Add mounts from /proc/1/mountinfo (#1007)

Some systems do not expose all mount information in
/proc/self/mountinfo. This PR fixes the issue by reading entries from
/proc/self/mountinfo and /proc/1/mountinfo.

Signed-off-by: Bala.FA <bala@minio.io>

Author: balamurugana

pkg/device/probe_linux.go

@@ -35,15 +35,15 @@ func newDevice(
 	majorMinor string,
 	udevData map[string]string,
 ) (device *Device, err error) {
-	var mountPoints []string
+	mountPoints := make(utils.StringSet)
 	for _, mountEntry := range mountInfo.FilterByMajorMinor(majorMinor).List() {
-		mountPoints = append(mountPoints, mountEntry.MountPoint)
+		mountPoints.Set(mountEntry.MountPoint)
 	}
 
 	device = &Device{
 		Name:        name,
 		MajorMinor:  majorMinor,
-		MountPoints: mountPoints,
+		MountPoints: mountPoints.ToSlice(),
 		CDROM:       cdroms.Exist(name),
 		SwapOn:      swaps.Exist(utils.AddDevPrefix(name)),
 		udevData:    udevData,

pkg/device/sync.go

@@ -195,12 +195,12 @@ func updateDrive(ctx context.Context, driveName string, deviceMap map[string][]d
 		mountPoint := types.GetDriveMountDir(drive.Status.FSUUID)
 		legacyMountPoint := path.Join(consts.LegacyAppRootDir, "mnt", drive.Status.FSUUID)
 
-		var mountPoints []string
+		mountPoints := make(utils.StringSet)
 		for _, mountEntry := range mountInfo.FilterByMountSource(devices[0].MajorMinor).FilterByRoot("/").List() {
 			switch mountEntry.MountPoint {
 			case mountPoint, legacyMountPoint:
 			default:
-				mountPoints = append(mountPoints, mountEntry.MountPoint)
+				mountPoints.Set(mountEntry.MountPoint)
 			}
 
 			check := func() error {
@@ -224,7 +224,7 @@ func updateDrive(ctx context.Context, driveName string, deviceMap map[string][]d
 		}
 
 		if len(mountPoints) != 0 {
-			klog.ErrorS(fmt.Errorf("device mounted outside of DirectPV"), "device", devices[0].Name, "mountPoints", mountPoints, "drive", drive.GetDriveID(), drive.GetDriveName())
+			klog.ErrorS(fmt.Errorf("device mounted outside of DirectPV"), "device", devices[0].Name, "mountPoints", mountPoints.ToSlice(), "drive", drive.GetDriveID(), drive.GetDriveName())
 		}
 
 		updated = syncDrive(drive, devices[0])

pkg/drive/event.go

@@ -229,15 +229,16 @@ func (handler *driveEventHandler) unmountDrive(drive *types.Drive, skipDriveMoun
 		}
 	}
 
-	if filteredMountInfo.Length() > 1 {
-		var devices []string
-		for _, mountEntry := range filteredMountInfo.List() {
-			devices = append(devices, mountEntry.MountSource)
-		}
-		return fmt.Errorf("multiple devices [%v] are mounted for FSUUID %v", strings.Join(devices, ","), drive.Status.FSUUID)
+	devices := make(utils.StringSet)
+	for _, mountEntry := range filteredMountInfo.List() {
+		devices.Set(mountEntry.MountSource)
+	}
+
+	if len(devices) > 1 {
+		return fmt.Errorf("multiple devices [%v] are mounted for FSUUID %v", strings.Join(devices.ToSlice(), ","), drive.Status.FSUUID)
 	}
 
-	for _, mountEntry := range mountInfo.FilterByMountSource(filteredMountInfo.List()[0].MountSource).List() {
+	for _, mountEntry := range mountInfo.FilterByMountSource(devices.ToSlice()[0]).List() {
 		if skipDriveMount && mountEntry.MountPoint == driveMountPoint {
 			continue
 		}

pkg/drive/repair.go

@@ -30,6 +30,7 @@ import (
 	"github.com/minio/directpv/pkg/consts"
 	"github.com/minio/directpv/pkg/sys"
 	"github.com/minio/directpv/pkg/types"
+	"github.com/minio/directpv/pkg/utils"
 	"github.com/minio/directpv/pkg/xfs"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/util/retry"
@@ -108,17 +109,17 @@ func repair(ctx context.Context, drive *types.Drive, force, disablePrefetch, dry
 		return err
 	}
 
-	var mountPoints []string
+	mountPoints := make(utils.StringSet)
 	for _, mountEntry := range mountInfo.FilterByMountSource(device).List() {
 		switch mountEntry.MountPoint {
 		case target, legacyTarget:
 		default:
-			mountPoints = append(mountPoints, mountEntry.MountPoint)
+			mountPoints.Set(mountEntry.MountPoint)
 		}
 	}
 
 	if len(mountPoints) != 0 {
-		return fmt.Errorf("unable to run xfs repair; device %v still mounted in [%v]", device, strings.Join(mountPoints, ","))
+		return fmt.Errorf("unable to run xfs repair; device %v still mounted in [%v]", device, strings.Join(mountPoints.ToSlice(), ","))
 	}
 
 	if err = unmount(target); err != nil {

pkg/initrequest/event.go

@@ -235,13 +235,13 @@ func (handler *initRequestEventHandler) initDevice(device pkgdevice.Device, forc
 		return err
 	}
 
-	var mountPoints []string
+	mountPoints := make(utils.StringSet)
 	for _, mountEntry := range mountInfo.FilterByMajorMinor(device.MajorMinor).List() {
-		mountPoints = append(mountPoints, mountEntry.MountPoint)
+		mountPoints.Set(mountEntry.MountPoint)
 	}
 
 	if len(mountPoints) != 0 {
-		return fmt.Errorf("device %v mounted at %v", devPath, mountPoints)
+		return fmt.Errorf("device %v mounted at %v", devPath, mountPoints.ToSlice())
 	}
 
 	fsuuid := uuid.New().String()

pkg/sys/mount_linux.go

@@ -32,11 +32,10 @@ import (
 	"k8s.io/klog/v2"
 )
 
-func parseMount(s string) *MountEntry {
+func parseMount(s string, xxHash uint64) *MountEntry {
 	// Refer https://man7.org/linux/man-pages/man5/proc_pid_mountinfo.5.html
 	// to know about this logic.
 	s = strings.TrimSpace(s)
-	xxHash := xxhash.Sum64String(s)
 	tokens := strings.Fields(s)
 	if len(tokens) < 8 {
 		return nil
@@ -70,12 +69,22 @@ func parseMount(s string) *MountEntry {
 	return &mount
 }
 
-func parseMountInfo(r io.Reader) (*MountInfo, error) {
-	infoMap := map[uint64]*MountEntry{}
-	mountPointMap := map[string][]uint64{}
-	mountSourceMap := map[string][]uint64{}
-	majorMinorMap := map[string][]uint64{}
-	rootMap := map[string][]uint64{}
+func parseMountInfo(r io.Reader, info *MountInfo) (*MountInfo, error) {
+	if info == nil {
+		info = &MountInfo{
+			infoMap:        map[uint64]*MountEntry{},
+			mountPointMap:  map[string][]uint64{},
+			mountSourceMap: map[string][]uint64{},
+			majorMinorMap:  map[string][]uint64{},
+			rootMap:        map[string][]uint64{},
+		}
+	}
+
+	infoMap := info.infoMap
+	mountPointMap := info.mountPointMap
+	mountSourceMap := info.mountSourceMap
+	majorMinorMap := info.majorMinorMap
+	rootMap := info.rootMap
 
 	reader := bufio.NewReader(r)
 
@@ -88,7 +97,12 @@ func parseMountInfo(r io.Reader) (*MountInfo, error) {
 			return nil, err
 		}
 
-		mount := parseMount(s)
+		xxHash := xxhash.Sum64String(s)
+		if _, found := infoMap[xxHash]; found {
+			continue
+		}
+
+		mount := parseMount(s, xxHash)
 		if mount == nil {
 			continue
 		}
@@ -100,23 +114,41 @@ func parseMountInfo(r io.Reader) (*MountInfo, error) {
 		rootMap[mount.Root] = append(rootMap[mount.Root], mount.xxHash)
 	}
 
-	return &MountInfo{
-		infoMap:        infoMap,
-		mountPointMap:  mountPointMap,
-		mountSourceMap: mountSourceMap,
-		majorMinorMap:  majorMinorMap,
-		rootMap:        rootMap,
-	}, nil
+	return info, nil
 }
 
 func newMountInfo() (*MountInfo, error) {
-	file, err := os.Open("/proc/self/mountinfo")
+	parseSelfInfo := func() (*MountInfo, error) {
+		file, err := os.Open("/proc/self/mountinfo")
+		if err != nil {
+			return nil, err
+		}
+
+		defer file.Close()
+		return parseMountInfo(file, nil)
+	}
+
+	parseRootInfo := func(info *MountInfo) (*MountInfo, error) {
+		file, err := os.Open("/proc/1/mountinfo")
+		if err != nil {
+			switch {
+			case errors.Is(err, os.ErrInvalid), errors.Is(err, os.ErrPermission), errors.Is(err, os.ErrExist), errors.Is(err, os.ErrNotExist), errors.Is(err, os.ErrClosed):
+			default:
+				klog.ErrorS(err, "unable to read /proc/1/mountinfo; open an issue in SUBNET with this log")
+			}
+			return info, nil
+		}
+
+		defer file.Close()
+		return parseMountInfo(file, info)
+	}
+
+	info, err := parseSelfInfo()
 	if err != nil {
 		return nil, err
 	}
 
-	defer file.Close()
-	return parseMountInfo(file)
+	return parseRootInfo(info)
 }
 
 var mountFlagMap = map[string]uintptr{