mirror of
https://github.com/k3s-io/kubernetes.git
synced 2025-11-23 04:08:59 +00:00
Split HostUtil functionality into its own files
This patch takes all the HostUtil functionality currently found in mount*.go files and copies it into hostutil*.go files. Care was taken to preserve git history to the fullest extent. As part of doing this, some common functionality was moved into mount_helper files in preperation for HostUtils to stay in k/k and Mount to move out. THe tests for each relevant function were moved to test files to match the appropriate location.
This commit is contained in:
Travis Rhoden
@@ -23,26 +23,19 @@ import (
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"fmt"
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"os"
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"os/exec"
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"path"
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"path/filepath"
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"strconv"
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"strings"
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"syscall"
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"golang.org/x/sys/unix"
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"k8s.io/klog"
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utilexec "k8s.io/utils/exec"
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utilio "k8s.io/utils/io"
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utilpath "k8s.io/utils/path"
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)
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const (
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// How many times to retry for a consistent read of /proc/mounts.
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maxListTries = 3
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// Number of fields per line in /proc/mounts as per the fstab man page.
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expectedNumFieldsPerLine = 6
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// At least number of fields per line in /proc/<pid>/mountinfo.
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expectedAtLeastNumFieldsPerMountInfo = 10
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// Location of the mount file to use
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procMountsPath = "/proc/mounts"
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// Location of the mountinfo file
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@@ -452,345 +445,6 @@ func parseProcMounts(content []byte) ([]MountPoint, error) {
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return out, nil
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}
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type hostUtil struct {
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}
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// NewHostUtil returns a struct that implements the HostUtils interface on
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// linux platforms
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func NewHostUtil() HostUtils {
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return &hostUtil{}
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}
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// DeviceOpened checks if block device in use by calling Open with O_EXCL flag.
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// If pathname is not a device, log and return false with nil error.
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// If open returns errno EBUSY, return true with nil error.
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// If open returns nil, return false with nil error.
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// Otherwise, return false with error
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func (hu *hostUtil) DeviceOpened(pathname string) (bool, error) {
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return ExclusiveOpenFailsOnDevice(pathname)
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}
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// PathIsDevice uses FileInfo returned from os.Stat to check if path refers
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// to a device.
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func (hu *hostUtil) PathIsDevice(pathname string) (bool, error) {
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pathType, err := hu.GetFileType(pathname)
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isDevice := pathType == FileTypeCharDev || pathType == FileTypeBlockDev
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return isDevice, err
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}
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// ExclusiveOpenFailsOnDevice is shared with NsEnterMounter
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func ExclusiveOpenFailsOnDevice(pathname string) (bool, error) {
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var isDevice bool
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finfo, err := os.Stat(pathname)
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if os.IsNotExist(err) {
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isDevice = false
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}
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// err in call to os.Stat
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if err != nil {
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return false, fmt.Errorf(
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"PathIsDevice failed for path %q: %v",
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pathname,
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err)
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}
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// path refers to a device
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if finfo.Mode()&os.ModeDevice != 0 {
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isDevice = true
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}
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if !isDevice {
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klog.Errorf("Path %q is not referring to a device.", pathname)
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return false, nil
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}
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fd, errno := unix.Open(pathname, unix.O_RDONLY|unix.O_EXCL|unix.O_CLOEXEC, 0)
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// If the device is in use, open will return an invalid fd.
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// When this happens, it is expected that Close will fail and throw an error.
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defer unix.Close(fd)
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if errno == nil {
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// device not in use
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return false, nil
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} else if errno == unix.EBUSY {
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// device is in use
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return true, nil
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}
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// error during call to Open
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return false, errno
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}
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//GetDeviceNameFromMount: given a mount point, find the device name from its global mount point
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func (hu *hostUtil) GetDeviceNameFromMount(mounter Interface, mountPath, pluginMountDir string) (string, error) {
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return GetDeviceNameFromMountLinux(mounter, mountPath, pluginMountDir)
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}
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func getDeviceNameFromMount(mounter Interface, mountPath, pluginMountDir string) (string, error) {
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return GetDeviceNameFromMountLinux(mounter, mountPath, pluginMountDir)
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}
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// GetDeviceNameFromMountLinux find the device name from /proc/mounts in which
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// the mount path reference should match the given plugin mount directory. In case no mount path reference
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// matches, returns the volume name taken from its given mountPath
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// This implementation is shared with NsEnterMounter
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func GetDeviceNameFromMountLinux(mounter Interface, mountPath, pluginMountDir string) (string, error) {
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refs, err := mounter.GetMountRefs(mountPath)
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if err != nil {
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klog.V(4).Infof("GetMountRefs failed for mount path %q: %v", mountPath, err)
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return "", err
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}
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if len(refs) == 0 {
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klog.V(4).Infof("Directory %s is not mounted", mountPath)
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return "", fmt.Errorf("directory %s is not mounted", mountPath)
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}
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for _, ref := range refs {
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if strings.HasPrefix(ref, pluginMountDir) {
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volumeID, err := filepath.Rel(pluginMountDir, ref)
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if err != nil {
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klog.Errorf("Failed to get volume id from mount %s - %v", mountPath, err)
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return "", err
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}
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return volumeID, nil
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}
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}
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return path.Base(mountPath), nil
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}
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func (hu *hostUtil) MakeRShared(path string) error {
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return DoMakeRShared(path, procMountInfoPath)
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}
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func (hu *hostUtil) GetFileType(pathname string) (FileType, error) {
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return getFileType(pathname)
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}
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func (hu *hostUtil) MakeDir(pathname string) error {
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err := os.MkdirAll(pathname, os.FileMode(0755))
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if err != nil {
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if !os.IsExist(err) {
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return err
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}
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}
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return nil
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}
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func (hu *hostUtil) MakeFile(pathname string) error {
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f, err := os.OpenFile(pathname, os.O_CREATE, os.FileMode(0644))
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defer f.Close()
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if err != nil {
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if !os.IsExist(err) {
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return err
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}
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}
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return nil
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}
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func (hu *hostUtil) PathExists(pathname string) (bool, error) {
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return utilpath.Exists(utilpath.CheckFollowSymlink, pathname)
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}
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func (hu *hostUtil) EvalHostSymlinks(pathname string) (string, error) {
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return filepath.EvalSymlinks(pathname)
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}
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// isShared returns true, if given path is on a mount point that has shared
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// mount propagation.
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func isShared(mount string, mountInfoPath string) (bool, error) {
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info, err := findMountInfo(mount, mountInfoPath)
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if err != nil {
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return false, err
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}
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// parse optional parameters
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for _, opt := range info.optionalFields {
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if strings.HasPrefix(opt, "shared:") {
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return true, nil
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}
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}
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return false, nil
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}
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// This represents a single line in /proc/<pid>/mountinfo.
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type mountInfo struct {
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// Unique ID for the mount (maybe reused after umount).
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id int
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// The ID of the parent mount (or of self for the root of this mount namespace's mount tree).
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parentID int
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// The value of `st_dev` for files on this filesystem.
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majorMinor string
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// The pathname of the directory in the filesystem which forms the root of this mount.
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root string
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// Mount source, filesystem-specific information. e.g. device, tmpfs name.
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source string
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// Mount point, the pathname of the mount point.
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mountPoint string
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// Optional fieds, zero or more fields of the form "tag[:value]".
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optionalFields []string
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// The filesystem type in the form "type[.subtype]".
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fsType string
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// Per-mount options.
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mountOptions []string
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// Per-superblock options.
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superOptions []string
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}
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// parseMountInfo parses /proc/xxx/mountinfo.
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func parseMountInfo(filename string) ([]mountInfo, error) {
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content, err := utilio.ConsistentRead(filename, maxListTries)
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if err != nil {
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return []mountInfo{}, err
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}
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contentStr := string(content)
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infos := []mountInfo{}
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for _, line := range strings.Split(contentStr, "\n") {
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if line == "" {
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// the last split() item is empty string following the last \n
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continue
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}
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// See `man proc` for authoritative description of format of the file.
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fields := strings.Fields(line)
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if len(fields) < expectedAtLeastNumFieldsPerMountInfo {
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return nil, fmt.Errorf("wrong number of fields in (expected at least %d, got %d): %s", expectedAtLeastNumFieldsPerMountInfo, len(fields), line)
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}
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id, err := strconv.Atoi(fields[0])
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if err != nil {
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return nil, err
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}
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parentID, err := strconv.Atoi(fields[1])
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if err != nil {
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return nil, err
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}
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info := mountInfo{
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id: id,
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parentID: parentID,
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majorMinor: fields[2],
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root: fields[3],
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mountPoint: fields[4],
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mountOptions: strings.Split(fields[5], ","),
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}
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// All fields until "-" are "optional fields".
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i := 6
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for ; i < len(fields) && fields[i] != "-"; i++ {
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info.optionalFields = append(info.optionalFields, fields[i])
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}
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// Parse the rest 3 fields.
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i++
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if len(fields)-i < 3 {
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return nil, fmt.Errorf("expect 3 fields in %s, got %d", line, len(fields)-i)
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}
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info.fsType = fields[i]
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info.source = fields[i+1]
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info.superOptions = strings.Split(fields[i+2], ",")
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infos = append(infos, info)
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}
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return infos, nil
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}
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func findMountInfo(path, mountInfoPath string) (mountInfo, error) {
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infos, err := parseMountInfo(mountInfoPath)
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if err != nil {
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return mountInfo{}, err
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}
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// process /proc/xxx/mountinfo in backward order and find the first mount
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// point that is prefix of 'path' - that's the mount where path resides
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var info *mountInfo
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for i := len(infos) - 1; i >= 0; i-- {
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if PathWithinBase(path, infos[i].mountPoint) {
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info = &infos[i]
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break
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}
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}
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if info == nil {
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return mountInfo{}, fmt.Errorf("cannot find mount point for %q", path)
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}
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return *info, nil
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}
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// DoMakeRShared is common implementation of MakeRShared on Linux. It checks if
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// path is shared and bind-mounts it as rshared if needed. mountCmd and
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// mountArgs are expected to contain mount-like command, DoMakeRShared will add
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// '--bind <path> <path>' and '--make-rshared <path>' to mountArgs.
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func DoMakeRShared(path string, mountInfoFilename string) error {
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shared, err := isShared(path, mountInfoFilename)
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if err != nil {
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return err
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}
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if shared {
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klog.V(4).Infof("Directory %s is already on a shared mount", path)
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return nil
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}
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klog.V(2).Infof("Bind-mounting %q with shared mount propagation", path)
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// mount --bind /var/lib/kubelet /var/lib/kubelet
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if err := syscall.Mount(path, path, "" /*fstype*/, syscall.MS_BIND, "" /*data*/); err != nil {
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return fmt.Errorf("failed to bind-mount %s: %v", path, err)
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}
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// mount --make-rshared /var/lib/kubelet
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if err := syscall.Mount(path, path, "" /*fstype*/, syscall.MS_SHARED|syscall.MS_REC, "" /*data*/); err != nil {
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return fmt.Errorf("failed to make %s rshared: %v", path, err)
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}
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return nil
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}
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// GetSELinux is common implementation of GetSELinuxSupport on Linux.
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func GetSELinux(path string, mountInfoFilename string) (bool, error) {
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info, err := findMountInfo(path, mountInfoFilename)
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if err != nil {
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return false, err
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}
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// "seclabel" can be both in mount options and super options.
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for _, opt := range info.superOptions {
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if opt == "seclabel" {
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return true, nil
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}
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}
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for _, opt := range info.mountOptions {
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if opt == "seclabel" {
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return true, nil
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}
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}
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return false, nil
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}
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func (hu *hostUtil) GetSELinuxSupport(pathname string) (bool, error) {
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return GetSELinux(pathname, procMountInfoPath)
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}
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// GetOwner returns the integer ID for the user and group of the given path
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func (hu *hostUtil) GetOwner(pathname string) (int64, int64, error) {
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realpath, err := filepath.EvalSymlinks(pathname)
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if err != nil {
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return -1, -1, err
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}
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return GetOwnerLinux(realpath)
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}
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func (hu *hostUtil) GetMode(pathname string) (os.FileMode, error) {
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return GetModeLinux(pathname)
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}
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// GetOwnerLinux is shared between Linux and NsEnterMounter
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// pathname must already be evaluated for symlinks
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func GetOwnerLinux(pathname string) (int64, int64, error) {
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info, err := os.Stat(pathname)
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if err != nil {
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return -1, -1, err
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}
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stat := info.Sys().(*syscall.Stat_t)
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return int64(stat.Uid), int64(stat.Gid), nil
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}
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// GetModeLinux is shared between Linux and NsEnterMounter
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func GetModeLinux(pathname string) (os.FileMode, error) {
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info, err := os.Stat(pathname)
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if err != nil {
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return 0, err
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}
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return info.Mode(), nil
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}
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// SearchMountPoints finds all mount references to the source, returns a list of
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// mountpoints.
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// This function assumes source cannot be device.
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Block a user