Golang mount.Interface类代码示例

// utility to mount a disk based filesystem
func diskSetUp(manager diskManager, b iscsiDiskBuilder, volPath string, mounter mount.Interface) error {
	globalPDPath := manager.MakeGlobalPDName(*b.iscsiDisk)
	// TODO: handle failed mounts here.
	notMnt, err := mounter.IsLikelyNotMountPoint(volPath)

	if err != nil && !os.IsNotExist(err) {
		glog.Errorf("cannot validate mountpoint: %s", volPath)
		return err
	}
	if !notMnt {
		return nil
	}
	if err := manager.AttachDisk(b); err != nil {
		glog.Errorf("failed to attach disk")
		return err
	}

	if err := os.MkdirAll(volPath, 0750); err != nil {
		glog.Errorf("failed to mkdir:%s", volPath)
		return err
	}
	// Perform a bind mount to the full path to allow duplicate mounts of the same disk.
	options := []string{"bind"}
	if b.readOnly {
		options = append(options, "ro")
	}
	err = mounter.Mount(globalPDPath, volPath, "", options)
	if err != nil {
		glog.Errorf("failed to bind mount:%s", globalPDPath)
		return err
	}
	return nil
}

// checks if the required cgroups subsystems are mounted.
// As of now, only 'cpu' and 'memory' are required.
func validateSystemRequirements(mountUtil mount.Interface) error {
	const (
		cgroupMountType = "cgroup"
		localErr        = "system validation failed"
	)
	mountPoints, err := mountUtil.List()
	if err != nil {
		return fmt.Errorf("%s - %v", localErr, err)
	}
	expectedCgroups := sets.NewString("cpu", "cpuacct", "cpuset", "memory")
	for _, mountPoint := range mountPoints {
		if mountPoint.Type == cgroupMountType {
			for _, opt := range mountPoint.Opts {
				if expectedCgroups.Has(opt) {
					expectedCgroups.Delete(opt)
				}
			}
		}
	}

	if expectedCgroups.Len() > 0 {
		return fmt.Errorf("%s - Following Cgroup subsystem not mounted: %v", localErr, expectedCgroups.List())
	}
	return nil
}

func (attacher *gcePersistentDiskAttacher) MountDevice(spec *volume.Spec, devicePath string, deviceMountPath string, mounter mount.Interface) error {
	// Only mount the PD globally once.
	notMnt, err := mounter.IsLikelyNotMountPoint(deviceMountPath)
	if err != nil {
		if os.IsNotExist(err) {
			if err := os.MkdirAll(deviceMountPath, 0750); err != nil {
				return err
			}
			notMnt = true
		} else {
			return err
		}
	}

	volumeSource, readOnly := getVolumeSource(spec)

	options := []string{}
	if readOnly {
		options = append(options, "ro")
	}
	if notMnt {
		diskMounter := &mount.SafeFormatAndMount{Interface: mounter, Runner: exec.New()}
		err = diskMounter.FormatAndMount(devicePath, deviceMountPath, volumeSource.FSType, options)
		if err != nil {
			os.Remove(deviceMountPath)
			return err
		}
	}
	return nil
}

// Unmount the global mount path, which should be the only one, and delete it.
func unmountPDAndRemoveGlobalPath(globalMountPath string, mounter mount.Interface) error {
	if pathExists, pathErr := pathExists(globalMountPath); pathErr != nil {
		return fmt.Errorf("Error checking if path exists: %v", pathErr)
	} else if !pathExists {
		glog.V(5).Infof("Warning: Unmount skipped because path does not exist: %v", globalMountPath)
		return nil
	}
	err := mounter.Unmount(globalMountPath)
	os.Remove(globalMountPath)
	return err
}

// getDevicePrefixRefCount: given a prefix of device path, find its reference count from /proc/mounts
// returns the reference count to the device and error code
// for services like iscsi construct multiple device paths with the same prefix pattern.
// this function aggregates all references to a service based on the prefix pattern
// More specifically, this prefix semantics is to aggregate disk paths that belong to the same iSCSI target/iqn pair.
// an iSCSI target could expose multiple LUNs through the same IQN, and Linux iSCSI initiator creates disk paths that start the same prefix but end with different LUN number
// When we decide whether it is time to logout a target, we have to see if none of the LUNs are used any more.
// That's where the prefix based ref count kicks in. If we only count the disks using exact match, we could log other disks out.
func getDevicePrefixRefCount(mounter mount.Interface, deviceNamePrefix string) (int, error) {
	mps, err := mounter.List()
	if err != nil {
		return -1, err
	}

	// Find the number of references to the device.
	refCount := 0
	for i := range mps {
		if strings.HasPrefix(mps[i].Path, deviceNamePrefix) {
			refCount++
		}
	}
	return refCount, nil
}

// checks if the required cgroups subsystems are mounted.
// As of now, only 'cpu' and 'memory' are required.
// cpu quota is a soft requirement.
func validateSystemRequirements(mountUtil mount.Interface) (features, error) {
	const (
		cgroupMountType = "cgroup"
		localErr        = "system validation failed"
	)
	var (
		cpuMountPoint string
		f             features
	)
	mountPoints, err := mountUtil.List()
	if err != nil {
		return f, fmt.Errorf("%s - %v", localErr, err)
	}

	expectedCgroups := sets.NewString("cpu", "cpuacct", "cpuset", "memory")
	for _, mountPoint := range mountPoints {
		if mountPoint.Type == cgroupMountType {
			for _, opt := range mountPoint.Opts {
				if expectedCgroups.Has(opt) {
					expectedCgroups.Delete(opt)
				}
				if opt == "cpu" {
					cpuMountPoint = mountPoint.Path
				}
			}
		}
	}

	if expectedCgroups.Len() > 0 {
		return f, fmt.Errorf("%s - Following Cgroup subsystem not mounted: %v", localErr, expectedCgroups.List())
	}

	// Check if cpu quota is available.
	// CPU cgroup is required and so it expected to be mounted at this point.
	periodExists, err := util.FileExists(path.Join(cpuMountPoint, "cpu.cfs_period_us"))
	if err != nil {
		glog.Errorf("failed to detect if CPU cgroup cpu.cfs_period_us is available - %v", err)
	}
	quotaExists, err := util.FileExists(path.Join(cpuMountPoint, "cpu.cfs_quota_us"))
	if err != nil {
		glog.Errorf("failed to detect if CPU cgroup cpu.cfs_quota_us is available - %v", err)
	}
	if quotaExists && periodExists {
		f.cpuHardcapping = true
	}
	return f, nil
}

// UnmountPath is a common unmount routine that unmounts the given path and
// deletes the remaining directory if successful.
func UnmountPath(mountPath string, mounter mount.Interface) error {
	if pathExists, pathErr := PathExists(mountPath); pathErr != nil {
		return fmt.Errorf("Error checking if path exists: %v", pathErr)
	} else if !pathExists {
		glog.Warningf("Warning: Unmount skipped because path does not exist: %v", mountPath)
		return nil
	}

	err := mounter.Unmount(mountPath)
	if err == nil {
		// Only delete directory on successful unmount
		glog.V(5).Infof("Unmounted %q. Deleting path.", mountPath)
		return os.Remove(mountPath)
	}

	return err
}

// UnmountPath is a common unmount routine that unmounts the given path and
// deletes the remaining directory if successful.
func UnmountPath(mountPath string, mounter mount.Interface) error {
	if pathExists, pathErr := PathExists(mountPath); pathErr != nil {
		return fmt.Errorf("Error checking if path exists: %v", pathErr)
	} else if !pathExists {
		glog.Warningf("Warning: Unmount skipped because path does not exist: %v", mountPath)
		return nil
	}

	notMnt, err := mounter.IsLikelyNotMountPoint(mountPath)
	if err != nil {
		return err
	}
	if notMnt {
		glog.Warningf("Warning: %q is not a mountpoint, deleting", mountPath)
		return os.Remove(mountPath)
	}

	// Unmount the mount path
	if err := mounter.Unmount(mountPath); err != nil {
		return err
	}
	notMnt, mntErr := mounter.IsLikelyNotMountPoint(mountPath)
	if mntErr != nil {
		return err
	}
	if notMnt {
		glog.V(4).Info("%q is unmounted, deleting the directory", mountPath)
		return os.Remove(mountPath)
	}
	return nil
}

// utility to tear down a disk based filesystem
func diskTearDown(manager diskManager, c iscsiDiskCleaner, volPath string, mounter mount.Interface) error {
	notMnt, err := mounter.IsLikelyNotMountPoint(volPath)
	if err != nil {
		glog.Errorf("cannot validate mountpoint %s", volPath)
		return err
	}
	if notMnt {
		return os.Remove(volPath)
	}

	refs, err := mount.GetMountRefs(mounter, volPath)
	if err != nil {
		glog.Errorf("failed to get reference count %s", volPath)
		return err
	}
	if err := mounter.Unmount(volPath); err != nil {
		glog.Errorf("failed to unmount %s", volPath)
		return err
	}
	// If len(refs) is 1, then all bind mounts have been removed, and the
	// remaining reference is the global mount. It is safe to detach.
	if len(refs) == 1 {
		mntPath := refs[0]
		if err := manager.DetachDisk(c, mntPath); err != nil {
			glog.Errorf("failed to detach disk from %s", mntPath)
			return err
		}
	}

	notMnt, mntErr := mounter.IsLikelyNotMountPoint(volPath)
	if mntErr != nil {
		glog.Errorf("IsLikelyNotMountPoint check failed: %v", mntErr)
		return err
	}
	if notMnt {
		if err := os.Remove(volPath); err != nil {
			return err
		}
	}
	return nil

}

// Unmount the global mount path, which should be the only one, and delete it.
func unmountPDAndRemoveGlobalPath(globalMountPath string, mounter mount.Interface) error {
	err := mounter.Unmount(globalMountPath)
	os.Remove(globalMountPath)
	return err
}

func (oe *operationExecutor) generateUnmountDeviceFunc(
	deviceToDetach AttachedVolume,
	actualStateOfWorld ActualStateOfWorldMounterUpdater,
	mounter mount.Interface) (func() error, error) {
	// Get attacher plugin
	attachableVolumePlugin, err :=
		oe.volumePluginMgr.FindAttachablePluginBySpec(deviceToDetach.VolumeSpec)
	if err != nil || attachableVolumePlugin == nil {
		return nil, fmt.Errorf(
			"UnmountDevice.FindAttachablePluginBySpec failed for volume %q (spec.Name: %q) with: %v",
			deviceToDetach.VolumeName,
			deviceToDetach.VolumeSpec.Name(),
			err)
	}

	volumeDetacher, err := attachableVolumePlugin.NewDetacher()
	if err != nil {
		return nil, fmt.Errorf(
			"UnmountDevice.NewDetacher failed for volume %q (spec.Name: %q) with: %v",
			deviceToDetach.VolumeName,
			deviceToDetach.VolumeSpec.Name(),
			err)
	}

	volumeAttacher, err := attachableVolumePlugin.NewAttacher()
	if err != nil {
		return nil, fmt.Errorf(
			"UnmountDevice.NewAttacher failed for volume %q (spec.Name: %q) with: %v",
			deviceToDetach.VolumeName,
			deviceToDetach.VolumeSpec.Name(),
			err)
	}

	return func() error {
		deviceMountPath, err :=
			volumeAttacher.GetDeviceMountPath(deviceToDetach.VolumeSpec)
		if err != nil {
			// On failure, return error. Caller will log and retry.
			return fmt.Errorf(
				"GetDeviceMountPath failed for volume %q (spec.Name: %q) with: %v",
				deviceToDetach.VolumeName,
				deviceToDetach.VolumeSpec.Name(),
				err)
		}
		refs, err := attachableVolumePlugin.GetDeviceMountRefs(deviceMountPath)
		if err != nil || len(refs) > 0 {
			if err == nil {
				err = fmt.Errorf("The device mount path %q is still mounted by other references %v", deviceMountPath, refs)
			}
			return fmt.Errorf(
				"GetDeviceMountRefs check failed for volume %q (spec.Name: %q) with: %v",
				deviceToDetach.VolumeName,
				deviceToDetach.VolumeSpec.Name(),
				err)
		}
		// Execute unmount
		unmountDeviceErr := volumeDetacher.UnmountDevice(deviceMountPath)
		if unmountDeviceErr != nil {
			// On failure, return error. Caller will log and retry.
			return fmt.Errorf(
				"UnmountDevice failed for volume %q (spec.Name: %q) with: %v",
				deviceToDetach.VolumeName,
				deviceToDetach.VolumeSpec.Name(),
				unmountDeviceErr)
		}
		// Before logging that UnmountDevice succeeded and moving on,
		// use mounter.PathIsDevice to check if the path is a device,
		// if so use mounter.DeviceOpened to check if the device is in use anywhere
		// else on the system. Retry if it returns true.
		isDevicePath, devicePathErr := mounter.PathIsDevice(deviceToDetach.DevicePath)
		var deviceOpened bool
		var deviceOpenedErr error
		if !isDevicePath && devicePathErr == nil {
			// not a device path or path doesn't exist
			//TODO: refer to #36092
			glog.V(3).Infof("Not checking device path %s", deviceToDetach.DevicePath)
			deviceOpened = false
		} else {
			deviceOpened, deviceOpenedErr = mounter.DeviceOpened(deviceToDetach.DevicePath)
			if deviceOpenedErr != nil {
				return fmt.Errorf(
					"UnmountDevice.DeviceOpened failed for volume %q (spec.Name: %q) with: %v",
					deviceToDetach.VolumeName,
					deviceToDetach.VolumeSpec.Name(),
					deviceOpenedErr)
			}
		}
		// The device is still in use elsewhere. Caller will log and retry.
		if deviceOpened {
			return fmt.Errorf(
				"UnmountDevice failed for volume %q (spec.Name: %q) because the device is in use when it was no longer expected to be in use",
				deviceToDetach.VolumeName,
				deviceToDetach.VolumeSpec.Name())
		}

		glog.Infof(
			"UnmountDevice succeeded for volume %q (spec.Name: %q).",
			deviceToDetach.VolumeName,
			deviceToDetach.VolumeSpec.Name())

//.........这里部分代码省略.........

func (oe *operationExecutor) generateUnmountDeviceFunc(
	deviceToDetach AttachedVolume,
	actualStateOfWorld ActualStateOfWorldMounterUpdater,
	mounter mount.Interface) (func() error, error) {
	// Get attacher plugin
	attachableVolumePlugin, err :=
		oe.volumePluginMgr.FindAttachablePluginBySpec(deviceToDetach.VolumeSpec)
	if err != nil || attachableVolumePlugin == nil {
		return nil, fmt.Errorf(
			"UnmountDevice.FindAttachablePluginBySpec failed for volume %q (spec.Name: %q) with: %v",
			deviceToDetach.VolumeName,
			deviceToDetach.VolumeSpec.Name(),
			err)
	}

	volumeDetacher, err := attachableVolumePlugin.NewDetacher()
	if err != nil {
		return nil, fmt.Errorf(
			"UnmountDevice.NewDetacher failed for volume %q (spec.Name: %q) with: %v",
			deviceToDetach.VolumeName,
			deviceToDetach.VolumeSpec.Name(),
			err)
	}

	volumeAttacher, err := attachableVolumePlugin.NewAttacher()
	if err != nil {
		return nil, fmt.Errorf(
			"UnmountDevice.NewAttacher failed for volume %q (spec.Name: %q) with: %v",
			deviceToDetach.VolumeName,
			deviceToDetach.VolumeSpec.Name(),
			err)
	}

	return func() error {
		deviceMountPath, err :=
			volumeAttacher.GetDeviceMountPath(deviceToDetach.VolumeSpec)
		if err != nil {
			// On failure, return error. Caller will log and retry.
			return fmt.Errorf(
				"GetDeviceMountPath failed for volume %q (spec.Name: %q) with: %v",
				deviceToDetach.VolumeName,
				deviceToDetach.VolumeSpec.Name(),
				err)
		}

		// Execute unmount
		unmountDeviceErr := volumeDetacher.UnmountDevice(deviceMountPath)
		if unmountDeviceErr != nil {
			// On failure, return error. Caller will log and retry.
			return fmt.Errorf(
				"UnmountDevice failed for volume %q (spec.Name: %q) with: %v",
				deviceToDetach.VolumeName,
				deviceToDetach.VolumeSpec.Name(),
				unmountDeviceErr)
		}
		// Before logging that UnmountDevice succeeded and moving on,
		// use mounter.DeviceOpened to check if the device is in use anywhere
		// else on the system. Retry if it returns true.
		deviceOpened, deviceOpenedErr := mounter.DeviceOpened(deviceToDetach.DevicePath)
		if deviceOpenedErr != nil {
			return fmt.Errorf(
				"UnmountDevice.DeviceOpened failed for volume %q (spec.Name: %q) with: %v",
				deviceToDetach.VolumeName,
				deviceToDetach.VolumeSpec.Name(),
				deviceOpenedErr)
		}
		// The device is still in use elsewhere. Caller will log and retry.
		if deviceOpened {
			return fmt.Errorf(
				"UnmountDevice failed for volume %q (spec.Name: %q) because the device is in use when it was no longer expected to be in use",
				deviceToDetach.VolumeName,
				deviceToDetach.VolumeSpec.Name())
		}

		glog.Infof(
			"UnmountDevice succeeded for volume %q (spec.Name: %q).",
			deviceToDetach.VolumeName,
			deviceToDetach.VolumeSpec.Name())

		// Update actual state of world
		markDeviceUnmountedErr := actualStateOfWorld.MarkDeviceAsUnmounted(
			deviceToDetach.VolumeName)
		if markDeviceUnmountedErr != nil {
			// On failure, return error. Caller will log and retry.
			return fmt.Errorf(
				"MarkDeviceAsUnmounted failed for device %q (spec.Name: %q) with: %v",
				deviceToDetach.VolumeName,
				deviceToDetach.VolumeSpec.Name(),
				markDeviceUnmountedErr)
		}

		return nil
	}, nil
}