Exemple #1
0
func aufsMount(ro []string, rw, target, mountLabel string) (err error) {
	defer func() {
		if err != nil {
			aufsUnmount(target)
		}
	}()

	// Mount options are clipped to page size(4096 bytes). If there are more
	// layers then these are remounted individually using append.

	offset := 54
	if useDirperm() {
		offset += len("dirperm1")
	}
	b := make([]byte, syscall.Getpagesize()-len(mountLabel)-offset) // room for xino & mountLabel
	bp := copy(b, fmt.Sprintf("br:%s=rw", rw))

	firstMount := true
	i := 0

	for {
		for ; i < len(ro); i++ {
			layer := fmt.Sprintf(":%s=ro+wh", ro[i])

			if firstMount {
				if bp+len(layer) > len(b) {
					break
				}
				bp += copy(b[bp:], layer)
			} else {
				data := utils.FormatMountLabel(fmt.Sprintf("append%s", layer), mountLabel)
				if err = syscall.Mount("none", target, "aufs", MsRemount, data); err != nil {
					return
				}
			}
		}

		if firstMount {
			opts := "dio,xino=/dev/shm/aufs.xino"
			if useDirperm() {
				opts += ",dirperm1"
			}
			data := utils.FormatMountLabel(fmt.Sprintf("%s,%s", string(b[:bp]), opts), mountLabel)
			if err = syscall.Mount("none", target, "aufs", 0, data); err != nil {
				return
			}
			firstMount = false
		}

		if i == len(ro) {
			break
		}
	}

	return
}
Exemple #2
0
func MountContainerToSharedDir(containerId, rootDir, sharedDir, mountLabel string) (string, error) {
	var (
		mountPoint = path.Join(sharedDir, containerId, "rootfs")
		upperDir   = path.Join(rootDir, containerId, "upper")
		workDir    = path.Join(rootDir, containerId, "work")
	)

	if _, err := os.Stat(mountPoint); err != nil {
		if err = os.MkdirAll(mountPoint, 0755); err != nil {
			return "", err
		}
	}
	lowerId, err := ioutil.ReadFile(path.Join(rootDir, containerId) + "/lower-id")
	if err != nil {
		return "", err
	}
	lowerDir := path.Join(rootDir, string(lowerId), "root")

	params := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s", lowerDir, upperDir, workDir)
	if err := syscall.Mount("overlay", mountPoint, "overlay", 0, utils.FormatMountLabel(params, mountLabel)); err != nil {
		return "", fmt.Errorf("error creating overlay mount to %s: %v", mountPoint, err)
	}
	return mountPoint, nil
}