Guard collection deletion against duplicate volume IDs

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

weed/server/master_grpc_server_collection.go

@@ -2,12 +2,14 @@ package weed_server
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/seaweedfs/raft"
 
 	"github.com/seaweedfs/seaweedfs/weed/operation"
 	"github.com/seaweedfs/seaweedfs/weed/pb/master_pb"
 	"github.com/seaweedfs/seaweedfs/weed/pb/volume_server_pb"
+	"github.com/seaweedfs/seaweedfs/weed/topology"
 )
 
 func (ms *MasterServer) CollectionList(ctx context.Context, req *master_pb.CollectionListRequest) (*master_pb.CollectionListResponse, error) {
@@ -35,6 +37,10 @@ func (ms *MasterServer) CollectionDelete(ctx context.Context, req *master_pb.Col
 
 	resp := &master_pb.CollectionDeleteResponse{}
 
+	if err := ms.ensureCollectionDeleteSafe(req.Name); err != nil {
+		return nil, err
+	}
+
 	err := ms.doDeleteNormalCollection(req.Name)
 
 	if err != nil {
@@ -50,6 +56,19 @@ func (ms *MasterServer) CollectionDelete(ctx context.Context, req *master_pb.Col
 	return resp, nil
 }
 
+func (ms *MasterServer) ensureCollectionDeleteSafe(collectionName string) error {
+	duplicates := ms.Topo.FindDuplicateVolumeIds(collectionName)
+	if len(duplicates) == 0 {
+		return nil
+	}
+
+	return fmt.Errorf(
+		"refusing to delete collection %q: duplicate volume IDs exist across collections (%s). Run `volume.check.duplicates` to inspect and resolve them first",
+		collectionName,
+		topology.FormatDuplicateVolumeIds(duplicates),
+	)
+}
+
 func (ms *MasterServer) doDeleteNormalCollection(collectionName string) error {
 
 	collection, ok := ms.Topo.FindCollection(collectionName)

weed/server/master_grpc_server_test.go

@@ -4,6 +4,11 @@ import (
 	"testing"
 
 	"github.com/seaweedfs/seaweedfs/weed/cluster"
+	"github.com/seaweedfs/seaweedfs/weed/sequence"
+	"github.com/seaweedfs/seaweedfs/weed/storage"
+	"github.com/seaweedfs/seaweedfs/weed/storage/needle"
+	"github.com/seaweedfs/seaweedfs/weed/storage/super_block"
+	"github.com/seaweedfs/seaweedfs/weed/topology"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -35,3 +40,41 @@ func TestInitialLockRingUpdateSkipsNonFilers(t *testing.T) {
 
 	assert.Nil(t, ms.initialLockRingUpdate(cluster.BrokerType, "group-a"))
 }
+
+func TestEnsureCollectionDeleteSafeRejectsDuplicateVolumeIds(t *testing.T) {
+	topo := topology.NewTopology("weedfs", sequence.NewMemorySequencer(), 32*1024, 5, false)
+	dc := topo.GetOrCreateDataCenter("dc1")
+	rack := dc.GetOrCreateRack("rack1")
+	maxVolumeCounts := map[string]uint32{"": 25}
+
+	dn1 := rack.GetOrCreateDataNode("127.0.0.1", 34534, 0, "127.0.0.1", "", maxVolumeCounts)
+	dn2 := rack.GetOrCreateDataNode("127.0.0.2", 34535, 0, "127.0.0.2", "", maxVolumeCounts)
+
+	replicaPlacement := &super_block.ReplicaPlacement{}
+	collectionA := storage.VolumeInfo{
+		Id:               needle.VolumeId(100),
+		Collection:       "collection-a",
+		Version:          needle.GetCurrentVersion(),
+		ReplicaPlacement: replicaPlacement,
+		Ttl:              needle.EMPTY_TTL,
+	}
+	collectionB := storage.VolumeInfo{
+		Id:               needle.VolumeId(100),
+		Collection:       "collection-b",
+		Version:          needle.GetCurrentVersion(),
+		ReplicaPlacement: replicaPlacement,
+		Ttl:              needle.EMPTY_TTL,
+	}
+
+	dn1.UpdateVolumes([]storage.VolumeInfo{collectionA})
+	dn2.UpdateVolumes([]storage.VolumeInfo{collectionB})
+	topo.RegisterVolumeLayout(collectionA, dn1)
+	topo.RegisterVolumeLayout(collectionB, dn2)
+
+	ms := &MasterServer{Topo: topo}
+
+	err := ms.ensureCollectionDeleteSafe("collection-a")
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "refusing to delete collection")
+	assert.Contains(t, err.Error(), "100:[collection-a, collection-b]")
+}

weed/server/master_server_handlers_admin.go

@@ -30,6 +30,10 @@ func (ms *MasterServer) collectionDeleteHandler(w http.ResponseWriter, r *http.R
 		writeJsonError(w, r, http.StatusBadRequest, fmt.Errorf("collection %s does not exist", collectionName))
 		return
 	}
+	if err := ms.ensureCollectionDeleteSafe(collectionName); err != nil {
+		writeJsonError(w, r, http.StatusConflict, err)
+		return
+	}
 	for _, server := range collection.ListVolumeServers() {
 		err := operation.WithVolumeServerClient(false, server.ServerAddress(), ms.grpcDialOption, func(client volume_server_pb.VolumeServerClient) error {
 			_, deleteErr := client.DeleteCollection(context.Background(), &volume_server_pb.DeleteCollectionRequest{