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Commit df0f108a authored by Yecheng Fu's avatar Yecheng Fu
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Fixes fsGroup check in local volume in containerized kubelet. Except

this, it also fixes fsGroup check when volume source is a normal directory whether kubelet is running on the host or in a container.
parent b5cd7d81
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Showing with 96 additions and 49 deletions
pkg/util/mount/mount_linux.go
View file @ df0f108a
......@@ -42,6 +42,8 @@ const (
maxListTries = 3
// Number of fields per line in /proc/mounts as per the fstab man page.
expectedNumFieldsPerLine = 6
// At least number of fields per line in /proc/<pid>/mountinfo.
expectedAtLeastNumFieldsPerMountInfo = 10
// Location of the mount file to use
procMountsPath = "/proc/mounts"
// Location of the mountinfo file
......@@ -598,7 +600,7 @@ func isShared(mount string, mountInfoPath string) (bool, error) {
}
// parse optional parameters
for _, opt := range info.optional {
for _, opt := range info.optionalFields {
if strings.HasPrefix(opt, "shared:") {
return true, nil
}
......@@ -606,14 +608,27 @@ func isShared(mount string, mountInfoPath string) (bool, error) {
return false, nil
}
// This represents a single line in /proc/<pid>/mountinfo.
type mountInfo struct {
// Path of the mount point
// Unique ID for the mount (maybe reused after umount).
id int
// The ID of the parent mount (or of self for the root of this mount namespace's mount tree).
parentID int
// The value of `st_dev` for files on this filesystem.
majorMinor string
// The pathname of the directory in the filesystem which forms the root of this mount.
root string
// Mount source, filesystem-specific information. e.g. device, tmpfs name.
source string
// Mount point, the pathname of the mount point.
mountPoint string
// list of "optional parameters", mount propagation is one of them
optional []string
// mount options
// Optional fieds, zero or more fields of the form "tag[:value]".
optionalFields []string
// The filesystem type in the form "type[.subtype]".
fsType string
// Per-mount options.
mountOptions []string
// super options: per-superblock options.
// Per-superblock options.
superOptions []string
}
......@@ -633,20 +648,38 @@ func parseMountInfo(filename string) ([]mountInfo, error) {
}
// See `man proc` for authoritative description of format of the file.
fields := strings.Fields(line)
if len(fields) < 10 {
return nil, fmt.Errorf("wrong number of fields in (expected %d, got %d): %s", 10, len(fields), line)
if len(fields) < expectedAtLeastNumFieldsPerMountInfo {
return nil, fmt.Errorf("wrong number of fields in (expected at least %d, got %d): %s", expectedAtLeastNumFieldsPerMountInfo, len(fields), line)
}
id, err := strconv.Atoi(fields[0])
if err != nil {
return nil, err
}
parentID, err := strconv.Atoi(fields[1])
if err != nil {
return nil, err
}
info := mountInfo{
id: id,
parentID: parentID,
majorMinor: fields[2],
root: fields[3],
mountPoint: fields[4],
mountOptions: strings.Split(fields[5], ","),
optional: []string{},
}
// All fields until "-" are "optional fields".
for i := 6; i < len(fields) && fields[i] != "-"; i++ {
info.optional = append(info.optional, fields[i])
i := 6
for ; i < len(fields) && fields[i] != "-"; i++ {
info.optionalFields = append(info.optionalFields, fields[i])
}
// Parse the rest 3 fields.
i += 1
if len(fields)-i < 3 {
return nil, fmt.Errorf("expect 3 fields in %s, got %d", line, len(fields)-i)
}
superOpts := fields[len(fields)-1]
info.superOptions = strings.Split(superOpts, ",")
info.fsType = fields[i]
info.source = fields[i+1]
info.superOptions = strings.Split(fields[i+2], ",")
infos = append(infos, info)
}
return infos, nil
......@@ -967,7 +1000,7 @@ func (mounter *Mounter) GetMountRefs(pathname string) ([]string, error) {
if err != nil {
return nil, err
}
return getMountRefsByDev(mounter, realpath)
return searchMountPoints(realpath, procMountInfoPath)
}
func (mounter *Mounter) GetSELinuxSupport(pathname string) (bool, error) {
......@@ -1216,3 +1249,51 @@ func doSafeOpen(pathname string, base string) (int, error) {
return finalFD, nil
}
// searchMountPoints finds all mount references to the source, returns a list of
// mountpoints.
// This function assumes source cannot be device.
// Some filesystems may share a source name, e.g. tmpfs. And for bind mounting,
// it's possible to mount a non-root path of a filesystem, so we need to use
// root path and major:minor to represent mount source uniquely.
// This implementation is shared between Linux and NsEnterMounter
func searchMountPoints(hostSource, mountInfoPath string) ([]string, error) {
mis, err := parseMountInfo(mountInfoPath)
if err != nil {
return nil, err
}
mountID := 0
rootPath := ""
majorMinor := ""
// Finding the underlying root path and major:minor if possible.
// We need search in backward order because it's possible for later mounts
// to overlap earlier mounts.
for i := len(mis) - 1; i >= 0; i-- {
if hostSource == mis[i].mountPoint || pathWithinBase(hostSource, mis[i].mountPoint) {
// If it's a mount point or path under a mount point.
mountID = mis[i].id
rootPath = filepath.Join(mis[i].root, strings.TrimPrefix(hostSource, mis[i].mountPoint))
majorMinor = mis[i].majorMinor
break
}
}
if rootPath == "" || majorMinor == "" {
return nil, fmt.Errorf("failed to get root path and major:minor for %s", hostSource)
}
var refs []string
for i := range mis {
if mis[i].id == mountID {
// Ignore mount entry for mount source itself.
continue
}
if mis[i].root == rootPath && mis[i].majorMinor == majorMinor {
refs = append(refs, mis[i].mountPoint)
}
}
return refs, nil
}
pkg/util/mount/nsenter_mount.go
View file @ df0f108a
......@@ -333,7 +333,7 @@ func (mounter *NsenterMounter) GetMountRefs(pathname string) ([]string, error) {
if err != nil {
return nil, err
}
return getMountRefsByDev(mounter, hostpath)
return searchMountPoints(hostpath, procMountInfoPath)
}
func (mounter *NsenterMounter) GetFSGroup(pathname string) (int64, error) {
......
test/e2e/storage/persistent_volumes-local.go
View file @ df0f108a
......@@ -290,14 +290,6 @@ var _ = utils.SIGDescribe("PersistentVolumes-local ", func() {
})
It("should set fsGroup for one pod", func() {
skipTypes := sets.NewString(
string(DirectoryBindMountedLocalVolumeType),
string(DirectoryLinkBindMountedLocalVolumeType),
)
if skipTypes.Has(string(testVolType)) {
// TODO(cofyc): Test it when bug is fixed.
framework.Skipf("Skipped when volume type is %v", testVolType)
}
By("Checking fsGroup is set")
pod := createPodWithFsGroupTest(config, testVol, 1234, 1234)
By("Deleting pod")
......@@ -305,14 +297,6 @@ var _ = utils.SIGDescribe("PersistentVolumes-local ", func() {
})
It("should set same fsGroup for two pods simultaneously", func() {
skipTypes := sets.NewString(
string(DirectoryBindMountedLocalVolumeType),
string(DirectoryLinkBindMountedLocalVolumeType),
)
if skipTypes.Has(string(testVolType)) {
// TODO(cofyc): Test it when bug is fixed.
framework.Skipf("Skipped when volume type is %v", testVolType)
}
fsGroup := int64(1234)
By("Create first pod and check fsGroup is set")
pod1 := createPodWithFsGroupTest(config, testVol, fsGroup, fsGroup)
......@@ -325,14 +309,6 @@ var _ = utils.SIGDescribe("PersistentVolumes-local ", func() {
})
It("should set different fsGroup for second pod if first pod is deleted", func() {
skipTypes := sets.NewString(
string(DirectoryBindMountedLocalVolumeType),
string(DirectoryLinkBindMountedLocalVolumeType),
)
if skipTypes.Has(string(testVolType)) {
// TODO(cofyc): Test it when bug is fixed.
framework.Skipf("Skipped when volume type is %v", testVolType)
}
fsGroup1, fsGroup2 := int64(1234), int64(4321)
By("Create first pod and check fsGroup is set")
pod1 := createPodWithFsGroupTest(config, testVol, fsGroup1, fsGroup1)
......@@ -346,16 +322,6 @@ var _ = utils.SIGDescribe("PersistentVolumes-local ", func() {
})
It("should not set different fsGroups for two pods simultaneously", func() {
skipTypes := sets.NewString(
string(DirectoryLocalVolumeType),
string(DirectoryLinkLocalVolumeType),
string(DirectoryBindMountedLocalVolumeType),
string(DirectoryLinkBindMountedLocalVolumeType),
)
if skipTypes.Has(string(testVolType)) {
// TODO(cofyc): Test it when bug is fixed.
framework.Skipf("Skipped when volume type is %v", testVolType)
}
fsGroup1, fsGroup2 := int64(1234), int64(4321)
By("Create first pod and check fsGroup is set")
pod1 := createPodWithFsGroupTest(config, testVol, fsGroup1, fsGroup1)
......
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