cleanup: create k8s.io/mount-utils Mounter only once

Recently the k8s.io/mount-utils package added more runtime dectection.
When creating a new Mounter, the detect is run every time. This is
unfortunate, as it logs a message like the following:

```
mount_linux.go:283] Detected umount with safe 'not mounted' behavior
```

This message might be useful, so it probably good to keep it.

In Ceph-CSI there are various locations where Mounter instances are
created. Moving that to the DefaultNodeServer type reduces it to a
single place. Some utility functions need to accept the additional
parameter too, so that has been modified as well.

See-also: kubernetes/kubernetes#109676
Signed-off-by: Niels de Vos <ndevos@redhat.com>

internal/cephfs/fuserecovery.go

@@ -51,8 +51,8 @@ func (ms mountState) String() string {
 	}[int(ms)]
 }
 
-func getMountState(path string) (mountState, error) {
-	isMnt, err := util.IsMountPoint(path)
+func (ns *NodeServer) getMountState(path string) (mountState, error) {
+	isMnt, err := util.IsMountPoint(ns.Mounter, path)
 	if err != nil {
 		if util.IsCorruptedMountError(err) {
 			return msCorrupted, nil
@@ -117,12 +117,12 @@ func (ns *NodeServer) tryRestoreFuseMountsInNodePublish(
 ) error {
 	// Check if there is anything to restore.
 
-	stagingTargetMs, err := getMountState(stagingTargetPath)
+	stagingTargetMs, err := ns.getMountState(stagingTargetPath)
 	if err != nil {
 		return err
 	}
 
-	targetMs, err := getMountState(targetPath)
+	targetMs, err := ns.getMountState(targetPath)
 	if err != nil {
 		return err
 	}
@@ -230,7 +230,7 @@ func (ns *NodeServer) tryRestoreFuseMountInNodeStage(
 ) error {
 	// Check if there is anything to restore.
 
-	stagingTargetMs, err := getMountState(stagingTargetPath)
+	stagingTargetMs, err := ns.getMountState(stagingTargetPath)
 	if err != nil {
 		return err
 	}

internal/cephfs/nodeserver.go

@@ -176,7 +176,7 @@ func (ns *NodeServer) NodeStageVolume(
 		return nil, status.Errorf(codes.Internal, "failed to try to restore FUSE mounts: %v", err)
 	}
 
-	isMnt, err := util.IsMountPoint(stagingTargetPath)
+	isMnt, err := util.IsMountPoint(ns.Mounter, stagingTargetPath)
 	if err != nil {
 		log.ErrorLog(ctx, "stat failed: %v", err)
 
@@ -426,7 +426,7 @@ func (ns *NodeServer) NodePublishVolume(
 
 	// Ensure staging target path is a mountpoint.
 
-	if isMnt, err := util.IsMountPoint(stagingTargetPath); err != nil {
+	if isMnt, err := util.IsMountPoint(ns.Mounter, stagingTargetPath); err != nil {
 		log.ErrorLog(ctx, "stat failed: %v", err)
 
 		return nil, status.Error(codes.Internal, err.Error())
@@ -438,7 +438,7 @@ func (ns *NodeServer) NodePublishVolume(
 
 	// Check if the volume is already mounted
 
-	isMnt, err := util.IsMountPoint(targetPath)
+	isMnt, err := util.IsMountPoint(ns.Mounter, targetPath)
 	if err != nil {
 		log.ErrorLog(ctx, "stat failed: %v", err)
 
@@ -482,7 +482,7 @@ func (ns *NodeServer) NodeUnpublishVolume(
 	// considering kubelet make sure node operations like unpublish/unstage...etc can not be called
 	// at same time, an explicit locking at time of nodeunpublish is not required.
 	targetPath := req.GetTargetPath()
-	isMnt, err := util.IsMountPoint(targetPath)
+	isMnt, err := util.IsMountPoint(ns.Mounter, targetPath)
 	if err != nil {
 		log.ErrorLog(ctx, "stat failed: %v", err)
 
@@ -551,7 +551,7 @@ func (ns *NodeServer) NodeUnstageVolume(
 		return nil, status.Error(codes.Internal, err.Error())
 	}
 
-	isMnt, err := util.IsMountPoint(stagingTargetPath)
+	isMnt, err := util.IsMountPoint(ns.Mounter, stagingTargetPath)
 	if err != nil {
 		log.ErrorLog(ctx, "stat failed: %v", err)
 
@@ -637,7 +637,7 @@ func (ns *NodeServer) NodeGetVolumeStats(
 	}
 
 	if stat.Mode().IsDir() {
-		return csicommon.FilesystemNodeGetVolumeStats(ctx, targetPath)
+		return csicommon.FilesystemNodeGetVolumeStats(ctx, ns.Mounter, targetPath)
 	}
 
 	return nil, status.Errorf(codes.InvalidArgument, "targetpath %q is not a directory or device", targetPath)

internal/csi-common/nodeserver-default.go

@@ -24,12 +24,14 @@ import (
 	"github.com/container-storage-interface/spec/lib/go/csi"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
+	mount "k8s.io/mount-utils"
 )
 
 // DefaultNodeServer stores driver object.
 type DefaultNodeServer struct {
-	Driver *CSIDriver
-	Type   string
+	Driver  *CSIDriver
+	Type    string
+	Mounter mount.Interface
 }
 
 // NodeExpandVolume returns unimplemented response.

internal/csi-common/utils.go

@@ -38,6 +38,7 @@ import (
 	"google.golang.org/grpc/status"
 	"k8s.io/klog/v2"
 	"k8s.io/kubernetes/pkg/volume"
+	mount "k8s.io/mount-utils"
 )
 
 func parseEndpoint(ep string) (string, string, error) {
@@ -61,8 +62,9 @@ func NewDefaultNodeServer(d *CSIDriver, t string, topology map[string]string) *D
 	d.topology = topology
 
 	return &DefaultNodeServer{
-		Driver: d,
-		Type:   t,
+		Driver:  d,
+		Type:    t,
+		Mounter: mount.New(""),
 	}
 }
 
@@ -229,8 +231,12 @@ func panicHandler(
 // requested by the NodeGetVolumeStats CSI procedure.
 // It is shared for FileMode volumes, both the CephFS and RBD NodeServers call
 // this.
-func FilesystemNodeGetVolumeStats(ctx context.Context, targetPath string) (*csi.NodeGetVolumeStatsResponse, error) {
-	isMnt, err := util.IsMountPoint(targetPath)
+func FilesystemNodeGetVolumeStats(
+	ctx context.Context,
+	mounter mount.Interface,
+	targetPath string,
+) (*csi.NodeGetVolumeStatsResponse, error) {
+	isMnt, err := util.IsMountPoint(mounter, targetPath)
 	if err != nil {
 		if os.IsNotExist(err) {
 			return nil, status.Errorf(codes.InvalidArgument, "targetpath %s does not exist", targetPath)

internal/csi-common/utils_test.go

@@ -26,6 +26,7 @@ import (
 	"github.com/container-storage-interface/spec/lib/go/csi"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	mount "k8s.io/mount-utils"
 )
 
 var fakeID = "fake-id"
@@ -87,7 +88,7 @@ func TestFilesystemNodeGetVolumeStats(t *testing.T) {
 
 	// retry until a mountpoint is found
 	for {
-		stats, err := FilesystemNodeGetVolumeStats(context.TODO(), cwd)
+		stats, err := FilesystemNodeGetVolumeStats(context.TODO(), mount.New(""), cwd)
 		if err != nil && cwd != "/" && strings.HasSuffix(err.Error(), "is not mounted") {
 			// try again with the parent directory
 			cwd = filepath.Dir(cwd)

internal/rbd/driver/driver.go

@@ -29,7 +29,6 @@ import (
 	"github.com/ceph/ceph-csi/internal/util/log"
 
 	"github.com/container-storage-interface/spec/lib/go/csi"
-	mount "k8s.io/mount-utils"
 )
 
 // Driver contains the default identity,node and controller struct.
@@ -73,11 +72,8 @@ func NewReplicationServer(c *rbd.ControllerServer) *rbd.ReplicationServer {
 
 // NewNodeServer initialize a node server for rbd CSI driver.
 func NewNodeServer(d *csicommon.CSIDriver, t string, topology map[string]string) (*rbd.NodeServer, error) {
-	mounter := mount.New("")
-
 	return &rbd.NodeServer{
 		DefaultNodeServer: csicommon.NewDefaultNodeServer(d, t, topology),
-		Mounter:           mounter,
 		VolumeLocks:       util.NewVolumeLocks(),
 	}, nil
 }

internal/rbd/nodeserver.go

@@ -42,7 +42,6 @@ import (
 // node server spec.
 type NodeServer struct {
 	*csicommon.DefaultNodeServer
-	Mounter mount.Interface
 	// A map storing all volumes with ongoing operations so that additional operations
 	// for that same volume (as defined by VolumeID) return an Aborted error
 	VolumeLocks *util.VolumeLocks
@@ -806,7 +805,7 @@ func (ns *NodeServer) mountVolume(ctx context.Context, stagingPath string, req *
 	if readOnly {
 		mountOptions = append(mountOptions, "ro")
 	}
-	if err := util.Mount(stagingPath, targetPath, fsType, mountOptions); err != nil {
+	if err := util.Mount(ns.Mounter, stagingPath, targetPath, fsType, mountOptions); err != nil {
 		return status.Error(codes.Internal, err.Error())
 	}
 
@@ -1241,7 +1240,7 @@ func (ns *NodeServer) NodeGetVolumeStats(
 	}
 
 	if stat.Mode().IsDir() {
-		return csicommon.FilesystemNodeGetVolumeStats(ctx, targetPath)
+		return csicommon.FilesystemNodeGetVolumeStats(ctx, ns.Mounter, targetPath)
 	} else if (stat.Mode() & os.ModeDevice) == os.ModeDevice {
 		return blockNodeGetVolumeStats(ctx, targetPath)
 	}

internal/util/util.go

@@ -325,9 +325,8 @@ func checkDirExists(p string) bool {
 }
 
 // IsMountPoint checks if the given path is mountpoint or not.
-func IsMountPoint(p string) (bool, error) {
-	dummyMount := mount.New("")
-	notMnt, err := dummyMount.IsLikelyNotMountPoint(p)
+func IsMountPoint(mounter mount.Interface, p string) (bool, error) {
+	notMnt, err := mounter.IsLikelyNotMountPoint(p)
 	if err != nil {
 		return false, err
 	}
@@ -348,10 +347,8 @@ func ReadMountInfoForProc(proc string) ([]mount.MountInfo, error) {
 }
 
 // Mount mounts the source to target path.
-func Mount(source, target, fstype string, options []string) error {
-	dummyMount := mount.New("")
-
-	return dummyMount.MountSensitiveWithoutSystemd(source, target, fstype, options, nil)
+func Mount(mounter mount.Interface, source, target, fstype string, options []string) error {
+	return mounter.MountSensitiveWithoutSystemd(source, target, fstype, options, nil)
 }
 
 // MountOptionsAdd adds the `add` mount options to the `options` and returns a