// parseBindMount validates the configuration of mount information in runconfig is valid.
func parseBindMount(spec, volumeDriver string) (*mountPoint, error) {
	bind := &mountPoint{
		RW: true,
	}
	arr := strings.Split(spec, ":")

	switch len(arr) {
	case 2:
		bind.Destination = arr[1]
	case 3:
		bind.Destination = arr[1]
		mode := arr[2]
		if !volume.ValidMountMode(mode) {
			return nil, fmt.Errorf("invalid mode for volumes-from: %s", mode)
		}
		bind.RW = volume.ReadWrite(mode)
		// Mode field is used by SELinux to decide whether to apply label
		bind.Mode = mode
	default:
		return nil, fmt.Errorf("Invalid volume specification: %s", spec)
	}

	//validate the volumes destination path
	if !filepath.IsAbs(bind.Destination) {
		return nil, fmt.Errorf("Invalid volume destination path: %s mount path must be absolute.", bind.Destination)
	}

	name, source, err := parseVolumeSource(arr[0])
	if err != nil {
		return nil, err
	}

	if len(source) == 0 {
		bind.Driver = volumeDriver
		if len(bind.Driver) == 0 {
			bind.Driver = volume.DefaultDriverName
		}
	} else {
		bind.Source = filepath.Clean(source)
	}

	bind.Name = name
	bind.Destination = filepath.Clean(bind.Destination)
	return bind, 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.
// 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 destination, point := range container.MountPoints {
		mountPoints[destination] = 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,
				Spec:        m.Spec,
				CopyData:    false,
			}

			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 {
		bind, err := volume.ParseMountRaw(b, hostConfig.VolumeDriver)
		if err != nil {
			return err
		}

		// #10618
		_, tmpfsExists := hostConfig.Tmpfs[bind.Destination]
		if binds[bind.Destination] || tmpfsExists {
			return fmt.Errorf("Duplicate mount point '%s'", bind.Destination)
		}

		if bind.Type == mounttypes.TypeVolume {
			// 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()
			if bind.Driver == volume.DefaultDriverName {
				setBindModeIfNull(bind)
			}
		}

		binds[bind.Destination] = true
		mountPoints[bind.Destination] = bind
	}

	for _, cfg := range hostConfig.Mounts {
		mp, err := volume.ParseMountSpec(cfg)
		if err != nil {
			return dockererrors.NewBadRequestError(err)
		}
//.........这里部分代码省略.........

// 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.
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, container.MountLabel, container.Config)
		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()
			// Since this is just a named volume and not a typical bind, set to shared mode `z`
			if bind.Mode == "" {
				bind.Mode = "z"
			}
		}

		if err := label.Relabel(bind.Source, container.MountLabel, bind.Mode); 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()
	container.MountPoints = mountPoints
	container.Volumes = bcVolumes
	container.VolumesRW = bcVolumesRW
//.........这里部分代码省略.........

// 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
}

// 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
		}

		_, tmpfsExists := hostConfig.Tmpfs[bind.Destination]
		if binds[bind.Destination] || tmpfsExists {
			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)
			}
		}

		binds[bind.Destination] = true
		mountPoints[bind.Destination] = bind
	}

	container.Lock()

	// 4. Cleanup old volumes that are about to be reassigned.
	for _, m := range mountPoints {
		if m.BackwardsCompatible() {
//.........这里部分代码省略.........