Beispiel #1
0
func Restore(blobpath string, c btncrypt.Cipher, bs blobstore.BlobStore, cb DecodeCallback) error {
	r, err := bs.OpenReader(blobpath)
	if err != nil {
		return err
	}

	cr, err := chunkstore.NewChunkReader(r, c)
	if err != nil {
		return err
	}
	logger.Debugf(mylog, "serialized blob size: %d", cr.Length())
	zr, err := zlib.NewReader(&io.LimitedReader{cr, int64(cr.Length())})
	if err != nil {
		return err
	}
	logger.Debugf(mylog, "statesnapshot.Restore: zlib init success!")
	dec := gob.NewDecoder(zr)

	es := []error{}
	if err := cb(dec); err != nil {
		es = append(es, fmt.Errorf("Failed to decode state: %v", err))
	}
	if err := zr.Close(); err != nil {
		es = append(es, fmt.Errorf("Failed to close zlib Reader: %v", err))
	}
	if err := r.Close(); err != nil {
		es = append(es, fmt.Errorf("Failed to close BlobHandle: %v", err))
	}

	if err := util.ToErrors(es); err != nil {
		return err
	}
	return nil
}
Beispiel #2
0
func (db *DB) applyTransactionInternal(tx DBTransaction, writeTxLogFlag bool) (TxID, error) {
	logger.Debugf(mylog, "applyTransactionInternal(%+v, writeTxLog: %t)", tx, writeTxLogFlag)

	if tx.TxID == AnyVersion {
		tx.TxID = db.state.version + 1
	} else if tx.TxID != db.state.version+1 {
		return 0, fmt.Errorf("Attempted to apply tx %d to dbver %d. Next accepted tx is %d", tx.TxID, db.state.version, db.state.version+1)
	}

	for _, op := range tx.Ops {
		if err := op.Apply(db.state); err != nil {
			if rerr := db.RestoreVersion(db.state.version); rerr != nil {
				logger.Panicf(mylog, "Following Error: %v. DB rollback failed!!!: %v", err, rerr)
			}
			return 0, err
		}
	}
	if writeTxLogFlag == writeTxLog {
		if err := db.txLogIO.AppendTransaction(tx); err != nil {
			if rerr := db.RestoreVersion(db.state.version); rerr != nil {
				logger.Panicf(mylog, "Failed to write txlog: %v. DB rollback failed!!!: %v", err, rerr)
			}
			return 0, fmt.Errorf("Failed to write txlog: %v", err)
		}
	}

	db.state.version = tx.TxID
	db.stats.LastTx = time.Now()
	return tx.TxID, nil
}
Beispiel #3
0
func (cbv *CachedBackendVersion) Query(blobpath string) (version.Version, error) {
	cbv.mu.Lock()
	defer cbv.mu.Unlock() // FIXME: unlock earlier?

	if ver, ok := cbv.cache[blobpath]; ok {
		logger.Debugf(mylog, "return cached ver for \"%s\" -> %d", blobpath, ver)
		return ver, nil
	}

	r, err := cbv.backendbs.OpenReader(blobpath)
	if err != nil {
		if err == ENOENT {
			cbv.cache[blobpath] = 0
			return 0, nil
		}
		return -1, fmt.Errorf("Failed to open backend blob for ver query: %v", err)
	}
	defer func() {
		if err := r.Close(); err != nil {
			logger.Criticalf(mylog, "Failed to close backend blob handle for querying version: %v", err)
		}
	}()
	ver, err := cbv.queryVersion(r)
	if err != nil {
		return -1, fmt.Errorf("Failed to query backend blob ver: %v", err)
	}

	cbv.cache[blobpath] = ver
	return ver, nil
}
func (txio *CachedDBTransactionLogIO) QueryTransactions(minID TxID) ([]DBTransaction, error) {
	if minID < txio.oldestTxID {
		logger.Debugf(clog, "Queried id range of \">= %d\" is not cached. Falling back to backend.", minID)
		return txio.be.QueryTransactions(minID)
	}

	return txio.QueryCachedTransactions(minID)
}
Beispiel #5
0
func (cfio *ChunkedFileIO) newFileChunk(newo int64) (inodedb.FileChunk, error) {
	bpath, err := blobstore.GenerateNewBlobPath(cfio.bs)
	if err != nil {
		return inodedb.FileChunk{}, fmt.Errorf("Failed to generate new blobpath: %v", err)
	}
	fc := inodedb.FileChunk{Offset: newo, Length: 0, BlobPath: bpath}
	logger.Debugf(mylog, "new chunk %+v", fc)
	return fc, nil
}
Beispiel #6
0
func (ch *ChunkIO) PRead(p []byte, offset int64) error {
	if err := ch.ensureHeader(); err != nil {
		return err
	}

	if offset < 0 || math.MaxInt32 < offset {
		return fmt.Errorf("Offset out of int32 range: %d", offset)
	}

	logger.Debugf(mylog, "ChunkIO: PRead off %d len %d. Chunk payload len: %d", offset, len(p), ch.PayloadLen())

	remo := int(offset)
	remp := p
	for len(remp) > 0 {
		i := remo / ContentFramePayloadLength
		f, err := ch.readContentFrame(i)
		if err != nil {
			return err
		}
		inframeOffset := remo - f.Offset
		if inframeOffset < 0 {
			panic("ASSERT: inframeOffset must be non-negative here")
		}
		// logger.Debugf(mylog, "ChunkIO: PRead: Decoded content frame. %+v", f)

		n := len(remp)
		valid := len(f.P) - inframeOffset // valid payload after offset
		logger.Debugf(mylog, "ChunkIO: PRead n: %d. valid: %d", n, valid)
		if n > valid {
			if f.IsLastFrame {
				return fmt.Errorf("Attempted to read beyond written size: %d. inframeOffset: %d, framePayloadLen: %d", remo, inframeOffset, len(f.P))
			}

			n = valid
		}

		copy(remp[:n], f.P[inframeOffset:])
		logger.Debugf(mylog, "ChunkIO: PRead: read %d bytes for off %d len %d", n, remo, len(remp))

		remo += n
		remp = remp[n:]
	}
	return nil
}
Beispiel #7
0
func (ch *ChunkIO) Sync() error {
	if ch.needsHeaderUpdate {
		if err := ch.header.WriteTo(&blobstore.OffsetWriter{ch.bh, 0}, ch.c); err != nil {
			return fmt.Errorf("Header write failed: %v", err)
		}
		logger.Debugf(mylog, "Wrote chunk header: %+v", ch.header)
		ch.needsHeaderUpdate = false
	}
	return nil
}
Beispiel #8
0
func (n FileNode) Open(ctx context.Context, req *bfuse.OpenRequest, resp *bfuse.OpenResponse) (bfs.Handle, error) {
	logger.Debugf(mylog, "Open flags: %s", req.Flags.String())

	fh, err := n.fs.OpenFile(n.id, Bazil2OtaruFlags(req.Flags))
	if err != nil {
		return nil, err
	}

	return FileHandle{fh}, nil
}
Beispiel #9
0
func TestWriterLogger(t *testing.T) {
	var b bytes.Buffer
	l := logger.WriterLogger{&b}
	logger.Debugf(l, "foobar")

	expre := regexp.MustCompile("writerlogger_test.go:\\d+: foobar\n")
	if !expre.Match(b.Bytes()) {
		t.Errorf("Unexpected: %s", b.String())
	}
}
Beispiel #10
0
func (wc *FileWriteCache) PWrite(p []byte, offset int64) error {
	pcopy := make([]byte, len(p))
	copy(pcopy, p)

	newp := intn.Patch{Offset: offset, P: pcopy}
	logger.Debugf(wclog, "PWrite: %v", newp)
	// logger.Debugf(wclog, "PWrite: p=%v", pcopy)

	wc.ps = wc.ps.Merge(newp)
	return nil
}
Beispiel #11
0
func (d DirNode) Setattr(ctx context.Context, req *bfuse.SetattrRequest, resp *bfuse.SetattrResponse) error {
	logger.Debugf(mylog, "Setattr mode %o", req.Mode)

	if err := otaruSetattr(d.fs, d.id, req); err != nil {
		return err
	}
	if err := d.Attr(ctx, &resp.Attr); err != nil {
		return err
	}

	return nil
}
Beispiel #12
0
func (fh FileHandle) Write(ctx context.Context, req *bfuse.WriteRequest, resp *bfuse.WriteResponse) error {
	logger.Debugf(mylog, "Write offset %d size %d", req.Offset, len(req.Data))

	if fh.h == nil {
		return EBADF
	}

	if err := fh.h.PWrite(req.Data, req.Offset); err != nil {
		return err
	}
	resp.Size = len(req.Data)

	return nil
}
Beispiel #13
0
func (fh FileHandle) Read(ctx context.Context, req *bfuse.ReadRequest, resp *bfuse.ReadResponse) error {
	logger.Debugf(mylog, "Read offset %d size %d", req.Offset, req.Size)

	if fh.h == nil {
		return EBADF
	}

	resp.Data = resp.Data[:req.Size]
	n, err := fh.h.ReadAt(resp.Data, req.Offset)
	if err != nil {
		return err
	}
	resp.Data = resp.Data[:n]

	return nil
}
Beispiel #14
0
func (wc *FileWriteCache) Sync(bh blobstore.PWriter) error {
	for _, p := range wc.ps {
		if p.IsSentinel() {
			continue
		}

		logger.Debugf(wclog, "Sync: %v", p)
		// logger.Debugf(wclog, "Sync: p=%v", p.P)
		if err := bh.PWrite(p.P, p.Offset); err != nil {
			return err
		}
	}
	wc.ps = wc.ps.Reset()

	return nil
}
Beispiel #15
0
func RetryIfNeeded(f func() error, mylog logger.Logger) (err error) {
	const numRetries = 3
	for i := 0; i < numRetries; i++ {
		start := time.Now()
		err = f()
		if err == nil {
			return
		}
		if !IsShouldRetryError(err) {
			return
		}
		if i < numRetries {
			logger.Debugf(mylog, "A Google Cloud Datastore operation has failed after %s. Retrying %d / %d...", time.Since(start), i+1, numRetries)
		}
	}
	return
}
Beispiel #16
0
func (loc *INodeDBSSLocator) DeleteAll() ([]string, error) {
	start := time.Now()

	cli, err := loc.cfg.getClient(context.TODO())
	if err != nil {
		return nil, err
	}

	dstx, err := cli.NewTransaction(context.TODO(), datastore.Serializable)
	if err != nil {
		return nil, err
	}

	keys := make([]*datastore.Key, 0)
	blobpaths := make([]string, 0)
	q := datastore.NewQuery(kindINodeDBSS).Ancestor(loc.rootKey).Transaction(dstx)
	it := cli.Run(context.TODO(), q)
	for {
		var e sslocentry
		k, err := it.Next(&e)
		if err != nil {
			if err == datastore.Done {
				break
			}
			dstx.Rollback()
			return nil, err
		}

		keys = append(keys, k)
		blobpaths = append(blobpaths, e.BlobPath)
	}

	logger.Debugf(sslog, "keys to delete: %v", keys)
	if err := dstx.DeleteMulti(keys); err != nil {
		dstx.Rollback()
		return nil, err
	}

	if _, err := dstx.Commit(); err != nil {
		return nil, err
	}
	logger.Infof(sslog, "DeleteAll() deleted %d entries. Took %s", len(keys), time.Since(start))
	return blobpaths, nil
}
Beispiel #17
0
func TestHandleCritical(t *testing.T) {
	called := false
	h := logger.HandleCritical(func() { called = true })

	logger.Debugf(h, "debug")
	if called {
		t.Errorf("Shouldn't be triggered from debug msg")
	}
	logger.Criticalf(h, "critical")
	if !called {
		t.Errorf("Should be triggered from debug msg")
	}

	called = false
	logger.Criticalf(h, "critical2")
	if !called {
		t.Errorf("Should be triggered only once")
	}
}
Beispiel #18
0
func (ch *ChunkIO) expandLengthBy(by int) error {
	if by < 0 {
		panic("Tried to expand by negative length")
	}

	if by == 0 {
		return nil
	}

	len64 := int64(ch.PayloadLen())
	if len64+int64(by) > MaxChunkPayloadLen {
		return fmt.Errorf("Payload length out of range. Current: %d += %d", len64, by)
	}

	ch.header.PayloadLen = uint32(ch.PayloadLen() + by)
	logger.Debugf(mylog, "ChunkIO expandLength +%d = %d", by, ch.header.PayloadLen)
	ch.needsHeaderUpdate = true

	return nil
}
Beispiel #19
0
func (n FileNode) Setattr(ctx context.Context, req *bfuse.SetattrRequest, resp *bfuse.SetattrResponse) error {
	if req.Valid.Size() {
		logger.Debugf(mylog, "Setattr size %d", req.Size)
		if req.Size > math.MaxInt64 {
			return fmt.Errorf("specified size too big: %d", req.Size)
		}
		if err := n.fs.TruncateFile(n.id, int64(req.Size)); err != nil {
			return err
		}
	}

	if err := otaruSetattr(n.fs, n.id, req); err != nil {
		return err
	}

	if err := n.Attr(ctx, &resp.Attr); err != nil {
		return err
	}

	return nil
}
Beispiel #20
0
func (ch *ChunkIO) writeContentFrame(i int, f *decryptedContentFrame) error {
	// the offset of the start of the frame in blob
	blobOffset := ch.encryptedFrameOffset(i)

	wr := &blobstore.OffsetWriter{ch.bh, int64(blobOffset)}
	bew, err := btncrypt.NewWriteCloser(wr, ch.c, len(f.P))
	if err != nil {
		return fmt.Errorf("Failed to create BtnEncryptWriteCloser: %v", err)
	}
	defer func() {
		if err := bew.Close(); err != nil {
			logger.Criticalf(mylog, "Failed to Close BtnEncryptWriteCloser: %v", err)
		}
	}()
	if _, err := bew.Write(f.P); err != nil {
		return fmt.Errorf("Failed to encrypt frame: %v", err)
	}
	ch.header.PayloadVersion++
	ch.needsHeaderUpdate = true

	logger.Debugf(mylog, "ChunkIO: Wrote content frame idx: %d", i)
	return nil
}
Beispiel #21
0
func (db *DB) RestoreVersion(version TxID) error {
	logger.Infof(mylog, "RestoreVersion(%s) start.", version)

	state, err := db.snapshotIO.RestoreSnapshot()
	if err != nil {
		return fmt.Errorf("Failed to restore snapshot: %v", err)
	}

	oldState := db.state
	db.state = state

	ssver := state.version
	logger.Infof(mylog, "Restored snapshot of ver %d.", ssver)

	if state.version > version {
		return fmt.Errorf("Can't rollback to old version %d which is older than snapshot version %d", version, state.version)
	}
	logger.Infof(mylog, "RestoreVersion(%s): restored ver: %s", version, ssver)

	txlog, err := db.txLogIO.QueryTransactions(ssver + 1)
	if txlog == nil || err != nil {
		db.state = oldState
		return fmt.Errorf("Failed to query txlog: %v", err)
	}

	for _, tx := range txlog {
		logger.Debugf(mylog, "RestoreVersion(%s): apply tx ver %s", version, tx.TxID)
		if _, err := db.applyTransactionInternal(tx, skipTxLog); err != nil {
			db.state = oldState
			return fmt.Errorf("Failed to replay tx: %v", err)
		}
	}

	logger.Infof(mylog, "Fast forward txlog from ver %d to %d", ssver, state.version)

	return nil
}
Beispiel #22
0
func (ch *ChunkIO) readContentFrame(i int) (*decryptedContentFrame, error) {
	// the frame carries a part of the content at offset
	offset := i * ContentFramePayloadLength

	// payload length of the encrypted frame
	framePayloadLen := ContentFramePayloadLength
	isLastFrame := false
	distToLast := ch.PayloadLen() - offset
	if distToLast <= ContentFramePayloadLength {
		framePayloadLen = distToLast
		isLastFrame = true
	}

	// the offset of the start of the frame in blob
	blobOffset := ch.encryptedFrameOffset(i)

	rd := &blobstore.OffsetReader{ch.bh, int64(blobOffset)}
	bdr, err := btncrypt.NewReader(rd, ch.c, framePayloadLen)
	if err != nil {
		return nil, fmt.Errorf("Failed to create BtnDecryptReader: %v", err)
	}

	p := make([]byte, framePayloadLen, ContentFramePayloadLength)
	if _, err := io.ReadFull(bdr, p); err != nil {
		return nil, fmt.Errorf("Failed to decrypt frame idx: %d, err: %v", i, err)
	}
	if !bdr.HasReadAll() {
		panic("Incomplete frame read")
	}

	logger.Debugf(mylog, "ChunkIO: Read content frame idx: %d", i)
	return &decryptedContentFrame{
		P: p, Offset: offset,
		IsLastFrame: isLastFrame,
	}, nil
}
Beispiel #23
0
func (wc *FileWriteCache) ReadAtThrough(p []byte, offset int64, r ReadAter) (int, error) {
	nr := 0
	remo := offset
	remp := p

	for _, patch := range wc.ps {
		if len(remp) == 0 {
			return nr, nil
		}

		if patch.IsSentinel() {
			break
		}

		if remo > patch.Right() {
			continue
		}

		if remo < patch.Left() {
			fallbackLen64 := util.Int64Min(int64(len(remp)), patch.Left()-remo)
			if fallbackLen64 > math.MaxInt32 {
				panic("Logic error: fallbackLen should always be in int32 range")
			}
			fallbackLen := int(fallbackLen64)

			n, err := r.ReadAt(remp[:fallbackLen], remo)
			logger.Debugf(wclog, "BeforePatch: ReadAt issued offset %d, len %d bytes, read %d bytes", remo, fallbackLen, n)
			if err != nil {
				return nr + n, err
			}
			if n < fallbackLen {
				zerofill(remp[n:fallbackLen])
			}

			nr += fallbackLen
			remp = remp[fallbackLen:]
			remo += int64(fallbackLen)
		}

		if len(remp) == 0 {
			return nr, nil
		}

		applyOffset64 := remo - patch.Offset
		if applyOffset64 > math.MaxInt32 {
			panic("Logic error: applyOffset should always be in int32 range")
		}
		applyOffset := int(applyOffset64)
		applyLen := util.IntMin(len(patch.P)-applyOffset, len(remp))
		copy(remp[:applyLen], patch.P[applyOffset:])

		nr += applyLen
		remp = remp[applyLen:]
		remo += int64(applyLen)
	}

	n, err := r.ReadAt(remp, remo)
	logger.Debugf(wclog, "Last: ReadAt read %d bytes", n)
	if err != nil {
		return nr, err
	}
	nr += n

	return nr, nil
}
Beispiel #24
0
func main() {
	log.SetFlags(log.Ldate | log.Ltime | log.Lshortfile)
	logger.Registry().AddOutput(logger.WriterLogger{os.Stderr})
	flag.Usage = Usage
	flag.Parse()

	cfg, err := facade.NewConfig(*flagConfigDir)
	if err != nil {
		logger.Criticalf(mylog, "%v", err)
		Usage()
		os.Exit(2)
	}
	if flag.NArg() != 1 {
		Usage()
		os.Exit(2)
	}
	mountpoint := flag.Arg(0)

	if err := facade.SetupFluentLogger(cfg); err != nil {
		logger.Criticalf(mylog, "Failed to setup fluentd logger: %v", err)
		os.Exit(1)
	}

	o, err := facade.NewOtaru(cfg, &facade.OneshotConfig{Mkfs: *flagMkfs})
	if err != nil {
		logger.Criticalf(mylog, "NewOtaru failed: %v", err)
		os.Exit(1)
	}
	var muClose sync.Mutex
	closeOtaruAndExit := func(exitCode int) {
		muClose.Lock()
		defer muClose.Unlock()

		if err := bfuse.Unmount(mountpoint); err != nil {
			logger.Warningf(mylog, "umount err: %v", err)
		}
		if o != nil {
			if err := o.Close(); err != nil {
				logger.Warningf(mylog, "Otaru.Close() returned errs: %v", err)
			}
			o = nil
		}
		os.Exit(exitCode)
	}
	defer closeOtaruAndExit(0)

	sigC := make(chan os.Signal, 1)
	signal.Notify(sigC, os.Interrupt)
	signal.Notify(sigC, syscall.SIGTERM)
	go func() {
		for s := range sigC {
			logger.Warningf(mylog, "Received signal: %v", s)
			closeOtaruAndExit(1)
		}
	}()
	logger.Registry().AddOutput(logger.HandleCritical(func() {
		logger.Warningf(mylog, "Starting shutdown due to critical event.")
		closeOtaruAndExit(1)
	}))

	bfuseLogger := logger.Registry().Category("bfuse")
	bfuse.Debug = func(msg interface{}) { logger.Debugf(bfuseLogger, "%v", msg) }
	if err := fuse.ServeFUSE(cfg.BucketName, mountpoint, o.FS, nil); err != nil {
		logger.Warningf(mylog, "ServeFUSE failed: %v", err)
		closeOtaruAndExit(1)
	}
	logger.Infof(mylog, "ServeFUSE end!")
}
Beispiel #25
0
func (cfio *ChunkedFileIO) PWrite(p []byte, offset int64) error {
	logger.Debugf(mylog, "PWrite: offset=%d, len=%d", offset, len(p))
	// logger.Debugf(mylog, "PWrite: p=%v", p)
	remo := offset
	remp := p
	if len(remp) == 0 {
		return nil
	}

	cs, err := cfio.caio.Read()
	if err != nil {
		return fmt.Errorf("Failed to read cs array: %v", err)
	}

	writeToChunk := func(c *inodedb.FileChunk, isNewChunk bool, maxChunkLen int64) error {
		if !fl.IsReadWriteAllowed(cfio.bs.Flags()) {
			return EPERM
		}

		flags := fl.O_RDWR
		if isNewChunk {
			flags |= fl.O_CREATE | fl.O_EXCL
		}
		bh, err := cfio.bs.Open(c.BlobPath, flags)
		if err != nil {
			return fmt.Errorf("Failed to open path \"%s\" for writing (isNewChunk: %t): %v", c.BlobPath, isNewChunk, err)
		}
		defer func() {
			if err := bh.Close(); err != nil {
				logger.Criticalf(mylog, "blobhandle Close failed: %v", err)
			}
		}()

		cio := cfio.newChunkIO(bh, cfio.c, c.Offset)
		defer func() {
			if err := cio.Close(); err != nil {
				logger.Criticalf(mylog, "cio Close failed: %v", err)
			}
		}()

		coff := remo - c.Offset
		n := util.IntMin(len(remp), int(maxChunkLen-coff))
		if n < 0 {
			return nil
		}
		if err := cio.PWrite(remp[:n], coff); err != nil {
			return err
		}
		oldLength := c.Length
		c.Length = int64(cio.Size())
		if oldLength != c.Length {
			if err := cfio.caio.Write(cs); err != nil {
				return fmt.Errorf("Failed to write updated cs array: %v", err)
			}
		}

		remo += int64(n)
		remp = remp[n:]
		return nil
	}

	for i := 0; i < len(cs); i++ {
		c := &cs[i]
		if c.Left() > remo {
			// Insert a new chunk @ i

			// try best to align offset at ChunkSplitSize
			newo := remo / ChunkSplitSize * ChunkSplitSize
			maxlen := int64(ChunkSplitSize)
			if i > 0 {
				prev := cs[i-1]
				pright := prev.Right()
				if newo < pright {
					maxlen -= pright - newo
					newo = pright
				}
			}
			if i < len(cs)-1 {
				next := cs[i+1]
				if newo+maxlen > next.Left() {
					maxlen = next.Left() - newo
				}
			}

			newc, err := cfio.newFileChunk(newo)
			if err != nil {
				return err
			}
			cs = append(cs, inodedb.FileChunk{})
			copy(cs[i+1:], cs[i:])
			cs[i] = newc
			if err := cfio.caio.Write(cs); err != nil {
				return fmt.Errorf("Failed to write updated cs array: %v", err)
			}

			if err := writeToChunk(&newc, NewChunk, maxlen); err != nil {
				return err
			}
			if len(remp) == 0 {
				break
			}

			continue
		}

		// Write to the chunk
		maxlen := int64(ChunkSplitSize)
		if i < len(cs)-1 {
			next := cs[i+1]
			if c.Left()+maxlen > next.Left() {
				maxlen = next.Left() - c.Left()
			}
		}
		if err := writeToChunk(c, ExistingChunk, maxlen); err != nil {
			return err
		}
		if len(remp) == 0 {
			break
		}
	}

	for len(remp) > 0 {
		// Append a new chunk at the end
		newo := remo / ChunkSplitSize * ChunkSplitSize
		maxlen := int64(ChunkSplitSize)

		if len(cs) > 0 {
			last := cs[len(cs)-1]
			lastRight := last.Right()
			if newo < lastRight {
				maxlen -= lastRight - newo
				newo = lastRight
			}
		}

		newc, err := cfio.newFileChunk(newo)
		if err != nil {
			return err
		}
		if err := writeToChunk(&newc, NewChunk, maxlen); err != nil {
			return err
		}

		cs = append(cs, newc)
		if err := cfio.caio.Write(cs); err != nil {
			return fmt.Errorf("Failed to write updated cs array: %v", err)
		}
	}

	return nil
}
Beispiel #26
0
func (ch *ChunkIO) PWrite(p []byte, offset int64) error {
	logger.Debugf(mylog, "PWrite: offset %d, len %d", offset, len(p))
	// logger.Debugf(mylog, "PWrite: p=%v", p)

	if err := ch.ensureHeader(); err != nil {
		return err
	}

	if len(p) == 0 {
		return nil
	}
	if offset < 0 || math.MaxInt32 < offset {
		return fmt.Errorf("Offset out of range: %d", offset)
	}

	remo := int(offset)
	remp := p

	if remo > ch.PayloadLen() {
		// if expanding, zero fill content frames up to write offset

		zfoff := ch.PayloadLen()
		zflen := remo - ch.PayloadLen()

		for zflen > 0 {
			logger.Debugf(mylog, "PWrite zfoff: %d, zflen: %d", zfoff, zflen)
			i := zfoff / ContentFramePayloadLength
			fOffset := i * ContentFramePayloadLength

			var f *decryptedContentFrame

			inframeOffset := zfoff - fOffset
			if zfoff == ch.PayloadLen() && inframeOffset == 0 {
				logger.Debugf(mylog, "PWrite: write new zero fill frame")

				// FIXME: maybe skip writing pure 0 frame.
				//        Old sambad writes a byte of the end of the file instead of ftruncate, which is a nightmare in the current impl.

				n := util.IntMin(zflen, ContentFramePayloadLength)

				f = &decryptedContentFrame{
					P:           ZeroContent[:n],
					Offset:      fOffset,
					IsLastFrame: false,
				}

				zfoff += n
				zflen -= n
				ch.expandLengthBy(n)
				logger.Debugf(mylog, " len: %d", n)
			} else {
				n := util.IntMin(zflen, ContentFramePayloadLength-inframeOffset)
				logger.Debugf(mylog, "PWrite: zero fill last of existing content frame. len: %d f.P[%d:%d] = 0", n, inframeOffset, inframeOffset+n)

				// read the frame
				var err error
				f, err = ch.readContentFrame(i)
				if err != nil {
					return err
				}
				if fOffset != f.Offset {
					panic("fOffset != f.Offset")
				}

				// expand & zero fill
				f.P = f.P[:inframeOffset+n]
				j := 0
				for j < n {
					f.P[inframeOffset+j] = 0
					j++
				}

				zfoff += n
				zflen -= n
				ch.expandLengthBy(n)
			}

			// writeback the frame
			if err := ch.writeContentFrame(i, f); err != nil {
				return fmt.Errorf("failed to write back the encrypted frame: %v", err)
			}
		}
	}

	for len(remp) > 0 {
		i := remo / ContentFramePayloadLength
		fOffset := i * ContentFramePayloadLength

		var f *decryptedContentFrame
		if remo == ch.PayloadLen() && fOffset == remo {
			logger.Debugf(mylog, "PWrite: Preparing new frame to append")
			f = &decryptedContentFrame{
				P:           make([]byte, 0, ContentFramePayloadLength),
				Offset:      fOffset,
				IsLastFrame: true,
			}
		} else {
			logger.Debugf(mylog, "PWrite: Read existing frame %d to append/update", i)
			var err error
			f, err = ch.readContentFrame(i)
			if err != nil {
				return err
			}
			if fOffset != f.Offset {
				panic("fOffset != f.Offset")
			}
		}

		// modify the payload
		inframeOffset := remo - f.Offset
		if inframeOffset < 0 {
			panic("ASSERT: inframeOffset must be non-negative here")
		}

		n := len(remp)
		valid := len(f.P) - inframeOffset // valid payload after offset
		if len(remp) > valid && f.IsLastFrame {
			// expand the last frame as needed
			newSize := inframeOffset + n
			if newSize > ContentFramePayloadLength {
				f.IsLastFrame = false
				newSize = ContentFramePayloadLength
			}

			logger.Debugf(mylog, "PWrite: Expanding the last frame from %d to %d", len(f.P), newSize)

			expandLen := newSize - len(f.P)
			if err := ch.expandLengthBy(expandLen); err != nil {
				return err
			}

			f.P = f.P[:newSize]
			valid = newSize - inframeOffset
		}
		if valid == 0 {
			panic("Inf loop")
		}
		n = util.IntMin(n, valid)

		copy(f.P[inframeOffset:inframeOffset+n], remp)

		// writeback the updated encrypted frame
		if err := ch.writeContentFrame(i, f); err != nil {
			return fmt.Errorf("failed to write back the encrypted frame: %v", err)
		}
		logger.Debugf(mylog, "PWrite: wrote %d bytes for off %d len %d", n, offset, len(remp))

		remo += n
		remp = remp[n:]
	}

	return nil
}