usbip: drop vhci secondary-controller plumbing

The secondary index threaded from sysfs status* files into
linuxClientSession only decorated one debug log string. Port numbers
are already globally unique across vhci controllers, so the port
alone identifies the attachment. Drop the field, the per-attach
sysfs glob+read for lookup, and the now-redundant filename parser;
the inline status* filter in readPrimaryVHCIStatus is enough to
guard the multi-file enumeration that vhciPickFreePort still needs.

service/usbip/host_linux.go

@@ -741,26 +741,25 @@ func (h *linuxImportHost) Attach(ctx context.Context, info DeviceInfoTruncated,
 		mode = "relay"
 	}
 	h.logger.Debug("usbip client handoff ", info.BusIDString(), ": ", mode)
-	port, secondary, attachErr := h.attachOnce(ctx, info, handoff)
+	port, attachErr := h.attachOnce(ctx, info, handoff)
 	if attachErr != nil {
 		_ = handoff.Close()
 		return nil, attachErr
 	}
 	_ = handoff.Start()
 	return &linuxClientSession{
-		handoff:   handoff,
-		host:      h,
-		port:      port,
-		secondary: secondary,
+		handoff: handoff,
+		host:    h,
+		port:    port,
 	}, nil
 }
 
-func (h *linuxImportHost) attachOnce(ctx context.Context, info DeviceInfoTruncated, handoff *kernelHandoffSession) (int, int, error) {
+func (h *linuxImportHost) attachOnce(ctx context.Context, info DeviceInfoTruncated, handoff *kernelHandoffSession) (int, error) {
 	triedPorts := make(map[int]struct{})
 	for {
 		port, err := vhciPickFreePort(info.Speed, triedPorts)
 		if err != nil {
-			return -1, 0, err
+			return -1, err
 		}
 		if !h.reservePort(port) {
 			triedPorts[port] = struct{}{}
@@ -774,29 +773,16 @@ func (h *linuxImportHost) attachOnce(ctx context.Context, info DeviceInfoTruncat
 				triedPorts[port] = struct{}{}
 				continue
 			}
-			return -1, 0, E.Cause(err, "vhci attach")
+			return -1, E.Cause(err, "vhci attach")
 		}
 		err = handoff.closeKernelFD()
 		if err != nil {
 			h.logger.Debug("close kernel fd ", info.BusIDString(), ": ", err)
 		}
-		return port, lookupSecondaryForPort(port), nil
+		return port, nil
 	}
 }
 
-func lookupSecondaryForPort(port int) int {
-	records, err := readPrimaryVHCIStatus()
-	if err != nil {
-		return 0
-	}
-	for _, record := range records {
-		if record.port == port {
-			return record.secondary
-		}
-	}
-	return 0
-}
-
 func (h *linuxImportHost) reservePort(port int) bool {
 	h.portsAccess.Lock()
 	defer h.portsAccess.Unlock()
@@ -818,10 +804,9 @@ func (h *linuxImportHost) releasePort(port int) {
 }
 
 type linuxClientSession struct {
-	handoff   *kernelHandoffSession
-	host      *linuxImportHost
-	port      int
-	secondary int
+	handoff *kernelHandoffSession
+	host    *linuxImportHost
+	port    int
 
 	closeOnce sync.Once
 	closeErr  error
@@ -850,8 +835,5 @@ func (s *linuxClientSession) Close() error {
 }
 
 func (s *linuxClientSession) Description() string {
-	if s.secondary == 0 {
-		return fmt.Sprintf("vhci_hcd.0 port %d", s.port)
-	}
-	return fmt.Sprintf("vhci_hcd.0 (controller %d) port %d", s.secondary, s.port)
+	return fmt.Sprintf("vhci_hcd.0 port %d", s.port)
 }

service/usbip/sysfs_linux.go

@@ -68,13 +68,11 @@ func (d *sysfsDevice) toProtocol() DeviceInfoTruncated {
 
 // vhciStatusRecord is one row of /sys/devices/platform/vhci_hcd.0/status
 // or status.N. The kernel emits globally unique port numbers across every
-// status* file; secondary identifies which file the row came from
-// (0 for status, N for status.N) and exists only for diagnostic logging.
+// status* file.
 type vhciStatusRecord struct {
-	secondary int
-	hub       string
-	port      int
-	state     int
+	hub   string
+	port  int
+	state int
 }
 
 func listUSBDevices() ([]sysfsDevice, error) {
@@ -213,8 +211,8 @@ func waitForUsbipStatusCleared(ctx context.Context, busid string) {
 
 // readPrimaryVHCIStatus reads every status* file under
 // /sys/devices/platform/vhci_hcd.0 and concatenates the rows in lexical
-// order. status reports controller 0; status.N reports controller N.
-// Port numbers are already globally unique — no remapping is needed.
+// order. Port numbers are already globally unique across controllers — no
+// remapping is needed.
 func readPrimaryVHCIStatus() ([]vhciStatusRecord, error) {
 	matches, err := filepath.Glob(filepath.Join(sysVHCIControllerV0, "status*"))
 	if err != nil {
@@ -223,15 +221,15 @@ func readPrimaryVHCIStatus() ([]vhciStatusRecord, error) {
 	sort.Strings(matches)
 	records := make([]vhciStatusRecord, 0)
 	for _, path := range matches {
-		secondary, parseErr := vhciSecondaryFromStatusFile(filepath.Base(path))
-		if parseErr != nil {
+		base := filepath.Base(path)
+		if base != "status" && !strings.HasPrefix(base, "status.") {
 			continue
 		}
 		raw, readErr := os.ReadFile(path)
 		if readErr != nil {
 			return nil, readErr
 		}
-		records = append(records, parseVHCIStatus(secondary, string(raw))...)
+		records = append(records, parseVHCIStatus(string(raw))...)
 	}
 	return records, nil
 }
@@ -267,18 +265,7 @@ func vhciPickFreePort(speed uint32, skip map[int]struct{}) (int, error) {
 	return -1, E.New("no free ", targetHub, " vhci port")
 }
 
-func vhciSecondaryFromStatusFile(name string) (int, error) {
-	if name == "status" {
-		return 0, nil
-	}
-	suffix := strings.TrimPrefix(name, "status.")
-	if suffix == name {
-		return 0, E.New("not a status file: ", name)
-	}
-	return strconv.Atoi(suffix)
-}
-
-func parseVHCIStatus(secondary int, raw string) []vhciStatusRecord {
+func parseVHCIStatus(raw string) []vhciStatusRecord {
 	scanner := bufio.NewScanner(strings.NewReader(raw))
 	records := make([]vhciStatusRecord, 0)
 	first := true
@@ -304,10 +291,9 @@ func parseVHCIStatus(secondary int, raw string) []vhciStatusRecord {
 			continue
 		}
 		records = append(records, vhciStatusRecord{
-			secondary: secondary,
-			hub:       fields[0],
-			port:      port,
-			state:     state,
+			hub:   fields[0],
+			port:  port,
+			state: state,
 		})
 	}
 	return records