1 files changed, 112 insertions, 35 deletions

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index ef071ca73fc3..072cbc9b175d 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -290,6 +290,8 @@ module_param_named(disable_numa, wq_disable_numa, bool, 0444);
 static bool wq_power_efficient = IS_ENABLED(CONFIG_WQ_POWER_EFFICIENT_DEFAULT);
 module_param_named(power_efficient, wq_power_efficient, bool, 0444);
 
+static bool wq_online;			/* can kworkers be created yet? */
+
 static bool wq_numa_enabled;		/* unbound NUMA affinity enabled */
 
 /* buf for wq_update_unbound_numa_attrs(), protected by CPU hotplug exclusion */
@@ -1521,8 +1523,6 @@ static void __queue_delayed_work(int cpu, struct workqueue_struct *wq,
 		return;
 	}
 
-	timer_stats_timer_set_start_info(&dwork->timer);
-
 	dwork->wq = wq;
 	dwork->cpu = cpu;
 	timer->expires = jiffies + delay;
@@ -2583,6 +2583,9 @@ void flush_workqueue(struct workqueue_struct *wq)
 	};
 	int next_color;
 
+	if (WARN_ON(!wq_online))
+		return;
+
 	lock_map_acquire(&wq->lockdep_map);
 	lock_map_release(&wq->lockdep_map);
 
@@ -2843,6 +2846,9 @@ bool flush_work(struct work_struct *work)
 {
 	struct wq_barrier barr;
 
+	if (WARN_ON(!wq_online))
+		return false;
+
 	lock_map_acquire(&work->lockdep_map);
 	lock_map_release(&work->lockdep_map);
 
@@ -2913,7 +2919,13 @@ static bool __cancel_work_timer(struct work_struct *work, bool is_dwork)
 	mark_work_canceling(work);
 	local_irq_restore(flags);
 
-	flush_work(work);
+	/*
+	 * This allows canceling during early boot.  We know that @work
+	 * isn't executing.
+	 */
+	if (wq_online)
+		flush_work(work);
+
 	clear_work_data(work);
 
 	/*
@@ -2974,6 +2986,31 @@ bool flush_delayed_work(struct delayed_work *dwork)
 }
 EXPORT_SYMBOL(flush_delayed_work);
 
+static bool __cancel_work(struct work_struct *work, bool is_dwork)
+{
+	unsigned long flags;
+	int ret;
+
+	do {
+		ret = try_to_grab_pending(work, is_dwork, &flags);
+	} while (unlikely(ret == -EAGAIN));
+
+	if (unlikely(ret < 0))
+		return false;
+
+	set_work_pool_and_clear_pending(work, get_work_pool_id(work));
+	local_irq_restore(flags);
+	return ret;
+}
+
+/*
+ * See cancel_delayed_work()
+ */
+bool cancel_work(struct work_struct *work)
+{
+	return __cancel_work(work, false);
+}
+
 /**
  * cancel_delayed_work - cancel a delayed work
  * @dwork: delayed_work to cancel
@@ -2992,20 +3029,7 @@ EXPORT_SYMBOL(flush_delayed_work);
  */
 bool cancel_delayed_work(struct delayed_work *dwork)
 {
-	unsigned long flags;
-	int ret;
-
-	do {
-		ret = try_to_grab_pending(&dwork->work, true, &flags);
-	} while (unlikely(ret == -EAGAIN));
-
-	if (unlikely(ret < 0))
-		return false;
-
-	set_work_pool_and_clear_pending(&dwork->work,
-					get_work_pool_id(&dwork->work));
-	local_irq_restore(flags);
-	return ret;
+	return __cancel_work(&dwork->work, true);
 }
 EXPORT_SYMBOL(cancel_delayed_work);
 
@@ -3352,7 +3376,7 @@ static struct worker_pool *get_unbound_pool(const struct workqueue_attrs *attrs)
 		goto fail;
 
 	/* create and start the initial worker */
-	if (!create_worker(pool))
+	if (wq_online && !create_worker(pool))
 		goto fail;
 
 	/* install */
@@ -3417,6 +3441,7 @@ static void pwq_adjust_max_active(struct pool_workqueue *pwq)
 {
 	struct workqueue_struct *wq = pwq->wq;
 	bool freezable = wq->flags & WQ_FREEZABLE;
+	unsigned long flags;
 
 	/* for @wq->saved_max_active */
 	lockdep_assert_held(&wq->mutex);
@@ -3425,7 +3450,8 @@ static void pwq_adjust_max_active(struct pool_workqueue *pwq)
 	if (!freezable && pwq->max_active == wq->saved_max_active)
 		return;
 
-	spin_lock_irq(&pwq->pool->lock);
+	/* this function can be called during early boot w/ irq disabled */
+	spin_lock_irqsave(&pwq->pool->lock, flags);
 
 	/*
 	 * During [un]freezing, the caller is responsible for ensuring that
@@ -3448,7 +3474,7 @@ static void pwq_adjust_max_active(struct pool_workqueue *pwq)
 		pwq->max_active = 0;
 	}
 
-	spin_unlock_irq(&pwq->pool->lock);
+	spin_unlock_irqrestore(&pwq->pool->lock, flags);
 }
 
 /* initialize newly alloced @pwq which is associated with @wq and @pool */
@@ -4021,6 +4047,7 @@ void destroy_workqueue(struct workqueue_struct *wq)
 		for (i = 0; i < WORK_NR_COLORS; i++) {
 			if (WARN_ON(pwq->nr_in_flight[i])) {
 				mutex_unlock(&wq->mutex);
+				show_workqueue_state();
 				return;
 			}
 		}
@@ -4029,6 +4056,7 @@ void destroy_workqueue(struct workqueue_struct *wq)
 		    WARN_ON(pwq->nr_active) ||
 		    WARN_ON(!list_empty(&pwq->delayed_works))) {
 			mutex_unlock(&wq->mutex);
+			show_workqueue_state();
 			return;
 		}
 	}
@@ -4249,7 +4277,7 @@ void print_worker_info(const char *log_lvl, struct task_struct *task)
 	 * This function is called without any synchronization and @task
 	 * could be in any state.  Be careful with dereferences.
 	 */
-	worker = probe_kthread_data(task);
+	worker = kthread_probe_data(task);
 
 	/*
 	 * Carefully copy the associated workqueue's workfn and name.  Keep
@@ -5455,7 +5483,17 @@ static void __init wq_numa_init(void)
 	wq_numa_enabled = true;
 }
 
-static int __init init_workqueues(void)
+/**
+ * workqueue_init_early - early init for workqueue subsystem
+ *
+ * This is the first half of two-staged workqueue subsystem initialization
+ * and invoked as soon as the bare basics - memory allocation, cpumasks and
+ * idr are up.  It sets up all the data structures and system workqueues
+ * and allows early boot code to create workqueues and queue/cancel work
+ * items.  Actual work item execution starts only after kthreads can be
+ * created and scheduled right before early initcalls.
+ */
+int __init workqueue_init_early(void)
 {
 	int std_nice[NR_STD_WORKER_POOLS] = { 0, HIGHPRI_NICE_LEVEL };
 	int i, cpu;
@@ -5467,8 +5505,6 @@ static int __init init_workqueues(void)
 
 	pwq_cache = KMEM_CACHE(pool_workqueue, SLAB_PANIC);
 
-	wq_numa_init();
-
 	/* initialize CPU pools */
 	for_each_possible_cpu(cpu) {
 		struct worker_pool *pool;
@@ -5488,16 +5524,6 @@ static int __init init_workqueues(void)
 		}
 	}
 
-	/* create the initial worker */
-	for_each_online_cpu(cpu) {
-		struct worker_pool *pool;
-
-		for_each_cpu_worker_pool(pool, cpu) {
-			pool->flags &= ~POOL_DISASSOCIATED;
-			BUG_ON(!create_worker(pool));
-		}
-	}
-
 	/* create default unbound and ordered wq attrs */
 	for (i = 0; i < NR_STD_WORKER_POOLS; i++) {
 		struct workqueue_attrs *attrs;
@@ -5534,8 +5560,59 @@ static int __init init_workqueues(void)
 	       !system_power_efficient_wq ||
 	       !system_freezable_power_efficient_wq);
 
+	return 0;
+}
+
+/**
+ * workqueue_init - bring workqueue subsystem fully online
+ *
+ * This is the latter half of two-staged workqueue subsystem initialization
+ * and invoked as soon as kthreads can be created and scheduled.
+ * Workqueues have been created and work items queued on them, but there
+ * are no kworkers executing the work items yet.  Populate the worker pools
+ * with the initial workers and enable future kworker creations.
+ */
+int __init workqueue_init(void)
+{
+	struct workqueue_struct *wq;
+	struct worker_pool *pool;
+	int cpu, bkt;
+
+	/*
+	 * It'd be simpler to initialize NUMA in workqueue_init_early() but
+	 * CPU to node mapping may not be available that early on some
+	 * archs such as power and arm64.  As per-cpu pools created
+	 * previously could be missing node hint and unbound pools NUMA
+	 * affinity, fix them up.
+	 */
+	wq_numa_init();
+
+	mutex_lock(&wq_pool_mutex);
+
+	for_each_possible_cpu(cpu) {
+		for_each_cpu_worker_pool(pool, cpu) {
+			pool->node = cpu_to_node(cpu);
+		}
+	}
+
+	list_for_each_entry(wq, &workqueues, list)
+		wq_update_unbound_numa(wq, smp_processor_id(), true);
+
+	mutex_unlock(&wq_pool_mutex);
+
+	/* create the initial workers */
+	for_each_online_cpu(cpu) {
+		for_each_cpu_worker_pool(pool, cpu) {
+			pool->flags &= ~POOL_DISASSOCIATED;
+			BUG_ON(!create_worker(pool));
+		}
+	}
+
+	hash_for_each(unbound_pool_hash, bkt, pool, hash_node)
+		BUG_ON(!create_worker(pool));
+
+	wq_online = true;
 	wq_watchdog_init();
 
 	return 0;
 }
-early_initcall(init_workqueues);