Exemple #1
0
    def truncate(self, path, length, fh=None):
        '''truncate(2) calls with fh == None; based on path but access
           must be checked.  ftruncate passes in open handle'''
        zero_enabled = self.shadow.zero_on_unlink

        # ALWAYS get the shelf by name, even if fh is valid.
        # FIXME: Compare self.shadow[fh] to returned shelf.
        # IMPLICIT ASSUMPTION: without tenants this will never EPERM
        rsp = self.librarian(self.lcp('get_shelf', path=path))
        req = self.lcp('resize_shelf',
                       path=path,
                       size_bytes=length,
                       id=rsp['id'],
                       zero_enabled=zero_enabled)
        rsp = self.librarian(req)

        # If books were removed from the shelf and added to a zeroing
        # shelf, start a process to zero the books on that shelf.
        if rsp['z_shelf_path'] is not None:
            z_rsp = self.librarian(
                self.lcp('get_shelf', path=rsp['z_shelf_path']))
            z_shelf = TMShelf(z_rsp)
            threading.Thread(target=self._zero, args=(z_shelf, )).start()

        # Refresh shelf info
        rsp = self.librarian(self.lcp('get_shelf', path=path))
        shelf = TMShelf(rsp)
        if shelf.size_bytes < length:
            raise TmfsOSError(errno.EINVAL)
        self.get_bos(shelf)
        return self.shadow.truncate(shelf, length, fh)
Exemple #2
0
    def unlink(self, path, *args, **kwargs):
        assert not args and not kwargs, 'unlink: unexpected args'
        shelf = TMShelf(self.librarian(self.lcp('get_shelf', path=path)))

        # Paranoia check for (dangling) opens.  Does VFS catch these first?
        cached = self.shadow[(shelf.id, None)]
        if cached is not None:  # Not a good sign
            open_handles = cached.open_handle
            # This was if not none, but cached.open_handle was returning empty dict,
            # not a NoneObject
            if open_handles:  # Definitely a bad sign
                raise TmfsOSError(errno.EBUSY)

                # Once upon a time I forced it...
                for fh in open_handles.values():
                    try:
                        self.librarian(
                            self.lcp('close_shelf', id=shelf.id, fh=fh))
                    except Exception as e:
                        pass

        self.shadow.unlink(shelf)  # empty cache INCLUDING dangling opens

        # Early exit: no explicit zeroing required if:
        # 1. it's zero bytes long
        # 2. it's passed through zeroing, meaning this is the second trip to
        #    unlink()..  Even if length is non-zero, remove it, assuming the
        #   _zero subprocess failed.
        # 3. The shadow subclass doesn't need it
        if ((not shelf.size_bytes) or shelf.name.startswith(self._ZERO_PREFIX)
                or (not self.shadow.zero_on_unlink)):
            self.librarian(self.lcp('destroy_shelf', path=path))
            return 0

        # Schedule for zeroing; a second entry to unlink() will occur on
        # this shelf with the new name.
        zeroname = '%s%d' % (self._ZERO_PREFIX, shelf.id)
        if zeroname != shelf.name:

            self.rename(self.get_shelf_path(shelf), zeroname)
            shelf.name = zeroname
            shelf.mode = stat.S_IFREG  # un-block it as was done on server
        if self.verbose <= 3:
            threading.Thread(target=self._zero, args=(shelf, )).start()
        else:
            set_trace()
            self._zero(shelf)  # this will block: lfs_fuse is single-threaded
        return 0
Exemple #3
0
    def cmd_create_shelf(self, cmdict):
        """ Create a new shelf
            In (dict)---
                name
            Out (dict) ---
                shelf data
        """
        path_list = self._path2list(cmdict['path'])
        cmdict['name'] = path_list[-1]
        parent_shelf = self._path2shelf(path_list[:-1])
        cmdict['parent_id'] = parent_shelf.id
        cmdict['link_count'] = 1  # normal files get one

        # POSIX: if extant, open it; else create and then open
        try:
            shelf = self.cmd_open_shelf(cmdict)
            return shelf
        except Exception as e:
            pass
        self.errno = errno.EINVAL
        shelf = TMShelf(cmdict)
        self.db.create_shelf(shelf)
        self.db.create_xattr(shelf,
                             BookPolicy.XATTR_ALLOCATION_POLICY,
                             BookPolicy.DEFAULT_ALLOCATION_POLICY)

        # Will be ignored until AllocationPolicy set to RequestIG.  I just
        # want it to show up in a full xattr dump (getfattr -d /lfs/xxxx)
        self.db.create_xattr(shelf, BookPolicy.XATTR_IG_REQ, '')
        self.db.create_xattr(shelf, BookPolicy.XATTR_IG_REQ_POS, '')

        return self.cmd_open_shelf(cmdict)  # Does the handle thang
Exemple #4
0
    def cmd_symlink(self, cmdict):
        """ Creates a symlink at path to target
            Input(dict)---
                path - path to create symlink at
                target - path where symlink is supposed to point to
            Output(shelf)---
                symlink shelf that was created
        """
        cmdict['mode'] = self._MODE_DEFAULT_LNK
        path_list = self._path2list(cmdict['path'])
        cmdict['name'] = path_list[-1]
        parent_shelf = self._path2shelf(path_list[:-1])
        cmdict['parent_id'] = parent_shelf.id
        cmdict['link_count'] = 1  # I think?

        try:
            shelf = self.cmd_get_shelf(cmdict)
            self.errno = errno.EEXIST
            return shelf
        except Exception as e:
            pass

        self.errno = errno.EINVAL
        shelf = TMShelf(cmdict)
        self.db.create_shelf(shelf)

        self.db.create_symlink(shelf, cmdict['target'])

        return shelf
Exemple #5
0
    def cmd_mkdir(self, cmdict):
        # currently similar to cmd_create_shelf with slight modifications
        path_list = self._path2list(cmdict['path'])
        cmdict['name'] = path_list[-1]
        parent_shelf = self._path2shelf(path_list[:-1])
        cmdict['parent_id'] = parent_shelf.id
        cmdict['link_count'] = 2  # . and .. for directories

        try:
            shelf = self.cmd_get_shelf(cmdict)
            self.errno = errno.EEXIST
            return shelf
        except Exception as e:
            pass

        self.errno = errno.EINVAL
        shelf = TMShelf(cmdict)
        self.db.create_shelf(shelf)

        # parent directory shelf has to also have link count incremented
        parent_shelf.link_count += 1
        parent_shelf.matchfields = ('link_count', )
        self.db.modify_shelf(parent_shelf, commit=True)

        return shelf # man 2 mkdir: 0 on success
Exemple #6
0
 def open(self, path, flags, mode=None):
     # looking for filehandles?  See FUSE docs.  Librarian will do
     # all access calculations so call it first.
     rsp = self.librarian(self.lcp('open_shelf', path=path))
     shelf = TMShelf(rsp)
     self.get_bos(shelf)
     # File handle is a proxy for FuSE to refer to "real" file descriptor.
     # Different shadow types may return different things for kernel.
     fx = self.shadow.open(shelf, flags, mode)
     return fx
Exemple #7
0
 def cmd_close_shelf(self, cmdict):
     """ Close a shelf against access by a node.
         In (dict)---
             shelf_id, handle
         Out (dict) ---
             TMShelf object
     """
     shelf = TMShelf(cmdict)
     shelf = self.db.modify_opened_shelves(shelf, 'put', cmdict['context'])
     return shelf
Exemple #8
0
    def write(self, path, buf, offset, fh):
        # FIXME: see read comment
        rsp = self.librarian(self.lcp('get_shelf', path=path))
        shelf = TMShelf(rsp)

        # Resize shelf "on the fly" for writes past EOF
        # BUG: what if shelf was resized elsewhere?  And what about read?
        req_size = offset + len(buf)
        if self.shadow[(shelf.id, None)].size_bytes < req_size:
            self.truncate(path, req_size, fh)  # updates the cache

        return self.shadow.write(shelf, buf, offset, fh)
Exemple #9
0
 def create(self, path, mode, fh=None, supermode=None):
     if fh is not None:
         # createat(2), methinks, but I never saw this in 8 months
         raise TmfsOSError(errno.ENOSYS)
     if supermode is None:
         mode &= 0o777
         tmpmode = stat.S_IFREG + mode
     else:
         mode = supermode & 0o777
         tmpmode = supermode
     tmp = self.lcp('create_shelf', path=path, mode=tmpmode)
     rsp = self.librarian(tmp)
     shelf = TMShelf(rsp)  # This is an open shelf...
     fx = self.shadow.create(shelf, mode)  # ...added to the cache...
     return fx  # ...with this value.
Exemple #10
0
 def rename(self, old, new):
     # 0 or raise
     rsp = self.librarian(self.lcp('get_shelf', path=new), errorOK=True)
     if 'errmsg' not in rsp:
         self.unlink(new)
     rsp = self.librarian(self.lcp('get_shelf', path=old))
     shelf = TMShelf(rsp)
     # one of the only places path2name still exists
     # renamed from old path2shelf
     new_name = self._legacy_path2name(new)
     old_name = self._legacy_path2name(old)
     self.shadow.rename(shelf, old_name, new_name)
     req = self.lcp('rename_shelf', path=old, id=shelf.id, newpath=new)
     self.librarian(req)  # None or raise
     return 0
Exemple #11
0
 def getattr(self, path, fh=None):
     # ROSS remove some root hardcoding now that a real root exists
     if fh is not None:
         raise TmfsOSError(errno.ENOENT)  # never saw this in 8 months
     rsp = self.librarian(self.lcp('get_shelf', path=path))
     shelf = TMShelf(rsp)
     tmp = {
         'st_ctime': shelf.ctime,
         'st_mtime': shelf.mtime,
         'st_uid': 42,
         'st_gid': 42,
         'st_mode': shelf.mode,
         'st_nlink': shelf.link_count,
         'st_size': shelf.size_bytes
     }
     if shelf.name.startswith('block'):
         tmp['st_mode'] = self._MODE_DEFAULT_BLK
     return tmp
Exemple #12
0
 def fallocate(self, path, mode, offset, length, fh=None):
     # LFS doesn't support sparse files or hole punching (lazy allocation).
     # mode == 0 is essentially posix_fallocate and that's all there is.
     # Case in point: mkfs on a shelf (or a loopback device to a shelf)
     # wants mode == 3 == FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE
     # for quick-and-dirty zeroed blocks.  See it in the e2fsprogs source
     # file lib/ext2fs/unix_io.c::unix_discard()
     if mode:
         raise TmfsOSError(errno.EOPNOTSUPP)
     if fh is None:
         rsp = self.librarian(self.lcp('get_shelf', path=path))
         shelf = TMShelf(rsp)
     else:
         shelf = self.shadow[(None, fh)]
         if not shelf:
             raise TmfsOSError(errno.ESTALE)
     if shelf.size_bytes >= offset + length:
         return 0
     return self.truncate(path, offset + length, None)
Exemple #13
0
    def _path2shelf(self, path):
        '''Returns shelf object corresponding to given path'''
        # accepts a string, or a list. either is handled in path2list
        path_list = self._path2list(path)
        # FIXME: not sure if this will work, attempting to start at root and move from there
        # if things break, this would be a reasonable place to look
        tmp = TMShelf(id=2)
        tmp.matchfields = ('id', )
        current_shelf = self.db.get_shelf(tmp)
        for name in path_list:
            tmp = TMShelf(parent_id=current_shelf.id, name=name)
            tmp.matchfields = ('parent_id', 'name')
            current_shelf = self.db.get_shelf(tmp)

        return current_shelf
Exemple #14
0
    def getxattr(self, path, xattr, position=0):
        """Called with a specific namespace.name xattr.  Can return either
           a bytes array OR an int."""
        if position:
            raise TmfsOSError(errno.ENOSYS)  # never saw this in 8 months

        rsp = self.librarian(self.lcp('get_shelf', path=path))
        shelf = TMShelf(rsp)

        # Does this also need changed to support path instead of name?
        # Piggy back for queries by kernel (globals & fault handling).
        if xattr.startswith('_obtain_'):
            # this will need some work
            data = self.shadow.getxattr(shelf, xattr)
            try:
                return bytes(data.encode())
            except AttributeError as e:  # probably the "encode()"
                self._ret_is_string = False
                return bytes(data)

        # "ls" starts with simple getattr but then comes here for
        # security.selinux, system.posix_acl_access, and posix_acl_default.
        # ls -l can also do the same thing on '/'.  Save the round trips.

        # if xattr.startswith('security.') or not shelf_name:  # path == '/'
        if xattr.startswith('security.'):  # path == '/' is legal now
            return bytes(0)

        try:
            rsp = self.librarian(self.lcp('get_xattr', path=path, xattr=xattr))
            value = rsp['value']
            assert value is not None  # 'No such attribute'
            if isinstance(value, int):
                return value
            elif isinstance(value, str):
                # http://stackoverflow.com/questions/606191/convert-bytes-to-a-python-string
                return bytes(value.encode('cp437'))
            else:
                bytes(value.encode())
        except Exception as e:
            raise TmfsOSError(errno.ENODATA)  # syn for ENOATTR
Exemple #15
0
    def cmd_get_shelf_path(self, cmdict):
        ''' Retrieves path to any given shelf
            "shelf" is an incomplete shelf generated from cmdict
            "current_shelf" is complete shelf fetched from db
        '''
        path = ['/']
        shelf = TMShelf(cmdict)
        shelf.matchfields = ('name', 'parent_id')
        current_shelf = self.db.get_shelf(shelf)  # shelf who needs path
        path.insert(1, current_shelf.name)
        while current_shelf.parent_id != 2:
            # modify passing command dict
            cmdict['id'] = current_shelf.parent_id
            shelf = TMShelf(cmdict)
            shelf.matchfields = ('id', )
            current_shelf = self.db.get_shelf(shelf)
            path.insert(1, '/')
            path.insert(1, current_shelf.name)

        return str().join(path)
Exemple #16
0
 def cmd_get_shelf(self, cmdict, match_id=False, match_parent_id=True):
     """ List a given shelf.
         In (dict)---
             path
             optional flag to force a match on id (ie, already open)
             optional flag to force a match on parent_id, defaulted to True
         Out (TMShelf object) ---
             TMShelf object
     """
     self.errno = errno.EINVAL
     path_list = self._path2list(cmdict['path'])
     try:
         cmdict['name'] = path_list[-1]
         parent_shelf = self._path2shelf(path_list[:-1])
         cmdict['parent_id'] = parent_shelf.id
     except IndexError:
         #case of getting root
         cmdict['name'] = '.'
         cmdict['parent_id'] = 2
     shelf = TMShelf(cmdict)
     assert shelf.name, 'Missing shelf name'
     if match_parent_id:
         assert shelf.parent_id, 'Missing parent id'
     if match_id and match_parent_id:
         shelf.matchfields = ('name', 'id', 'parent_id')
     elif match_parent_id:
         shelf.matchfields = ('name', 'parent_id')
     elif match_id:
         shelf.matchfields = ('name', 'id')
     else:
         shelf.matchfields = ('name', )
     shelf = self.db.get_shelf(shelf)
     if shelf is None:
         self.errno = errno.ENOENT  # FIXME: raise OSError instead?
         raise AssertionError('no such shelf %s' % cmdict['name'])
     # consistency checks
     self.errno = errno.EBADF
     assert self._nbooks(shelf.size_bytes) == shelf.book_count, (
         '%s size metadata mismatch' % shelf.name)
     self.errno = errno.ESTALE
     return shelf
Exemple #17
0
    def cmd_resize_shelf(self, cmdict):
        """ Resize given shelf to new size in bytes.
            In (dict)---
                path
                id
                size_bytes
                zero_enabled
            Out (dict) ---
                z_shelf_path
        """
        shelf = self.cmd_get_shelf(cmdict, match_id=True)
        bos = self._list_shelf_books(shelf)
        new_size_bytes = int(cmdict['size_bytes'])
        self.errno = errno.EINVAL
        assert new_size_bytes >= 0, 'Bad size'
        new_book_count = self._nbooks(new_size_bytes)
        out_buf = {'z_shelf_path': None}
        if bos:
            seqs = [ b.seq_num for b in bos ]
            self.errno = errno.EBADFD
            assert set(seqs) == set(range(1, shelf.book_count + 1)), (
                'Corrupt BOS sequence progression for %s' % shelf.name)

        # Can I leave real early?
        if new_size_bytes == shelf.size_bytes:
            return out_buf

        # Can this call be rejected?
        openers = self.db.get_shelf_openers(
            shelf, cmdict['context'], include_me=False)
        self.errno = errno.EMFILE
        assert not openers or new_size_bytes > shelf.size_bytes, \
            'Cannot shrink multiply-opened shelf'

        # Go for it
        shelf.size_bytes = new_size_bytes

        # How about a little early?
        if new_book_count == shelf.book_count:
            shelf.matchfields = 'size_bytes'
            shelf = self.db.modify_shelf(shelf, commit=True)
            return out_buf

        books_needed = new_book_count - shelf.book_count
        if books_needed > 0:
            policy = BookPolicy(self, shelf, cmdict['context'])
            freebooks = policy(books_needed)
            self.errno = errno.ENOSPC
            assert len(freebooks) == books_needed, \
                'out of space for "%s"' % shelf.name
            seq_num = shelf.book_count
            for book in freebooks:  # Mark book in use and create BOS entry
                book = self._set_book_alloc(book, TMBook.ALLOC_INUSE)
                seq_num += 1
                thisbos = TMBos(
                    shelf_id=shelf.id, book_id=book.id, seq_num=seq_num)
                thisbos = self.db.create_bos(thisbos)
        elif books_needed < 0:
            books_2bdel = -books_needed  # it all reads so much better
            self.errno = errno.EREMOTEIO
            assert len(bos) >= books_2bdel, 'Book removal problem'
            # The unlink workflow has one step which zero truncates
            # a file with a certain name.  IOW not all shelves are USED,
            # some may be full of ZOMBIES
            freeing = shelf.name.startswith(
                _ZERO_PREFIX) and not new_book_count
            zero_enabled = cmdict['zero_enabled']

            if not freeing and zero_enabled:
                # Create a zeroing shelf for the books being removed
                z_shelf_name = (_ZERO_PREFIX + shelf.name + '_' + str(shelf.parent_id) +
                                '_' + str(time.time()) + '_' + cmdict['context']['physloc'])
                # all are placed in root, so path is easy
                z_shelf_path = '/' + z_shelf_name
                z_shelf_data = {}
                z_shelf_data.update({'context': cmdict['context']})
                z_shelf_data.update({'name': z_shelf_name})
                # place all zeroing shelves at root (/lfs) with parent_id = 2
                # this makes sure that they are not placed in a directory that
                # is removed before they can be zeroed and deleted themselves
                z_shelf_data.update({'parent_id': 2})
                self.errno = errno.EINVAL
                z_shelf = TMShelf(z_shelf_data)
                self.db.create_shelf(z_shelf)
                z_seq_num = 1

            while books_2bdel > 0:
                try:
                    thisbos = bos.pop()
                    self.db.delete_bos(thisbos)         # Orphans the book
                    new_state = TMBook.ALLOC_ZOMBIE
                    book = self.db.get_book_by_id(thisbos.book_id)
                    if freeing and book.allocated == TMBook.ALLOC_ZOMBIE:
                        new_state = TMBook.ALLOC_FREE
                    if new_state != book.allocated:     # staying ZOMBIE
                        _ = self._set_book_alloc(book, new_state)
                    books_2bdel -= 1

                    if not freeing and zero_enabled:
                        # Add removed book to zeroing shelf
                        z_thisbos = TMBos(shelf_id=z_shelf.id,
                                          book_id=book.id, seq_num=z_seq_num)
                        z_thisbos = self.db.create_bos(z_thisbos)
                        z_shelf.size_bytes += self.book_size_bytes
                        z_shelf.book_count += 1
                        z_seq_num += 1

                except Exception as e:
                    self.db.rollback()
                    self.errno = errno.EREMOTEIO
                    raise RuntimeError(
                        'Resizing shelf smaller failed: %s' % str(e))

            if not freeing and zero_enabled:
                z_shelf.matchfields = ('size_bytes', 'book_count')
                z_shelf = self.db.modify_shelf(z_shelf, commit=True)
                out_buf = {'z_shelf_path': z_shelf_path}

        else:
            self.db.rollback()
            self.errno = errno.EREMOTEIO
            raise RuntimeError('Bad code path in cmd_resize_shelf()')

        shelf.book_count = new_book_count
        shelf.matchfields = ('size_bytes', 'book_count')
        shelf = self.db.modify_shelf(shelf, commit=True)
        return out_buf
Exemple #18
0
 def ioctl(self, path, cmd, arg, fh, flags, data):
     rsp = self.librarian(self.lcp('get_shelf', path=path))
     shelf = TMShelf(rsp)
     return self.shadow.ioctl(shelf, cmd, arg, fh, flags, data)
Exemple #19
0
def create_empty_db(cur):
    try:
        table_create = """
            CREATE TABLE globals (
            schema_version TEXT,
            book_size_bytes INT,
            nvm_bytes_total INT,
            books_total INT,
            nodes_total INT
            )
            """
        cur.execute(table_create)

        # FRD: max 80.
        # index == quadruple.
        table_create = """
            CREATE TABLE FRDnodes (
            node_id,
            rack INT,
            enc INT,
            node INT,
            coordinate TEXT,
            serialNumber TEXT
            )
            """
        cur.execute(table_create)

        # SOC
        table_create = """
            CREATE TABLE SOCs (
            node_id,
            MAC TEXT,
            status INT,
            coordinate TEXT,
            tlsPublicCertificate TEXT,
            heartbeat INT,
            cpu_percent INT,
            rootfs_percent INT,
            network_in INT,
            network_out INT,
            mem_percent INT
            )
            """
        cur.execute(table_create)

        # FRD: 4 per node. CID is raw descriptor table encoded value
        table_create = """
            CREATE TABLE FAModules (
            node_id INT,
            IG INT,
            module_size_books INT,
            rawCID INT,
            status INT,
            coordinate TEXT,
            memorySize INT
            )
            """
        cur.execute(table_create)

        # Book numbers are now relative to an interleave group.
        # intlv_group 1-128 is less than eight bits.  For 990 usage there
        # is now a tag field above bits 15-0 (plenty of room for legacy IGs).
        table_create = """
            CREATE TABLE books (
            id INTEGER PRIMARY KEY,
            intlv_group INT,
            book_num INT,
            allocated INT,
            attributes INT
            )
            """
        cur.execute(table_create)
        cur.commit()

        table_create = """
            CREATE TABLE shelves (
            id INTEGER PRIMARY KEY,
            creator_id INT,
            size_bytes INT,
            book_count INT,
            ctime INT,
            mtime INT,
            name TEXT,
            mode INT,
            parent_id INT,
            link_count INT
            )
            """
        cur.execute(table_create)
        cur.commit()

        # cur.execute('CREATE UNIQUE INDEX IDX_shelves ON shelves (name)')
        # cur.commit()

        table_create = """
            CREATE TABLE books_on_shelves (
            shelf_id INT,
            book_id INT,
            seq_num INT
            )
            """
        cur.execute(table_create)
        cur.commit()

        # The id will be used as the open_handle.  It's called id because
        # it matches some internal operations harcoded to that name.
        table_create = """
            CREATE TABLE opened_shelves (
            id INTEGER PRIMARY KEY,
            shelf_id INT,
            node_id INT,
            pid INT
            )
            """
        cur.execute(table_create)
        cur.commit()

        table_create = """
            CREATE TABLE shelf_xattrs (
            shelf_id INT,
            xattr TEXT,
            value TEXT
            )
            """
        cur.execute(table_create)
        cur.commit()

        # creating linking table. Will currently house shelf id for
        # symbolic link shelves, the path for the file being linked to,
        # and another "magic" field for whatever else needs to be put in
        # that I can't think of now. Thought about adding a primary key
        # id for possible debugging purposes, but can't think of what I
        # would do with it. Will just be for linking other stuff together
        table_create = """
            CREATE TABLE links (
            shelf_id INT,
            target TEXT,
            other TEXT
            )
            """
        cur.execute(table_create)
        cur.commit()

        cur.execute('''CREATE UNIQUE INDEX IDX_xattrs
                       ON shelf_xattrs (shelf_id, xattr)''')
        cur.commit()

    except Exception as e:
        raise SystemExit('DB operation failed at line %d: %s' % (
            sys.exc_info()[2].tb_lineno, str(e)))

    # Idiot checks
    book = TMBook()
    assert book.schema == cur.schema('books'), 'Bad schema: books'
    shelf = TMShelf()
    assert shelf.schema == cur.schema('shelves'), 'Bad schema: shelves'
    bos = TMBos()
    assert bos.schema == cur.schema('books_on_shelves'), 'Bad schema: BOS'
    opened_shelves = TMOpenedShelves()
    assert opened_shelves.schema == cur.schema(
        'opened_shelves'), 'Bad schema: opened_shelves'
Exemple #20
0
 def read(self, path, length, offset, fh):
     # FIXME: this might break shadow directories and shadow files
     # but those have not been made to work with subs anyway
     rsp = self.librarian(self.lcp('get_shelf', path=path))
     shelf = TMShelf(rsp)
     return self.shadow.read(shelf, length, offset, fh)