Merge branch 'for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull workqueue updates from Tejun Heo:
 "Mostly cleanups and other trivial changes.

  The only interesting change is Sebastian's rcuwait conversion for RT"

* 'for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: use BUILD_BUG_ON() for compile time test instead of WARN_ON()
  workqueue: fix a piece of comment about reserved bits for work flags
  workqueue: remove useless unlock() and lock() in series
  workqueue: void unneeded requeuing the pwq in rescuer thread
  workqueue: Convert the pool::lock and wq_mayday_lock to raw_spinlock_t
  workqueue: Use rcuwait for wq_manager_wait
  workqueue: Remove unnecessary kfree() call in rcu_free_wq()
  workqueue: Fix an use after free in init_rescuer()
  workqueue: Use IS_ERR and PTR_ERR instead of PTR_ERR_OR_ZERO.

2 files changed, 110 insertions, 99 deletions

diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 8b505d22fc0e..26de0cae2a0a 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -62,7 +62,7 @@ enum {
 	WORK_CPU_UNBOUND	= NR_CPUS,
 
 	/*
-	 * Reserve 7 bits off of pwq pointer w/ debugobjects turned off.
+	 * Reserve 8 bits off of pwq pointer w/ debugobjects turned off.
 	 * This makes pwqs aligned to 256 bytes and allows 15 workqueue
 	 * flush colors.
 	 */
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 891ccad5f271..9fbe1e237563 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -145,7 +145,7 @@ enum {
 /* struct worker is defined in workqueue_internal.h */
 
 struct worker_pool {
-	spinlock_t		lock;		/* the pool lock */
+	raw_spinlock_t		lock;		/* the pool lock */
 	int			cpu;		/* I: the associated cpu */
 	int			node;		/* I: the associated node ID */
 	int			id;		/* I: pool ID */
@@ -300,8 +300,9 @@ static struct workqueue_attrs *wq_update_unbound_numa_attrs_buf;
 
 static DEFINE_MUTEX(wq_pool_mutex);	/* protects pools and workqueues list */
 static DEFINE_MUTEX(wq_pool_attach_mutex); /* protects worker attach/detach */
-static DEFINE_SPINLOCK(wq_mayday_lock);	/* protects wq->maydays list */
-static DECLARE_WAIT_QUEUE_HEAD(wq_manager_wait); /* wait for manager to go away */
+static DEFINE_RAW_SPINLOCK(wq_mayday_lock);	/* protects wq->maydays list */
+/* wait for manager to go away */
+static struct rcuwait manager_wait = __RCUWAIT_INITIALIZER(manager_wait);
 
 static LIST_HEAD(workqueues);		/* PR: list of all workqueues */
 static bool workqueue_freezing;		/* PL: have wqs started freezing? */
@@ -826,7 +827,7 @@ static struct worker *first_idle_worker(struct worker_pool *pool)
  * Wake up the first idle worker of @pool.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock).
+ * raw_spin_lock_irq(pool->lock).
  */
 static void wake_up_worker(struct worker_pool *pool)
 {
@@ -881,7 +882,7 @@ void wq_worker_sleeping(struct task_struct *task)
 		return;
 
 	worker->sleeping = 1;
-	spin_lock_irq(&pool->lock);
+	raw_spin_lock_irq(&pool->lock);
 
 	/*
 	 * The counterpart of the following dec_and_test, implied mb,
@@ -900,7 +901,7 @@ void wq_worker_sleeping(struct task_struct *task)
 		if (next)
 			wake_up_process(next->task);
 	}
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 }
 
 /**
@@ -911,7 +912,7 @@ void wq_worker_sleeping(struct task_struct *task)
  * the scheduler to get a worker's last known identity.
  *
  * CONTEXT:
- * spin_lock_irq(rq->lock)
+ * raw_spin_lock_irq(rq->lock)
  *
  * This function is called during schedule() when a kworker is going
  * to sleep. It's used by psi to identify aggregation workers during
@@ -942,7 +943,7 @@ work_func_t wq_worker_last_func(struct task_struct *task)
  * Set @flags in @worker->flags and adjust nr_running accordingly.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock)
+ * raw_spin_lock_irq(pool->lock)
  */
 static inline void worker_set_flags(struct worker *worker, unsigned int flags)
 {
@@ -967,7 +968,7 @@ static inline void worker_set_flags(struct worker *worker, unsigned int flags)
  * Clear @flags in @worker->flags and adjust nr_running accordingly.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock)
+ * raw_spin_lock_irq(pool->lock)
  */
 static inline void worker_clr_flags(struct worker *worker, unsigned int flags)
 {
@@ -1015,7 +1016,7 @@ static inline void worker_clr_flags(struct worker *worker, unsigned int flags)
  * actually occurs, it should be easy to locate the culprit work function.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock).
+ * raw_spin_lock_irq(pool->lock).
  *
  * Return:
  * Pointer to worker which is executing @work if found, %NULL
@@ -1050,7 +1051,7 @@ static struct worker *find_worker_executing_work(struct worker_pool *pool,
  * nested inside outer list_for_each_entry_safe().
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock).
+ * raw_spin_lock_irq(pool->lock).
  */
 static void move_linked_works(struct work_struct *work, struct list_head *head,
 			      struct work_struct **nextp)
@@ -1128,9 +1129,9 @@ static void put_pwq_unlocked(struct pool_workqueue *pwq)
 		 * As both pwqs and pools are RCU protected, the
 		 * following lock operations are safe.
 		 */
-		spin_lock_irq(&pwq->pool->lock);
+		raw_spin_lock_irq(&pwq->pool->lock);
 		put_pwq(pwq);
-		spin_unlock_irq(&pwq->pool->lock);
+		raw_spin_unlock_irq(&pwq->pool->lock);
 	}
 }
 
@@ -1163,7 +1164,7 @@ static void pwq_activate_first_delayed(struct pool_workqueue *pwq)
  * decrement nr_in_flight of its pwq and handle workqueue flushing.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock).
+ * raw_spin_lock_irq(pool->lock).
  */
 static void pwq_dec_nr_in_flight(struct pool_workqueue *pwq, int color)
 {
@@ -1262,7 +1263,7 @@ static int try_to_grab_pending(struct work_struct *work, bool is_dwork,
 	if (!pool)
 		goto fail;
 
-	spin_lock(&pool->lock);
+	raw_spin_lock(&pool->lock);
 	/*
 	 * work->data is guaranteed to point to pwq only while the work
 	 * item is queued on pwq->wq, and both updating work->data to point
@@ -1291,11 +1292,11 @@ static int try_to_grab_pending(struct work_struct *work, bool is_dwork,
 		/* work->data points to pwq iff queued, point to pool */
 		set_work_pool_and_keep_pending(work, pool->id);
 
-		spin_unlock(&pool->lock);
+		raw_spin_unlock(&pool->lock);
 		rcu_read_unlock();
 		return 1;
 	}
-	spin_unlock(&pool->lock);
+	raw_spin_unlock(&pool->lock);
 fail:
 	rcu_read_unlock();
 	local_irq_restore(*flags);
@@ -1316,7 +1317,7 @@ fail:
  * work_struct flags.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock).
+ * raw_spin_lock_irq(pool->lock).
  */
 static void insert_work(struct pool_workqueue *pwq, struct work_struct *work,
 			struct list_head *head, unsigned int extra_flags)
@@ -1433,7 +1434,7 @@ retry:
 	if (last_pool && last_pool != pwq->pool) {
 		struct worker *worker;
 
-		spin_lock(&last_pool->lock);
+		raw_spin_lock(&last_pool->lock);
 
 		worker = find_worker_executing_work(last_pool, work);
 
@@ -1441,11 +1442,11 @@ retry:
 			pwq = worker->current_pwq;
 		} else {
 			/* meh... not running there, queue here */
-			spin_unlock(&last_pool->lock);
-			spin_lock(&pwq->pool->lock);
+			raw_spin_unlock(&last_pool->lock);
+			raw_spin_lock(&pwq->pool->lock);
 		}
 	} else {
-		spin_lock(&pwq->pool->lock);
+		raw_spin_lock(&pwq->pool->lock);
 	}
 
 	/*
@@ -1458,7 +1459,7 @@ retry:
 	 */
 	if (unlikely(!pwq->refcnt)) {
 		if (wq->flags & WQ_UNBOUND) {
-			spin_unlock(&pwq->pool->lock);
+			raw_spin_unlock(&pwq->pool->lock);
 			cpu_relax();
 			goto retry;
 		}
@@ -1490,7 +1491,7 @@ retry:
 	insert_work(pwq, work, worklist, work_flags);
 
 out:
-	spin_unlock(&pwq->pool->lock);
+	raw_spin_unlock(&pwq->pool->lock);
 	rcu_read_unlock();
 }
 
@@ -1759,7 +1760,7 @@ EXPORT_SYMBOL(queue_rcu_work);
  * necessary.
  *
  * LOCKING:
- * spin_lock_irq(pool->lock).
+ * raw_spin_lock_irq(pool->lock).
  */
 static void worker_enter_idle(struct worker *worker)
 {
@@ -1799,7 +1800,7 @@ static void worker_enter_idle(struct worker *worker)
  * @worker is leaving idle state.  Update stats.
  *
  * LOCKING:
- * spin_lock_irq(pool->lock).
+ * raw_spin_lock_irq(pool->lock).
  */
 static void worker_leave_idle(struct worker *worker)
 {
@@ -1937,11 +1938,11 @@ static struct worker *create_worker(struct worker_pool *pool)
 	worker_attach_to_pool(worker, pool);
 
 	/* start the newly created worker */
-	spin_lock_irq(&pool->lock);
+	raw_spin_lock_irq(&pool->lock);
 	worker->pool->nr_workers++;
 	worker_enter_idle(worker);
 	wake_up_process(worker->task);
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 
 	return worker;
 
@@ -1960,7 +1961,7 @@ fail:
  * be idle.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock).
+ * raw_spin_lock_irq(pool->lock).
  */
 static void destroy_worker(struct worker *worker)
 {
@@ -1986,7 +1987,7 @@ static void idle_worker_timeout(struct timer_list *t)
 {
 	struct worker_pool *pool = from_timer(pool, t, idle_timer);
 
-	spin_lock_irq(&pool->lock);
+	raw_spin_lock_irq(&pool->lock);
 
 	while (too_many_workers(pool)) {
 		struct worker *worker;
@@ -2004,7 +2005,7 @@ static void idle_worker_timeout(struct timer_list *t)
 		destroy_worker(worker);
 	}
 
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 }
 
 static void send_mayday(struct work_struct *work)
@@ -2035,8 +2036,8 @@ static void pool_mayday_timeout(struct timer_list *t)
 	struct worker_pool *pool = from_timer(pool, t, mayday_timer);
 	struct work_struct *work;
 
-	spin_lock_irq(&pool->lock);
-	spin_lock(&wq_mayday_lock);		/* for wq->maydays */
+	raw_spin_lock_irq(&pool->lock);
+	raw_spin_lock(&wq_mayday_lock);		/* for wq->maydays */
 
 	if (need_to_create_worker(pool)) {
 		/*
@@ -2049,8 +2050,8 @@ static void pool_mayday_timeout(struct timer_list *t)
 			send_mayday(work);
 	}
 
-	spin_unlock(&wq_mayday_lock);
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock(&wq_mayday_lock);
+	raw_spin_unlock_irq(&pool->lock);
 
 	mod_timer(&pool->mayday_timer, jiffies + MAYDAY_INTERVAL);
 }
@@ -2069,7 +2070,7 @@ static void pool_mayday_timeout(struct timer_list *t)
  * may_start_working() %true.
  *
  * LOCKING:
- * spin_lock_irq(pool->lock) which may be released and regrabbed
+ * raw_spin_lock_irq(pool->lock) which may be released and regrabbed
  * multiple times.  Does GFP_KERNEL allocations.  Called only from
  * manager.
  */
@@ -2078,7 +2079,7 @@ __releases(&pool->lock)
 __acquires(&pool->lock)
 {
 restart:
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 
 	/* if we don't make progress in MAYDAY_INITIAL_TIMEOUT, call for help */
 	mod_timer(&pool->mayday_timer, jiffies + MAYDAY_INITIAL_TIMEOUT);
@@ -2094,7 +2095,7 @@ restart:
 	}
 
 	del_timer_sync(&pool->mayday_timer);
-	spin_lock_irq(&pool->lock);
+	raw_spin_lock_irq(&pool->lock);
 	/*
 	 * This is necessary even after a new worker was just successfully
 	 * created as @pool->lock was dropped and the new worker might have
@@ -2117,7 +2118,7 @@ restart:
  * and may_start_working() is true.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock) which may be released and regrabbed
+ * raw_spin_lock_irq(pool->lock) which may be released and regrabbed
  * multiple times.  Does GFP_KERNEL allocations.
  *
  * Return:
@@ -2140,7 +2141,7 @@ static bool manage_workers(struct worker *worker)
 
 	pool->manager = NULL;
 	pool->flags &= ~POOL_MANAGER_ACTIVE;
-	wake_up(&wq_manager_wait);
+	rcuwait_wake_up(&manager_wait);
 	return true;
 }
 
@@ -2156,7 +2157,7 @@ static bool manage_workers(struct worker *worker)
  * call this function to process a work.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock) which is released and regrabbed.
+ * raw_spin_lock_irq(pool->lock) which is released and regrabbed.
  */
 static void process_one_work(struct worker *worker, struct work_struct *work)
 __releases(&pool->lock)
@@ -2238,7 +2239,7 @@ __acquires(&pool->lock)
 	 */
 	set_work_pool_and_clear_pending(work, pool->id);
 
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 
 	lock_map_acquire(&pwq->wq->lockdep_map);
 	lock_map_acquire(&lockdep_map);
@@ -2293,7 +2294,7 @@ __acquires(&pool->lock)
 	 */
 	cond_resched();
 
-	spin_lock_irq(&pool->lock);
+	raw_spin_lock_irq(&pool->lock);
 
 	/* clear cpu intensive status */
 	if (unlikely(cpu_intensive))
@@ -2319,7 +2320,7 @@ __acquires(&pool->lock)
  * fetches a work from the top and executes it.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock) which may be released and regrabbed
+ * raw_spin_lock_irq(pool->lock) which may be released and regrabbed
  * multiple times.
  */
 static void process_scheduled_works(struct worker *worker)
@@ -2361,11 +2362,11 @@ static int worker_thread(void *__worker)
 	/* tell the scheduler that this is a workqueue worker */
 	set_pf_worker(true);
 woke_up:
-	spin_lock_irq(&pool->lock);
+	raw_spin_lock_irq(&pool->lock);
 
 	/* am I supposed to die? */
 	if (unlikely(worker->flags & WORKER_DIE)) {
-		spin_unlock_irq(&pool->lock);
+		raw_spin_unlock_irq(&pool->lock);
 		WARN_ON_ONCE(!list_empty(&worker->entry));
 		set_pf_worker(false);
 
@@ -2431,7 +2432,7 @@ sleep:
 	 */
 	worker_enter_idle(worker);
 	__set_current_state(TASK_IDLE);
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 	schedule();
 	goto woke_up;
 }
@@ -2485,7 +2486,7 @@ repeat:
 	should_stop = kthread_should_stop();
 
 	/* see whether any pwq is asking for help */
-	spin_lock_irq(&wq_mayday_lock);
+	raw_spin_lock_irq(&wq_mayday_lock);
 
 	while (!list_empty(&wq->maydays)) {
 		struct pool_workqueue *pwq = list_first_entry(&wq->maydays,
@@ -2497,11 +2498,11 @@ repeat:
 		__set_current_state(TASK_RUNNING);
 		list_del_init(&pwq->mayday_node);
 
-		spin_unlock_irq(&wq_mayday_lock);
+		raw_spin_unlock_irq(&wq_mayday_lock);
 
 		worker_attach_to_pool(rescuer, pool);
 
-		spin_lock_irq(&pool->lock);
+		raw_spin_lock_irq(&pool->lock);
 
 		/*
 		 * Slurp in all works issued via this workqueue and
@@ -2529,8 +2530,8 @@ repeat:
 			 * being used to relieve memory pressure, don't
 			 * incur MAYDAY_INTERVAL delay inbetween.
 			 */
-			if (need_to_create_worker(pool)) {
-				spin_lock(&wq_mayday_lock);
+			if (pwq->nr_active && need_to_create_worker(pool)) {
+				raw_spin_lock(&wq_mayday_lock);
 				/*
 				 * Queue iff we aren't racing destruction
 				 * and somebody else hasn't queued it already.
@@ -2539,7 +2540,7 @@ repeat:
 					get_pwq(pwq);
 					list_add_tail(&pwq->mayday_node, &wq->maydays);
 				}
-				spin_unlock(&wq_mayday_lock);
+				raw_spin_unlock(&wq_mayday_lock);
 			}
 		}
 
@@ -2557,14 +2558,14 @@ repeat:
 		if (need_more_worker(pool))
 			wake_up_worker(pool);
 
-		spin_unlock_irq(&pool->lock);
+		raw_spin_unlock_irq(&pool->lock);
 
 		worker_detach_from_pool(rescuer);
 
-		spin_lock_irq(&wq_mayday_lock);
+		raw_spin_lock_irq(&wq_mayday_lock);
 	}
 
-	spin_unlock_irq(&wq_mayday_lock);
+	raw_spin_unlock_irq(&wq_mayday_lock);
 
 	if (should_stop) {
 		__set_current_state(TASK_RUNNING);
@@ -2644,7 +2645,7 @@ static void wq_barrier_func(struct work_struct *work)
  * underneath us, so we can't reliably determine pwq from @target.
  *
  * CONTEXT:
- * spin_lock_irq(pool->lock).
+ * raw_spin_lock_irq(pool->lock).
  */
 static void insert_wq_barrier(struct pool_workqueue *pwq,
 			      struct wq_barrier *barr,
@@ -2731,7 +2732,7 @@ static bool flush_workqueue_prep_pwqs(struct workqueue_struct *wq,
 	for_each_pwq(pwq, wq) {
 		struct worker_pool *pool = pwq->pool;
 
-		spin_lock_irq(&pool->lock);
+		raw_spin_lock_irq(&pool->lock);
 
 		if (flush_color >= 0) {
 			WARN_ON_ONCE(pwq->flush_color != -1);
@@ -2748,7 +2749,7 @@ static bool flush_workqueue_prep_pwqs(struct workqueue_struct *wq,
 			pwq->work_color = work_color;
 		}
 
-		spin_unlock_irq(&pool->lock);
+		raw_spin_unlock_irq(&pool->lock);
 	}
 
 	if (flush_color >= 0 && atomic_dec_and_test(&wq->nr_pwqs_to_flush))
@@ -2948,9 +2949,9 @@ reflush:
 	for_each_pwq(pwq, wq) {
 		bool drained;
 
-		spin_lock_irq(&pwq->pool->lock);
+		raw_spin_lock_irq(&pwq->pool->lock);
 		drained = !pwq->nr_active && list_empty(&pwq->delayed_works);
-		spin_unlock_irq(&pwq->pool->lock);
+		raw_spin_unlock_irq(&pwq->pool->lock);
 
 		if (drained)
 			continue;
@@ -2986,7 +2987,7 @@ static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr,
 		return false;
 	}
 
-	spin_lock_irq(&pool->lock);
+	raw_spin_lock_irq(&pool->lock);
 	/* see the comment in try_to_grab_pending() with the same code */
 	pwq = get_work_pwq(work);
 	if (pwq) {
@@ -3002,7 +3003,7 @@ static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr,
 	check_flush_dependency(pwq->wq, work);
 
 	insert_wq_barrier(pwq, barr, work, worker);
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 
 	/*
 	 * Force a lock recursion deadlock when using flush_work() inside a
@@ -3021,7 +3022,7 @@ static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr,
 	rcu_read_unlock();
 	return true;
 already_gone:
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 	rcu_read_unlock();
 	return false;
 }
@@ -3414,7 +3415,7 @@ static bool wqattrs_equal(const struct workqueue_attrs *a,
  */
 static int init_worker_pool(struct worker_pool *pool)
 {
-	spin_lock_init(&pool->lock);
+	raw_spin_lock_init(&pool->lock);
 	pool->id = -1;
 	pool->cpu = -1;
 	pool->node = NUMA_NO_NODE;
@@ -3491,7 +3492,6 @@ static void rcu_free_wq(struct rcu_head *rcu)
 	else
 		free_workqueue_attrs(wq->unbound_attrs);
 
-	kfree(wq->rescuer);
 	kfree(wq);
 }
 
@@ -3504,6 +3504,18 @@ static void rcu_free_pool(struct rcu_head *rcu)
 	kfree(pool);
 }
 
+/* This returns with the lock held on success (pool manager is inactive). */
+static bool wq_manager_inactive(struct worker_pool *pool)
+{
+	raw_spin_lock_irq(&pool->lock);
+
+	if (pool->flags & POOL_MANAGER_ACTIVE) {
+		raw_spin_unlock_irq(&pool->lock);
+		return false;
+	}
+	return true;
+}
+
 /**
  * put_unbound_pool - put a worker_pool
  * @pool: worker_pool to put
@@ -3539,16 +3551,17 @@ static void put_unbound_pool(struct worker_pool *pool)
 	 * Become the manager and destroy all workers.  This prevents
 	 * @pool's workers from blocking on attach_mutex.  We're the last
 	 * manager and @pool gets freed with the flag set.
+	 * Because of how wq_manager_inactive() works, we will hold the
+	 * spinlock after a successful wait.
 	 */
-	spin_lock_irq(&pool->lock);
-	wait_event_lock_irq(wq_manager_wait,
-			    !(pool->flags & POOL_MANAGER_ACTIVE), pool->lock);
+	rcuwait_wait_event(&manager_wait, wq_manager_inactive(pool),
+			   TASK_UNINTERRUPTIBLE);
 	pool->flags |= POOL_MANAGER_ACTIVE;
 
 	while ((worker = first_idle_worker(pool)))
 		destroy_worker(worker);
 	WARN_ON(pool->nr_workers || pool->nr_idle);
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 
 	mutex_lock(&wq_pool_attach_mutex);
 	if (!list_empty(&pool->workers))
@@ -3704,7 +3717,7 @@ static void pwq_adjust_max_active(struct pool_workqueue *pwq)
 		return;
 
 	/* this function can be called during early boot w/ irq disabled */
-	spin_lock_irqsave(&pwq->pool->lock, flags);
+	raw_spin_lock_irqsave(&pwq->pool->lock, flags);
 
 	/*
 	 * During [un]freezing, the caller is responsible for ensuring that
@@ -3727,7 +3740,7 @@ static void pwq_adjust_max_active(struct pool_workqueue *pwq)
 		pwq->max_active = 0;
 	}
 
-	spin_unlock_irqrestore(&pwq->pool->lock, flags);
+	raw_spin_unlock_irqrestore(&pwq->pool->lock, flags);
 }
 
 /* initialize newly alloced @pwq which is associated with @wq and @pool */
@@ -4129,9 +4142,9 @@ static void wq_update_unbound_numa(struct workqueue_struct *wq, int cpu,
 
 use_dfl_pwq:
 	mutex_lock(&wq->mutex);
-	spin_lock_irq(&wq->dfl_pwq->pool->lock);
+	raw_spin_lock_irq(&wq->dfl_pwq->pool->lock);
 	get_pwq(wq->dfl_pwq);
-	spin_unlock_irq(&wq->dfl_pwq->pool->lock);
+	raw_spin_unlock_irq(&wq->dfl_pwq->pool->lock);
 	old_pwq = numa_pwq_tbl_install(wq, node, wq->dfl_pwq);
 out_unlock:
 	mutex_unlock(&wq->mutex);
@@ -4208,8 +4221,8 @@ static int init_rescuer(struct workqueue_struct *wq)
 
 	rescuer->rescue_wq = wq;
 	rescuer->task = kthread_create(rescuer_thread, rescuer, "%s", wq->name);
-	ret = PTR_ERR_OR_ZERO(rescuer->task);
-	if (ret) {
+	if (IS_ERR(rescuer->task)) {
+		ret = PTR_ERR(rescuer->task);
 		kfree(rescuer);
 		return ret;
 	}
@@ -4360,9 +4373,9 @@ void destroy_workqueue(struct workqueue_struct *wq)
 		struct worker *rescuer = wq->rescuer;
 
 		/* this prevents new queueing */
-		spin_lock_irq(&wq_mayday_lock);
+		raw_spin_lock_irq(&wq_mayday_lock);
 		wq->rescuer = NULL;
-		spin_unlock_irq(&wq_mayday_lock);
+		raw_spin_unlock_irq(&wq_mayday_lock);
 
 		/* rescuer will empty maydays list before exiting */
 		kthread_stop(rescuer->task);
@@ -4376,27 +4389,25 @@ void destroy_workqueue(struct workqueue_struct *wq)
 	mutex_lock(&wq_pool_mutex);
 	mutex_lock(&wq->mutex);
 	for_each_pwq(pwq, wq) {
-		spin_lock_irq(&pwq->pool->lock);
+		raw_spin_lock_irq(&pwq->pool->lock);
 		if (WARN_ON(pwq_busy(pwq))) {
 			pr_warn("%s: %s has the following busy pwq\n",
 				__func__, wq->name);
 			show_pwq(pwq);
-			spin_unlock_irq(&pwq->pool->lock);
+			raw_spin_unlock_irq(&pwq->pool->lock);
 			mutex_unlock(&wq->mutex);
 			mutex_unlock(&wq_pool_mutex);
 			show_workqueue_state();
 			return;
 		}
-		spin_unlock_irq(&pwq->pool->lock);
+		raw_spin_unlock_irq(&pwq->pool->lock);
 	}
 	mutex_unlock(&wq->mutex);
-	mutex_unlock(&wq_pool_mutex);
 
 	/*
 	 * wq list is used to freeze wq, remove from list after
 	 * flushing is complete in case freeze races us.
 	 */
-	mutex_lock(&wq_pool_mutex);
 	list_del_rcu(&wq->list);
 	mutex_unlock(&wq_pool_mutex);
 
@@ -4558,10 +4569,10 @@ unsigned int work_busy(struct work_struct *work)
 	rcu_read_lock();
 	pool = get_work_pool(work);
 	if (pool) {
-		spin_lock_irqsave(&pool->lock, flags);
+		raw_spin_lock_irqsave(&pool->lock, flags);
 		if (find_worker_executing_work(pool, work))
 			ret |= WORK_BUSY_RUNNING;
-		spin_unlock_irqrestore(&pool->lock, flags);
+		raw_spin_unlock_irqrestore(&pool->lock, flags);
 	}
 	rcu_read_unlock();
 
@@ -4768,10 +4779,10 @@ void show_workqueue_state(void)
 		pr_info("workqueue %s: flags=0x%x\n", wq->name, wq->flags);
 
 		for_each_pwq(pwq, wq) {
-			spin_lock_irqsave(&pwq->pool->lock, flags);
+			raw_spin_lock_irqsave(&pwq->pool->lock, flags);
 			if (pwq->nr_active || !list_empty(&pwq->delayed_works))
 				show_pwq(pwq);
-			spin_unlock_irqrestore(&pwq->pool->lock, flags);
+			raw_spin_unlock_irqrestore(&pwq->pool->lock, flags);
 			/*
 			 * We could be printing a lot from atomic context, e.g.
 			 * sysrq-t -> show_workqueue_state(). Avoid triggering
@@ -4785,7 +4796,7 @@ void show_workqueue_state(void)
 		struct worker *worker;
 		bool first = true;
 
-		spin_lock_irqsave(&pool->lock, flags);
+		raw_spin_lock_irqsave(&pool->lock, flags);
 		if (pool->nr_workers == pool->nr_idle)
 			goto next_pool;
 
@@ -4804,7 +4815,7 @@ void show_workqueue_state(void)
 		}
 		pr_cont("\n");
 	next_pool:
-		spin_unlock_irqrestore(&pool->lock, flags);
+		raw_spin_unlock_irqrestore(&pool->lock, flags);
 		/*
 		 * We could be printing a lot from atomic context, e.g.
 		 * sysrq-t -> show_workqueue_state(). Avoid triggering
@@ -4834,7 +4845,7 @@ void wq_worker_comm(char *buf, size_t size, struct task_struct *task)
 		struct worker_pool *pool = worker->pool;
 
 		if (pool) {
-			spin_lock_irq(&pool->lock);
+			raw_spin_lock_irq(&pool->lock);
 			/*
 			 * ->desc tracks information (wq name or
 			 * set_worker_desc()) for the latest execution.  If
@@ -4848,7 +4859,7 @@ void wq_worker_comm(char *buf, size_t size, struct task_struct *task)
 					scnprintf(buf + off, size - off, "-%s",
 						  worker->desc);
 			}
-			spin_unlock_irq(&pool->lock);
+			raw_spin_unlock_irq(&pool->lock);
 		}
 	}
 
@@ -4879,7 +4890,7 @@ static void unbind_workers(int cpu)
 
 	for_each_cpu_worker_pool(pool, cpu) {
 		mutex_lock(&wq_pool_attach_mutex);
-		spin_lock_irq(&pool->lock);
+		raw_spin_lock_irq(&pool->lock);
 
 		/*
 		 * We've blocked all attach/detach operations. Make all workers
@@ -4893,7 +4904,7 @@ static void unbind_workers(int cpu)
 
 		pool->flags |= POOL_DISASSOCIATED;
 
-		spin_unlock_irq(&pool->lock);
+		raw_spin_unlock_irq(&pool->lock);
 		mutex_unlock(&wq_pool_attach_mutex);
 
 		/*
@@ -4919,9 +4930,9 @@ static void unbind_workers(int cpu)
 		 * worker blocking could lead to lengthy stalls.  Kick off
 		 * unbound chain execution of currently pending work items.
 		 */
-		spin_lock_irq(&pool->lock);
+		raw_spin_lock_irq(&pool->lock);
 		wake_up_worker(pool);
-		spin_unlock_irq(&pool->lock);
+		raw_spin_unlock_irq(&pool->lock);
 	}
 }
 
@@ -4948,7 +4959,7 @@ static void rebind_workers(struct worker_pool *pool)
 		WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task,
 						  pool->attrs->cpumask) < 0);
 
-	spin_lock_irq(&pool->lock);
+	raw_spin_lock_irq(&pool->lock);
 
 	pool->flags &= ~POOL_DISASSOCIATED;
 
@@ -4987,7 +4998,7 @@ static void rebind_workers(struct worker_pool *pool)
 		WRITE_ONCE(worker->flags, worker_flags);
 	}
 
-	spin_unlock_irq(&pool->lock);
+	raw_spin_unlock_irq(&pool->lock);
 }
 
 /**
@@ -5906,7 +5917,7 @@ void __init workqueue_init_early(void)
 	int hk_flags = HK_FLAG_DOMAIN | HK_FLAG_WQ;
 	int i, cpu;
 
-	WARN_ON(__alignof__(struct pool_workqueue) < __alignof__(long long));
+	BUILD_BUG_ON(__alignof__(struct pool_workqueue) < __alignof__(long long));
 
 	BUG_ON(!alloc_cpumask_var(&wq_unbound_cpumask, GFP_KERNEL));
 	cpumask_copy(wq_unbound_cpumask, housekeeping_cpumask(hk_flags));