sync: Fix --max-duration so it doesn't retry when the duration is exceeded

Before this change, if the --max-duration limit was reached then
rclone would retry the sync as a fatal error wasn't raised.

This checks the deadline and raises a fatal error if necessary at the
end of the sync.

Fixes #6002

fs/sync/sync.go

@@ -73,6 +73,7 @@ type syncCopyMove struct {
 	compareCopyDest        []fs.Fs                // place to check for files to server side copy
 	backupDir              fs.Fs                  // place to store overwrites/deletes
 	checkFirst             bool                   // if set run all the checkers before starting transfers
+	maxDurationEndTime     time.Time              // end time if --max-duration is set
 }
 
 type trackRenamesStrategy byte
@@ -146,9 +147,9 @@ func newSyncCopyMove(ctx context.Context, fdst, fsrc fs.Fs, deleteMode fs.Delete
 	}
 	// If a max session duration has been defined add a deadline to the context
 	if ci.MaxDuration > 0 {
-		endTime := time.Now().Add(ci.MaxDuration)
-		fs.Infof(s.fdst, "Transfer session deadline: %s", endTime.Format("2006/01/02 15:04:05"))
-		s.ctx, s.cancel = context.WithDeadline(ctx, endTime)
+		s.maxDurationEndTime = time.Now().Add(ci.MaxDuration)
+		fs.Infof(s.fdst, "Transfer session deadline: %s", s.maxDurationEndTime.Format("2006/01/02 15:04:05"))
+		s.ctx, s.cancel = context.WithDeadline(ctx, s.maxDurationEndTime)
 	} else {
 		s.ctx, s.cancel = context.WithCancel(ctx)
 	}
@@ -809,6 +810,10 @@ func (s *syncCopyMove) tryRename(src fs.Object) bool {
 	return true
 }
 
+// errorMaxDurationReached defines error when transfer duration is reached
+// Used for checking on exit and matching to correct exit code.
+var errorMaxDurationReached = fserrors.FatalError(errors.New("Max transfer duration reached as set by --max-duration"))
+
 // Syncs fsrc into fdst
 //
 // If Delete is true then it deletes any files in fdst that aren't in fsrc
@@ -902,6 +907,12 @@ func (s *syncCopyMove) run() error {
 	// Read the error out of the context if there is one
 	s.processError(s.ctx.Err())
 
+	// If the duration was exceeded then add a Fatal Error so we don't retry
+	if !s.maxDurationEndTime.IsZero() && time.Since(s.maxDurationEndTime) > 0 {
+		fs.Errorf(s.fdst, "%v", errorMaxDurationReached)
+		s.processError(errorMaxDurationReached)
+	}
+
 	// Print nothing to transfer message if there were no transfers and no errors
 	if s.deleteMode != fs.DeleteModeOnly && accounting.Stats(s.ctx).GetTransfers() == 0 && s.currentError() == nil {
 		fs.Infof(nil, "There was nothing to transfer")

fs/sync/sync_test.go

@@ -1029,7 +1029,7 @@ func TestSyncWithMaxDuration(t *testing.T) {
 	accounting.GlobalStats().ResetCounters()
 	startTime := time.Now()
 	err := Sync(ctx, r.Fremote, r.Flocal, false)
-	require.True(t, errors.Is(err, context.DeadlineExceeded))
+	require.True(t, errors.Is(err, errorMaxDurationReached))
 
 	elapsed := time.Since(startTime)
 	maxTransferTime := (time.Duration(len(testFiles)) * 60 * time.Second) / time.Duration(bytesPerSecond)