time.sleep(_HARDLINK_POLL_LATENCY)

	return True
Пример #8
0
    def _setitem(self, cpv, values):
        if "_eclasses_" in values:
            values = ProtectedDict(values)
            values["INHERITED"] = ' '.join(sorted(values["_eclasses_"]))

        new_content = []
        for k in self.auxdbkey_order:
            new_content.append(values.get(k, ''))
            new_content.append('\n')
        for i in range(magic_line_count - len(self.auxdbkey_order)):
            new_content.append('\n')
        new_content = ''.join(new_content)
        new_content = _unicode_encode(new_content,
                                      _encodings['repo.content'],
                                      errors='backslashreplace')

        new_fp = os.path.join(self.location, cpv)
        try:
            f = open(
                _unicode_encode(new_fp,
                                encoding=_encodings['fs'],
                                errors='strict'), 'rb')
        except EnvironmentError:
            pass
        else:
            try:
                try:
                    existing_st = os.fstat(f.fileno())
                    existing_content = f.read()
                finally:
                    f.close()
            except EnvironmentError:
                pass
            else:
                existing_mtime = existing_st[stat.ST_MTIME]
                if values['_mtime_'] == existing_mtime and \
                 existing_content == new_content:
                    return

                if self.raise_stat_collision and \
                 values['_mtime_'] == existing_mtime and \
                 len(new_content) == existing_st.st_size:
                    raise cache_errors.StatCollision(cpv, new_fp,
                                                     existing_mtime,
                                                     existing_st.st_size)

        s = cpv.rfind("/")
        fp = os.path.join(self.location, cpv[:s],
                          ".update.%i.%s" % (os.getpid(), cpv[s + 1:]))
        try:
            myf = open(
                _unicode_encode(fp, encoding=_encodings['fs'],
                                errors='strict'), 'wb')
        except EnvironmentError as e:
            if errno.ENOENT == e.errno:
                try:
                    self._ensure_dirs(cpv)
                    myf = open(
                        _unicode_encode(fp,
                                        encoding=_encodings['fs'],
                                        errors='strict'), 'wb')
                except EnvironmentError as e:
                    raise cache_errors.CacheCorruption(cpv, e)
            else:
                raise cache_errors.CacheCorruption(cpv, e)

        try:
            myf.write(new_content)
        finally:
            myf.close()
        self._ensure_access(fp, mtime=values["_mtime_"])

        try:
            os.rename(fp, new_fp)
        except EnvironmentError as e:
            try:
                os.unlink(fp)
            except EnvironmentError:
                pass
            raise cache_errors.CacheCorruption(cpv, e)
Пример #9
0
def hardlink_lockfile(lockfilename,
                      max_wait=DeprecationWarning,
                      waiting_msg=None,
                      flags=0):
    """Does the NFS, hardlink shuffle to ensure locking on the disk.
	We create a PRIVATE hardlink to the real lockfile, that is just a
	placeholder on the disk.
	If our file can 2 references, then we have the lock. :)
	Otherwise we lather, rise, and repeat.
	"""

    if max_wait is not DeprecationWarning:
        warnings.warn(
            "The 'max_wait' parameter of "
            "portage.locks.hardlink_lockfile() is now unused. Use "
            "flags=os.O_NONBLOCK instead.",
            DeprecationWarning,
            stacklevel=2)

    global _quiet
    out = None
    displayed_waiting_msg = False
    preexisting = os.path.exists(lockfilename)
    myhardlock = hardlock_name(lockfilename)

    # Since Python 3.4, chown requires int type (no proxies).
    portage_gid = int(portage.data.portage_gid)

    # myhardlock must not exist prior to our link() call, and we can
    # safely unlink it since its file name is unique to our PID
    try:
        os.unlink(myhardlock)
    except OSError as e:
        if e.errno in (errno.ENOENT, errno.ESTALE):
            pass
        else:
            func_call = "unlink('%s')" % myhardlock
            if e.errno == OperationNotPermitted.errno:
                raise OperationNotPermitted(func_call)
            elif e.errno == PermissionDenied.errno:
                raise PermissionDenied(func_call)
            else:
                raise

    while True:
        # create lockfilename if it doesn't exist yet
        try:
            myfd = os.open(lockfilename, os.O_CREAT | os.O_RDWR, 0o660)
        except OSError as e:
            func_call = "open('%s')" % lockfilename
            if e.errno == OperationNotPermitted.errno:
                raise OperationNotPermitted(func_call)
            elif e.errno == PermissionDenied.errno:
                raise PermissionDenied(func_call)
            elif e.errno == ReadOnlyFileSystem.errno:
                raise ReadOnlyFileSystem(func_call)
            else:
                raise
        else:
            myfd_st = None
            try:
                myfd_st = os.fstat(myfd)
                if not preexisting:
                    # Don't chown the file if it is preexisting, since we
                    # want to preserve existing permissions in that case.
                    if portage.data.secpass >= 1 and myfd_st.st_gid != portage_gid:
                        os.fchown(myfd, -1, portage_gid)
            except OSError as e:
                if e.errno not in (errno.ENOENT, errno.ESTALE):
                    writemsg("%s: fchown('%s', -1, %d)\n" % \
                     (e, lockfilename, portage_gid), noiselevel=-1)
                    writemsg(_("Cannot chown a lockfile: '%s'\n") % \
                     lockfilename, noiselevel=-1)
                    writemsg(_("Group IDs of current user: %s\n") % \
                     " ".join(str(n) for n in os.getgroups()),
                     noiselevel=-1)
                else:
                    # another process has removed the file, so we'll have
                    # to create it again
                    continue
            finally:
                os.close(myfd)

            # If fstat shows more than one hardlink, then it's extremely
            # unlikely that the following link call will result in a lock,
            # so optimize away the wasteful link call and sleep or raise
            # TryAgain.
            if myfd_st is not None and myfd_st.st_nlink < 2:
                try:
                    os.link(lockfilename, myhardlock)
                except OSError as e:
                    func_call = "link('%s', '%s')" % (lockfilename, myhardlock)
                    if e.errno == OperationNotPermitted.errno:
                        raise OperationNotPermitted(func_call)
                    elif e.errno == PermissionDenied.errno:
                        raise PermissionDenied(func_call)
                    elif e.errno in (errno.ESTALE, errno.ENOENT):
                        # another process has removed the file, so we'll have
                        # to create it again
                        continue
                    else:
                        raise
                else:
                    if hardlink_is_mine(myhardlock, lockfilename):
                        if out is not None:
                            out.eend(os.EX_OK)
                        break

                    try:
                        os.unlink(myhardlock)
                    except OSError as e:
                        # This should not happen, since the file name of
                        # myhardlock is unique to our host and PID,
                        # and the above link() call succeeded.
                        if e.errno not in (errno.ENOENT, errno.ESTALE):
                            raise
                        raise FileNotFound(myhardlock)

        if flags & os.O_NONBLOCK:
            raise TryAgain(lockfilename)

        if out is None and not _quiet:
            out = portage.output.EOutput()
        if out is not None and not displayed_waiting_msg:
            displayed_waiting_msg = True
            if waiting_msg is None:
                waiting_msg = _("waiting for lock on %s\n") % lockfilename
            out.ebegin(waiting_msg)

        time.sleep(_HARDLINK_POLL_LATENCY)

    return True
Пример #10
0
def _lockfile_was_removed(lock_fd, lock_path):
    """
	Check if lock_fd still refers to a file located at lock_path, since
	the file may have been removed by a concurrent process that held the
	lock earlier. This implementation includes support for NFS, where
	stat is not reliable for removed files due to the default file
	attribute cache behavior ('ac' mount option).

	@param lock_fd: an open file descriptor for a lock file
	@type lock_fd: int
	@param lock_path: path of lock file
	@type lock_path: str
	@rtype: bool
	@return: True if lock_path exists and corresponds to lock_fd, False otherwise
	"""
    try:
        fstat_st = os.fstat(lock_fd)
    except OSError as e:
        if e.errno not in (errno.ENOENT, errno.ESTALE):
            _raise_exc(e)
        return True

    # Since stat is not reliable for removed files on NFS with the default
    # file attribute cache behavior ('ac' mount option), create a temporary
    # hardlink in order to prove that the file path exists on the NFS server.
    hardlink_path = hardlock_name(lock_path)
    try:
        os.unlink(hardlink_path)
    except OSError as e:
        if e.errno not in (errno.ENOENT, errno.ESTALE):
            _raise_exc(e)
    try:
        try:
            os.link(lock_path, hardlink_path)
        except OSError as e:
            if e.errno not in (errno.ENOENT, errno.ESTALE):
                _raise_exc(e)
            return True

        hardlink_stat = os.stat(hardlink_path)
        if hardlink_stat.st_ino != fstat_st.st_ino or hardlink_stat.st_dev != fstat_st.st_dev:
            # Create another hardlink in order to detect whether or not
            # hardlink inode numbers are expected to match. For example,
            # inode numbers are not expected to match for sshfs.
            inode_test = hardlink_path + '-inode-test'
            try:
                os.unlink(inode_test)
            except OSError as e:
                if e.errno not in (errno.ENOENT, errno.ESTALE):
                    _raise_exc(e)
            try:
                os.link(hardlink_path, inode_test)
            except OSError as e:
                if e.errno not in (errno.ENOENT, errno.ESTALE):
                    _raise_exc(e)
                return True
            else:
                if not os.path.samefile(hardlink_path, inode_test):
                    # This implies that inode numbers are not expected
                    # to match for this file system, so use a simple
                    # stat call to detect if lock_path has been removed.
                    return not os.path.exists(lock_path)
            finally:
                try:
                    os.unlink(inode_test)
                except OSError as e:
                    if e.errno not in (errno.ENOENT, errno.ESTALE):
                        _raise_exc(e)
            return True
    finally:
        try:
            os.unlink(hardlink_path)
        except OSError as e:
            if e.errno not in (errno.ENOENT, errno.ESTALE):
                _raise_exc(e)
    return False
Пример #11
0
def _lockfile_iteration(mypath,
                        wantnewlockfile=False,
                        unlinkfile=False,
                        waiting_msg=None,
                        flags=0):
    """
    Acquire a lock on mypath, without retry. Return None if the lockfile
    was removed by previous lock holder (caller must retry).

    @param mypath: lock file path
    @type mypath: str
    @param wantnewlockfile: use a separate new lock file
    @type wantnewlockfile: bool
    @param unlinkfile: remove lock file prior to unlock
    @type unlinkfile: bool
    @param waiting_msg: message to show before blocking
    @type waiting_msg: str
    @param flags: lock flags (only supports os.O_NONBLOCK)
    @type flags: int
    @rtype: bool
    @return: unlockfile tuple on success, None if retry is needed
    """
    if not mypath:
        raise InvalidData(_("Empty path given"))

    # Since Python 3.4, chown requires int type (no proxies).
    portage_gid = int(portage.data.portage_gid)

    # Support for file object or integer file descriptor parameters is
    # deprecated due to ambiguity in whether or not it's safe to close
    # the file descriptor, making it prone to "Bad file descriptor" errors
    # or file descriptor leaks.
    if isinstance(mypath, str) and mypath[-1] == "/":
        mypath = mypath[:-1]

    lockfilename_path = mypath
    if hasattr(mypath, "fileno"):
        warnings.warn(
            "portage.locks.lockfile() support for "
            "file object parameters is deprecated. Use a file path instead.",
            DeprecationWarning,
            stacklevel=2,
        )
        lockfilename_path = getattr(mypath, "name", None)
        mypath = mypath.fileno()
    if isinstance(mypath, int):
        warnings.warn(
            "portage.locks.lockfile() support for integer file "
            "descriptor parameters is deprecated. Use a file path instead.",
            DeprecationWarning,
            stacklevel=2,
        )
        lockfilename = mypath
        wantnewlockfile = 0
        unlinkfile = 0
    elif wantnewlockfile:
        base, tail = os.path.split(mypath)
        lockfilename = os.path.join(base, "." + tail + ".portage_lockfile")
        lockfilename_path = lockfilename
        unlinkfile = 1
    else:
        lockfilename = mypath

    if isinstance(mypath, str):
        if not os.path.exists(os.path.dirname(mypath)):
            raise DirectoryNotFound(os.path.dirname(mypath))
        preexisting = os.path.exists(lockfilename)
        old_mask = os.umask(000)
        try:
            while True:
                try:
                    myfd = os.open(lockfilename, os.O_CREAT | os.O_RDWR, 0o660)
                except OSError as e:
                    if e.errno in (errno.ENOENT,
                                   errno.ESTALE) and os.path.isdir(
                                       os.path.dirname(lockfilename)):
                        # Retry required for NFS (see bug 636798).
                        continue
                    else:
                        _raise_exc(e)
                else:
                    break

            if not preexisting:
                try:
                    if (portage.data.secpass >= 1
                            and os.stat(lockfilename).st_gid != portage_gid):
                        os.chown(lockfilename, -1, portage_gid)
                except OSError as e:
                    if e.errno in (errno.ENOENT, errno.ESTALE):
                        os.close(myfd)
                        return None
                    writemsg(
                        "%s: chown('%s', -1, %d)\n" %
                        (e, lockfilename, portage_gid),
                        noiselevel=-1,
                    )
                    writemsg(
                        _("Cannot chown a lockfile: '%s'\n") % lockfilename,
                        noiselevel=-1,
                    )
                    writemsg(
                        _("Group IDs of current user: %s\n") %
                        " ".join(str(n) for n in os.getgroups()),
                        noiselevel=-1,
                    )
        finally:
            os.umask(old_mask)

    elif isinstance(mypath, int):
        myfd = mypath

    else:
        raise ValueError(
            _("Unknown type passed in '%s': '%s'") % (type(mypath), mypath))

    # try for a non-blocking lock, if it's held, throw a message
    # we're waiting on lockfile and use a blocking attempt.
    locking_method = portage._eintr_func_wrapper(_get_lock_fn())
    try:
        if "__PORTAGE_TEST_HARDLINK_LOCKS" in os.environ:
            raise IOError(errno.ENOSYS, "Function not implemented")
        locking_method(myfd, fcntl.LOCK_EX | fcntl.LOCK_NB)
    except IOError as e:
        if not hasattr(e, "errno"):
            raise
        if e.errno in (errno.EACCES, errno.EAGAIN, errno.ENOLCK):
            # resource temp unavailable; eg, someone beat us to the lock.
            if flags & os.O_NONBLOCK:
                os.close(myfd)
                raise TryAgain(mypath)

            global _quiet
            if _quiet:
                out = None
            else:
                out = portage.output.EOutput()
            if waiting_msg is None:
                if isinstance(mypath, int):
                    waiting_msg = _("waiting for lock on fd %i") % myfd
                else:
                    waiting_msg = _("waiting for lock on %s") % lockfilename
            if out is not None:
                out.ebegin(waiting_msg)
            # try for the exclusive lock now.
            enolock_msg_shown = False
            while True:
                try:
                    locking_method(myfd, fcntl.LOCK_EX)
                except EnvironmentError as e:
                    if e.errno == errno.ENOLCK:
                        # This is known to occur on Solaris NFS (see
                        # bug #462694). Assume that the error is due
                        # to temporary exhaustion of record locks,
                        # and loop until one becomes available.
                        if not enolock_msg_shown:
                            enolock_msg_shown = True
                            if isinstance(mypath, int):
                                context_desc = (_("Error while waiting "
                                                  "to lock fd %i") % myfd)
                            else:
                                context_desc = (_("Error while waiting "
                                                  "to lock '%s'") %
                                                lockfilename)
                            writemsg("\n!!! %s: %s\n" % (context_desc, e),
                                     noiselevel=-1)

                        time.sleep(_HARDLINK_POLL_LATENCY)
                        continue

                    if out is not None:
                        out.eend(1, str(e))
                    raise
                else:
                    break

            if out is not None:
                out.eend(os.EX_OK)
        elif e.errno in (errno.ENOSYS, ):
            # We're not allowed to lock on this FS.
            if not isinstance(lockfilename, int):
                # If a file object was passed in, it's not safe
                # to close the file descriptor because it may
                # still be in use.
                os.close(myfd)
            lockfilename_path = _unicode_decode(lockfilename_path,
                                                encoding=_encodings["fs"],
                                                errors="strict")
            if not isinstance(lockfilename_path, str):
                raise
            link_success = hardlink_lockfile(lockfilename_path,
                                             waiting_msg=waiting_msg,
                                             flags=flags)
            if not link_success:
                raise
            lockfilename = lockfilename_path
            locking_method = None
            myfd = HARDLINK_FD
        else:
            raise

    fstat_result = None
    if isinstance(lockfilename, str) and myfd != HARDLINK_FD and unlinkfile:
        try:
            (removed, fstat_result) = _lockfile_was_removed(myfd, lockfilename)
        except Exception:
            # Do not leak the file descriptor here.
            os.close(myfd)
            raise
        else:
            if removed:
                # Removed by previous lock holder... Caller will retry...
                os.close(myfd)
                return None

    if myfd != HARDLINK_FD:
        _lock_manager(myfd,
                      os.fstat(myfd) if fstat_result is None else fstat_result,
                      mypath)

    writemsg(str((lockfilename, myfd, unlinkfile)) + "\n", 1)
    return (lockfilename, myfd, unlinkfile, locking_method)
Пример #12
0
    def write(self, sign=False, force=False):
        """ Write Manifest instance to disk, optionally signing it. Returns
		True if the Manifest is actually written, and False if the write
		is skipped due to existing Manifest being identical."""
        rval = False
        if not self.allow_create:
            return rval
        self.checkIntegrity()
        try:
            myentries = list(self._createManifestEntries())
            update_manifest = True
            preserved_stats = {}
            preserved_stats[self.pkgdir.rstrip(os.sep)] = os.stat(self.pkgdir)
            if myentries and not force:
                try:
                    f = io.open(_unicode_encode(self.getFullname(),
                                                encoding=_encodings['fs'],
                                                errors='strict'),
                                mode='r',
                                encoding=_encodings['repo.content'],
                                errors='replace')
                    oldentries = list(self._parseManifestLines(f))
                    preserved_stats[self.getFullname()] = os.fstat(f.fileno())
                    f.close()
                    if len(oldentries) == len(myentries):
                        update_manifest = False
                        for i in range(len(oldentries)):
                            if oldentries[i] != myentries[i]:
                                update_manifest = True
                                break
                except (IOError, OSError) as e:
                    if e.errno == errno.ENOENT:
                        pass
                    else:
                        raise

            if update_manifest:
                if myentries or not (self.thin or self.allow_missing):
                    # If myentries is empty, don't write an empty manifest
                    # when thin or allow_missing is enabled. Except for
                    # thin manifests with no DIST entries, myentries is
                    # non-empty for all currently known use cases.
                    write_atomic(
                        self.getFullname(), "".join("%s\n" % str(myentry)
                                                    for myentry in myentries))
                    self._apply_max_mtime(preserved_stats, myentries)
                    rval = True
                else:
                    # With thin manifest, there's no need to have
                    # a Manifest file if there are no DIST entries.
                    try:
                        os.unlink(self.getFullname())
                    except OSError as e:
                        if e.errno != errno.ENOENT:
                            raise
                    rval = True

            if sign:
                self.sign()
        except (IOError, OSError) as e:
            if e.errno == errno.EACCES:
                raise PermissionDenied(str(e))
            raise
        return rval
Пример #13
0
	def _setitem(self, cpv, values):
		if "_eclasses_" in values:
			values = ProtectedDict(values)
			values["INHERITED"] = ' '.join(sorted(values["_eclasses_"]))

		new_content = []
		for k in self.auxdbkey_order:
			new_content.append(values.get(k, ''))
			new_content.append('\n')
		for i in range(magic_line_count - len(self.auxdbkey_order)):
			new_content.append('\n')
		new_content = ''.join(new_content)
		new_content = _unicode_encode(new_content,
			_encodings['repo.content'], errors='backslashreplace')

		new_fp = os.path.join(self.location, cpv)
		try:
			f = open(_unicode_encode(new_fp,
				encoding=_encodings['fs'], errors='strict'), 'rb')
		except EnvironmentError:
			pass
		else:
			try:
				try:
					existing_st = os.fstat(f.fileno())
					existing_content = f.read()
				finally:
					f.close()
			except EnvironmentError:
				pass
			else:
				existing_mtime = existing_st[stat.ST_MTIME]
				if values['_mtime_'] == existing_mtime and \
					existing_content == new_content:
					return

				if self.raise_stat_collision and \
					values['_mtime_'] == existing_mtime and \
					len(new_content) == existing_st.st_size:
					raise cache_errors.StatCollision(cpv, new_fp,
						existing_mtime, existing_st.st_size)

		s = cpv.rfind("/")
		fp = os.path.join(self.location,cpv[:s],
			".update.%i.%s" % (os.getpid(), cpv[s+1:]))
		try:
			myf = open(_unicode_encode(fp,
				encoding=_encodings['fs'], errors='strict'), 'wb')
		except EnvironmentError as e:
			if errno.ENOENT == e.errno:
				try:
					self._ensure_dirs(cpv)
					myf = open(_unicode_encode(fp,
						encoding=_encodings['fs'], errors='strict'), 'wb')
				except EnvironmentError as e:
					raise cache_errors.CacheCorruption(cpv, e)
			else:
				raise cache_errors.CacheCorruption(cpv, e)

		try:
			myf.write(new_content)
		finally:
			myf.close()
		self._ensure_access(fp, mtime=values["_mtime_"])

		try:
			os.rename(fp, new_fp)
		except EnvironmentError as e:
			try:
				os.unlink(fp)
			except EnvironmentError:
				pass
			raise cache_errors.CacheCorruption(cpv, e)
Пример #14
0
def _lockfile_was_removed(lock_fd, lock_path):
	"""
	Check if lock_fd still refers to a file located at lock_path, since
	the file may have been removed by a concurrent process that held the
	lock earlier. This implementation includes support for NFS, where
	stat is not reliable for removed files due to the default file
	attribute cache behavior ('ac' mount option).

	@param lock_fd: an open file descriptor for a lock file
	@type lock_fd: int
	@param lock_path: path of lock file
	@type lock_path: str
	@rtype: bool
	@return: True if lock_path exists and corresponds to lock_fd, False otherwise
	"""
	try:
		fstat_st = os.fstat(lock_fd)
	except OSError as e:
		if e.errno not in (errno.ENOENT, errno.ESTALE):
			_raise_exc(e)
		return True

	# Since stat is not reliable for removed files on NFS with the default
	# file attribute cache behavior ('ac' mount option), create a temporary
	# hardlink in order to prove that the file path exists on the NFS server.
	hardlink_path = hardlock_name(lock_path)
	try:
		os.unlink(hardlink_path)
	except OSError as e:
		if e.errno not in (errno.ENOENT, errno.ESTALE):
			_raise_exc(e)
	try:
		try:
			os.link(lock_path, hardlink_path)
		except OSError as e:
			if e.errno not in (errno.ENOENT, errno.ESTALE):
				_raise_exc(e)
			return True

		hardlink_stat = os.stat(hardlink_path)
		if hardlink_stat.st_ino != fstat_st.st_ino or hardlink_stat.st_dev != fstat_st.st_dev:
			# Create another hardlink in order to detect whether or not
			# hardlink inode numbers are expected to match. For example,
			# inode numbers are not expected to match for sshfs.
			inode_test = hardlink_path + '-inode-test'
			try:
				os.unlink(inode_test)
			except OSError as e:
				if e.errno not in (errno.ENOENT, errno.ESTALE):
					_raise_exc(e)
			try:
				os.link(hardlink_path, inode_test)
			except OSError as e:
				if e.errno not in (errno.ENOENT, errno.ESTALE):
					_raise_exc(e)
				return True
			else:
				if not os.path.samefile(hardlink_path, inode_test):
					# This implies that inode numbers are not expected
					# to match for this file system, so use a simple
					# stat call to detect if lock_path has been removed.
					return not os.path.exists(lock_path)
			finally:
				try:
					os.unlink(inode_test)
				except OSError as e:
					if e.errno not in (errno.ENOENT, errno.ESTALE):
						_raise_exc(e)
			return True
	finally:
		try:
			os.unlink(hardlink_path)
		except OSError as e:
			if e.errno not in (errno.ENOENT, errno.ESTALE):
				_raise_exc(e)
	return False