// 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 the 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) {
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.Warn("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
}
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("overlay2", backingFs))
}
d := &Driver{
home: home,
uidMaps: uidMaps,
gidMaps: gidMaps,
ctr: graphdriver.NewRefCounter(graphdriver.NewFsChecker(graphdriver.FsMagicOverlay)),
supportsDType: supportsDType,
}
d.naiveDiff = graphdriver.NewNaiveDiffDriver(d, uidMaps, gidMaps)
if backingFs == "xfs" {
// Try to enable project quota support over xfs.
if d.quotaCtl, err = quota.NewControl(home); err == nil {
projectQuotaSupported = true
}
}
logrus.Debugf("backingFs=%s, projectQuotaSupported=%v", backingFs, projectQuotaSupported)
return d, nil
}