diff --git a/other/java/client/src/main/proto/filer.proto b/other/java/client/src/main/proto/filer.proto
index 2f6a4bd99..80d5f9952 100644
--- a/other/java/client/src/main/proto/filer.proto
+++ b/other/java/client/src/main/proto/filer.proto
@@ -203,9 +203,21 @@ message CreateEntryRequest {
     bool skip_check_parent_directory = 6;
 }
 
+// Structured error codes for filer entry operations.
+// Values are stable — do not reorder or reuse numbers.
+enum FilerError {
+    OK                    = 0;
+    ENTRY_NAME_TOO_LONG   = 1; // name exceeds max_file_name_length
+    PARENT_IS_FILE        = 2; // parent path component is a file, not a directory
+    EXISTING_IS_DIRECTORY = 3; // cannot overwrite directory with file
+    EXISTING_IS_FILE      = 4; // cannot overwrite file with directory
+    ENTRY_ALREADY_EXISTS  = 5; // O_EXCL and entry already exists
+}
+
 message CreateEntryResponse {
-    string error = 1;
+    string error = 1;                          // kept for human readability + backward compat
     SubscribeMetadataResponse metadata_event = 2;
+    FilerError error_code = 3;                 // machine-readable error code
 }
 
 message UpdateEntryRequest {
diff --git a/weed/filer/filer.go b/weed/filer/filer.go
index 25fce8bf3..87ecb28c5 100644
--- a/weed/filer/filer.go
+++ b/weed/filer/filer.go
@@ -23,7 +23,6 @@ import (
 	"github.com/seaweedfs/seaweedfs/weed/glog"
 	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
 	"github.com/seaweedfs/seaweedfs/weed/util"
-	"github.com/seaweedfs/seaweedfs/weed/util/constants"
 	"github.com/seaweedfs/seaweedfs/weed/util/log_buffer"
 	"github.com/seaweedfs/seaweedfs/weed/wdclient"
 	"golang.org/x/sync/singleflight"
@@ -204,7 +203,7 @@ func (f *Filer) CreateEntry(ctx context.Context, entry *Entry, o_excl bool, isFr
 	}
 
 	if entry.FullPath.IsLongerFileName(maxFilenameLength) {
-		return fmt.Errorf(constants.ErrMsgEntryNameTooLong)
+		return filer_pb.ErrEntryNameTooLong
 	}
 
 	if entry.IsDirectory() {
@@ -238,7 +237,7 @@ func (f *Filer) CreateEntry(ctx context.Context, entry *Entry, o_excl bool, isFr
 	} else {
 		if o_excl {
 			glog.V(3).InfofCtx(ctx, "EEXIST: entry %s already exists", entry.FullPath)
-			return fmt.Errorf("EEXIST: entry %s already exists", entry.FullPath)
+			return fmt.Errorf("%s: %w", entry.FullPath, filer_pb.ErrEntryAlreadyExists)
 		}
 		glog.V(4).InfofCtx(ctx, "UpdateEntry %s: old entry: %v", entry.FullPath, oldEntry.Name())
 		if err := f.UpdateEntry(ctx, oldEntry, entry); err != nil {
@@ -324,8 +323,16 @@ func (f *Filer) ensureParentDirectoryEntry(ctx context.Context, entry *Entry, di
 		}
 
 	} else if !dirEntry.IsDirectory() {
-		glog.ErrorfCtx(ctx, "CreateEntry %s: %s should be a directory", entry.FullPath, dirPath)
-		return fmt.Errorf("%s%s", dirPath, constants.ErrMsgIsAFile)
+		// S3 allows both "foo/bar" (object) and "foo/bar/xyzzy" (another
+		// object) to coexist because S3 has a flat key space. Promote the
+		// existing file to a directory, preserving its content/chunks so
+		// the original object data remains accessible.
+		glog.V(2).InfofCtx(ctx, "promoting %s from file to directory for %s", dirPath, entry.FullPath)
+		dirEntry.Attr.Mode |= os.ModeDir | 0111
+		if updateErr := f.Store.UpdateEntry(ctx, dirEntry); updateErr != nil {
+			return fmt.Errorf("promote %s to directory: %v", dirPath, updateErr)
+		}
+		f.NotifyUpdateEvent(ctx, nil, dirEntry, false, isFromOtherCluster, nil)
 	}
 
 	return nil
@@ -336,11 +343,11 @@ func (f *Filer) UpdateEntry(ctx context.Context, oldEntry, entry *Entry) (err er
 		entry.Attr.Crtime = oldEntry.Attr.Crtime
 		if oldEntry.IsDirectory() && !entry.IsDirectory() {
 			glog.ErrorfCtx(ctx, "existing %s is a directory", oldEntry.FullPath)
-			return fmt.Errorf("%s%s%s", constants.ErrMsgExistingPrefix, oldEntry.FullPath, constants.ErrMsgIsADirectory)
+			return fmt.Errorf("%s: %w", oldEntry.FullPath, filer_pb.ErrExistingIsDirectory)
 		}
 		if !oldEntry.IsDirectory() && entry.IsDirectory() {
 			glog.ErrorfCtx(ctx, "existing %s is a file", oldEntry.FullPath)
-			return fmt.Errorf("%s%s%s", constants.ErrMsgExistingPrefix, oldEntry.FullPath, constants.ErrMsgIsAFile)
+			return fmt.Errorf("%s: %w", oldEntry.FullPath, filer_pb.ErrExistingIsFile)
 		}
 	}
 	return f.Store.UpdateEntry(ctx, entry)
diff --git a/weed/pb/filer.proto b/weed/pb/filer.proto
index 2f6a4bd99..80d5f9952 100644
--- a/weed/pb/filer.proto
+++ b/weed/pb/filer.proto
@@ -203,9 +203,21 @@ message CreateEntryRequest {
     bool skip_check_parent_directory = 6;
 }
 
+// Structured error codes for filer entry operations.
+// Values are stable — do not reorder or reuse numbers.
+enum FilerError {
+    OK                    = 0;
+    ENTRY_NAME_TOO_LONG   = 1; // name exceeds max_file_name_length
+    PARENT_IS_FILE        = 2; // parent path component is a file, not a directory
+    EXISTING_IS_DIRECTORY = 3; // cannot overwrite directory with file
+    EXISTING_IS_FILE      = 4; // cannot overwrite file with directory
+    ENTRY_ALREADY_EXISTS  = 5; // O_EXCL and entry already exists
+}
+
 message CreateEntryResponse {
-    string error = 1;
+    string error = 1;                          // kept for human readability + backward compat
     SubscribeMetadataResponse metadata_event = 2;
+    FilerError error_code = 3;                 // machine-readable error code
 }
 
 message UpdateEntryRequest {
diff --git a/weed/pb/filer_pb/filer.pb.go b/weed/pb/filer_pb/filer.pb.go
index b6d39a3a7..23df9cae1 100644
--- a/weed/pb/filer_pb/filer.pb.go
+++ b/weed/pb/filer_pb/filer.pb.go
@@ -73,6 +73,66 @@ func (SSEType) EnumDescriptor() ([]byte, []int) {
 	return file_filer_proto_rawDescGZIP(), []int{0}
 }
 
+// Structured error codes for filer entry operations.
+// Values are stable — do not reorder or reuse numbers.
+type FilerError int32
+
+const (
+	FilerError_OK                    FilerError = 0
+	FilerError_ENTRY_NAME_TOO_LONG   FilerError = 1 // name exceeds max_file_name_length
+	FilerError_PARENT_IS_FILE        FilerError = 2 // parent path component is a file, not a directory
+	FilerError_EXISTING_IS_DIRECTORY FilerError = 3 // cannot overwrite directory with file
+	FilerError_EXISTING_IS_FILE      FilerError = 4 // cannot overwrite file with directory
+	FilerError_ENTRY_ALREADY_EXISTS  FilerError = 5 // O_EXCL and entry already exists
+)
+
+// Enum value maps for FilerError.
+var (
+	FilerError_name = map[int32]string{
+		0: "OK",
+		1: "ENTRY_NAME_TOO_LONG",
+		2: "PARENT_IS_FILE",
+		3: "EXISTING_IS_DIRECTORY",
+		4: "EXISTING_IS_FILE",
+		5: "ENTRY_ALREADY_EXISTS",
+	}
+	FilerError_value = map[string]int32{
+		"OK":                    0,
+		"ENTRY_NAME_TOO_LONG":   1,
+		"PARENT_IS_FILE":        2,
+		"EXISTING_IS_DIRECTORY": 3,
+		"EXISTING_IS_FILE":      4,
+		"ENTRY_ALREADY_EXISTS":  5,
+	}
+)
+
+func (x FilerError) Enum() *FilerError {
+	p := new(FilerError)
+	*p = x
+	return p
+}
+
+func (x FilerError) String() string {
+	return protoimpl.X.EnumStringOf(x.Descriptor(), protoreflect.EnumNumber(x))
+}
+
+func (FilerError) Descriptor() protoreflect.EnumDescriptor {
+	return file_filer_proto_enumTypes[1].Descriptor()
+}
+
+func (FilerError) Type() protoreflect.EnumType {
+	return &file_filer_proto_enumTypes[1]
+}
+
+func (x FilerError) Number() protoreflect.EnumNumber {
+	return protoreflect.EnumNumber(x)
+}
+
+// Deprecated: Use FilerError.Descriptor instead.
+func (FilerError) EnumDescriptor() ([]byte, []int) {
+	return file_filer_proto_rawDescGZIP(), []int{1}
+}
+
 type LookupDirectoryEntryRequest struct {
 	state         protoimpl.MessageState `protogen:"open.v1"`
 	Directory     string                 `protobuf:"bytes,1,opt,name=directory,proto3" json:"directory,omitempty"`
@@ -1119,8 +1179,9 @@ func (x *CreateEntryRequest) GetSkipCheckParentDirectory() bool {
 
 type CreateEntryResponse struct {
 	state         protoimpl.MessageState     `protogen:"open.v1"`
-	Error         string                     `protobuf:"bytes,1,opt,name=error,proto3" json:"error,omitempty"`
+	Error         string                     `protobuf:"bytes,1,opt,name=error,proto3" json:"error,omitempty"` // kept for human readability + backward compat
 	MetadataEvent *SubscribeMetadataResponse `protobuf:"bytes,2,opt,name=metadata_event,json=metadataEvent,proto3" json:"metadata_event,omitempty"`
+	ErrorCode     FilerError                 `protobuf:"varint,3,opt,name=error_code,json=errorCode,proto3,enum=filer_pb.FilerError" json:"error_code,omitempty"` // machine-readable error code
 	unknownFields protoimpl.UnknownFields
 	sizeCache     protoimpl.SizeCache
 }
@@ -1169,6 +1230,13 @@ func (x *CreateEntryResponse) GetMetadataEvent() *SubscribeMetadataResponse {
 	return nil
 }
 
+func (x *CreateEntryResponse) GetErrorCode() FilerError {
+	if x != nil {
+		return x.ErrorCode
+	}
+	return FilerError_OK
+}
+
 type UpdateEntryRequest struct {
 	state              protoimpl.MessageState `protogen:"open.v1"`
 	Directory          string                 `protobuf:"bytes,1,opt,name=directory,proto3" json:"directory,omitempty"`
@@ -4571,10 +4639,12 @@ const file_filer_proto_rawDesc = "" +
 	"\n" +
 	"signatures\x18\x05 \x03(\x05R\n" +
 	"signatures\x12=\n" +
-	"\x1bskip_check_parent_directory\x18\x06 \x01(\bR\x18skipCheckParentDirectory\"w\n" +
+	"\x1bskip_check_parent_directory\x18\x06 \x01(\bR\x18skipCheckParentDirectory\"\xac\x01\n" +
 	"\x13CreateEntryResponse\x12\x14\n" +
 	"\x05error\x18\x01 \x01(\tR\x05error\x12J\n" +
-	"\x0emetadata_event\x18\x02 \x01(\v2#.filer_pb.SubscribeMetadataResponseR\rmetadataEvent\"\xd2\x02\n" +
+	"\x0emetadata_event\x18\x02 \x01(\v2#.filer_pb.SubscribeMetadataResponseR\rmetadataEvent\x123\n" +
+	"\n" +
+	"error_code\x18\x03 \x01(\x0e2\x14.filer_pb.FilerErrorR\terrorCode\"\xd2\x02\n" +
 	"\x12UpdateEntryRequest\x12\x1c\n" +
 	"\tdirectory\x18\x01 \x01(\tR\tdirectory\x12%\n" +
 	"\x05entry\x18\x02 \x01(\v2\x0f.filer_pb.EntryR\x05entry\x121\n" +
@@ -4851,7 +4921,15 @@ const file_filer_proto_rawDesc = "" +
 	"\x05SSE_C\x10\x01\x12\v\n" +
 	"\aSSE_KMS\x10\x02\x12\n" +
 	"\n" +
-	"\x06SSE_S3\x10\x032\xf7\x10\n" +
+	"\x06SSE_S3\x10\x03*\x8c\x01\n" +
+	"\n" +
+	"FilerError\x12\x06\n" +
+	"\x02OK\x10\x00\x12\x17\n" +
+	"\x13ENTRY_NAME_TOO_LONG\x10\x01\x12\x12\n" +
+	"\x0ePARENT_IS_FILE\x10\x02\x12\x19\n" +
+	"\x15EXISTING_IS_DIRECTORY\x10\x03\x12\x14\n" +
+	"\x10EXISTING_IS_FILE\x10\x04\x12\x18\n" +
+	"\x14ENTRY_ALREADY_EXISTS\x10\x052\xf7\x10\n" +
 	"\fSeaweedFiler\x12g\n" +
 	"\x14LookupDirectoryEntry\x12%.filer_pb.LookupDirectoryEntryRequest\x1a&.filer_pb.LookupDirectoryEntryResponse\"\x00\x12N\n" +
 	"\vListEntries\x12\x1c.filer_pb.ListEntriesRequest\x1a\x1d.filer_pb.ListEntriesResponse\"\x000\x01\x12L\n" +
@@ -4894,171 +4972,173 @@ func file_filer_proto_rawDescGZIP() []byte {
 	return file_filer_proto_rawDescData
 }
 
-var file_filer_proto_enumTypes = make([]protoimpl.EnumInfo, 1)
+var file_filer_proto_enumTypes = make([]protoimpl.EnumInfo, 2)
 var file_filer_proto_msgTypes = make([]protoimpl.MessageInfo, 71)
 var file_filer_proto_goTypes = []any{
 	(SSEType)(0),                                    // 0: filer_pb.SSEType
-	(*LookupDirectoryEntryRequest)(nil),             // 1: filer_pb.LookupDirectoryEntryRequest
-	(*LookupDirectoryEntryResponse)(nil),            // 2: filer_pb.LookupDirectoryEntryResponse
-	(*ListEntriesRequest)(nil),                      // 3: filer_pb.ListEntriesRequest
-	(*ListEntriesResponse)(nil),                     // 4: filer_pb.ListEntriesResponse
-	(*RemoteEntry)(nil),                             // 5: filer_pb.RemoteEntry
-	(*Entry)(nil),                                   // 6: filer_pb.Entry
-	(*FullEntry)(nil),                               // 7: filer_pb.FullEntry
-	(*EventNotification)(nil),                       // 8: filer_pb.EventNotification
-	(*FileChunk)(nil),                               // 9: filer_pb.FileChunk
-	(*FileChunkManifest)(nil),                       // 10: filer_pb.FileChunkManifest
-	(*FileId)(nil),                                  // 11: filer_pb.FileId
-	(*FuseAttributes)(nil),                          // 12: filer_pb.FuseAttributes
-	(*CreateEntryRequest)(nil),                      // 13: filer_pb.CreateEntryRequest
-	(*CreateEntryResponse)(nil),                     // 14: filer_pb.CreateEntryResponse
-	(*UpdateEntryRequest)(nil),                      // 15: filer_pb.UpdateEntryRequest
-	(*UpdateEntryResponse)(nil),                     // 16: filer_pb.UpdateEntryResponse
-	(*AppendToEntryRequest)(nil),                    // 17: filer_pb.AppendToEntryRequest
-	(*AppendToEntryResponse)(nil),                   // 18: filer_pb.AppendToEntryResponse
-	(*DeleteEntryRequest)(nil),                      // 19: filer_pb.DeleteEntryRequest
-	(*DeleteEntryResponse)(nil),                     // 20: filer_pb.DeleteEntryResponse
-	(*AtomicRenameEntryRequest)(nil),                // 21: filer_pb.AtomicRenameEntryRequest
-	(*AtomicRenameEntryResponse)(nil),               // 22: filer_pb.AtomicRenameEntryResponse
-	(*StreamRenameEntryRequest)(nil),                // 23: filer_pb.StreamRenameEntryRequest
-	(*StreamRenameEntryResponse)(nil),               // 24: filer_pb.StreamRenameEntryResponse
-	(*AssignVolumeRequest)(nil),                     // 25: filer_pb.AssignVolumeRequest
-	(*AssignVolumeResponse)(nil),                    // 26: filer_pb.AssignVolumeResponse
-	(*LookupVolumeRequest)(nil),                     // 27: filer_pb.LookupVolumeRequest
-	(*Locations)(nil),                               // 28: filer_pb.Locations
-	(*Location)(nil),                                // 29: filer_pb.Location
-	(*LookupVolumeResponse)(nil),                    // 30: filer_pb.LookupVolumeResponse
-	(*Collection)(nil),                              // 31: filer_pb.Collection
-	(*CollectionListRequest)(nil),                   // 32: filer_pb.CollectionListRequest
-	(*CollectionListResponse)(nil),                  // 33: filer_pb.CollectionListResponse
-	(*DeleteCollectionRequest)(nil),                 // 34: filer_pb.DeleteCollectionRequest
-	(*DeleteCollectionResponse)(nil),                // 35: filer_pb.DeleteCollectionResponse
-	(*StatisticsRequest)(nil),                       // 36: filer_pb.StatisticsRequest
-	(*StatisticsResponse)(nil),                      // 37: filer_pb.StatisticsResponse
-	(*PingRequest)(nil),                             // 38: filer_pb.PingRequest
-	(*PingResponse)(nil),                            // 39: filer_pb.PingResponse
-	(*GetFilerConfigurationRequest)(nil),            // 40: filer_pb.GetFilerConfigurationRequest
-	(*GetFilerConfigurationResponse)(nil),           // 41: filer_pb.GetFilerConfigurationResponse
-	(*SubscribeMetadataRequest)(nil),                // 42: filer_pb.SubscribeMetadataRequest
-	(*SubscribeMetadataResponse)(nil),               // 43: filer_pb.SubscribeMetadataResponse
-	(*TraverseBfsMetadataRequest)(nil),              // 44: filer_pb.TraverseBfsMetadataRequest
-	(*TraverseBfsMetadataResponse)(nil),             // 45: filer_pb.TraverseBfsMetadataResponse
-	(*LogEntry)(nil),                                // 46: filer_pb.LogEntry
-	(*KeepConnectedRequest)(nil),                    // 47: filer_pb.KeepConnectedRequest
-	(*KeepConnectedResponse)(nil),                   // 48: filer_pb.KeepConnectedResponse
-	(*LocateBrokerRequest)(nil),                     // 49: filer_pb.LocateBrokerRequest
-	(*LocateBrokerResponse)(nil),                    // 50: filer_pb.LocateBrokerResponse
-	(*KvGetRequest)(nil),                            // 51: filer_pb.KvGetRequest
-	(*KvGetResponse)(nil),                           // 52: filer_pb.KvGetResponse
-	(*KvPutRequest)(nil),                            // 53: filer_pb.KvPutRequest
-	(*KvPutResponse)(nil),                           // 54: filer_pb.KvPutResponse
-	(*FilerConf)(nil),                               // 55: filer_pb.FilerConf
-	(*CacheRemoteObjectToLocalClusterRequest)(nil),  // 56: filer_pb.CacheRemoteObjectToLocalClusterRequest
-	(*CacheRemoteObjectToLocalClusterResponse)(nil), // 57: filer_pb.CacheRemoteObjectToLocalClusterResponse
-	(*LockRequest)(nil),                             // 58: filer_pb.LockRequest
-	(*LockResponse)(nil),                            // 59: filer_pb.LockResponse
-	(*UnlockRequest)(nil),                           // 60: filer_pb.UnlockRequest
-	(*UnlockResponse)(nil),                          // 61: filer_pb.UnlockResponse
-	(*FindLockOwnerRequest)(nil),                    // 62: filer_pb.FindLockOwnerRequest
-	(*FindLockOwnerResponse)(nil),                   // 63: filer_pb.FindLockOwnerResponse
-	(*Lock)(nil),                                    // 64: filer_pb.Lock
-	(*TransferLocksRequest)(nil),                    // 65: filer_pb.TransferLocksRequest
-	(*TransferLocksResponse)(nil),                   // 66: filer_pb.TransferLocksResponse
-	nil,                                             // 67: filer_pb.Entry.ExtendedEntry
-	nil,                                             // 68: filer_pb.UpdateEntryRequest.ExpectedExtendedEntry
-	nil,                                             // 69: filer_pb.LookupVolumeResponse.LocationsMapEntry
-	(*LocateBrokerResponse_Resource)(nil),           // 70: filer_pb.LocateBrokerResponse.Resource
-	(*FilerConf_PathConf)(nil),                      // 71: filer_pb.FilerConf.PathConf
+	(FilerError)(0),                                 // 1: filer_pb.FilerError
+	(*LookupDirectoryEntryRequest)(nil),             // 2: filer_pb.LookupDirectoryEntryRequest
+	(*LookupDirectoryEntryResponse)(nil),            // 3: filer_pb.LookupDirectoryEntryResponse
+	(*ListEntriesRequest)(nil),                      // 4: filer_pb.ListEntriesRequest
+	(*ListEntriesResponse)(nil),                     // 5: filer_pb.ListEntriesResponse
+	(*RemoteEntry)(nil),                             // 6: filer_pb.RemoteEntry
+	(*Entry)(nil),                                   // 7: filer_pb.Entry
+	(*FullEntry)(nil),                               // 8: filer_pb.FullEntry
+	(*EventNotification)(nil),                       // 9: filer_pb.EventNotification
+	(*FileChunk)(nil),                               // 10: filer_pb.FileChunk
+	(*FileChunkManifest)(nil),                       // 11: filer_pb.FileChunkManifest
+	(*FileId)(nil),                                  // 12: filer_pb.FileId
+	(*FuseAttributes)(nil),                          // 13: filer_pb.FuseAttributes
+	(*CreateEntryRequest)(nil),                      // 14: filer_pb.CreateEntryRequest
+	(*CreateEntryResponse)(nil),                     // 15: filer_pb.CreateEntryResponse
+	(*UpdateEntryRequest)(nil),                      // 16: filer_pb.UpdateEntryRequest
+	(*UpdateEntryResponse)(nil),                     // 17: filer_pb.UpdateEntryResponse
+	(*AppendToEntryRequest)(nil),                    // 18: filer_pb.AppendToEntryRequest
+	(*AppendToEntryResponse)(nil),                   // 19: filer_pb.AppendToEntryResponse
+	(*DeleteEntryRequest)(nil),                      // 20: filer_pb.DeleteEntryRequest
+	(*DeleteEntryResponse)(nil),                     // 21: filer_pb.DeleteEntryResponse
+	(*AtomicRenameEntryRequest)(nil),                // 22: filer_pb.AtomicRenameEntryRequest
+	(*AtomicRenameEntryResponse)(nil),               // 23: filer_pb.AtomicRenameEntryResponse
+	(*StreamRenameEntryRequest)(nil),                // 24: filer_pb.StreamRenameEntryRequest
+	(*StreamRenameEntryResponse)(nil),               // 25: filer_pb.StreamRenameEntryResponse
+	(*AssignVolumeRequest)(nil),                     // 26: filer_pb.AssignVolumeRequest
+	(*AssignVolumeResponse)(nil),                    // 27: filer_pb.AssignVolumeResponse
+	(*LookupVolumeRequest)(nil),                     // 28: filer_pb.LookupVolumeRequest
+	(*Locations)(nil),                               // 29: filer_pb.Locations
+	(*Location)(nil),                                // 30: filer_pb.Location
+	(*LookupVolumeResponse)(nil),                    // 31: filer_pb.LookupVolumeResponse
+	(*Collection)(nil),                              // 32: filer_pb.Collection
+	(*CollectionListRequest)(nil),                   // 33: filer_pb.CollectionListRequest
+	(*CollectionListResponse)(nil),                  // 34: filer_pb.CollectionListResponse
+	(*DeleteCollectionRequest)(nil),                 // 35: filer_pb.DeleteCollectionRequest
+	(*DeleteCollectionResponse)(nil),                // 36: filer_pb.DeleteCollectionResponse
+	(*StatisticsRequest)(nil),                       // 37: filer_pb.StatisticsRequest
+	(*StatisticsResponse)(nil),                      // 38: filer_pb.StatisticsResponse
+	(*PingRequest)(nil),                             // 39: filer_pb.PingRequest
+	(*PingResponse)(nil),                            // 40: filer_pb.PingResponse
+	(*GetFilerConfigurationRequest)(nil),            // 41: filer_pb.GetFilerConfigurationRequest
+	(*GetFilerConfigurationResponse)(nil),           // 42: filer_pb.GetFilerConfigurationResponse
+	(*SubscribeMetadataRequest)(nil),                // 43: filer_pb.SubscribeMetadataRequest
+	(*SubscribeMetadataResponse)(nil),               // 44: filer_pb.SubscribeMetadataResponse
+	(*TraverseBfsMetadataRequest)(nil),              // 45: filer_pb.TraverseBfsMetadataRequest
+	(*TraverseBfsMetadataResponse)(nil),             // 46: filer_pb.TraverseBfsMetadataResponse
+	(*LogEntry)(nil),                                // 47: filer_pb.LogEntry
+	(*KeepConnectedRequest)(nil),                    // 48: filer_pb.KeepConnectedRequest
+	(*KeepConnectedResponse)(nil),                   // 49: filer_pb.KeepConnectedResponse
+	(*LocateBrokerRequest)(nil),                     // 50: filer_pb.LocateBrokerRequest
+	(*LocateBrokerResponse)(nil),                    // 51: filer_pb.LocateBrokerResponse
+	(*KvGetRequest)(nil),                            // 52: filer_pb.KvGetRequest
+	(*KvGetResponse)(nil),                           // 53: filer_pb.KvGetResponse
+	(*KvPutRequest)(nil),                            // 54: filer_pb.KvPutRequest
+	(*KvPutResponse)(nil),                           // 55: filer_pb.KvPutResponse
+	(*FilerConf)(nil),                               // 56: filer_pb.FilerConf
+	(*CacheRemoteObjectToLocalClusterRequest)(nil),  // 57: filer_pb.CacheRemoteObjectToLocalClusterRequest
+	(*CacheRemoteObjectToLocalClusterResponse)(nil), // 58: filer_pb.CacheRemoteObjectToLocalClusterResponse
+	(*LockRequest)(nil),                             // 59: filer_pb.LockRequest
+	(*LockResponse)(nil),                            // 60: filer_pb.LockResponse
+	(*UnlockRequest)(nil),                           // 61: filer_pb.UnlockRequest
+	(*UnlockResponse)(nil),                          // 62: filer_pb.UnlockResponse
+	(*FindLockOwnerRequest)(nil),                    // 63: filer_pb.FindLockOwnerRequest
+	(*FindLockOwnerResponse)(nil),                   // 64: filer_pb.FindLockOwnerResponse
+	(*Lock)(nil),                                    // 65: filer_pb.Lock
+	(*TransferLocksRequest)(nil),                    // 66: filer_pb.TransferLocksRequest
+	(*TransferLocksResponse)(nil),                   // 67: filer_pb.TransferLocksResponse
+	nil,                                             // 68: filer_pb.Entry.ExtendedEntry
+	nil,                                             // 69: filer_pb.UpdateEntryRequest.ExpectedExtendedEntry
+	nil,                                             // 70: filer_pb.LookupVolumeResponse.LocationsMapEntry
+	(*LocateBrokerResponse_Resource)(nil),           // 71: filer_pb.LocateBrokerResponse.Resource
+	(*FilerConf_PathConf)(nil),                      // 72: filer_pb.FilerConf.PathConf
 }
 var file_filer_proto_depIdxs = []int32{
-	6,  // 0: filer_pb.LookupDirectoryEntryResponse.entry:type_name -> filer_pb.Entry
-	6,  // 1: filer_pb.ListEntriesResponse.entry:type_name -> filer_pb.Entry
-	9,  // 2: filer_pb.Entry.chunks:type_name -> filer_pb.FileChunk
-	12, // 3: filer_pb.Entry.attributes:type_name -> filer_pb.FuseAttributes
-	67, // 4: filer_pb.Entry.extended:type_name -> filer_pb.Entry.ExtendedEntry
-	5,  // 5: filer_pb.Entry.remote_entry:type_name -> filer_pb.RemoteEntry
-	6,  // 6: filer_pb.FullEntry.entry:type_name -> filer_pb.Entry
-	6,  // 7: filer_pb.EventNotification.old_entry:type_name -> filer_pb.Entry
-	6,  // 8: filer_pb.EventNotification.new_entry:type_name -> filer_pb.Entry
-	11, // 9: filer_pb.FileChunk.fid:type_name -> filer_pb.FileId
-	11, // 10: filer_pb.FileChunk.source_fid:type_name -> filer_pb.FileId
+	7,  // 0: filer_pb.LookupDirectoryEntryResponse.entry:type_name -> filer_pb.Entry
+	7,  // 1: filer_pb.ListEntriesResponse.entry:type_name -> filer_pb.Entry
+	10, // 2: filer_pb.Entry.chunks:type_name -> filer_pb.FileChunk
+	13, // 3: filer_pb.Entry.attributes:type_name -> filer_pb.FuseAttributes
+	68, // 4: filer_pb.Entry.extended:type_name -> filer_pb.Entry.ExtendedEntry
+	6,  // 5: filer_pb.Entry.remote_entry:type_name -> filer_pb.RemoteEntry
+	7,  // 6: filer_pb.FullEntry.entry:type_name -> filer_pb.Entry
+	7,  // 7: filer_pb.EventNotification.old_entry:type_name -> filer_pb.Entry
+	7,  // 8: filer_pb.EventNotification.new_entry:type_name -> filer_pb.Entry
+	12, // 9: filer_pb.FileChunk.fid:type_name -> filer_pb.FileId
+	12, // 10: filer_pb.FileChunk.source_fid:type_name -> filer_pb.FileId
 	0,  // 11: filer_pb.FileChunk.sse_type:type_name -> filer_pb.SSEType
-	9,  // 12: filer_pb.FileChunkManifest.chunks:type_name -> filer_pb.FileChunk
-	6,  // 13: filer_pb.CreateEntryRequest.entry:type_name -> filer_pb.Entry
-	43, // 14: filer_pb.CreateEntryResponse.metadata_event:type_name -> filer_pb.SubscribeMetadataResponse
-	6,  // 15: filer_pb.UpdateEntryRequest.entry:type_name -> filer_pb.Entry
-	68, // 16: filer_pb.UpdateEntryRequest.expected_extended:type_name -> filer_pb.UpdateEntryRequest.ExpectedExtendedEntry
-	43, // 17: filer_pb.UpdateEntryResponse.metadata_event:type_name -> filer_pb.SubscribeMetadataResponse
-	9,  // 18: filer_pb.AppendToEntryRequest.chunks:type_name -> filer_pb.FileChunk
-	43, // 19: filer_pb.DeleteEntryResponse.metadata_event:type_name -> filer_pb.SubscribeMetadataResponse
-	8,  // 20: filer_pb.StreamRenameEntryResponse.event_notification:type_name -> filer_pb.EventNotification
-	29, // 21: filer_pb.AssignVolumeResponse.location:type_name -> filer_pb.Location
-	29, // 22: filer_pb.Locations.locations:type_name -> filer_pb.Location
-	69, // 23: filer_pb.LookupVolumeResponse.locations_map:type_name -> filer_pb.LookupVolumeResponse.LocationsMapEntry
-	31, // 24: filer_pb.CollectionListResponse.collections:type_name -> filer_pb.Collection
-	8,  // 25: filer_pb.SubscribeMetadataResponse.event_notification:type_name -> filer_pb.EventNotification
-	6,  // 26: filer_pb.TraverseBfsMetadataResponse.entry:type_name -> filer_pb.Entry
-	70, // 27: filer_pb.LocateBrokerResponse.resources:type_name -> filer_pb.LocateBrokerResponse.Resource
-	71, // 28: filer_pb.FilerConf.locations:type_name -> filer_pb.FilerConf.PathConf
-	6,  // 29: filer_pb.CacheRemoteObjectToLocalClusterResponse.entry:type_name -> filer_pb.Entry
-	43, // 30: filer_pb.CacheRemoteObjectToLocalClusterResponse.metadata_event:type_name -> filer_pb.SubscribeMetadataResponse
-	64, // 31: filer_pb.TransferLocksRequest.locks:type_name -> filer_pb.Lock
-	28, // 32: filer_pb.LookupVolumeResponse.LocationsMapEntry.value:type_name -> filer_pb.Locations
-	1,  // 33: filer_pb.SeaweedFiler.LookupDirectoryEntry:input_type -> filer_pb.LookupDirectoryEntryRequest
-	3,  // 34: filer_pb.SeaweedFiler.ListEntries:input_type -> filer_pb.ListEntriesRequest
-	13, // 35: filer_pb.SeaweedFiler.CreateEntry:input_type -> filer_pb.CreateEntryRequest
-	15, // 36: filer_pb.SeaweedFiler.UpdateEntry:input_type -> filer_pb.UpdateEntryRequest
-	17, // 37: filer_pb.SeaweedFiler.AppendToEntry:input_type -> filer_pb.AppendToEntryRequest
-	19, // 38: filer_pb.SeaweedFiler.DeleteEntry:input_type -> filer_pb.DeleteEntryRequest
-	21, // 39: filer_pb.SeaweedFiler.AtomicRenameEntry:input_type -> filer_pb.AtomicRenameEntryRequest
-	23, // 40: filer_pb.SeaweedFiler.StreamRenameEntry:input_type -> filer_pb.StreamRenameEntryRequest
-	25, // 41: filer_pb.SeaweedFiler.AssignVolume:input_type -> filer_pb.AssignVolumeRequest
-	27, // 42: filer_pb.SeaweedFiler.LookupVolume:input_type -> filer_pb.LookupVolumeRequest
-	32, // 43: filer_pb.SeaweedFiler.CollectionList:input_type -> filer_pb.CollectionListRequest
-	34, // 44: filer_pb.SeaweedFiler.DeleteCollection:input_type -> filer_pb.DeleteCollectionRequest
-	36, // 45: filer_pb.SeaweedFiler.Statistics:input_type -> filer_pb.StatisticsRequest
-	38, // 46: filer_pb.SeaweedFiler.Ping:input_type -> filer_pb.PingRequest
-	40, // 47: filer_pb.SeaweedFiler.GetFilerConfiguration:input_type -> filer_pb.GetFilerConfigurationRequest
-	44, // 48: filer_pb.SeaweedFiler.TraverseBfsMetadata:input_type -> filer_pb.TraverseBfsMetadataRequest
-	42, // 49: filer_pb.SeaweedFiler.SubscribeMetadata:input_type -> filer_pb.SubscribeMetadataRequest
-	42, // 50: filer_pb.SeaweedFiler.SubscribeLocalMetadata:input_type -> filer_pb.SubscribeMetadataRequest
-	51, // 51: filer_pb.SeaweedFiler.KvGet:input_type -> filer_pb.KvGetRequest
-	53, // 52: filer_pb.SeaweedFiler.KvPut:input_type -> filer_pb.KvPutRequest
-	56, // 53: filer_pb.SeaweedFiler.CacheRemoteObjectToLocalCluster:input_type -> filer_pb.CacheRemoteObjectToLocalClusterRequest
-	58, // 54: filer_pb.SeaweedFiler.DistributedLock:input_type -> filer_pb.LockRequest
-	60, // 55: filer_pb.SeaweedFiler.DistributedUnlock:input_type -> filer_pb.UnlockRequest
-	62, // 56: filer_pb.SeaweedFiler.FindLockOwner:input_type -> filer_pb.FindLockOwnerRequest
-	65, // 57: filer_pb.SeaweedFiler.TransferLocks:input_type -> filer_pb.TransferLocksRequest
-	2,  // 58: filer_pb.SeaweedFiler.LookupDirectoryEntry:output_type -> filer_pb.LookupDirectoryEntryResponse
-	4,  // 59: filer_pb.SeaweedFiler.ListEntries:output_type -> filer_pb.ListEntriesResponse
-	14, // 60: filer_pb.SeaweedFiler.CreateEntry:output_type -> filer_pb.CreateEntryResponse
-	16, // 61: filer_pb.SeaweedFiler.UpdateEntry:output_type -> filer_pb.UpdateEntryResponse
-	18, // 62: filer_pb.SeaweedFiler.AppendToEntry:output_type -> filer_pb.AppendToEntryResponse
-	20, // 63: filer_pb.SeaweedFiler.DeleteEntry:output_type -> filer_pb.DeleteEntryResponse
-	22, // 64: filer_pb.SeaweedFiler.AtomicRenameEntry:output_type -> filer_pb.AtomicRenameEntryResponse
-	24, // 65: filer_pb.SeaweedFiler.StreamRenameEntry:output_type -> filer_pb.StreamRenameEntryResponse
-	26, // 66: filer_pb.SeaweedFiler.AssignVolume:output_type -> filer_pb.AssignVolumeResponse
-	30, // 67: filer_pb.SeaweedFiler.LookupVolume:output_type -> filer_pb.LookupVolumeResponse
-	33, // 68: filer_pb.SeaweedFiler.CollectionList:output_type -> filer_pb.CollectionListResponse
-	35, // 69: filer_pb.SeaweedFiler.DeleteCollection:output_type -> filer_pb.DeleteCollectionResponse
-	37, // 70: filer_pb.SeaweedFiler.Statistics:output_type -> filer_pb.StatisticsResponse
-	39, // 71: filer_pb.SeaweedFiler.Ping:output_type -> filer_pb.PingResponse
-	41, // 72: filer_pb.SeaweedFiler.GetFilerConfiguration:output_type -> filer_pb.GetFilerConfigurationResponse
-	45, // 73: filer_pb.SeaweedFiler.TraverseBfsMetadata:output_type -> filer_pb.TraverseBfsMetadataResponse
-	43, // 74: filer_pb.SeaweedFiler.SubscribeMetadata:output_type -> filer_pb.SubscribeMetadataResponse
-	43, // 75: filer_pb.SeaweedFiler.SubscribeLocalMetadata:output_type -> filer_pb.SubscribeMetadataResponse
-	52, // 76: filer_pb.SeaweedFiler.KvGet:output_type -> filer_pb.KvGetResponse
-	54, // 77: filer_pb.SeaweedFiler.KvPut:output_type -> filer_pb.KvPutResponse
-	57, // 78: filer_pb.SeaweedFiler.CacheRemoteObjectToLocalCluster:output_type -> filer_pb.CacheRemoteObjectToLocalClusterResponse
-	59, // 79: filer_pb.SeaweedFiler.DistributedLock:output_type -> filer_pb.LockResponse
-	61, // 80: filer_pb.SeaweedFiler.DistributedUnlock:output_type -> filer_pb.UnlockResponse
-	63, // 81: filer_pb.SeaweedFiler.FindLockOwner:output_type -> filer_pb.FindLockOwnerResponse
-	66, // 82: filer_pb.SeaweedFiler.TransferLocks:output_type -> filer_pb.TransferLocksResponse
-	58, // [58:83] is the sub-list for method output_type
-	33, // [33:58] is the sub-list for method input_type
-	33, // [33:33] is the sub-list for extension type_name
-	33, // [33:33] is the sub-list for extension extendee
-	0,  // [0:33] is the sub-list for field type_name
+	10, // 12: filer_pb.FileChunkManifest.chunks:type_name -> filer_pb.FileChunk
+	7,  // 13: filer_pb.CreateEntryRequest.entry:type_name -> filer_pb.Entry
+	44, // 14: filer_pb.CreateEntryResponse.metadata_event:type_name -> filer_pb.SubscribeMetadataResponse
+	1,  // 15: filer_pb.CreateEntryResponse.error_code:type_name -> filer_pb.FilerError
+	7,  // 16: filer_pb.UpdateEntryRequest.entry:type_name -> filer_pb.Entry
+	69, // 17: filer_pb.UpdateEntryRequest.expected_extended:type_name -> filer_pb.UpdateEntryRequest.ExpectedExtendedEntry
+	44, // 18: filer_pb.UpdateEntryResponse.metadata_event:type_name -> filer_pb.SubscribeMetadataResponse
+	10, // 19: filer_pb.AppendToEntryRequest.chunks:type_name -> filer_pb.FileChunk
+	44, // 20: filer_pb.DeleteEntryResponse.metadata_event:type_name -> filer_pb.SubscribeMetadataResponse
+	9,  // 21: filer_pb.StreamRenameEntryResponse.event_notification:type_name -> filer_pb.EventNotification
+	30, // 22: filer_pb.AssignVolumeResponse.location:type_name -> filer_pb.Location
+	30, // 23: filer_pb.Locations.locations:type_name -> filer_pb.Location
+	70, // 24: filer_pb.LookupVolumeResponse.locations_map:type_name -> filer_pb.LookupVolumeResponse.LocationsMapEntry
+	32, // 25: filer_pb.CollectionListResponse.collections:type_name -> filer_pb.Collection
+	9,  // 26: filer_pb.SubscribeMetadataResponse.event_notification:type_name -> filer_pb.EventNotification
+	7,  // 27: filer_pb.TraverseBfsMetadataResponse.entry:type_name -> filer_pb.Entry
+	71, // 28: filer_pb.LocateBrokerResponse.resources:type_name -> filer_pb.LocateBrokerResponse.Resource
+	72, // 29: filer_pb.FilerConf.locations:type_name -> filer_pb.FilerConf.PathConf
+	7,  // 30: filer_pb.CacheRemoteObjectToLocalClusterResponse.entry:type_name -> filer_pb.Entry
+	44, // 31: filer_pb.CacheRemoteObjectToLocalClusterResponse.metadata_event:type_name -> filer_pb.SubscribeMetadataResponse
+	65, // 32: filer_pb.TransferLocksRequest.locks:type_name -> filer_pb.Lock
+	29, // 33: filer_pb.LookupVolumeResponse.LocationsMapEntry.value:type_name -> filer_pb.Locations
+	2,  // 34: filer_pb.SeaweedFiler.LookupDirectoryEntry:input_type -> filer_pb.LookupDirectoryEntryRequest
+	4,  // 35: filer_pb.SeaweedFiler.ListEntries:input_type -> filer_pb.ListEntriesRequest
+	14, // 36: filer_pb.SeaweedFiler.CreateEntry:input_type -> filer_pb.CreateEntryRequest
+	16, // 37: filer_pb.SeaweedFiler.UpdateEntry:input_type -> filer_pb.UpdateEntryRequest
+	18, // 38: filer_pb.SeaweedFiler.AppendToEntry:input_type -> filer_pb.AppendToEntryRequest
+	20, // 39: filer_pb.SeaweedFiler.DeleteEntry:input_type -> filer_pb.DeleteEntryRequest
+	22, // 40: filer_pb.SeaweedFiler.AtomicRenameEntry:input_type -> filer_pb.AtomicRenameEntryRequest
+	24, // 41: filer_pb.SeaweedFiler.StreamRenameEntry:input_type -> filer_pb.StreamRenameEntryRequest
+	26, // 42: filer_pb.SeaweedFiler.AssignVolume:input_type -> filer_pb.AssignVolumeRequest
+	28, // 43: filer_pb.SeaweedFiler.LookupVolume:input_type -> filer_pb.LookupVolumeRequest
+	33, // 44: filer_pb.SeaweedFiler.CollectionList:input_type -> filer_pb.CollectionListRequest
+	35, // 45: filer_pb.SeaweedFiler.DeleteCollection:input_type -> filer_pb.DeleteCollectionRequest
+	37, // 46: filer_pb.SeaweedFiler.Statistics:input_type -> filer_pb.StatisticsRequest
+	39, // 47: filer_pb.SeaweedFiler.Ping:input_type -> filer_pb.PingRequest
+	41, // 48: filer_pb.SeaweedFiler.GetFilerConfiguration:input_type -> filer_pb.GetFilerConfigurationRequest
+	45, // 49: filer_pb.SeaweedFiler.TraverseBfsMetadata:input_type -> filer_pb.TraverseBfsMetadataRequest
+	43, // 50: filer_pb.SeaweedFiler.SubscribeMetadata:input_type -> filer_pb.SubscribeMetadataRequest
+	43, // 51: filer_pb.SeaweedFiler.SubscribeLocalMetadata:input_type -> filer_pb.SubscribeMetadataRequest
+	52, // 52: filer_pb.SeaweedFiler.KvGet:input_type -> filer_pb.KvGetRequest
+	54, // 53: filer_pb.SeaweedFiler.KvPut:input_type -> filer_pb.KvPutRequest
+	57, // 54: filer_pb.SeaweedFiler.CacheRemoteObjectToLocalCluster:input_type -> filer_pb.CacheRemoteObjectToLocalClusterRequest
+	59, // 55: filer_pb.SeaweedFiler.DistributedLock:input_type -> filer_pb.LockRequest
+	61, // 56: filer_pb.SeaweedFiler.DistributedUnlock:input_type -> filer_pb.UnlockRequest
+	63, // 57: filer_pb.SeaweedFiler.FindLockOwner:input_type -> filer_pb.FindLockOwnerRequest
+	66, // 58: filer_pb.SeaweedFiler.TransferLocks:input_type -> filer_pb.TransferLocksRequest
+	3,  // 59: filer_pb.SeaweedFiler.LookupDirectoryEntry:output_type -> filer_pb.LookupDirectoryEntryResponse
+	5,  // 60: filer_pb.SeaweedFiler.ListEntries:output_type -> filer_pb.ListEntriesResponse
+	15, // 61: filer_pb.SeaweedFiler.CreateEntry:output_type -> filer_pb.CreateEntryResponse
+	17, // 62: filer_pb.SeaweedFiler.UpdateEntry:output_type -> filer_pb.UpdateEntryResponse
+	19, // 63: filer_pb.SeaweedFiler.AppendToEntry:output_type -> filer_pb.AppendToEntryResponse
+	21, // 64: filer_pb.SeaweedFiler.DeleteEntry:output_type -> filer_pb.DeleteEntryResponse
+	23, // 65: filer_pb.SeaweedFiler.AtomicRenameEntry:output_type -> filer_pb.AtomicRenameEntryResponse
+	25, // 66: filer_pb.SeaweedFiler.StreamRenameEntry:output_type -> filer_pb.StreamRenameEntryResponse
+	27, // 67: filer_pb.SeaweedFiler.AssignVolume:output_type -> filer_pb.AssignVolumeResponse
+	31, // 68: filer_pb.SeaweedFiler.LookupVolume:output_type -> filer_pb.LookupVolumeResponse
+	34, // 69: filer_pb.SeaweedFiler.CollectionList:output_type -> filer_pb.CollectionListResponse
+	36, // 70: filer_pb.SeaweedFiler.DeleteCollection:output_type -> filer_pb.DeleteCollectionResponse
+	38, // 71: filer_pb.SeaweedFiler.Statistics:output_type -> filer_pb.StatisticsResponse
+	40, // 72: filer_pb.SeaweedFiler.Ping:output_type -> filer_pb.PingResponse
+	42, // 73: filer_pb.SeaweedFiler.GetFilerConfiguration:output_type -> filer_pb.GetFilerConfigurationResponse
+	46, // 74: filer_pb.SeaweedFiler.TraverseBfsMetadata:output_type -> filer_pb.TraverseBfsMetadataResponse
+	44, // 75: filer_pb.SeaweedFiler.SubscribeMetadata:output_type -> filer_pb.SubscribeMetadataResponse
+	44, // 76: filer_pb.SeaweedFiler.SubscribeLocalMetadata:output_type -> filer_pb.SubscribeMetadataResponse
+	53, // 77: filer_pb.SeaweedFiler.KvGet:output_type -> filer_pb.KvGetResponse
+	55, // 78: filer_pb.SeaweedFiler.KvPut:output_type -> filer_pb.KvPutResponse
+	58, // 79: filer_pb.SeaweedFiler.CacheRemoteObjectToLocalCluster:output_type -> filer_pb.CacheRemoteObjectToLocalClusterResponse
+	60, // 80: filer_pb.SeaweedFiler.DistributedLock:output_type -> filer_pb.LockResponse
+	62, // 81: filer_pb.SeaweedFiler.DistributedUnlock:output_type -> filer_pb.UnlockResponse
+	64, // 82: filer_pb.SeaweedFiler.FindLockOwner:output_type -> filer_pb.FindLockOwnerResponse
+	67, // 83: filer_pb.SeaweedFiler.TransferLocks:output_type -> filer_pb.TransferLocksResponse
+	59, // [59:84] is the sub-list for method output_type
+	34, // [34:59] is the sub-list for method input_type
+	34, // [34:34] is the sub-list for extension type_name
+	34, // [34:34] is the sub-list for extension extendee
+	0,  // [0:34] is the sub-list for field type_name
 }
 
 func init() { file_filer_proto_init() }
@@ -5071,7 +5151,7 @@ func file_filer_proto_init() {
 		File: protoimpl.DescBuilder{
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: unsafe.Slice(unsafe.StringData(file_filer_proto_rawDesc), len(file_filer_proto_rawDesc)),
-			NumEnums:      1,
+			NumEnums:      2,
 			NumMessages:   71,
 			NumExtensions: 0,
 			NumServices:   1,
diff --git a/weed/pb/filer_pb/filer_pb_helper.go b/weed/pb/filer_pb/filer_pb_helper.go
index fed902824..a6d6fa10b 100644
--- a/weed/pb/filer_pb/filer_pb_helper.go
+++ b/weed/pb/filer_pb/filer_pb_helper.go
@@ -145,6 +145,13 @@ func CreateEntryWithResponse(ctx context.Context, client SeaweedFilerClient, req
 		glog.V(1).InfofCtx(ctx, "create entry %s/%s %v: %v", request.Directory, request.Entry.Name, request.OExcl, err)
 		return nil, fmt.Errorf("CreateEntry: %w", err)
 	}
+	if resp.ErrorCode != FilerError_OK {
+		glog.V(1).InfofCtx(ctx, "create entry %s/%s %v: %v (code %v)", request.Directory, request.Entry.Name, request.OExcl, resp.Error, resp.ErrorCode)
+		if sentinel := FilerErrorToSentinel(resp.ErrorCode); sentinel != nil {
+			return nil, fmt.Errorf("CreateEntry %s/%s: %w", request.Directory, request.Entry.Name, sentinel)
+		}
+		return nil, fmt.Errorf("CreateEntry: %w", errors.New(resp.Error))
+	}
 	if resp.Error != "" {
 		glog.V(1).InfofCtx(ctx, "create entry %s/%s %v: %v", request.Directory, request.Entry.Name, request.OExcl, resp.Error)
 		return nil, fmt.Errorf("CreateEntry: %w", errors.New(resp.Error))
@@ -183,6 +190,37 @@ func LookupEntry(ctx context.Context, client SeaweedFilerClient, request *Lookup
 
 var ErrNotFound = errors.New("filer: no entry is found in filer store")
 
+// Sentinel errors for filer entry operations.
+// These are set by the filer and reconstructed from FilerError codes after
+// crossing the gRPC boundary, so consumers can use errors.Is() instead of
+// parsing error strings.
+var (
+	ErrEntryNameTooLong    = errors.New("entry name too long")
+	ErrParentIsFile        = errors.New("parent path is a file")
+	ErrExistingIsDirectory = errors.New("existing entry is a directory")
+	ErrExistingIsFile      = errors.New("existing entry is a file")
+	ErrEntryAlreadyExists  = errors.New("entry already exists")
+)
+
+// FilerErrorToSentinel maps a proto FilerError code to its sentinel error.
+// Returns nil for OK or unknown codes.
+func FilerErrorToSentinel(code FilerError) error {
+	switch code {
+	case FilerError_ENTRY_NAME_TOO_LONG:
+		return ErrEntryNameTooLong
+	case FilerError_PARENT_IS_FILE:
+		return ErrParentIsFile
+	case FilerError_EXISTING_IS_DIRECTORY:
+		return ErrExistingIsDirectory
+	case FilerError_EXISTING_IS_FILE:
+		return ErrExistingIsFile
+	case FilerError_ENTRY_ALREADY_EXISTS:
+		return ErrEntryAlreadyExists
+	default:
+		return nil
+	}
+}
+
 func IsEmpty(event *SubscribeMetadataResponse) bool {
 	return event.EventNotification.NewEntry == nil && event.EventNotification.OldEntry == nil
 }
diff --git a/weed/s3api/iceberg/metadata_files.go b/weed/s3api/iceberg/metadata_files.go
index 296876def..e18189040 100644
--- a/weed/s3api/iceberg/metadata_files.go
+++ b/weed/s3api/iceberg/metadata_files.go
@@ -51,7 +51,7 @@ func (s *Server) saveMetadataFile(ctx context.Context, bucketName, tablePath, me
 			if createErr != nil {
 				return fmt.Errorf("failed to create %s: %w", errorContext, createErr)
 			}
-			if resp.Error != "" && !strings.Contains(resp.Error, "exist") {
+			if resp.ErrorCode != filer_pb.FilerError_OK && resp.ErrorCode != filer_pb.FilerError_ENTRY_ALREADY_EXISTS {
 				return fmt.Errorf("failed to create %s: %s", errorContext, resp.Error)
 			}
 			return nil
@@ -104,8 +104,11 @@ func (s *Server) saveMetadataFile(ctx context.Context, bucketName, tablePath, me
 		if err != nil {
 			return fmt.Errorf("failed to write metadata file: %w", err)
 		}
-		if resp.Error != "" {
-			return fmt.Errorf("failed to write metadata file: %s", resp.Error)
+		if resp.ErrorCode != filer_pb.FilerError_OK {
+			if sentinel := filer_pb.FilerErrorToSentinel(resp.ErrorCode); sentinel != nil {
+				return fmt.Errorf("failed to write metadata file: %w", sentinel)
+			}
+			return fmt.Errorf("failed to write metadata file: code=%v %s", resp.ErrorCode, resp.Error)
 		}
 		return nil
 	})
diff --git a/weed/s3api/iceberg/stage_create.go b/weed/s3api/iceberg/stage_create.go
index 2ab5b6643..ccc53e166 100644
--- a/weed/s3api/iceberg/stage_create.go
+++ b/weed/s3api/iceberg/stage_create.go
@@ -198,7 +198,7 @@ func (s *Server) writeStageCreateMarker(ctx context.Context, bucketName string,
 			if createErr != nil {
 				return fmt.Errorf("failed to create %s: %w", errorContext, createErr)
 			}
-			if resp.Error != "" && !strings.Contains(resp.Error, "exist") {
+			if resp.ErrorCode != filer_pb.FilerError_OK && resp.ErrorCode != filer_pb.FilerError_ENTRY_ALREADY_EXISTS {
 				return fmt.Errorf("failed to create %s: %s", errorContext, resp.Error)
 			}
 			return nil
@@ -236,8 +236,11 @@ func (s *Server) writeStageCreateMarker(ctx context.Context, bucketName string,
 		if createErr != nil {
 			return createErr
 		}
-		if resp.Error != "" {
-			return errors.New(resp.Error)
+		if resp.ErrorCode != filer_pb.FilerError_OK {
+			if sentinel := filer_pb.FilerErrorToSentinel(resp.ErrorCode); sentinel != nil {
+				return fmt.Errorf("create stage marker: %w", sentinel)
+			}
+			return fmt.Errorf("create stage marker: code=%v %s", resp.ErrorCode, resp.Error)
 		}
 		return nil
 	})
diff --git a/weed/s3api/s3_sse_s3.go b/weed/s3api/s3_sse_s3.go
index a9c22e666..e869308f3 100644
--- a/weed/s3api/s3_sse_s3.go
+++ b/weed/s3api/s3_sse_s3.go
@@ -15,7 +15,6 @@ import (
 	mathrand "math/rand"
 	"net/http"
 	"os"
-	"strings"
 	"sync"
 	"time"
 
@@ -359,8 +358,8 @@ func (km *SSES3KeyManager) generateAndSaveSuperKeyToFiler() error {
 		// Set appropriate permissions for the directory
 		entry.Attributes.FileMode = uint32(0700 | os.ModeDir)
 	}); err != nil {
-		// Only ignore "file exists" errors.
-		if !strings.Contains(err.Error(), "file exists") {
+		// Only ignore "already exists" errors.
+		if !errors.Is(err, filer_pb.ErrEntryAlreadyExists) {
 			return fmt.Errorf("failed to create KEK directory %s: %w", SSES3KEKDirectory, err)
 		}
 		glog.V(3).Infof("Parent directory %s already exists, continuing.", SSES3KEKDirectory)
diff --git a/weed/s3api/s3api_object_handlers_put.go b/weed/s3api/s3api_object_handlers_put.go
index b0e2ac703..bb160fa55 100644
--- a/weed/s3api/s3api_object_handlers_put.go
+++ b/weed/s3api/s3api_object_handlers_put.go
@@ -793,21 +793,25 @@ func filerErrorToS3Error(err error) s3err.ErrorCode {
 		return s3err.ErrNone
 	}
 
-	errString := err.Error()
+	// Filer sentinel errors — matched via errors.Is() after crossing gRPC boundary
+	switch {
+	case errors.Is(err, filer_pb.ErrEntryNameTooLong):
+		return s3err.ErrKeyTooLongError
+	case errors.Is(err, filer_pb.ErrParentIsFile), errors.Is(err, filer_pb.ErrExistingIsFile):
+		return s3err.ErrExistingObjectIsFile
+	case errors.Is(err, filer_pb.ErrExistingIsDirectory):
+		return s3err.ErrExistingObjectIsDirectory
+	case errors.Is(err, weed_server.ErrReadOnly):
+		return s3err.ErrAccessDenied
+	}
 
+	// Non-filer errors that don't go through CreateEntryResponse — string matching required
+	errString := err.Error()
 	switch {
 	case errString == constants.ErrMsgBadDigest:
 		return s3err.ErrBadDigest
-	case errors.Is(err, weed_server.ErrReadOnly):
-		return s3err.ErrAccessDenied
 	case strings.Contains(errString, "context canceled") || strings.Contains(errString, "code = Canceled"):
 		return s3err.ErrInvalidRequest
-	case strings.Contains(errString, constants.ErrMsgExistingPrefix) && strings.HasSuffix(errString, constants.ErrMsgIsADirectory):
-		return s3err.ErrExistingObjectIsDirectory
-	case strings.HasSuffix(errString, constants.ErrMsgIsAFile):
-		return s3err.ErrExistingObjectIsFile
-	case strings.Contains(errString, constants.ErrMsgEntryNameTooLong):
-		return s3err.ErrKeyTooLongError
 	default:
 		return s3err.ErrInternalError
 	}
diff --git a/weed/s3api/s3api_object_handlers_put_test.go b/weed/s3api/s3api_object_handlers_put_test.go
index ef6b9a757..dd5dee34e 100644
--- a/weed/s3api/s3api_object_handlers_put_test.go
+++ b/weed/s3api/s3api_object_handlers_put_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"github.com/gorilla/mux"
+	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
 	"github.com/seaweedfs/seaweedfs/weed/s3api/s3_constants"
 	"github.com/seaweedfs/seaweedfs/weed/s3api/s3err"
 	weed_server "github.com/seaweedfs/seaweedfs/weed/server"
@@ -53,28 +54,28 @@ func TestFilerErrorToS3Error(t *testing.T) {
 			expectedErr: s3err.ErrInvalidRequest,
 		},
 		{
-			name:        "Directory exists error",
-			err:         errors.New("existing /path/to/file is a directory"),
+			name:        "Directory exists error (sentinel)",
+			err:         fmt.Errorf("CreateEntry /path: %w", filer_pb.ErrExistingIsDirectory),
 			expectedErr: s3err.ErrExistingObjectIsDirectory,
 		},
 		{
-			name:        "Directory exists error (CreateEntry-wrapped)",
-			err:         errors.New("CreateEntry: existing /path/to/file is a directory"),
-			expectedErr: s3err.ErrExistingObjectIsDirectory,
+			name:        "Parent is file error (sentinel)",
+			err:         fmt.Errorf("CreateEntry /path: %w", filer_pb.ErrParentIsFile),
+			expectedErr: s3err.ErrExistingObjectIsFile,
 		},
 		{
-			name:        "File exists error",
-			err:         errors.New("/path/to/file is a file"),
+			name:        "Existing is file error (sentinel)",
+			err:         fmt.Errorf("CreateEntry /path: %w", filer_pb.ErrExistingIsFile),
 			expectedErr: s3err.ErrExistingObjectIsFile,
 		},
 		{
-			name:        "Entry name too long error",
-			err:         errors.New("CreateEntry: entry name too long"),
+			name:        "Entry name too long (sentinel)",
+			err:         fmt.Errorf("CreateEntry: %w", filer_pb.ErrEntryNameTooLong),
 			expectedErr: s3err.ErrKeyTooLongError,
 		},
 		{
-			name:        "Entry name too long error (unwrapped)",
-			err:         errors.New("entry name too long"),
+			name:        "Entry name too long (bare sentinel)",
+			err:         filer_pb.ErrEntryNameTooLong,
 			expectedErr: s3err.ErrKeyTooLongError,
 		},
 		{
diff --git a/weed/server/filer_grpc_server.go b/weed/server/filer_grpc_server.go
index 1b7b050c0..c79640a03 100644
--- a/weed/server/filer_grpc_server.go
+++ b/weed/server/filer_grpc_server.go
@@ -3,6 +3,7 @@ package weed_server
 import (
 	"bytes"
 	"context"
+	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -191,6 +192,18 @@ func (fs *FilerServer) CreateEntry(ctx context.Context, req *filer_pb.CreateEntr
 	} else {
 		glog.V(3).InfofCtx(ctx, "CreateEntry %s: %v", filepath.Join(req.Directory, req.Entry.Name), createErr)
 		resp.Error = createErr.Error()
+		switch {
+		case errors.Is(createErr, filer_pb.ErrEntryNameTooLong):
+			resp.ErrorCode = filer_pb.FilerError_ENTRY_NAME_TOO_LONG
+		case errors.Is(createErr, filer_pb.ErrParentIsFile):
+			resp.ErrorCode = filer_pb.FilerError_PARENT_IS_FILE
+		case errors.Is(createErr, filer_pb.ErrExistingIsDirectory):
+			resp.ErrorCode = filer_pb.FilerError_EXISTING_IS_DIRECTORY
+		case errors.Is(createErr, filer_pb.ErrExistingIsFile):
+			resp.ErrorCode = filer_pb.FilerError_EXISTING_IS_FILE
+		case errors.Is(createErr, filer_pb.ErrEntryAlreadyExists):
+			resp.ErrorCode = filer_pb.FilerError_ENTRY_ALREADY_EXISTS
+		}
 	}
 
 	return