feat: snapshot path to include src volume name/uuid

pkg/nfs/controllerserver.go

@@ -18,6 +18,7 @@ package nfs
 
 import (
 	"fmt"
+	"io/fs"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -71,10 +72,20 @@ type nfsSnapshot struct {
 	baseDir string
 	// Snapshot name.
 	uuid string
+	// Source volume.
+	src string
+}
+
+func (snap nfsSnapshot) archiveSubPath() string {
+	return snap.uuid
 }
 
 func (snap nfsSnapshot) archiveName() string {
-	return fmt.Sprintf("%v.tar.gz", snap.uuid)
+	return fmt.Sprintf("%v.tar.gz", snap.src)
+}
+
+func (snap nfsSnapshot) archivePath() string {
+	return filepath.Join(snap.archiveSubPath(), snap.archiveName())
 }
 
 // Ordering of elements in the CSI volume id.
@@ -92,14 +103,15 @@ const (
 )
 
 // Ordering of elements in the CSI snapshot id.
-// ID is of the form {server}/{baseDir}/snapshots.
+// ID is of the form {server}/{baseDir}/{snap_name}/{src_name}.
 // Adding a new element should always go at the end
 // before totalSnapIDElements
 const (
 	idSnapServer = iota
 	idSnapBaseDir
 	idSnapUUID
-	idSnapArchive
+	idSnapArchivePath
+	idSnapArchiveName
 	totalIDSnapElements // Always last
 )
 
@@ -309,6 +321,13 @@ func (cs *ControllerServer) CreateSnapshot(ctx context.Context, req *csi.CreateS
 			klog.Warningf("failed to unmount snapshot nfs server: %v", err)
 		}
 	}()
+	snapInternalVolPath := filepath.Join(getInternalVolumePath(cs.Driver.workingMountDir, snapVol), snapshot.archiveSubPath())
+	if err = os.MkdirAll(snapInternalVolPath, 0777); err != nil {
+		return nil, status.Errorf(codes.Internal, "failed to make subdirectory: %v", err)
+	}
+	if err := validateSnapshot(snapInternalVolPath, snapshot); err != nil {
+		return nil, err
+	}
 
 	if err = cs.internalMount(ctx, srcVol, nil, nil); err != nil {
 		return nil, status.Errorf(codes.Internal, "failed to mount src nfs server: %v", err)
@@ -320,7 +339,7 @@ func (cs *ControllerServer) CreateSnapshot(ctx context.Context, req *csi.CreateS
 	}()
 
 	srcPath := getInternalVolumePath(cs.Driver.workingMountDir, srcVol)
-	dstPath := filepath.Join(getInternalVolumePath(cs.Driver.workingMountDir, snapVol), snapshot.archiveName())
+	dstPath := filepath.Join(snapInternalVolPath, snapshot.archiveName())
 	klog.V(2).Infof("archiving %v -> %v", srcPath, dstPath)
 	out, err := exec.Command("tar", "-C", srcPath, "-czvf", dstPath, ".").CombinedOutput()
 	if err != nil {
@@ -380,7 +399,7 @@ func (cs *ControllerServer) DeleteSnapshot(ctx context.Context, req *csi.DeleteS
 	}()
 
 	// delete snapshot archive
-	internalVolumePath := filepath.Join(getInternalVolumePath(cs.Driver.workingMountDir, vol), snap.archiveName())
+	internalVolumePath := filepath.Join(getInternalVolumePath(cs.Driver.workingMountDir, vol), snap.archiveSubPath())
 	klog.V(2).Infof("Removing snapshot archive at %v", internalVolumePath)
 	if err = os.RemoveAll(internalVolumePath); err != nil {
 		return nil, status.Errorf(codes.Internal, "failed to delete subdirectory: %v", err.Error())
@@ -397,17 +416,6 @@ func (cs *ControllerServer) ControllerExpandVolume(ctx context.Context, req *csi
 	return nil, status.Error(codes.Unimplemented, "")
 }
 
-// Volume for snapshot internal mount/unmount
-func volumeFromSnapshot(snap *nfsSnapshot) *nfsVolume {
-	return &nfsVolume{
-		id:      snap.id,
-		server:  snap.server,
-		baseDir: snap.baseDir,
-		subDir:  snap.baseDir,
-		uuid:    snap.uuid,
-	}
-}
-
 // Mount nfs server at base-dir
 func (cs *ControllerServer) internalMount(ctx context.Context, vol *nfsVolume, volumeContext map[string]string, volCap *csi.VolumeCapability) error {
 	if volCap == nil {
@@ -485,7 +493,7 @@ func (cs *ControllerServer) copyFromSnapshot(ctx context.Context, req *csi.Creat
 	}()
 
 	// untar snapshot archive to dst path
-	snapPath := filepath.Join(getInternalVolumePath(cs.Driver.workingMountDir, snapVol), snap.archiveName())
+	snapPath := filepath.Join(getInternalVolumePath(cs.Driver.workingMountDir, snapVol), snap.archivePath())
 	dstPath := getInternalVolumePath(cs.Driver.workingMountDir, dstVol)
 	klog.V(2).Infof("copy volume from snapshot %v -> %v", snapPath, dstPath)
 	out, err := exec.Command("tar", "-xzvf", snapPath, "-C", dstPath).CombinedOutput()
@@ -568,6 +576,15 @@ func newNFSSnapshot(name string, params map[string]string, vol *nfsVolume) (*nfs
 		baseDir: baseDir,
 		uuid:    name,
 	}
+	if vol.uuid != "" {
+		snapshot.src = vol.uuid
+	}
+	if vol.subDir != "" {
+		snapshot.src = vol.subDir
+	}
+	if snapshot.src == "" {
+		return nil, fmt.Errorf("missing required source volume name")
+	}
 	snapshot.id = getSnapshotIDFromNfsSnapshot(snapshot)
 	return snapshot, nil
 }
@@ -656,7 +673,8 @@ func getSnapshotIDFromNfsSnapshot(snap *nfsSnapshot) string {
 	idElements[idSnapServer] = strings.Trim(snap.server, "/")
 	idElements[idSnapBaseDir] = strings.Trim(snap.baseDir, "/")
 	idElements[idSnapUUID] = snap.uuid
-	idElements[idSnapArchive] = snap.archiveName()
+	idElements[idSnapArchivePath] = snap.uuid
+	idElements[idSnapArchiveName] = snap.src
 	return strings.Join(idElements, separator)
 }
 
@@ -702,14 +720,15 @@ func getNfsVolFromID(id string) (*nfsVolume, error) {
 // Given a CSI snapshot ID, return a nfsSnapshot
 // sample snapshot ID:
 //
-//	nfs-server.default.svc.cluster.local#share#snapshot-016f784f-56f4-44d1-9041-5f59e82dbce1#snapshot-016f784f-56f4-44d1-9041-5f59e82dbce1.tar.gz
+//	nfs-server.default.svc.cluster.local#share#snapshot-016f784f-56f4-44d1-9041-5f59e82dbce1#snapshot-016f784f-56f4-44d1-9041-5f59e82dbce1#pvc-4bcbf944-b6f7-4bd0-b50f-3c3dd00efc64
 func getNfsSnapFromID(id string) (*nfsSnapshot, error) {
 	segments := strings.Split(id, separator)
-	if len(segments) == 4 {
+	if len(segments) == totalIDSnapElements {
 		return &nfsSnapshot{
 			id:      id,
 			server:  segments[idSnapServer],
 			baseDir: segments[idSnapBaseDir],
+			src:     segments[idSnapArchiveName],
 			uuid:    segments[idSnapUUID],
 		}, nil
 	}
@@ -729,3 +748,32 @@ func isValidVolumeCapabilities(volCaps []*csi.VolumeCapability) error {
 	}
 	return nil
 }
+
+// Validate snapshot after internal mount
+func validateSnapshot(snapInternalVolPath string, snap *nfsSnapshot) error {
+	return filepath.WalkDir(snapInternalVolPath, func(path string, d fs.DirEntry, err error) error {
+		if path == snapInternalVolPath {
+			// skip root
+			return nil
+		}
+		if err != nil {
+			return err
+		}
+		if d.Name() != snap.archiveName() {
+			// there should be just one archive in the snapshot path and archive name should match
+			return status.Errorf(codes.AlreadyExists, "snapshot with the same name but different source volume ID already exists: found %q, desired %q", d.Name(), snap.archiveName())
+		}
+		return nil
+	})
+}
+
+// Volume for snapshot internal mount/unmount
+func volumeFromSnapshot(snap *nfsSnapshot) *nfsVolume {
+	return &nfsVolume{
+		id:      snap.id,
+		server:  snap.server,
+		baseDir: snap.baseDir,
+		subDir:  snap.baseDir,
+		uuid:    snap.uuid,
+	}
+}