func openNextAvailableLoopback(index int, sparseFile *os.File) (loopFile *os.File, err error) {
	// Start looking for a free /dev/loop
	for {
		target := fmt.Sprintf("/dev/loop%d", index)
		index++

		fi, err := os.Stat(target)
		if err != nil {
			if os.IsNotExist(err) {
				utils.Errorf("There are no more loopback devices available.")
			}
			return nil, ErrAttachLoopbackDevice
		}

		if fi.Mode()&os.ModeDevice != os.ModeDevice {
			utils.Errorf("Loopback device %s is not a block device.", target)
			continue
		}

		// OpenFile adds O_CLOEXEC
		loopFile, err = os.OpenFile(target, os.O_RDWR, 0644)
		if err != nil {
			utils.Errorf("Error openning loopback device: %s", err)
			return nil, ErrAttachLoopbackDevice
		}

		// Try to attach to the loop file
		if err := ioctlLoopSetFd(loopFile.Fd(), sparseFile.Fd()); err != nil {
			loopFile.Close()

			// If the error is EBUSY, then try the next loopback
			if err != syscall.EBUSY {
				utils.Errorf("Cannot set up loopback device %s: %s", target, err)
				return nil, ErrAttachLoopbackDevice
			}

			// Otherwise, we keep going with the loop
			continue
		}
		// In case of success, we finished. Break the loop.
		break
	}

	// This can't happen, but let's be sure
	if loopFile == nil {
		utils.Errorf("Unreachable code reached! Error attaching %s to a loopback device.", sparseFile.Name())
		return nil, ErrAttachLoopbackDevice
	}

	return loopFile, nil
}
Example #2
0
func LoopbackSetCapacity(file *os.File) error {
	if err := ioctlLoopSetCapacity(file.Fd(), 0); err != nil {
		utils.Errorf("Error loopbackSetCapacity: %s", err)
		return ErrLoopbackSetCapacity
	}
	return nil
}
Example #3
0
func GetBlockDeviceSize(file *os.File) (uint64, error) {
	size, err := ioctlBlkGetSize64(file.Fd())
	if err != nil {
		utils.Errorf("Error getblockdevicesize: %s", err)
		return 0, ErrGetBlockSize
	}
	return uint64(size), nil
}
Example #4
0
func getLoopbackBackingFile(file *os.File) (uint64, uint64, error) {
	loopInfo, err := ioctlLoopGetStatus64(file.Fd())
	if err != nil {
		utils.Errorf("Error get loopback backing file: %s\n", err)
		return 0, 0, ErrGetLoopbackBackingFile
	}
	return loopInfo.loDevice, loopInfo.loInode, nil
}
Example #5
0
func Unmount(target string) error {
	if err := exec.Command("auplink", target, "flush").Run(); err != nil {
		utils.Errorf("[warning]: couldn't run auplink before unmount: %s", err)
	}
	if err := syscall.Unmount(target, 0); err != nil {
		return err
	}
	return nil
}
// attachLoopDevice attaches the given sparse file to the next
// available loopback device. It returns an opened *os.File.
func attachLoopDevice(sparseName string) (loop *os.File, err error) {

	// Try to retrieve the next available loopback device via syscall.
	// If it fails, we discard error and start loopking for a
	// loopback from index 0.
	startIndex, err := getNextFreeLoopbackIndex()
	if err != nil {
		utils.Debugf("Error retrieving the next available loopback: %s", err)
	}

	// OpenFile adds O_CLOEXEC
	sparseFile, err := os.OpenFile(sparseName, os.O_RDWR, 0644)
	if err != nil {
		utils.Errorf("Error openning sparse file %s: %s", sparseName, err)
		return nil, ErrAttachLoopbackDevice
	}
	defer sparseFile.Close()

	loopFile, err := openNextAvailableLoopback(startIndex, sparseFile)
	if err != nil {
		return nil, err
	}

	// Set the status of the loopback device
	loopInfo := &LoopInfo64{
		loFileName: stringToLoopName(loopFile.Name()),
		loOffset:   0,
		loFlags:    LoFlagsAutoClear,
	}

	if err := ioctlLoopSetStatus64(loopFile.Fd(), loopInfo); err != nil {
		utils.Errorf("Cannot set up loopback device info: %s", err)

		// If the call failed, then free the loopback device
		if err := ioctlLoopClrFd(loopFile.Fd()); err != nil {
			utils.Errorf("Error while cleaning up the loopback device")
		}
		loopFile.Close()
		return nil, ErrAttachLoopbackDevice
	}

	return loopFile, nil
}
Example #7
0
// During cleanup aufs needs to unmount all mountpoints
func (a *Driver) Cleanup() error {
	ids, err := loadIds(path.Join(a.rootPath(), "layers"))
	if err != nil {
		return err
	}

	for _, id := range ids {
		if err := a.unmount(id); err != nil {
			utils.Errorf("Unmounting %s: %s", utils.TruncateID(id), err)
		}
	}

	return mountpk.Unmount(a.root)
}
Example #8
0
func (devices *DeviceSet) deactivateDevice(info *DevInfo) error {
	utils.Debugf("[devmapper] deactivateDevice(%s)", info.Hash)
	defer utils.Debugf("[devmapper] deactivateDevice END")

	// Wait for the unmount to be effective,
	// by watching the value of Info.OpenCount for the device
	if err := devices.waitClose(info); err != nil {
		utils.Errorf("Warning: error waiting for device %s to close: %s\n", info.Hash, err)
	}

	devinfo, err := getInfo(info.Name())
	if err != nil {
		return err
	}
	if devinfo.Exists != 0 {
		if err := devices.removeDeviceAndWait(info.Name()); err != nil {
			return err
		}
	}

	return nil
}
Example #9
0
// Write writes bytes to all writers. Failed writers will be evicted during
// this call.
func (w *BroadcastWriter) Write(p []byte) (n int, err error) {
	created := time.Now().UTC()
	w.Lock()
	if writers, ok := w.streams[""]; ok {
		for sw := range writers {
			if n, err := sw.Write(p); err != nil || n != len(p) {
				// On error, evict the writer
				delete(writers, sw)
			}
		}
	}
	w.buf.Write(p)
	for {
		line, err := w.buf.ReadString('\n')
		if err != nil {
			w.buf.Write([]byte(line))
			break
		}
		for stream, writers := range w.streams {
			if stream == "" {
				continue
			}
			b, err := json.Marshal(utils.JSONLog{Log: line, Stream: stream, Created: created})
			if err != nil {
				utils.Errorf("Error making JSON log line: %s", err)
				continue
			}
			b = append(b, '\n')
			for sw := range writers {
				if _, err := sw.Write(b); err != nil {
					delete(writers, sw)
				}
			}
		}
	}
	w.Unlock()
	return len(p), nil
}
Example #10
0
// Unmount and remove the dir information
func (a *Driver) Remove(id string) error {
	// Protect the a.active from concurrent access
	a.Lock()
	defer a.Unlock()

	if a.active[id] != 0 {
		utils.Errorf("Warning: removing active id %s\n", id)
	}

	// Make sure the dir is umounted first
	if err := a.unmount(id); err != nil {
		return err
	}
	tmpDirs := []string{
		"mnt",
		"diff",
	}

	// Atomically remove each directory in turn by first moving it out of the
	// way (so that docker doesn't find it anymore) before doing removal of
	// the whole tree.
	for _, p := range tmpDirs {

		realPath := path.Join(a.rootPath(), p, id)
		tmpPath := path.Join(a.rootPath(), p, fmt.Sprintf("%s-removing", id))
		if err := os.Rename(realPath, tmpPath); err != nil && !os.IsNotExist(err) {
			return err
		}
		defer os.RemoveAll(tmpPath)
	}

	// Remove the layers file for the id
	if err := os.Remove(path.Join(a.rootPath(), "layers", id)); err != nil && !os.IsNotExist(err) {
		return err
	}
	return nil
}
Example #11
0
func (d *Driver) Put(id string) {
	if err := d.DeviceSet.UnmountDevice(id); err != nil {
		utils.Errorf("Warning: error unmounting device %s: %s\n", id, err)
	}
}
Example #12
0
// TarWithOptions creates an archive from the directory at `path`, only including files whose relative
// paths are included in `options.Includes` (if non-nil) or not in `options.Excludes`.
func TarWithOptions(srcPath string, options *TarOptions) (io.ReadCloser, error) {
	pipeReader, pipeWriter := io.Pipe()

	compressWriter, err := CompressStream(pipeWriter, options.Compression)
	if err != nil {
		return nil, err
	}

	tw := tar.NewWriter(compressWriter)

	go func() {
		// In general we log errors here but ignore them because
		// during e.g. a diff operation the container can continue
		// mutating the filesystem and we can see transient errors
		// from this

		if options.Includes == nil {
			options.Includes = []string{"."}
		}

		twBuf := bufio.NewWriterSize(nil, twBufSize)

		for _, include := range options.Includes {
			filepath.Walk(filepath.Join(srcPath, include), func(filePath string, f os.FileInfo, err error) error {
				if err != nil {
					utils.Debugf("Tar: Can't stat file %s to tar: %s\n", srcPath, err)
					return nil
				}

				relFilePath, err := filepath.Rel(srcPath, filePath)
				if err != nil {
					return nil
				}

				for _, exclude := range options.Excludes {
					matched, err := filepath.Match(exclude, relFilePath)
					if err != nil {
						utils.Errorf("Error matching: %s (pattern: %s)", relFilePath, exclude)
						return err
					}
					if matched {
						if filepath.Clean(relFilePath) == "." {
							utils.Errorf("Can't exclude whole path, excluding pattern: %s", exclude)
							continue
						}
						utils.Debugf("Skipping excluded path: %s", relFilePath)
						if f.IsDir() {
							return filepath.SkipDir
						}
						return nil
					}
				}

				if err := addTarFile(filePath, relFilePath, tw, twBuf); err != nil {
					utils.Debugf("Can't add file %s to tar: %s\n", srcPath, err)
				}
				return nil
			})
		}

		// Make sure to check the error on Close.
		if err := tw.Close(); err != nil {
			utils.Debugf("Can't close tar writer: %s\n", err)
		}
		if err := compressWriter.Close(); err != nil {
			utils.Debugf("Can't close compress writer: %s\n", err)
		}
		if err := pipeWriter.Close(); err != nil {
			utils.Debugf("Can't close pipe writer: %s\n", err)
		}
	}()

	return pipeReader, nil
}