shell: report a failed tier download source restore

A restore that leaves the source unmounted or frozen was only printed, so the
command still returned success. Join the restore error into the result.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

weed/shell/command_volume_tier_download.go

@@ -2,6 +2,7 @@ package shell
 
 import (
 	"context"
+	"errors"
 	"flag"
 	"fmt"
 	"io"
@@ -151,7 +152,7 @@ func doVolumeTierDownload(commandEnv *CommandEnv, writer io.Writer, topoInfo *ma
 // one replica, copies that local volume over every other replica, and only
 // then deletes the remote object, so no replica is ever left referencing a
 // deleted object.
-func downloadAndReplicateFromRemoteTier(grpcDialOption grpc.DialOption, writer io.Writer, readTopology func() (*master_pb.TopologyInfo, error), vid needle.VolumeId, collection string, concurrency int) error {
+func downloadAndReplicateFromRemoteTier(grpcDialOption grpc.DialOption, writer io.Writer, readTopology func() (*master_pb.TopologyInfo, error), vid needle.VolumeId, collection string, concurrency int) (err error) {
 	topoInfo, err := readTopology()
 	if err != nil {
 		return err
@@ -191,7 +192,11 @@ func downloadAndReplicateFromRemoteTier(grpcDialOption grpc.DialOption, writer i
 
 	restore, err := freezeTierDownloadSource(grpcDialOption, vid, source)
 	if restore != nil {
-		defer restore(writer)
+		defer func() {
+			if restoreErr := restore(); restoreErr != nil {
+				err = errors.Join(err, fmt.Errorf("restore volume %d state on %s: %v", vid, source, restoreErr))
+			}
+		}()
 	}
 	if err != nil {
 		return fmt.Errorf("block deletes on volume %d at %s: %v", vid, source, err)
@@ -249,7 +254,7 @@ func downloadAndReplicateFromRemoteTier(grpcDialOption grpc.DialOption, writer i
 // after VolumeCopy read the source index would be lost on the replaced replica.
 // restore brings back the writable mark, or reloads the persisted state. It is
 // also returned when the mark fails, since the server may have applied it.
-func freezeTierDownloadSource(grpcDialOption grpc.DialOption, vid needle.VolumeId, source pb.ServerAddress) (restore func(io.Writer), err error) {
+func freezeTierDownloadSource(grpcDialOption grpc.DialOption, vid needle.VolumeId, source pb.ServerAddress) (restore func() error, err error) {
 	var wasWritable, statusRead bool
 	err = operation.WithVolumeServerClient(false, source, grpcDialOption, func(client volume_server_pb.VolumeServerClient) error {
 		resp, statusErr := client.VolumeStatus(context.Background(), &volume_server_pb.VolumeStatusRequest{VolumeId: uint32(vid)})
@@ -263,17 +268,14 @@ func freezeTierDownloadSource(grpcDialOption grpc.DialOption, vid needle.VolumeI
 	if !statusRead {
 		return nil, err
 	}
-	restore = func(writer io.Writer) {
-		restoreErr := operation.WithVolumeServerClient(false, source, grpcDialOption, func(client volume_server_pb.VolumeServerClient) error {
+	restore = func() error {
+		return operation.WithVolumeServerClient(false, source, grpcDialOption, func(client volume_server_pb.VolumeServerClient) error {
 			if wasWritable {
 				_, markErr := client.VolumeMarkWritable(context.Background(), &volume_server_pb.VolumeMarkWritableRequest{VolumeId: uint32(vid)})
 				return markErr
 			}
 			return remountVolume(client, vid)
 		})
-		if restoreErr != nil {
-			fmt.Fprintf(writer, "restore volume %d state on %s: %v\n", vid, source, restoreErr)
-		}
 	}
 	return
 }

weed/shell/command_volume_tier_download_test.go

@@ -45,7 +45,8 @@ type tierDownloadCluster struct {
 	// staleTwin lists a remote-backed twin of the volume on another disk
 	staleTwin map[pb.ServerAddress]bool
 	// markFails applies the readonly mark, then fails as a lost master notification does
-	markFails map[pb.ServerAddress]bool
+	markFails  map[pb.ServerAddress]bool
+	mountFails map[pb.ServerAddress]bool
 }
 
 type tierDownloadTestServer struct {
@@ -89,6 +90,9 @@ func (s *tierDownloadTestServer) VolumeMount(context.Context, *volume_server_pb.
 	c := s.cluster
 	c.mu.Lock()
 	defer c.mu.Unlock()
+	if c.mountFails[s.addr] {
+		return nil, fmt.Errorf("mount volume: disk error")
+	}
 	c.frozen[s.addr] = false
 	c.remounts[s.addr]++
 	return &volume_server_pb.VolumeMountResponse{}, nil
@@ -171,6 +175,7 @@ func newTierDownloadCluster(t *testing.T, states ...string) *tierDownloadCluster
 		remounts:     make(map[pb.ServerAddress]int),
 		staleTwin:    make(map[pb.ServerAddress]bool),
 		markFails:    make(map[pb.ServerAddress]bool),
+		mountFails:   make(map[pb.ServerAddress]bool),
 	}
 	for _, state := range states {
 		lis, err := net.Listen("tcp", "127.0.0.1:0")
@@ -412,3 +417,14 @@ func TestTierDownloadRestoresSourceWhenMarkFailsAfterApplying(t *testing.T) {
 		}
 	}
 }
+
+func TestTierDownloadReportsSourceRestoreFailure(t *testing.T) {
+	c := newTierDownloadCluster(t, tierReplicaLocal, tierReplicaRemote, tierReplicaRemote)
+	source := c.servers[0]
+	c.mountFails[source] = true
+	err := c.run(t)
+	if err == nil || !strings.Contains(err.Error(), "restore volume 7 state") {
+		t.Fatalf("tier download should report the failed source restore, got %v", err)
+	}
+	c.assertAllLocal(t)
+}