func (daemon *Daemon) createRootfs(container *Container) error {
// Step 1: create the container directory.
// This doubles as a barrier to avoid race conditions.
rootUID, rootGID, err := idtools.GetRootUIDGID(daemon.uidMaps, daemon.gidMaps)
if err != nil {
return err
}
if err := idtools.MkdirAs(container.root, 0700, rootUID, rootGID); err != nil {
return err
}
initID := fmt.Sprintf("%s-init", container.ID)
if err := daemon.driver.Create(initID, container.ImageID); err != nil {
return err
}
initPath, err := daemon.driver.Get(initID, "")
if err != nil {
return err
}
if err := setupInitLayer(initPath, rootUID, rootGID); err != nil {
daemon.driver.Put(initID)
return err
}
// We want to unmount init layer before we take snapshot of it
// for the actual container.
daemon.driver.Put(initID)
if err := daemon.driver.Create(container.ID, initID); err != nil {
return err
}
return nil
}
// Get returns the mountpoint for the given id after creating the target directories if necessary.
func (d *Driver) Get(id, mountLabel string) (string, error) {
mountpoint := d.mountPath(id)
filesystem := d.zfsPath(id)
options := label.FormatMountLabel("", mountLabel)
logrus.Debugf(`[zfs] mount("%s", "%s", "%s")`, filesystem, mountpoint, options)
rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
if err != nil {
return "", err
}
// Create the target directories if they don't exist
if err := idtools.MkdirAllAs(mountpoint, 0755, rootUID, rootGID); err != nil {
return "", err
}
if err := mount.Mount(filesystem, mountpoint, "zfs", options); err != nil {
return "", fmt.Errorf("error creating zfs mount of %s to %s: %v", filesystem, mountpoint, err)
}
// this could be our first mount after creation of the filesystem, and the root dir may still have root
// permissions instead of the remapped root uid:gid (if user namespaces are enabled):
if err := os.Chown(mountpoint, rootUID, rootGID); err != nil {
return "", fmt.Errorf("error modifying zfs mountpoint (%s) directory ownership: %v", mountpoint, err)
}
return mountpoint, nil
}
// Create prepares the filesystem for the VFS driver and copies the directory for the given id under the parent.
func (d *Driver) Create(id, parent, mountLabel string) error {
dir := d.dir(id)
rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
if err != nil {
return err
}
if err := idtools.MkdirAllAs(filepath.Dir(dir), 0700, rootUID, rootGID); err != nil {
return err
}
if err := idtools.MkdirAs(dir, 0755, rootUID, rootGID); err != nil {
return err
}
opts := []string{"level:s0"}
if _, mountLabel, err := label.InitLabels(opts); err == nil {
label.SetFileLabel(dir, mountLabel)
}
if parent == "" {
return nil
}
parentDir, err := d.Get(parent, "")
if err != nil {
return fmt.Errorf("%s: %s", parent, err)
}
if err := chrootarchive.CopyWithTar(parentDir, dir); err != nil {
return err
}
return nil
}
// Init returns a new BTRFS driver.
// An error is returned if BTRFS is not supported.
func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
fsMagic, err := graphdriver.GetFSMagic(home)
if err != nil {
return nil, err
}
if fsMagic != graphdriver.FsMagicBtrfs {
return nil, graphdriver.ErrPrerequisites
}
rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
if err != nil {
return nil, err
}
if err := idtools.MkdirAllAs(home, 0700, rootUID, rootGID); err != nil {
return nil, err
}
if err := mount.MakePrivate(home); err != nil {
return nil, err
}
driver := &Driver{
home: home,
uidMaps: uidMaps,
gidMaps: gidMaps,
}
return graphdriver.NewNaiveDiffDriver(driver, uidMaps, gidMaps), nil
}
// Create the filesystem with given id.
func (d *Driver) Create(id, parent, mountLabel string) error {
subvolumes := path.Join(d.home, "subvolumes")
rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
if err != nil {
return err
}
if err := idtools.MkdirAllAs(subvolumes, 0700, rootUID, rootGID); err != nil {
return err
}
if parent == "" {
if err := subvolCreate(subvolumes, id); err != nil {
return err
}
} else {
parentDir, err := d.Get(parent, "")
if err != nil {
return err
}
if err := subvolSnapshot(parentDir, subvolumes, id); err != nil {
return err
}
}
// if we have a remapped root (user namespaces enabled), change the created snapshot
// dir ownership to match
if rootUID != 0 || rootGID != 0 {
if err := os.Chown(path.Join(subvolumes, id), rootUID, rootGID); err != nil {
return err
}
}
return label.Relabel(path.Join(subvolumes, id), mountLabel, false)
}
// Init returns a new AUFS driver.
// An error is returned if AUFS is not supported.
func Init(root string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
// Try to load the aufs kernel module
if err := supportsAufs(); err != nil {
return nil, graphdriver.ErrNotSupported
}
fsMagic, err := graphdriver.GetFSMagic(root)
if err != nil {
return nil, err
}
if fsName, ok := graphdriver.FsNames[fsMagic]; ok {
backingFs = fsName
}
for _, magic := range incompatibleFsMagic {
if fsMagic == magic {
return nil, graphdriver.ErrIncompatibleFS
}
}
paths := []string{
"mnt",
"diff",
"layers",
}
a := &Driver{
root: root,
uidMaps: uidMaps,
gidMaps: gidMaps,
pathCache: make(map[string]string),
}
rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
if err != nil {
return nil, err
}
// Create the root aufs driver dir and return
// if it already exists
// If not populate the dir structure
if err := idtools.MkdirAllAs(root, 0700, rootUID, rootGID); err != nil {
if os.IsExist(err) {
return a, nil
}
return nil, err
}
if err := mountpk.MakePrivate(root); err != nil {
return nil, err
}
// Populate the dir structure
for _, p := range paths {
if err := idtools.MkdirAllAs(path.Join(root, p), 0700, rootUID, rootGID); err != nil {
return nil, err
}
}
return a, nil
}
// Create prepares the filesystem for the VFS driver and copies the directory for the given id under the parent.
func (d *Driver) Create(id, parent, mountLabel string, storageOpt map[string]string) error {
if len(storageOpt) != 0 {
return fmt.Errorf("--storage-opt is not supported for vfs")
}
dir := d.dir(id)
rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
if err != nil {
return err
}
if err := idtools.MkdirAllAs(filepath.Dir(dir), 0700, rootUID, rootGID); err != nil {
return err
}
if err := idtools.MkdirAs(dir, 0755, rootUID, rootGID); err != nil {
return err
}
opts := []string{"level:s0"}
if _, mountLabel, err := label.InitLabels(opts); err == nil {
label.SetFileLabel(dir, mountLabel)
}
if parent == "" {
return nil
}
parentDir, err := d.Get(parent, "")
if err != nil {
return fmt.Errorf("%s: %s", parent, err)
}
if err := CopyWithTar(parentDir, dir); err != nil {
return err
}
return nil
}
// CreateDaemonRoot creates the root for the daemon
func CreateDaemonRoot(config *Config) error {
// get the canonical path to the Docker root directory
var realRoot string
if _, err := os.Stat(config.Root); err != nil && os.IsNotExist(err) {
realRoot = config.Root
} else {
realRoot, err = fileutils.ReadSymlinkedDirectory(config.Root)
if err != nil {
return fmt.Errorf("Unable to get the full path to root (%s): %s", config.Root, err)
}
}
uidMaps, gidMaps, err := setupRemappedRoot(config)
if err != nil {
return err
}
rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
if err != nil {
return err
}
if err := setupDaemonRoot(config, realRoot, rootUID, rootGID); err != nil {
return err
}
return nil
}
// NewGraph instantiates a new graph at the given root path in the filesystem.
// `root` will be created if it doesn't exist.
func NewGraph(root string, driver graphdriver.Driver, uidMaps, gidMaps []idtools.IDMap) (*Graph, error) {
abspath, err := filepath.Abs(root)
if err != nil {
return nil, err
}
rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
if err != nil {
return nil, err
}
// Create the root directory if it doesn't exists
if err := idtools.MkdirAllAs(root, 0700, rootUID, rootGID); err != nil && !os.IsExist(err) {
return nil, err
}
graph := &Graph{
root: abspath,
idIndex: truncindex.NewTruncIndex([]string{}),
driver: driver,
retained: &retainedLayers{layerHolders: make(map[string]map[string]struct{})},
uidMaps: uidMaps,
gidMaps: gidMaps,
parentRefs: make(map[string]int),
}
// Windows does not currently support tarsplit functionality.
if runtime.GOOS == "windows" {
graph.tarSplitDisabled = true
}
if err := graph.restore(); err != nil {
return nil, err
}
return graph, nil
}
// Init returns a new BTRFS driver.
// An error is returned if BTRFS is not supported.
func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
rootdir := path.Dir(home)
var buf syscall.Statfs_t
if err := syscall.Statfs(rootdir, &buf); err != nil {
return nil, err
}
if graphdriver.FsMagic(buf.Type) != graphdriver.FsMagicBtrfs {
return nil, graphdriver.ErrPrerequisites
}
rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
if err != nil {
return nil, err
}
if err := idtools.MkdirAllAs(home, 0700, rootUID, rootGID); err != nil {
return nil, err
}
if err := mount.MakePrivate(home); err != nil {
return nil, err
}
driver := &Driver{
home: home,
uidMaps: uidMaps,
gidMaps: gidMaps,
}
return graphdriver.NewNaiveDiffDriver(driver, uidMaps, gidMaps), nil
}
// Create the filesystem with given id.
func (d *Driver) Create(id, parent, mountLabel string) error {
subvolumes := path.Join(d.home, "subvolumes")
rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
if err != nil {
return err
}
if err := idtools.MkdirAllAs(subvolumes, 0700, rootUID, rootGID); err != nil {
return err
}
if parent == "" {
if err := subvolCreate(subvolumes, id); err != nil {
return err
}
} else {
parentDir, err := d.Get(parent, "")
if err != nil {
return err
}
if err := subvolSnapshot(parentDir, subvolumes, id); err != nil {
return err
}
}
return label.Relabel(path.Join(subvolumes, id), mountLabel, false)
}
// Init returns the a native diff driver for overlay filesystem.
// If overlay filesystem is not supported on the host, graphdriver.ErrNotSupported is returned as error.
// If a overlay filesystem is not supported over a existing filesystem then error graphdriver.ErrIncompatibleFS is returned.
func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
opts, err := parseOptions(options)
if err != nil {
return nil, err
}
if err := supportsOverlay(); err != nil {
return nil, graphdriver.ErrNotSupported
}
// require kernel 4.0.0 to ensure multiple lower dirs are supported
v, err := kernel.GetKernelVersion()
if err != nil {
return nil, err
}
if kernel.CompareKernelVersion(*v, kernel.VersionInfo{Kernel: 4, Major: 0, Minor: 0}) < 0 {
if !opts.overrideKernelCheck {
return nil, graphdriver.ErrNotSupported
}
logrus.Warnf("Using pre-4.0.0 kernel for overlay2, mount failures may require kernel update")
}
fsMagic, err := graphdriver.GetFSMagic(home)
if err != nil {
return nil, err
}
if fsName, ok := graphdriver.FsNames[fsMagic]; ok {
backingFs = fsName
}
// check if they are running over btrfs, aufs, zfs, overlay, or ecryptfs
switch fsMagic {
case graphdriver.FsMagicBtrfs, graphdriver.FsMagicAufs, graphdriver.FsMagicZfs, graphdriver.FsMagicOverlay, graphdriver.FsMagicEcryptfs:
logrus.Errorf("'overlay2' is not supported over %s", backingFs)
return nil, graphdriver.ErrIncompatibleFS
}
rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
if err != nil {
return nil, err
}
// Create the driver home dir
if err := idtools.MkdirAllAs(path.Join(home, linkDir), 0700, rootUID, rootGID); err != nil && !os.IsExist(err) {
return nil, err
}
if err := mount.MakePrivate(home); err != nil {
return nil, err
}
d := &Driver{
home: home,
uidMaps: uidMaps,
gidMaps: gidMaps,
ctr: graphdriver.NewRefCounter(graphdriver.NewFsChecker(graphdriver.FsMagicOverlay)),
}
return d, nil
}
// Create the filesystem with given id.
func (d *Driver) Create(id, parent string, opts *graphdriver.CreateOpts) error {
subvolumes := path.Join(d.home, "subvolumes")
rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
if err != nil {
return err
}
if err := idtools.MkdirAllAs(subvolumes, 0700, rootUID, rootGID); err != nil {
return err
}
if parent == "" {
if err := subvolCreate(subvolumes, id); err != nil {
return err
}
} else {
parentDir := d.subvolumesDirID(parent)
st, err := os.Stat(parentDir)
if err != nil {
return err
}
if !st.IsDir() {
return fmt.Errorf("%s: not a directory", parentDir)
}
if err := subvolSnapshot(parentDir, subvolumes, id); err != nil {
return err
}
}
var storageOpt map[string]string
if opts != nil {
storageOpt = opts.StorageOpt
}
if _, ok := storageOpt["size"]; ok {
driver := &Driver{}
if err := d.parseStorageOpt(storageOpt, driver); err != nil {
return err
}
if err := d.setStorageSize(path.Join(subvolumes, id), driver); err != nil {
return err
}
}
// if we have a remapped root (user namespaces enabled), change the created snapshot
// dir ownership to match
if rootUID != 0 || rootGID != 0 {
if err := os.Chown(path.Join(subvolumes, id), rootUID, rootGID); err != nil {
return err
}
}
mountLabel := ""
if opts != nil {
mountLabel = opts.MountLabel
}
return label.Relabel(path.Join(subvolumes, id), mountLabel, false)
}
// Get creates and mounts the required file system for the given id and returns the mount path.
func (d *Driver) Get(id string, mountLabel string) (string, error) {
// Protect the d.active from concurrent access
d.Lock()
defer d.Unlock()
mount := d.active[id]
if mount != nil {
mount.count++
return mount.path, nil
}
mount = &ActiveMount{count: 1}
dir := d.dir(id)
if _, err := os.Stat(dir); err != nil {
return "", err
}
// If id has a root, just return it
rootDir := path.Join(dir, "root")
if _, err := os.Stat(rootDir); err == nil {
mount.path = rootDir
d.active[id] = mount
return mount.path, nil
}
lowerID, err := ioutil.ReadFile(path.Join(dir, "lower-id"))
if err != nil {
return "", err
}
lowerDir := path.Join(d.dir(string(lowerID)), "root")
upperDir := path.Join(dir, "upper")
workDir := path.Join(dir, "work")
mergedDir := path.Join(dir, "merged")
opts := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s", lowerDir, upperDir, workDir)
if err := syscall.Mount("overlay", mergedDir, "overlay", 0, label.FormatMountLabel(opts, mountLabel)); err != nil {
return "", fmt.Errorf("error creating overlay mount to %s: %v", mergedDir, err)
}
// chown "workdir/work" to the remapped root UID/GID. Overlay fs inside a
// user namespace requires this to move a directory from lower to upper.
rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
if err != nil {
return "", err
}
if err := os.Chown(path.Join(workDir, "work"), rootUID, rootGID); err != nil {
return "", err
}
mount.path = mergedDir
mount.mounted = true
d.active[id] = mount
return mount.path, nil
}
// Get creates and mounts the required file system for the given id and returns the mount path.
func (d *Driver) Get(id string, mountLabel string) (string, error) {
dir := d.dir(id)
if _, err := os.Stat(dir); err != nil {
return "", err
}
// If id has a root, just return it
rootDir := path.Join(dir, "root")
if _, err := os.Stat(rootDir); err == nil {
d.pathCacheLock.Lock()
d.pathCache[id] = rootDir
d.pathCacheLock.Unlock()
return rootDir, nil
}
lowerID, err := ioutil.ReadFile(path.Join(dir, "lower-id"))
if err != nil {
return "", err
}
lowerDir := path.Join(d.dir(string(lowerID)), "root")
upperDir := path.Join(dir, "upper")
workDir := path.Join(dir, "work")
mergedDir := path.Join(dir, "merged")
opts := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s", lowerDir, upperDir, workDir)
// if it's mounted already, just return
mounted, err := d.mounted(mergedDir)
if err != nil {
return "", err
}
if mounted {
return mergedDir, nil
}
if err := syscall.Mount("overlay", mergedDir, "overlay", 0, label.FormatMountLabel(opts, mountLabel)); err != nil {
return "", fmt.Errorf("error creating overlay mount to %s: %v", mergedDir, err)
}
// chown "workdir/work" to the remapped root UID/GID. Overlay fs inside a
// user namespace requires this to move a directory from lower to upper.
rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
if err != nil {
return "", err
}
if err := os.Chown(path.Join(workDir, "work"), rootUID, rootGID); err != nil {
return "", err
}
d.pathCacheLock.Lock()
d.pathCache[id] = mergedDir
d.pathCacheLock.Unlock()
return mergedDir, nil
}
// mktemp creates a temporary sub-directory inside the graph's filesystem.
func (graph *Graph) mktemp() (string, error) {
dir := filepath.Join(graph.root, "_tmp", stringid.GenerateNonCryptoID())
rootUID, rootGID, err := idtools.GetRootUIDGID(graph.uidMaps, graph.gidMaps)
if err != nil {
return "", err
}
if err := idtools.MkdirAllAs(dir, 0700, rootUID, rootGID); err != nil {
return "", err
}
return dir, nil
}
// Init returns the NaiveDiffDriver, a native diff driver for overlay filesystem.
// If overlay filesystem is not supported on the host, graphdriver.ErrNotSupported is returned as error.
// If a overlay filesystem is not supported over a existing filesystem then error graphdriver.ErrIncompatibleFS is returned.
func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
if err := supportsOverlay(); err != nil {
return nil, graphdriver.ErrNotSupported
}
fsMagic, err := graphdriver.GetFSMagic(home)
if err != nil {
return nil, err
}
if fsName, ok := graphdriver.FsNames[fsMagic]; ok {
backingFs = fsName
}
// check if they are running over btrfs, aufs, zfs or overlay
switch fsMagic {
case graphdriver.FsMagicBtrfs:
logrus.Error("'overlay' is not supported over btrfs.")
return nil, graphdriver.ErrIncompatibleFS
case graphdriver.FsMagicAufs:
logrus.Error("'overlay' is not supported over aufs.")
return nil, graphdriver.ErrIncompatibleFS
case graphdriver.FsMagicZfs:
logrus.Error("'overlay' is not supported over zfs.")
return nil, graphdriver.ErrIncompatibleFS
case graphdriver.FsMagicOverlay:
logrus.Error("'overlay' is not supported over overlay.")
return nil, graphdriver.ErrIncompatibleFS
}
rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
if err != nil {
return nil, err
}
// Create the driver home dir
if err := idtools.MkdirAllAs(home, 0700, rootUID, rootGID); err != nil && !os.IsExist(err) {
return nil, err
}
if err := mount.MakePrivate(home); err != nil {
return nil, err
}
d := &Driver{
home: home,
pathCache: make(map[string]string),
uidMaps: uidMaps,
gidMaps: gidMaps,
ctr: graphdriver.NewRefCounter(),
}
return NaiveDiffDriverWithApply(d, uidMaps, gidMaps), nil
}
// Get creates and mounts the required file system for the given id and returns the mount path.
func (d *Driver) Get(id string, mountLabel string) (s string, err error) {
dir := d.dir(id)
if _, err := os.Stat(dir); err != nil {
return "", err
}
diffDir := path.Join(dir, "diff")
lowers, err := ioutil.ReadFile(path.Join(dir, lowerFile))
if err != nil {
// If no lower, just return diff directory
if os.IsNotExist(err) {
return diffDir, nil
}
return "", err
}
mergedDir := path.Join(dir, "merged")
if count := d.ctr.Increment(mergedDir); count > 1 {
return mergedDir, nil
}
defer func() {
if err != nil {
if c := d.ctr.Decrement(mergedDir); c <= 0 {
syscall.Unmount(mergedDir, 0)
}
}
}()
workDir := path.Join(dir, "work")
opts := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s", string(lowers), path.Join(id, "diff"), path.Join(id, "work"))
mountLabel = label.FormatMountLabel(opts, mountLabel)
if len(mountLabel) > syscall.Getpagesize() {
return "", fmt.Errorf("cannot mount layer, mount label too large %d", len(mountLabel))
}
if err := mountFrom(d.home, "overlay", path.Join(id, "merged"), "overlay", mountLabel); err != nil {
return "", fmt.Errorf("error creating overlay mount to %s: %v", mergedDir, err)
}
// chown "workdir/work" to the remapped root UID/GID. Overlay fs inside a
// user namespace requires this to move a directory from lower to upper.
rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
if err != nil {
return "", err
}
if err := os.Chown(path.Join(workDir, "work"), rootUID, rootGID); err != nil {
return "", err
}
return mergedDir, nil
}
// Init returns the NaiveDiffDriver, a native diff driver for overlay filesystem.
// If overlay filesystem is not supported on the host, graphdriver.ErrNotSupported is returned as error.
// If an overlay filesystem is not supported over an existing filesystem then error graphdriver.ErrIncompatibleFS is returned.
func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
if err := supportsOverlay(); err != nil {
return nil, graphdriver.ErrNotSupported
}
fsMagic, err := graphdriver.GetFSMagic(home)
if err != nil {
return nil, err
}
if fsName, ok := graphdriver.FsNames[fsMagic]; ok {
backingFs = fsName
}
switch fsMagic {
case graphdriver.FsMagicAufs, graphdriver.FsMagicBtrfs, graphdriver.FsMagicOverlay, graphdriver.FsMagicZfs, graphdriver.FsMagicEcryptfs:
logrus.Errorf("'overlay' is not supported over %s", backingFs)
return nil, graphdriver.ErrIncompatibleFS
}
rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
if err != nil {
return nil, err
}
// Create the driver home dir
if err := idtools.MkdirAllAs(home, 0700, rootUID, rootGID); err != nil && !os.IsExist(err) {
return nil, err
}
if err := mount.MakePrivate(home); err != nil {
return nil, err
}
supportsDType, err := fsutils.SupportsDType(home)
if err != nil {
return nil, err
}
if !supportsDType {
// not a fatal error until v1.16 (#27443)
logrus.Warn(overlayutils.ErrDTypeNotSupported("overlay", backingFs))
}
d := &Driver{
home: home,
uidMaps: uidMaps,
gidMaps: gidMaps,
ctr: graphdriver.NewRefCounter(graphdriver.NewFsChecker(graphdriver.FsMagicOverlay)),
supportsDType: supportsDType,
}
return NaiveDiffDriverWithApply(d, uidMaps, gidMaps), nil
}
// Init returns a new VFS driver.
// This sets the home directory for the driver and returns NaiveDiffDriver.
func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
d := &Driver{
home: home,
uidMaps: uidMaps,
gidMaps: gidMaps,
}
rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
if err != nil {
return nil, err
}
if err := idtools.MkdirAllAs(home, 0700, rootUID, rootGID); err != nil {
return nil, err
}
return graphdriver.NewNaiveDiffDriver(d, uidMaps, gidMaps), nil
}
// Get mounts a device with given id into the root filesystem
func (d *Driver) Get(id, mountLabel string) (string, error) {
mp := path.Join(d.home, "mnt", id)
rootFs := path.Join(mp, "rootfs")
if count := d.ctr.Increment(mp); count > 1 {
return rootFs, nil
}
uid, gid, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
if err != nil {
d.ctr.Decrement(mp)
return "", err
}
// Create the target directories if they don't exist
if err := idtools.MkdirAllAs(path.Join(d.home, "mnt"), 0755, uid, gid); err != nil && !os.IsExist(err) {
d.ctr.Decrement(mp)
return "", err
}
if err := idtools.MkdirAs(mp, 0755, uid, gid); err != nil && !os.IsExist(err) {
d.ctr.Decrement(mp)
return "", err
}
// Mount the device
if err := d.DeviceSet.MountDevice(id, mp, mountLabel); err != nil {
d.ctr.Decrement(mp)
return "", err
}
if err := idtools.MkdirAllAs(rootFs, 0755, uid, gid); err != nil && !os.IsExist(err) {
d.ctr.Decrement(mp)
d.DeviceSet.UnmountDevice(id, mp)
return "", err
}
idFile := path.Join(mp, "id")
if _, err := os.Stat(idFile); err != nil && os.IsNotExist(err) {
// Create an "id" file with the container/image id in it to help reconstruct this in case
// of later problems
if err := ioutil.WriteFile(idFile, []byte(id), 0600); err != nil {
d.ctr.Decrement(mp)
d.DeviceSet.UnmountDevice(id, mp)
return "", err
}
}
return rootFs, nil
}
func (a *Driver) migrateContainers(pth string, setupInit func(p string, rootUID, rootGID int) error) error {
fis, err := ioutil.ReadDir(pth)
if err != nil {
return err
}
rootUID, rootGID, err := idtools.GetRootUIDGID(a.uidMaps, a.gidMaps)
if err != nil {
return err
}
for _, fi := range fis {
if id := fi.Name(); fi.IsDir() && pathExists(path.Join(pth, id, "rw")) {
if err := tryRelocate(path.Join(pth, id, "rw"), path.Join(a.rootPath(), "diff", id)); err != nil {
return err
}
if !a.Exists(id) {
metadata, err := loadMetadata(path.Join(pth, id, "config.json"))
if err != nil {
return err
}
initID := fmt.Sprintf("%s-init", id)
if err := a.Create(initID, metadata.Image, ""); err != nil {
return err
}
initPath, err := a.Get(initID, "")
if err != nil {
return err
}
// setup init layer
if err := setupInit(initPath, rootUID, rootGID); err != nil {
return err
}
if err := a.Create(id, initID, ""); err != nil {
return err
}
}
}
}
return nil
}
func (a *Driver) createDirsFor(id string) error {
paths := []string{
"mnt",
"diff",
}
rootUID, rootGID, err := idtools.GetRootUIDGID(a.uidMaps, a.gidMaps)
if err != nil {
return err
}
for _, p := range paths {
if err := idtools.MkdirAllAs(path.Join(a.rootPath(), p, id), 0755, rootUID, rootGID); err != nil {
return err
}
}
return nil
}
// Get creates and mounts the required file system for the given id and returns the mount path.
func (d *Driver) Get(id string, mountLabel string) (s string, err error) {
dir := d.dir(id)
if _, err := os.Stat(dir); err != nil {
return "", err
}
// If id has a root, just return it
rootDir := path.Join(dir, "root")
if _, err := os.Stat(rootDir); err == nil {
return rootDir, nil
}
mergedDir := path.Join(dir, "merged")
if count := d.ctr.Increment(mergedDir); count > 1 {
return mergedDir, nil
}
defer func() {
if err != nil {
if c := d.ctr.Decrement(mergedDir); c <= 0 {
syscall.Unmount(mergedDir, 0)
}
}
}()
lowerID, err := ioutil.ReadFile(path.Join(dir, "lower-id"))
if err != nil {
return "", err
}
var (
lowerDir = path.Join(d.dir(string(lowerID)), "root")
upperDir = path.Join(dir, "upper")
workDir = path.Join(dir, "work")
opts = fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s", lowerDir, upperDir, workDir)
)
if err := syscall.Mount("overlay", mergedDir, "overlay", 0, label.FormatMountLabel(opts, mountLabel)); err != nil {
return "", fmt.Errorf("error creating overlay mount to %s: %v", mergedDir, err)
}
// chown "workdir/work" to the remapped root UID/GID. Overlay fs inside a
// user namespace requires this to move a directory from lower to upper.
rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
if err != nil {
return "", err
}
if err := os.Chown(path.Join(workDir, "work"), rootUID, rootGID); err != nil {
return "", err
}
return mergedDir, nil
}
// Init returns a new BTRFS driver.
// An error is returned if BTRFS is not supported.
func Init(home string, options []string, uidMaps, gidMaps []idtools.IDMap) (graphdriver.Driver, error) {
fsMagic, err := graphdriver.GetFSMagic(home)
if err != nil {
return nil, err
}
if fsMagic != graphdriver.FsMagicBtrfs {
return nil, graphdriver.ErrPrerequisites
}
rootUID, rootGID, err := idtools.GetRootUIDGID(uidMaps, gidMaps)
if err != nil {
return nil, err
}
if err := idtools.MkdirAllAs(home, 0700, rootUID, rootGID); err != nil {
return nil, err
}
if err := mount.MakePrivate(home); err != nil {
return nil, err
}
opt, err := parseOptions(options)
if err != nil {
return nil, err
}
if userDiskQuota {
if err := subvolEnableQuota(home); err != nil {
return nil, err
}
quotaEnabled = true
}
driver := &Driver{
home: home,
uidMaps: uidMaps,
gidMaps: gidMaps,
options: opt,
}
return graphdriver.NewNaiveDiffDriver(driver, uidMaps, gidMaps), nil
}
// Create the filesystem with given id.
func (d *Driver) Create(id, parent, mountLabel string, storageOpt map[string]string) error {
if len(storageOpt) != 0 {
return fmt.Errorf("--storage-opt is not supported for btrfs")
}
subvolumes := path.Join(d.home, "subvolumes")
rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
if err != nil {
return err
}
if err := idtools.MkdirAllAs(subvolumes, 0700, rootUID, rootGID); err != nil {
return err
}
if parent == "" {
if err := subvolCreate(subvolumes, id); err != nil {
return err
}
} else {
parentDir := d.subvolumesDirID(parent)
st, err := os.Stat(parentDir)
if err != nil {
return err
}
if !st.IsDir() {
return fmt.Errorf("%s: not a directory", parentDir)
}
if err := subvolSnapshot(parentDir, subvolumes, id); err != nil {
return err
}
}
// if we have a remapped root (user namespaces enabled), change the created snapshot
// dir ownership to match
if rootUID != 0 || rootGID != 0 {
if err := os.Chown(path.Join(subvolumes, id), rootUID, rootGID); err != nil {
return err
}
}
return label.Relabel(path.Join(subvolumes, id), mountLabel, false)
}
// createDirsFor creates two directories for the given id.
// mnt and diff
func (a *Driver) createDirsFor(id string) error {
paths := []string{
"mnt",
"diff",
}
rootUID, rootGID, err := idtools.GetRootUIDGID(a.uidMaps, a.gidMaps)
if err != nil {
return err
}
// Directory permission is 0755.
// The path of directories are <aufs_root_path>/mnt/<image_id>
// and <aufs_root_path>/diff/<image_id>
for _, p := range paths {
if err := idtools.MkdirAllAs(path.Join(a.rootPath(), p, id), 0755, rootUID, rootGID); err != nil {
return err
}
}
return nil
}
// Get returns the mountpoint for the given id after creating the target directories if necessary.
func (d *Driver) Get(id, mountLabel string) (string, error) {
mountpoint := d.mountPath(id)
filesystem := d.zfsPath(id)
options := label.FormatMountLabel("", mountLabel)
logrus.Debugf(`[zfs] mount("%s", "%s", "%s")`, filesystem, mountpoint, options)
rootUID, rootGID, err := idtools.GetRootUIDGID(d.uidMaps, d.gidMaps)
if err != nil {
return "", err
}
// Create the target directories if they don't exist
if err := idtools.MkdirAllAs(mountpoint, 0755, rootUID, rootGID); err != nil {
return "", err
}
err = mount.Mount(filesystem, mountpoint, "zfs", options)
if err != nil {
return "", fmt.Errorf("error creating zfs mount of %s to %s: %v", filesystem, mountpoint, err)
}
return mountpoint, nil
}
// Handler for teasing out the automatic decompression
func untarHandler(tarArchive io.Reader, dest string, options *archive.TarOptions, decompress bool) error {
if tarArchive == nil {
return fmt.Errorf("Empty archive")
}
if options == nil {
options = &archive.TarOptions{}
}
if options.ExcludePatterns == nil {
options.ExcludePatterns = []string{}
}
rootUID, rootGID, err := idtools.GetRootUIDGID(options.UIDMaps, options.GIDMaps)
if err != nil {
return err
}
dest = filepath.Clean(dest)
if _, err := os.Stat(dest); os.IsNotExist(err) {
if err := idtools.MkdirAllNewAs(dest, 0755, rootUID, rootGID); err != nil {
return err
}
}
r := ioutil.NopCloser(tarArchive)
if decompress {
decompressedArchive, err := archive.DecompressStream(tarArchive)
if err != nil {
return err
}
defer decompressedArchive.Close()
r = decompressedArchive
}
return invokeUnpack(r, dest, options)
}
// CopyWithTar creates a tar archive of filesystem path `src`, and
// unpacks it at filesystem path `dst`.
// The archive is streamed directly with fixed buffering and no
// intermediary disk IO.
func (archiver *Archiver) CopyWithTar(src, dst string) error {
srcSt, err := os.Stat(src)
if err != nil {
return err
}
if !srcSt.IsDir() {
return archiver.CopyFileWithTar(src, dst)
}
// if this archiver is set up with ID mapping we need to create
// the new destination directory with the remapped root UID/GID pair
// as owner
rootUID, rootGID, err := idtools.GetRootUIDGID(archiver.UIDMaps, archiver.GIDMaps)
if err != nil {
return err
}
// Create dst, copy src's content into it
logrus.Debugf("Creating dest directory: %s", dst)
if err := idtools.MkdirAllNewAs(dst, 0755, rootUID, rootGID); err != nil {
return err
}
logrus.Debugf("Calling TarUntar(%s, %s)", src, dst)
return archiver.TarUntar(src, dst)
}