fix: deduplicate logind shutdown inhibitors during silent updates (#318)

Use a shared refcounted inhibitor so overlapping update/check flows only
hold one logind inhibit lock at a time, preventing duplicate
org.deepin.dde.Lastore1 shutdown blockers.

Bug: https://pms.uniontech.com/bug-view-350063.html

Author: zhaohuiw42

src/lastore-daemon/inhibitor.go

@@ -5,12 +5,24 @@
 package main
 
 import (
+	"sync"
 	"syscall"
 
 	"github.com/godbus/dbus/v5"
 	login1 "github.com/linuxdeepin/go-dbus-factory/system/org.freedesktop.login1"
 )
 
+var (
+	sharedInhibitMu  sync.Mutex
+	sharedInhibitRef int
+	sharedInhibitFd  dbus.UnixFD = -1
+)
+
+var (
+	inhibitorFn    = Inhibitor
+	closeInhibitFd = func(fd dbus.UnixFD) error { return syscall.Close(int(fd)) }
+)
+
 type methodCaller uint
 
 const (
@@ -47,24 +59,58 @@ func (m *Manager) updateSystemOnChanging(onChanging bool, caller methodCaller) {
 		default:
 			why = Tr("Preventing from shutting down")
 		}
-		fd, err := Inhibitor("shutdown:sleep", dbusServiceName, why)
-		logger.Infof("Prevent shutdown...: fd:%v\n", fd)
+		fd, err := sharedInhibitAcquire(why)
 		if err != nil {
-			logger.Infof("Prevent shutdown failed: fd:%v, err:%v\n", fd, err)
+			logger.Infof("Prevent shutdown failed: err:%v\n", err)
 			return
 		}
+		logger.Info("Prevent shutdown...")
 		m.inhibitFd = fd
 	} else if !onChanging && m.inhibitFd != -1 {
-		err := syscall.Close(int(m.inhibitFd))
+		err := sharedInhibitRelease()
 		if err != nil {
-			logger.Infof("Enable shutdown...: fd:%d, err:%s\n", m.inhibitFd, err)
+			logger.Infof("Enable shutdown failed: err:%v\n", err)
 		} else {
 			logger.Info("Enable shutdown...")
 		}
 		m.inhibitFd = -1
 	}
 }
 
+func sharedInhibitAcquire(why string) (dbus.UnixFD, error) {
+	sharedInhibitMu.Lock()
+	defer sharedInhibitMu.Unlock()
+
+	if sharedInhibitRef == 0 {
+		fd, err := inhibitorFn("shutdown:sleep", dbusServiceName, why)
+		if err != nil {
+			return 0, err
+		}
+		sharedInhibitFd = fd
+	}
+	sharedInhibitRef++
+	return sharedInhibitFd, nil
+}
+
+func sharedInhibitRelease() error {
+	sharedInhibitMu.Lock()
+	defer sharedInhibitMu.Unlock()
+
+	if sharedInhibitRef == 0 {
+		return nil
+	}
+	sharedInhibitRef--
+	if sharedInhibitRef != 0 {
+		return nil
+	}
+	if sharedInhibitFd == -1 {
+		return nil
+	}
+	fd := sharedInhibitFd
+	sharedInhibitFd = -1
+	return closeInhibitFd(fd)
+}
+
 func Inhibitor(what, who, why string) (dbus.UnixFD, error) {
 	systemConn, err := dbus.SystemBus()
 	if err != nil {

src/lastore-daemon/manager_check.go

@@ -9,7 +9,6 @@ import (
 	"errors"
 	"fmt"
 	"os"
-	"syscall"
 	"time"
 
 	"github.com/linuxdeepin/lastore-daemon/src/internal/system"
@@ -44,30 +43,32 @@ func (m *Manager) checkUpgrade(sender dbus.Sender, checkMode system.UpdateType,
 	if m.rebootTimeoutTimer != nil {
 		m.rebootTimeoutTimer.Stop()
 	}
-	var inhibitFd dbus.UnixFD = -1
 	why := Tr("Checking and installing updates...")
+	var inhibitHeld bool
 	inhibit := func(enable bool) {
-		logger.Infof("handle inhibit:%v fd:%v", enable, inhibitFd)
+		logger.Infof("handle inhibit:%v held:%v", enable, inhibitHeld)
 		if enable {
-			if inhibitFd == -1 {
-				fd, err := Inhibitor("shutdown:sleep", dbusServiceName, why)
-				if err != nil {
-					logger.Infof("checkUpgrade:prevent shutdown failed: fd:%v, err:%v\n", fd, err)
-				} else {
-					logger.Infof("checkUpgrade:prevent shutdown: fd:%v\n", fd)
-					inhibitFd = fd
-				}
+			if inhibitHeld {
+				return
+			}
+			_, err := sharedInhibitAcquire(why)
+			if err != nil {
+				logger.Infof("checkUpgrade:prevent shutdown failed: err:%v\n", err)
+				return
 			}
+			logger.Info("checkUpgrade:prevent shutdown")
+			inhibitHeld = true
 		} else {
-			if inhibitFd != -1 {
-				err := syscall.Close(int(inhibitFd))
-				if err != nil {
-					logger.Infof("checkUpgrade:enable shutdown failed: fd:%d, err:%s\n", inhibitFd, err)
-				} else {
-					logger.Info("checkUpgrade:enable shutdown")
-					inhibitFd = -1
-				}
+			if !inhibitHeld {
+				return
+			}
+			err := sharedInhibitRelease()
+			if err != nil {
+				logger.Infof("checkUpgrade:enable shutdown failed: err:%v\n", err)
+				return
 			}
+			logger.Info("checkUpgrade:enable shutdown")
+			inhibitHeld = false
 		}
 	}
 	var job *Job

src/lastore-daemon/manager_upgrade.go

@@ -15,7 +15,6 @@ import (
 	"path/filepath"
 	"strings"
 	"sync"
-	"syscall"
 	"time"
 
 	"github.com/linuxdeepin/lastore-daemon/src/internal/config"
@@ -100,30 +99,32 @@ func (m *Manager) distUpgradePartly(sender dbus.Sender, origin system.UpdateType
 		}
 		return "/", dbusutil.ToError(createJobErr)
 	}
-	var inhibitFd dbus.UnixFD = -1
 	why := Tr("Backing up and installing updates...")
+	var inhibitHeld bool
 	inhibit := func(enable bool) {
-		logger.Infof("DistUpgradePartly:handle inhibit:%v fd:%v", enable, inhibitFd)
+		logger.Infof("DistUpgradePartly:handle inhibit:%v held:%v", enable, inhibitHeld)
 		if enable {
-			if inhibitFd == -1 {
-				fd, err := Inhibitor("shutdown:sleep", dbusServiceName, why)
-				if err != nil {
-					logger.Infof("DistUpgradePartly:prevent shutdown failed: fd:%v, err:%v\n", fd, err)
-				} else {
-					logger.Infof("DistUpgradePartly:prevent shutdown: fd:%v\n", fd)
-					inhibitFd = fd
-				}
+			if inhibitHeld {
+				return
+			}
+			_, err := sharedInhibitAcquire(why)
+			if err != nil {
+				logger.Infof("DistUpgradePartly:prevent shutdown failed: err:%v\n", err)
+				return
 			}
+			logger.Info("DistUpgradePartly:prevent shutdown")
+			inhibitHeld = true
 		} else {
-			if inhibitFd != -1 {
-				err := syscall.Close(int(inhibitFd))
-				if err != nil {
-					logger.Infof("DistUpgradePartly:enable shutdown failed: fd:%d, err:%s\n", inhibitFd, err)
-				} else {
-					logger.Info("DistUpgradePartly:enable shutdown")
-					inhibitFd = -1
-				}
+			if !inhibitHeld {
+				return
+			}
+			err := sharedInhibitRelease()
+			if err != nil {
+				logger.Infof("DistUpgradePartly:enable shutdown failed: err:%v\n", err)
+				return
 			}
+			logger.Info("DistUpgradePartly:enable shutdown")
+			inhibitHeld = false
 		}
 	}
 	// 开始更新job