rcutorture: Abstract torture_shutdown_notify()

Because handling the race between rmmod and system shutdown is not
specific to RCU, this commit abstracts torture_shutdown_notify(),
placing this code into kernel/torture.c.  This change also allows
fullstop_mutex to be private to kernel/torture.c.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

diff --git a/include/linux/torture.h b/include/linux/torture.h
index 31d69930e5cf84c9f2537df9ac20654c83526692..742d8a402f19fbd90dae67d5f698387c2f87e137 100644 (file)
--- a/include/linux/torture.h
+++ b/include/linux/torture.h
@@ -46,8 +46,6 @@
 #define FULLSTOP_SHUTDOWN 1    /* System shutdown with rcutorture running. */
 #define FULLSTOP_RMMOD    2    /* Normal rmmod of rcutorture. */
 extern int fullstop;
-/* Protect fullstop transitions and spawning of kthreads.  */
-extern struct mutex fullstop_mutex;
 
 #define TORTURE_FLAG "-torture:"
 #define TOROUT_STRING(s) \

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 68a689fc6ffa85b6f832616c1714e4b914552a07..2560e9313887649e8fb5109a2c2539ddf1708209 100644 (file)
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -189,23 +189,6 @@ static DECLARE_WAIT_QUEUE_HEAD(barrier_wq);
 /* Forward reference. */
 static void rcu_torture_cleanup(void);
 
-/*
- * Detect and respond to a system shutdown.
- */
-static int
-rcutorture_shutdown_notify(struct notifier_block *unused1,
-                          unsigned long unused2, void *unused3)
-{
-       mutex_lock(&fullstop_mutex);
-       if (fullstop == FULLSTOP_DONTSTOP)
-               fullstop = FULLSTOP_SHUTDOWN;
-       else
-               pr_warn(/* but going down anyway, so... */
-                      "Concurrent 'rmmod rcutorture' and shutdown illegal!\n");
-       mutex_unlock(&fullstop_mutex);
-       return NOTIFY_DONE;
-}
-
 /*
  * Allocate an element from the rcu_tortures pool.
  */
@@ -1098,10 +1081,6 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
                 onoff_interval, onoff_holdoff);
 }
 
-static struct notifier_block rcutorture_shutdown_nb = {
-       .notifier_call = rcutorture_shutdown_notify,
-};
-
 static void rcutorture_booster_cleanup(int cpu)
 {
        struct task_struct *t;
@@ -1428,7 +1407,6 @@ rcu_torture_cleanup(void)
                        cur_ops->cb_barrier();
                return;
        }
-       unregister_reboot_notifier(&rcutorture_shutdown_nb);
 
        rcu_torture_barrier_cleanup();
        rcu_torture_stall_cleanup();
@@ -1774,7 +1752,6 @@ rcu_torture_init(void)
                firsterr = i;
                goto unwind;
        }
-       register_reboot_notifier(&rcutorture_shutdown_nb);
        i = rcu_torture_stall_init();
        if (i != 0) {
                firsterr = i;

diff --git a/kernel/torture.c b/kernel/torture.c
index 41ae5cc3c4c352146d5f589fc5c6789d831fab93..b02fa2785bbb42bdd1c83a2dacb321938221f126 100644 (file)
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -54,8 +54,7 @@ static bool verbose;
 
 int fullstop = FULLSTOP_RMMOD;
 EXPORT_SYMBOL_GPL(fullstop);
-DEFINE_MUTEX(fullstop_mutex);
-EXPORT_SYMBOL_GPL(fullstop_mutex);
+static DEFINE_MUTEX(fullstop_mutex);
 
 #ifdef CONFIG_HOTPLUG_CPU
 
@@ -422,14 +421,32 @@ EXPORT_SYMBOL_GPL(torture_shuffle_cleanup);
 void torture_shutdown_absorb(const char *title)
 {
        while (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) {
-               pr_notice(
-                      "torture thread %s parking due to system shutdown\n",
-                      title);
+               pr_notice("torture thread %s parking due to system shutdown\n",
+                         title);
                schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT);
        }
 }
 EXPORT_SYMBOL_GPL(torture_shutdown_absorb);
 
+/*
+ * Detect and respond to a system shutdown.
+ */
+static int torture_shutdown_notify(struct notifier_block *unused1,
+                                  unsigned long unused2, void *unused3)
+{
+       mutex_lock(&fullstop_mutex);
+       if (fullstop == FULLSTOP_DONTSTOP)
+               fullstop = FULLSTOP_SHUTDOWN;
+       else
+               pr_warn("Concurrent rmmod and shutdown illegal!\n");
+       mutex_unlock(&fullstop_mutex);
+       return NOTIFY_DONE;
+}
+
+static struct notifier_block torture_shutdown_nb = {
+       .notifier_call = torture_shutdown_notify,
+};
+
 /*
  * Initialize torture module.  Please note that this is -not- invoked via
  * the usual module_init() mechanism, but rather by an explicit call from
@@ -451,6 +468,7 @@ EXPORT_SYMBOL_GPL(torture_init_begin);
 void __init torture_init_end(void)
 {
        mutex_unlock(&fullstop_mutex);
+       register_reboot_notifier(&torture_shutdown_nb);
 }
 EXPORT_SYMBOL_GPL(torture_init_end);
 
@@ -474,6 +492,7 @@ bool torture_cleanup(void)
        }
        fullstop = FULLSTOP_RMMOD;
        mutex_unlock(&fullstop_mutex);
+       unregister_reboot_notifier(&torture_shutdown_nb);
        torture_shuffle_cleanup();
        torture_onoff_cleanup();
        return false;