cephfs: Add clusterName as metadata on snapshots

Example:
sh-4.4$ ceph fs subvolume snapshot metadata ls myfs csi-vol-ba248f9e-0e75-11ed-b774-8e97192ff5ec \
			csi-snap-ce24e3bb-0e75-11ed-b774-8e97192ff5ec --group_name csi
{
    "csi.ceph.com/cluster/name": "\"K8s-cluster-1\"",
    "csi.storage.k8s.io/volumesnapshot/name": "cephfs-pvc-snapshot",
    "csi.storage.k8s.io/volumesnapshot/namespace": "rook-ceph",
    "csi.storage.k8s.io/volumesnapshotcontent/name": "snapcontent-2e89e1b2-e6e9-48fe-b365-edb493d7022e"
}

Signed-off-by: Prasanna Kumar Kalever <prasanna.kalever@redhat.com>

internal/cephfs/controllerserver.go

@@ -602,6 +602,7 @@ func cleanUpBackingVolume(
 			snapParentVolOptions.GetConnection(),
 			snapID.FsSnapshotName,
 			volOptions.ClusterID,
+			clusterName,
 			&snapParentVolOptions.SubVolume,
 		)
 
@@ -780,7 +781,7 @@ func (cs *ControllerServer) CreateSnapshot(
 	}
 	defer cs.VolumeLocks.Release(sourceVolID)
 	snapName := req.GetName()
-	sid, snapInfo, err := store.CheckSnapExists(ctx, parentVolOptions, cephfsSnap, cr)
+	sid, snapInfo, err := store.CheckSnapExists(ctx, parentVolOptions, cephfsSnap, cs.ClusterName, cr)
 	if err != nil {
 		return nil, status.Error(codes.Internal, err.Error())
 	}
@@ -824,6 +825,7 @@ func (cs *ControllerServer) CreateSnapshot(
 			parentVolOptions.GetConnection(),
 			sid.FsSnapshotName,
 			parentVolOptions.ClusterID,
+			cs.ClusterName,
 			&parentVolOptions.SubVolume)
 		if !(snapInfo.Protected == core.SnapshotIsProtected) {
 			err = snapClient.ProtectSnapshot(ctx)
@@ -868,7 +870,7 @@ func (cs *ControllerServer) CreateSnapshot(
 			}
 		}
 	}()
-	snap, err := doSnapshot(ctx, parentVolOptions, sID.FsSnapshotName, metadata)
+	snap, err := doSnapshot(ctx, parentVolOptions, sID.FsSnapshotName, cs.ClusterName, metadata)
 	if err != nil {
 		return nil, status.Error(codes.Internal, err.Error())
 	}
@@ -887,12 +889,14 @@ func (cs *ControllerServer) CreateSnapshot(
 func doSnapshot(
 	ctx context.Context,
 	volOpt *store.VolumeOptions,
-	snapshotName string,
+	snapshotName,
+	clusterName string,
 	metadata map[string]string,
 ) (core.SnapshotInfo, error) {
 	snapID := fsutil.VolumeID(snapshotName)
 	snap := core.SnapshotInfo{}
-	snapClient := core.NewSnapshot(volOpt.GetConnection(), snapshotName, volOpt.ClusterID, &volOpt.SubVolume)
+	snapClient := core.NewSnapshot(volOpt.GetConnection(), snapshotName,
+		volOpt.ClusterID, clusterName, &volOpt.SubVolume)
 	err := snapClient.CreateSnapshot(ctx)
 	if err != nil {
 		log.ErrorLog(ctx, "failed to create snapshot %s %v", snapID, err)
@@ -1049,7 +1053,8 @@ func (cs *ControllerServer) DeleteSnapshot(
 	if snapInfo.HasPendingClones == "yes" {
 		return nil, status.Errorf(codes.FailedPrecondition, "snapshot %s has pending clones", snapshotID)
 	}
-	snapClient := core.NewSnapshot(volOpt.GetConnection(), sid.FsSnapshotName, volOpt.ClusterID, &volOpt.SubVolume)
+	snapClient := core.NewSnapshot(volOpt.GetConnection(), sid.FsSnapshotName,
+		volOpt.ClusterID, cs.ClusterName, &volOpt.SubVolume)
 	if snapInfo.Protected == core.SnapshotIsProtected {
 		err = snapClient.UnprotectSnapshot(ctx)
 		if err != nil {

internal/cephfs/core/clone.go

@@ -66,7 +66,7 @@ func (s *subVolumeClient) CreateCloneFromSubvolume(
 	parentvolOpt *SubVolume,
 ) error {
 	snapshotID := s.VolID
-	snapClient := NewSnapshot(s.conn, snapshotID, s.clusterID, parentvolOpt)
+	snapClient := NewSnapshot(s.conn, snapshotID, s.clusterID, s.clusterName, parentvolOpt)
 	err := snapClient.CreateSnapshot(ctx)
 	if err != nil {
 		log.ErrorLog(ctx, "failed to create snapshot %s %v", snapshotID, err)
@@ -165,7 +165,7 @@ func (s *subVolumeClient) CleanupSnapshotFromSubvolume(
 	// snapshot name is same as clone name as we need a name which can be
 	// identified during PVC-PVC cloning.
 	snapShotID := s.VolID
-	snapClient := NewSnapshot(s.conn, snapShotID, s.clusterID, parentVol)
+	snapClient := NewSnapshot(s.conn, snapShotID, s.clusterID, s.clusterName, parentVol)
 	snapInfo, err := snapClient.GetSnapshotInfo(ctx)
 	if err != nil {
 		if errors.Is(err, cerrors.ErrSnapNotFound) {
@@ -198,7 +198,7 @@ func (s *subVolumeClient) CreateCloneFromSnapshot(
 	ctx context.Context, snap Snapshot,
 ) error {
 	snapID := snap.SnapshotID
-	snapClient := NewSnapshot(s.conn, snapID, s.clusterID, snap.SubVolume)
+	snapClient := NewSnapshot(s.conn, snapID, s.clusterID, s.clusterName, snap.SubVolume)
 	err := snapClient.CloneSnapshot(ctx, s.SubVolume)
 	if err != nil {
 		return err

internal/cephfs/core/snapshot.go

@@ -63,6 +63,7 @@ type SnapshotClient interface {
 type snapshotClient struct {
 	*Snapshot                           // Embedded snapshot struct.
 	clusterID   string                  // Cluster ID.
+	clusterName string                  // Cluster Name.
 	conn        *util.ClusterConnection // Cluster connection.
 }
 
@@ -73,13 +74,20 @@ type Snapshot struct {
 }
 
 // NewSnapshot creates a new snapshot client.
-func NewSnapshot(conn *util.ClusterConnection, snapshotID, clusterID string, vol *SubVolume) SnapshotClient {
+func NewSnapshot(
+	conn *util.ClusterConnection,
+	snapshotID,
+	clusterID,
+	clusterName string,
+	vol *SubVolume,
+) SnapshotClient {
 	return &snapshotClient{
 		Snapshot: &Snapshot{
 			SnapshotID: snapshotID,
 			SubVolume:  vol,
 		},
 		clusterID:   clusterID,
+		clusterName: clusterName,
 		conn:        conn,
 	}
 }

internal/cephfs/core/snapshot_metadata.go

@@ -99,6 +99,14 @@ func (s *snapshotClient) SetAllSnapshotMetadata(parameters map[string]string) er
 		}
 	}
 
+	if s.clusterName != "" {
+		err := s.setSnapshotMetadata(clusterNameKey, s.clusterName)
+		if err != nil {
+			return fmt.Errorf("failed to set metadata key %q, value %q on subvolume snapshot %s %s in fs %s: %w",
+				clusterNameKey, s.clusterName, s.SnapshotID, s.VolID, s.FsName, err)
+		}
+	}
+
 	return nil
 }
 
@@ -114,5 +122,12 @@ func (s *snapshotClient) UnsetAllSnapshotMetadata(keys []string) error {
 		}
 	}
 
+	err := s.removeSnapshotMetadata(clusterNameKey)
+	// TODO: replace string comparison with errno.
+	if err != nil && !strings.Contains(err.Error(), "No such file or directory") {
+		return fmt.Errorf("failed to unset metadata key %q on subvolume snapshot %s %s in fs %s: %w",
+			clusterNameKey, s.SnapshotID, s.VolID, s.FsName, err)
+	}
+
 	return nil
 }

internal/cephfs/store/fsjournal.go

@@ -377,6 +377,7 @@ func CheckSnapExists(
 	ctx context.Context,
 	volOptions *VolumeOptions,
 	snap *SnapshotOption,
+	clusterName string,
 	cr *util.Credentials,
 ) (*SnapshotIdentifier, *core.SnapshotInfo, error) {
 	// Connect to cephfs' default radosNamespace (csi)
@@ -398,7 +399,7 @@ func CheckSnapExists(
 	snapUUID := snapData.ImageUUID
 	snapID := snapData.ImageAttributes.ImageName
 	sid.FsSnapshotName = snapData.ImageAttributes.ImageName
-	snapClient := core.NewSnapshot(volOptions.conn, snapID, volOptions.ClusterID, &volOptions.SubVolume)
+	snapClient := core.NewSnapshot(volOptions.conn, snapID, volOptions.ClusterID, clusterName, &volOptions.SubVolume)
 	snapInfo, err := snapClient.GetSnapshotInfo(ctx)
 	if err != nil {
 		if errors.Is(err, cerrors.ErrSnapNotFound) {

internal/cephfs/store/volumeoptions.go

@@ -735,7 +735,8 @@ func NewSnapshotOptionsFromID(
 	volOptions.Features = subvolInfo.Features
 	volOptions.Size = subvolInfo.BytesQuota
 	volOptions.RootPath = subvolInfo.Path
-	snap := core.NewSnapshot(volOptions.conn, sid.FsSnapshotName, volOptions.ClusterID, &volOptions.SubVolume)
+	snap := core.NewSnapshot(volOptions.conn, sid.FsSnapshotName,
+		volOptions.ClusterID, clusterName, &volOptions.SubVolume)
 	info, err := snap.GetSnapshotInfo(ctx)
 	if err != nil {
 		return &volOptions, nil, &sid, err