Golang label.IsShared函數代碼示例

// Setup sets up a mount point by either mounting the volume if it is
// configured, or creating the source directory if supplied.
func (m *MountPoint) Setup(mountLabel string) (string, error) {
	if m.Volume != nil {
		if m.ID == "" {
			m.ID = stringid.GenerateNonCryptoID()
		}
		return m.Volume.Mount(m.ID)
	}
	if len(m.Source) == 0 {
		return "", fmt.Errorf("Unable to setup mount point, neither source nor volume defined")
	}
	// system.MkdirAll() produces an error if m.Source exists and is a file (not a directory),
	if err := system.MkdirAll(m.Source, 0755); err != nil {
		if perr, ok := err.(*os.PathError); ok {
			if perr.Err != syscall.ENOTDIR {
				return "", err
			}
		}
	}
	if label.RelabelNeeded(m.Mode) {
		if err := label.Relabel(m.Source, mountLabel, label.IsShared(m.Mode)); err != nil {
			return "", err
		}
	}
	return m.Source, nil
}

// Setup sets up a mount point by either mounting the volume if it is
// configured, or creating the source directory if supplied.
func (m *MountPoint) Setup(mountLabel string, rootUID, rootGID int) (string, error) {
	if m.Volume != nil {
		if m.ID == "" {
			m.ID = stringid.GenerateNonCryptoID()
		}
		path, err := m.Volume.Mount(m.ID)
		return path, errors.Wrapf(err, "error while mounting volume '%s'", m.Source)
	}
	if len(m.Source) == 0 {
		return "", fmt.Errorf("Unable to setup mount point, neither source nor volume defined")
	}
	// system.MkdirAll() produces an error if m.Source exists and is a file (not a directory),
	if m.Type == mounttypes.TypeBind {
		// idtools.MkdirAllNewAs() produces an error if m.Source exists and is a file (not a directory)
		// also, makes sure that if the directory is created, the correct remapped rootUID/rootGID will own it
		if err := idtools.MkdirAllNewAs(m.Source, 0755, rootUID, rootGID); err != nil {
			if perr, ok := err.(*os.PathError); ok {
				if perr.Err != syscall.ENOTDIR {
					return "", errors.Wrapf(err, "error while creating mount source path '%s'", m.Source)
				}
			}
		}
	}
	if label.RelabelNeeded(m.Mode) {
		if err := label.Relabel(m.Source, mountLabel, label.IsShared(m.Mode)); err != nil {
			return "", errors.Wrapf(err, "error setting label on mount source '%s'", m.Source)
		}
	}
	return m.Source, nil
}

func mountToRootfs(m *configs.Mount, rootfs, mountLabel string) error {
	var (
		dest = m.Destination
	)
	if !strings.HasPrefix(dest, rootfs) {
		dest = filepath.Join(rootfs, dest)
	}

	switch m.Device {
	case "proc", "sysfs":
		if err := os.MkdirAll(dest, 0755); err != nil {
			return err
		}
		// Selinux kernels do not support labeling of /proc or /sys
		return mountPropagate(m, rootfs, "")
	case "mqueue":
		if err := os.MkdirAll(dest, 0755); err != nil {
			return err
		}
		if err := mountPropagate(m, rootfs, mountLabel); err != nil {
			// older kernels do not support labeling of /dev/mqueue
			if err := mountPropagate(m, rootfs, ""); err != nil {
				return err
			}
		}
		return label.SetFileLabel(dest, mountLabel)
	case "tmpfs":
		stat, err := os.Stat(dest)
		if err != nil {
			if err := os.MkdirAll(dest, 0755); err != nil {
				return err
			}
		}
		if err := mountPropagate(m, rootfs, mountLabel); err != nil {
			return err
		}
		if stat != nil {
			if err = os.Chmod(dest, stat.Mode()); err != nil {
				return err
			}
		}
		return nil
	case "devpts":
		if err := os.MkdirAll(dest, 0755); err != nil {
			return err
		}
		return mountPropagate(m, rootfs, mountLabel)
	case "securityfs":
		if err := os.MkdirAll(dest, 0755); err != nil {
			return err
		}
		return mountPropagate(m, rootfs, mountLabel)
	case "bind":
		stat, err := os.Stat(m.Source)
		if err != nil {
			// error out if the source of a bind mount does not exist as we will be
			// unable to bind anything to it.
			return err
		}
		// ensure that the destination of the bind mount is resolved of symlinks at mount time because
		// any previous mounts can invalidate the next mount's destination.
		// this can happen when a user specifies mounts within other mounts to cause breakouts or other
		// evil stuff to try to escape the container's rootfs.
		if dest, err = symlink.FollowSymlinkInScope(filepath.Join(rootfs, m.Destination), rootfs); err != nil {
			return err
		}
		if err := checkMountDestination(rootfs, dest); err != nil {
			return err
		}
		// update the mount with the correct dest after symlinks are resolved.
		m.Destination = dest
		if err := createIfNotExists(dest, stat.IsDir()); err != nil {
			return err
		}
		if err := mountPropagate(m, rootfs, mountLabel); err != nil {
			return err
		}
		// bind mount won't change mount options, we need remount to make mount options effective.
		// first check that we have non-default options required before attempting a remount
		if m.Flags&^(syscall.MS_REC|syscall.MS_REMOUNT|syscall.MS_BIND) != 0 {
			// only remount if unique mount options are set
			if err := remount(m, rootfs); err != nil {
				return err
			}
		}

		if m.Relabel != "" {
			if err := label.Validate(m.Relabel); err != nil {
				return err
			}
			shared := label.IsShared(m.Relabel)
			if err := label.Relabel(m.Source, mountLabel, shared); err != nil {
				return err
			}
		}
	case "cgroup":
		binds, err := getCgroupMounts(m)
		if err != nil {
			return err
		}
//.........這裏部分代碼省略.........

// registerMountPoints initializes the container mount points with the configured volumes and bind mounts.
// It follows the next sequence to decide what to mount in each final destination:
//
// 1. Select the previously configured mount points for the containers, if any.
// 2. Select the volumes mounted from another containers. Overrides previously configured mount point destination.
// 3. Select the bind mounts set by the client. Overrides previously configured mount point destinations.
// 4. Cleanup old volumes that are about to be reasigned.
func (daemon *Daemon) registerMountPoints(container *Container, hostConfig *runconfig.HostConfig) error {
	binds := map[string]bool{}
	mountPoints := map[string]*volume.MountPoint{}

	// 1. Read already configured mount points.
	for name, point := range container.MountPoints {
		mountPoints[name] = point
	}

	// 2. Read volumes from other containers.
	for _, v := range hostConfig.VolumesFrom {
		containerID, mode, err := volume.ParseVolumesFrom(v)
		if err != nil {
			return err
		}

		c, err := daemon.Get(containerID)
		if err != nil {
			return err
		}

		for _, m := range c.MountPoints {
			cp := &volume.MountPoint{
				Name:        m.Name,
				Source:      m.Source,
				RW:          m.RW && volume.ReadWrite(mode),
				Driver:      m.Driver,
				Destination: m.Destination,
			}

			if len(cp.Source) == 0 {
				v, err := daemon.createVolume(cp.Name, cp.Driver, nil)
				if err != nil {
					return err
				}
				cp.Volume = v
			}

			mountPoints[cp.Destination] = cp
		}
	}

	// 3. Read bind mounts
	for _, b := range hostConfig.Binds {
		// #10618
		bind, err := volume.ParseMountSpec(b, hostConfig.VolumeDriver)
		if err != nil {
			return err
		}

		if binds[bind.Destination] {
			return derr.ErrorCodeVolumeDup.WithArgs(bind.Destination)
		}

		if len(bind.Name) > 0 && len(bind.Driver) > 0 {
			// create the volume
			v, err := daemon.createVolume(bind.Name, bind.Driver, nil)
			if err != nil {
				return err
			}
			bind.Volume = v
			bind.Source = v.Path()
			// bind.Name is an already existing volume, we need to use that here
			bind.Driver = v.DriverName()
			bind = setBindModeIfNull(bind)
		}
		if label.RelabelNeeded(bind.Mode) {
			if err := label.Relabel(bind.Source, container.MountLabel, label.IsShared(bind.Mode)); err != nil {
				return err
			}
		}
		binds[bind.Destination] = true
		mountPoints[bind.Destination] = bind
	}

	container.Lock()

	// 4. Cleanup old volumes that are about to be reasigned.
	for _, m := range mountPoints {
		if m.BackwardsCompatible() {
			if mp, exists := container.MountPoints[m.Destination]; exists && mp.Volume != nil {
				daemon.volumes.Decrement(mp.Volume)
			}
		}
	}
	container.MountPoints = mountPoints

	container.Unlock()

	return nil
}

//.........這裏部分代碼省略.........
		stat, err := os.Stat(m.Source)
		if err != nil {
			// error out if the source of a bind mount does not exist as we will be
			// unable to bind anything to it.
			return err
		}
		// ensure that the destination of the bind mount is resolved of symlinks at mount time because
		// any previous mounts can invalidate the next mount's destination.
		// this can happen when a user specifies mounts within other mounts to cause breakouts or other
		// evil stuff to try to escape the container's rootfs.
		if dest, err = symlink.FollowSymlinkInScope(filepath.Join(rootfs, m.Destination), rootfs); err != nil {
			return err
		}
		if err := checkMountDestination(rootfs, dest); err != nil {
			return err
		}
		// update the mount with the correct dest after symlinks are resolved.
		m.Destination = dest
		if err := createIfNotExists(dest, stat.IsDir()); err != nil {
			return err
		}
		if err := mountPropagate(m, rootfs, mountLabel); err != nil {
			return err
		}
		// bind mount won't change mount options, we need remount to make mount options effective.
		// first check that we have non-default options required before attempting a remount
		if m.Flags&^(syscall.MS_REC|syscall.MS_REMOUNT|syscall.MS_BIND) != 0 {
			// only remount if unique mount options are set
			if err := remount(m, rootfs); err != nil {
				return err
			}
		}

		if m.Relabel != "" {
			if err := label.Validate(m.Relabel); err != nil {
				return err
			}
			shared := label.IsShared(m.Relabel)
			if err := label.Relabel(m.Source, mountLabel, shared); err != nil {
				return err
			}
		}
	case "cgroup":
		binds, err := getCgroupMounts(m)
		if err != nil {
			return err
		}
		var merged []string
		for _, b := range binds {
			ss := filepath.Base(b.Destination)
			if strings.Contains(ss, ",") {
				merged = append(merged, ss)
			}
		}
		tmpfs := &configs.Mount{
			Source:           "tmpfs",
			Device:           "tmpfs",
			Destination:      m.Destination,
			Flags:            defaultMountFlags,
			Data:             "mode=755",
			PropagationFlags: m.PropagationFlags,
		}
		if err := mountToRootfs(tmpfs, rootfs, mountLabel); err != nil {
			return err
		}
		for _, b := range binds {
			if err := mountToRootfs(b, rootfs, mountLabel); err != nil {
				return err
			}
		}
		for _, mc := range merged {
			for _, ss := range strings.Split(mc, ",") {
				// symlink(2) is very dumb, it will just shove the path into
				// the link and doesn't do any checks or relative path
				// conversion. Also, don't error out if the cgroup already exists.
				if err := os.Symlink(mc, filepath.Join(rootfs, m.Destination, ss)); err != nil && !os.IsExist(err) {
					return err
				}
			}
		}
		if m.Flags&syscall.MS_RDONLY != 0 {
			// remount cgroup root as readonly
			mcgrouproot := &configs.Mount{
				Source:      m.Destination,
				Device:      "bind",
				Destination: m.Destination,
				Flags:       defaultMountFlags | syscall.MS_RDONLY | syscall.MS_BIND,
			}
			if err := remount(mcgrouproot, rootfs); err != nil {
				return err
			}
		}
	default:
		if err := os.MkdirAll(dest, 0755); err != nil {
			return err
		}
		return mountPropagate(m, rootfs, mountLabel)
	}
	return nil
}

// registerMountPoints initializes the container mount points with the configured volumes and bind mounts.
// It follows the next sequence to decide what to mount in each final destination:
//
// 1. Select the previously configured mount points for the containers, if any.
// 2. Select the volumes mounted from another containers. Overrides previously configured mount point destination.
// 3. Select the bind mounts set by the client. Overrides previously configured mount point destinations.
func (daemon *Daemon) registerMountPoints(container *Container, hostConfig *runconfig.HostConfig) error {
	binds := map[string]bool{}
	mountPoints := map[string]*mountPoint{}

	// 1. Read already configured mount points.
	for name, point := range container.MountPoints {
		mountPoints[name] = point
	}

	// 2. Read volumes from other containers.
	for _, v := range hostConfig.VolumesFrom {
		containerID, mode, err := parseVolumesFrom(v)
		if err != nil {
			return err
		}

		c, err := daemon.Get(containerID)
		if err != nil {
			return err
		}

		for _, m := range c.MountPoints {
			cp := &mountPoint{
				Name:        m.Name,
				Source:      m.Source,
				RW:          m.RW && volume.ReadWrite(mode),
				Driver:      m.Driver,
				Destination: m.Destination,
			}

			if len(cp.Source) == 0 {
				v, err := daemon.createVolume(cp.Name, cp.Driver, nil)
				if err != nil {
					return err
				}
				cp.Volume = v
			}

			mountPoints[cp.Destination] = cp
		}
	}

	// 3. Read bind mounts
	for _, b := range hostConfig.Binds {
		// #10618
		bind, err := parseBindMount(b, hostConfig.VolumeDriver)
		if err != nil {
			return err
		}

		if binds[bind.Destination] {
			return fmt.Errorf("Duplicate bind mount %s", bind.Destination)
		}

		if len(bind.Name) > 0 && len(bind.Driver) > 0 {
			// create the volume
			v, err := daemon.createVolume(bind.Name, bind.Driver, nil)
			if err != nil {
				return err
			}
			bind.Volume = v
			bind.Source = v.Path()
			// bind.Name is an already existing volume, we need to use that here
			bind.Driver = v.DriverName()
			// Since this is just a named volume and not a typical bind, set to shared mode `z`
			if bind.Mode == "" {
				bind.Mode = "z"
			}
		}

		shared := label.IsShared(bind.Mode)
		if err := label.Relabel(bind.Source, container.MountLabel, shared); err != nil {
			return err
		}
		binds[bind.Destination] = true
		mountPoints[bind.Destination] = bind
	}

	// Keep backwards compatible structures
	bcVolumes := map[string]string{}
	bcVolumesRW := map[string]bool{}
	for _, m := range mountPoints {
		if m.BackwardsCompatible() {
			bcVolumes[m.Destination] = m.Path()
			bcVolumesRW[m.Destination] = m.RW

			// This mountpoint is replacing an existing one, so the count needs to be decremented
			if mp, exists := container.MountPoints[m.Destination]; exists && mp.Volume != nil {
				daemon.volumes.Decrement(mp.Volume)
			}
		}
	}

	container.Lock()
//.........這裏部分代碼省略.........

func mountToRootfs(m *configs.Mount, rootfs, mountLabel string) error {
	var (
		dest = m.Destination
		data = label.FormatMountLabel(m.Data, mountLabel)
	)
	if !strings.HasPrefix(dest, rootfs) {
		dest = filepath.Join(rootfs, dest)
	}

	switch m.Device {
	case "proc", "sysfs":
		if err := os.MkdirAll(dest, 0755); err != nil {
			return err
		}
		return syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), "")
	case "mqueue":
		if err := os.MkdirAll(dest, 0755); err != nil {
			return err
		}
		if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), ""); err != nil {
			return err
		}
		return label.SetFileLabel(dest, mountLabel)
	case "tmpfs":
		stat, err := os.Stat(dest)
		if err != nil {
			if err := os.MkdirAll(dest, 0755); err != nil {
				return err
			}
		}
		if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data); err != nil {
			return err
		}
		if stat != nil {
			if err = os.Chmod(dest, stat.Mode()); err != nil {
				return err
			}
		}
		return nil
	case "devpts":
		if err := os.MkdirAll(dest, 0755); err != nil {
			return err
		}
		return syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data)
	case "securityfs":
		if err := os.MkdirAll(dest, 0755); err != nil {
			return err
		}
		return syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data)
	case "bind":
		stat, err := os.Stat(m.Source)
		if err != nil {
			// error out if the source of a bind mount does not exist as we will be
			// unable to bind anything to it.
			return err
		}
		// ensure that the destination of the bind mount is resolved of symlinks at mount time because
		// any previous mounts can invalidate the next mount's destination.
		// this can happen when a user specifies mounts within other mounts to cause breakouts or other
		// evil stuff to try to escape the container's rootfs.
		if dest, err = symlink.FollowSymlinkInScope(filepath.Join(rootfs, m.Destination), rootfs); err != nil {
			return err
		}
		if err := checkMountDestination(rootfs, dest); err != nil {
			return err
		}
		if err := createIfNotExists(dest, stat.IsDir()); err != nil {
			return err
		}
		if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags), data); err != nil {
			return err
		}
		if m.Flags&syscall.MS_RDONLY != 0 {
			if err := syscall.Mount(m.Source, dest, m.Device, uintptr(m.Flags|syscall.MS_REMOUNT), ""); err != nil {
				return err
			}
		}
		if m.Relabel != "" {
			if err := label.Validate(m.Relabel); err != nil {
				return err
			}
			shared := label.IsShared(m.Relabel)
			if err := label.Relabel(m.Source, mountLabel, shared); err != nil {
				return err
			}
		}
		if m.Flags&syscall.MS_PRIVATE != 0 {
			if err := syscall.Mount("", dest, "none", uintptr(syscall.MS_PRIVATE), ""); err != nil {
				return err
			}
		}
	case "cgroup":
		binds, err := getCgroupMounts(m)
		if err != nil {
			return err
		}
		var merged []string
		for _, b := range binds {
			ss := filepath.Base(b.Destination)
			if strings.Contains(ss, ",") {
//.........這裏部分代碼省略.........

// registerMountPoints initializes the container mount points with the configured volumes and bind mounts.
// It follows the next sequence to decide what to mount in each final destination:
//
// 1. Select the previously configured mount points for the containers, if any.
// 2. Select the volumes mounted from another containers. Overrides previously configured mount point destination.
// 3. Select the bind mounts set by the client. Overrides previously configured mount point destinations.
// 4. Cleanup old volumes that are about to be reassigned.
func (daemon *Daemon) registerMountPoints(container *container.Container, hostConfig *containertypes.HostConfig) (retErr error) {
	binds := map[string]bool{}
	mountPoints := map[string]*volume.MountPoint{}
	defer func() {
		// clean up the container mountpoints once return with error
		if retErr != nil {
			for _, m := range mountPoints {
				if m.Volume == nil {
					continue
				}
				daemon.volumes.Dereference(m.Volume, container.ID)
			}
		}
	}()

	// 1. Read already configured mount points.
	for name, point := range container.MountPoints {
		mountPoints[name] = point
	}

	// 2. Read volumes from other containers.
	for _, v := range hostConfig.VolumesFrom {
		containerID, mode, err := volume.ParseVolumesFrom(v)
		if err != nil {
			return err
		}

		c, err := daemon.GetContainer(containerID)
		if err != nil {
			return err
		}

		for _, m := range c.MountPoints {
			cp := &volume.MountPoint{
				Name:        m.Name,
				Source:      m.Source,
				RW:          m.RW && volume.ReadWrite(mode),
				Driver:      m.Driver,
				Destination: m.Destination,
				Propagation: m.Propagation,
				Named:       m.Named,
			}

			if len(cp.Source) == 0 {
				v, err := daemon.volumes.GetWithRef(cp.Name, cp.Driver, container.ID)
				if err != nil {
					return err
				}
				cp.Volume = v
			}

			mountPoints[cp.Destination] = cp
		}
	}

	// 3. Read bind mounts
	for _, b := range hostConfig.Binds {
		// #10618
		bind, err := volume.ParseMountSpec(b, hostConfig.VolumeDriver)
		if err != nil {
			return err
		}

		if binds[bind.Destination] {
			return fmt.Errorf("Duplicate mount point '%s'", bind.Destination)
		}

		if len(bind.Name) > 0 {
			// create the volume
			v, err := daemon.volumes.CreateWithRef(bind.Name, bind.Driver, container.ID, nil, nil)
			if err != nil {
				return err
			}
			bind.Volume = v
			bind.Source = v.Path()
			// bind.Name is an already existing volume, we need to use that here
			bind.Driver = v.DriverName()
			bind.Named = true
			if bind.Driver == "local" {
				bind = setBindModeIfNull(bind)
			}
		}

		if label.RelabelNeeded(bind.Mode) {
			if err := label.Relabel(bind.Source, container.MountLabel, label.IsShared(bind.Mode)); err != nil {
				return err
			}
		}
		binds[bind.Destination] = true
		mountPoints[bind.Destination] = bind
	}

	container.Lock()
//.........這裏部分代碼省略.........