re-open cgmanager socket after fork in daemonized start

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

src/lxc/cgmanager.c

@@ -114,7 +114,8 @@ static bool cgm_dbus_connect(void)
 
 static void cgm_dbus_disconnect(void)
 {
-	nih_free(cgroup_manager);
+	if (cgroup_manager)
+		nih_free(cgroup_manager);
 	cgroup_manager = NULL;
 }
 
@@ -886,5 +887,6 @@ static struct cgroup_ops cgmanager_ops = {
 	.attach = cgm_attach,
 	.mount_cgroup = cgm_mount_cgroup,
 	.nrtasks = cgm_get_nrtasks,
+	.disconnect = cgm_dbus_disconnect,
 };
 #endif

src/lxc/cgroup.c

@@ -167,3 +167,11 @@ int lxc_cgroup_get(const char *filename, char *value, size_t len, const char *na
 		return ops->get(filename, value, len, name, lxcpath);
 	return -1;
 }
+
+void restart_cgroups(void)
+{
+	if (ops && ops->disconnect)
+		ops->disconnect();
+	ops = NULL;
+	cgroup_ops_init();
+}

src/lxc/cgroup.h

@@ -49,6 +49,7 @@ struct cgroup_ops {
 	bool (*attach)(const char *name, const char *lxcpath, pid_t pid);
 	bool (*mount_cgroup)(void *hdata, const char *root, int type);
 	int (*nrtasks)(void *hdata);
+	void (*disconnect)(void);
 };
 
 extern bool cgroup_attach(const char *name, const char *lxcpath, pid_t pid);
@@ -64,5 +65,6 @@ extern bool cgroup_create_legacy(struct lxc_handler *handler);
 extern int cgroup_nrtasks(struct lxc_handler *handler);
 extern const char *cgroup_get_cgroup(struct lxc_handler *handler, const char *subsystem);
 extern bool cgroup_unfreeze(struct lxc_handler *handler);
+extern void restart_cgroups(void);
 
 #endif

src/lxc/lxccontainer.c

@@ -637,6 +637,7 @@ static bool lxcapi_start(struct lxc_container *c, int useinit, char * const argv
 		open("/dev/null", O_RDWR);
 		open("/dev/null", O_RDWR);
 		setsid();
+		restart_cgroups();
 	} else {
 		if (!am_single_threaded()) {
 			ERROR("Cannot start non-daemonized container when threaded");