Revert "Merge pull request 101888 from kolyshkin/update-runc-rc94"

This reverts commit b1b06fe0a4, reversing
changes made to 382a33986b.

vendor/github.com/opencontainers/runc/libcontainer/cgroups/systemd/dbus.go

@@ -1,96 +0,0 @@
-// +build linux
-
-package systemd
-
-import (
-	"context"
-	"sync"
-
-	systemdDbus "github.com/coreos/go-systemd/v22/dbus"
-	dbus "github.com/godbus/dbus/v5"
-)
-
-var (
-	dbusC        *systemdDbus.Conn
-	dbusMu       sync.RWMutex
-	dbusInited   bool
-	dbusRootless bool
-)
-
-type dbusConnManager struct {
-}
-
-// newDbusConnManager initializes systemd dbus connection manager.
-func newDbusConnManager(rootless bool) *dbusConnManager {
-	if dbusInited && rootless != dbusRootless {
-		panic("can't have both root and rootless dbus")
-	}
-	dbusRootless = rootless
-	return &dbusConnManager{}
-}
-
-// getConnection lazily initializes and returns systemd dbus connection.
-func (d *dbusConnManager) getConnection() (*systemdDbus.Conn, error) {
-	// In the case where dbusC != nil
-	// Use the read lock the first time to ensure
-	// that Conn can be acquired at the same time.
-	dbusMu.RLock()
-	if conn := dbusC; conn != nil {
-		dbusMu.RUnlock()
-		return conn, nil
-	}
-	dbusMu.RUnlock()
-
-	// In the case where dbusC == nil
-	// Use write lock to ensure that only one
-	// will be created
-	dbusMu.Lock()
-	defer dbusMu.Unlock()
-	if conn := dbusC; conn != nil {
-		return conn, nil
-	}
-
-	conn, err := d.newConnection()
-	if err != nil {
-		return nil, err
-	}
-	dbusC = conn
-	return conn, nil
-}
-
-func (d *dbusConnManager) newConnection() (*systemdDbus.Conn, error) {
-	if dbusRootless {
-		return newUserSystemdDbus()
-	}
-	return systemdDbus.NewWithContext(context.TODO())
-}
-
-// resetConnection resets the connection to its initial state
-// (so it can be reconnected if necessary).
-func (d *dbusConnManager) resetConnection(conn *systemdDbus.Conn) {
-	dbusMu.Lock()
-	defer dbusMu.Unlock()
-	if dbusC != nil && dbusC == conn {
-		dbusC.Close()
-		dbusC = nil
-	}
-}
-
-var errDbusConnClosed = dbus.ErrClosed.Error()
-
-// retryOnDisconnect calls op, and if the error it returns is about closed dbus
-// connection, the connection is re-established and the op is retried. This helps
-// with the situation when dbus is restarted and we have a stale connection.
-func (d *dbusConnManager) retryOnDisconnect(op func(*systemdDbus.Conn) error) error {
-	for {
-		conn, err := d.getConnection()
-		if err != nil {
-			return err
-		}
-		err = op(conn)
-		if !isDbusError(err, errDbusConnClosed) {
-			return err
-		}
-		d.resetConnection(conn)
-	}
-}