daemon: getPluginExecRoot(): pass config

This makes it more transparent that it's unused for Linux,
and we don't pass "root", which has no relation with the
path on Linux.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

daemon/daemon.go

@@ -903,13 +903,13 @@ func NewDaemon(ctx context.Context, config *config.Config, pluginStore *plugin.S
 			}
 			rt = *rtPtr
 		}
-		return pluginexec.New(ctx, getPluginExecRoot(config.Root), pluginCli, config.ContainerdPluginNamespace, m, rt)
+		return pluginexec.New(ctx, getPluginExecRoot(config), pluginCli, config.ContainerdPluginNamespace, m, rt)
 	}
 
 	// Plugin system initialization should happen before restore. Do not change order.
 	d.pluginManager, err = plugin.NewManager(plugin.ManagerConfig{
 		Root:               filepath.Join(config.Root, "plugins"),
-		ExecRoot:           getPluginExecRoot(config.Root),
+		ExecRoot:           getPluginExecRoot(config),
 		Store:              d.PluginStore,
 		CreateExecutor:     createPluginExec,
 		RegistryService:    registryService,

daemon/daemon_linux.go

@@ -20,7 +20,7 @@ import (
 // instead of deriving path from daemon's exec-root. This is because
 // plugin socket files are created here and they cannot exceed max
 // path length of 108 bytes.
-func getPluginExecRoot(root string) string {
+func getPluginExecRoot(_ *config.Config) string {
 	return "/run/docker/plugins"
 }
 

daemon/daemon_windows.go

@@ -55,8 +55,8 @@ func adjustParallelLimit(n int, limit int) int {
 }
 
 // Windows has no concept of an execution state directory. So use config.Root here.
-func getPluginExecRoot(root string) string {
-	return filepath.Join(root, "plugins")
+func getPluginExecRoot(cfg *config.Config) string {
+	return filepath.Join(cfg.Root, "plugins")
 }
 
 func (daemon *Daemon) parseSecurityOpt(container *container.Container, hostConfig *containertypes.HostConfig) error {