handle DryRun send size estimate errors with bookmarks

client/status.go

@@ -235,12 +235,14 @@ func (t *tui) drawBar(name string, maxNameLength int, status string, bytes int64
 	t.write(rightPad(status, 14, " "))
 	t.write(" ")
 
-	if totalBytes > 0 {
 	length := 50
-		completedLength := int(int64(length) * bytes / totalBytes)
+	var completedLength int
+	if totalBytes > 0 {
+		completedLength = int(int64(length) * bytes / totalBytes)
 		if completedLength > length {
 			completedLength = length
 		}
+	}
 
 	t.write("[")
 	t.write(times("=", completedLength))
@@ -249,8 +251,11 @@ func (t *tui) drawBar(name string, maxNameLength int, status string, bytes int64
 	t.write("]")
 
 	t.write(" ")
-		t.write(rightPad(ByteCountBinary(bytes) + "/" + ByteCountBinary(totalBytes), 20, " "))
+	totalBytesStr := ByteCountBinary(totalBytes)
+	if totalBytes == 0 {
+		totalBytesStr = "??? B"
 	}
+	t.write(rightPad(ByteCountBinary(bytes)+"/"+totalBytesStr, 20, " "))
 
 	t.newline()
 }

endpoint/endpoint.go

@@ -77,6 +77,9 @@ func (p *Sender) Send(ctx context.Context, r *pdu.SendReq) (*pdu.SendRes, io.Rea
 
 	if r.DryRun {
 		size, err := zfs.ZFSSendDry(r.Filesystem, r.From, r.To)
+		if err == zfs.BookmarkSizeEstimationNotSupported {
+			return &pdu.SendRes{ExpectedSize: 0}, nil, nil
+		}
 		if err != nil {
 			return nil, nil, err
 		}

replication/fsrep/fsfsm.go

@@ -59,7 +59,7 @@ type StepReport struct {
 	Status   StepState
 	Problem  string
 	Bytes    int64
-	ExpectedBytes int64
+	ExpectedBytes int64 // 0 means no size estimate possible
 }
 
 type Report struct {
@@ -185,7 +185,7 @@ type ReplicationStep struct {
 	err error
 
 	byteCounter  *util.ByteCounterReader
-	expectedSize int64
+	expectedSize int64 // 0 means no size estimate present / possible
 }
 
 func (f *Replication) TakeStep(ctx context.Context, sender Sender, receiver Receiver) (post State, nextStepDate time.Time) {
@@ -457,6 +457,7 @@ func (s *ReplicationStep) updateSizeEstimate(ctx context.Context, sender Sender)
 	sres, _, err := sender.Send(ctx, sr)
 	if err != nil {
 		log.WithError(err).Error("dry run send request failed")
+		return err
 	}
 	s.expectedSize = sres.ExpectedSize
 	return nil

replication/pdu/pdu.pb.go

@@ -493,7 +493,8 @@ func (m *Property) GetValue() string {
 type SendRes struct {
 	// Whether the resume token provided in the request has been used or not.
 	UsedResumeToken bool `protobuf:"varint,1,opt,name=UsedResumeToken,proto3" json:"UsedResumeToken,omitempty"`
-	// Expected stream size determined by dry run, not exact
+	// Expected stream size determined by dry run, not exact.
+	// 0 indicates that for the given SendReq, no size estimate could be made.
 	ExpectedSize         int64       `protobuf:"varint,2,opt,name=ExpectedSize,proto3" json:"ExpectedSize,omitempty"`
 	Properties           []*Property `protobuf:"bytes,3,rep,name=Properties,proto3" json:"Properties,omitempty"`
 	XXX_NoUnkeyedLiteral struct{}    `json:"-"`

replication/pdu/pdu.proto

@@ -65,7 +65,8 @@ message SendRes {
     // Whether the resume token provided in the request has been used or not.
     bool UsedResumeToken = 1;
 
-    // Expected stream size determined by dry run, not exact
+    // Expected stream size determined by dry run, not exact.
+    // 0 indicates that for the given SendReq, no size estimate could be made.
     int64 ExpectedSize = 2;
 
     repeated Property Properties = 3;

zfs/zfs.go

@@ -309,6 +309,9 @@ func ZFSSend(fs string, from, to string) (stream io.ReadCloser, err error) {
 	return
 }
 
+var BookmarkSizeEstimationNotSupported error = fmt.Errorf("size estimation is not supported for bookmarks")
+
+// May return BookmarkSizeEstimationNotSupported as err if from is a bookmark.
 func ZFSSendDry(fs string, from, to string) (size int64, err error) {
 
 	fromV, err := absVersion(fs, from)
@@ -324,6 +327,16 @@ func ZFSSendDry(fs string, from, to string) (size int64, err error) {
 		}
 	}
 
+	if strings.Contains(fromV, "#") {
+		/* TODO:
+		 * ZFS at the time of writing does not support dry-run send because size-estimation
+		 * uses fromSnap's deadlist. However, for a bookmark, that deadlist no longer exists.
+		 * Redacted send & recv will bring this functionality, see
+		 * 	https://github.com/openzfs/openzfs/pull/484
+		 */
+		 return 0, BookmarkSizeEstimationNotSupported
+	}
+
 	args := make([]string, 0)
 	args = append(args, "send", "-n", "-v", "-P")