Merge pull request #71 from garenchan/ck-dev1

Fix #70: use bind mount rather than symbolic link

2 files changed, 21 insertions, 8 deletions

diff --git a/pkg/driver/nodeserver.go b/pkg/driver/nodeserver.go
index 5a7206e..6c792c7 100644
--- a/pkg/driver/nodeserver.go
+++ b/pkg/driver/nodeserver.go
@@ -111,7 +111,7 @@ func (ns *NodeServer) NodePublishVolume(ctx context.Context, req *csi.NodePublis
 
 	// When pod uses a volume in read-only mode, k8s will automatically
 	// mount the volume as a read-only file system.
-	if err := volume.(*Volume).Publish(targetPath); err != nil {
+	if err := volume.(*Volume).Publish(targetPath, req.GetReadonly()); err != nil {
 		return nil, status.Error(codes.Internal, err.Error())
 	}
 
diff --git a/pkg/driver/volume.go b/pkg/driver/volume.go
index 6a4e86d..fd1e18f 100644
--- a/pkg/driver/volume.go
+++ b/pkg/driver/volume.go
@@ -9,6 +9,7 @@ import (
 	"github.com/chrislusf/seaweedfs/weed/pb/mount_pb"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials/insecure"
+	"k8s.io/utils/mount"
 )
 
 type Volume struct {
@@ -57,13 +58,24 @@ func (vol *Volume) Stage(stagingTargetPath string) error {
 	return nil
 }
 
-func (vol *Volume) Publish(targetPath string) error {
-	if err := os.Remove(targetPath); err != nil && !os.IsNotExist(err) {
+func (vol *Volume) Publish(targetPath string, readOnly bool) error {
+	// check whether it can be mounted
+	if notMnt, err := checkMount(targetPath); err != nil {
 		return err
+	} else if !notMnt {
+		// maybe already mounted?
+		return nil
 	}
 
-	if err := os.Symlink(vol.stagingTargetPath, targetPath); err != nil {
-		return err
+	// Use bind mount to create an alias of the real mount point.
+	mountOptions := []string{"bind"}
+	if readOnly {
+		mountOptions = append(mountOptions, "ro")
+	}
+
+	mounter := mount.New("")
+	if err := mounter.Mount(vol.stagingTargetPath, targetPath, "", mountOptions); err != nil {
+		return nil
 	}
 
 	vol.targetPaths[targetPath] = true
@@ -98,12 +110,13 @@ func (vol *Volume) Unpublish(targetPath string) error {
 		return nil
 	}
 
-	delete(vol.targetPaths, targetPath)
-
-	if err := os.Remove(targetPath); err != nil && !os.IsNotExist(err) {
+	// Try unmounting target path and deleting it.
+	mounter := mount.New("")
+	if err := mount.CleanupMountPoint(targetPath, mounter, true); err != nil {
 		return err
 	}
 
+	delete(vol.targetPaths, targetPath)
 	return nil
 }