Merge branch 'for-3.7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull workqueue fixes from Tejun Heo:
 "So, safe fixes my ass.

  Commit 8852aac25e79 ("workqueue: mod_delayed_work_on() shouldn't queue
  timer on 0 delay") had the side-effect of performing delayed_work
  sanity checks even when @delay is 0, which should be fine for any sane
  use cases.

  Unfortunately, megaraid was being overly ingenious.  It seemingly
  wanted to use cancel_delayed_work_sync() before cancel_work_sync() was
  introduced, but didn't want to waste the space for full delayed_work
  as it was only going to use 0 @delay.  So, it only allocated space for
  struct work_struct and then cast it to struct delayed_work and passed
  it into delayed_work functions - truly awesome engineering tradeoff to
  save some bytes.

  Xiaotian fixed it by making megraid allocate full delayed_work for
  now.  It should be converted to use work_struct and cancel_work_sync()
  but I think we better do that after 3.7.

  I added another commit to change BUG_ON()s in __queue_delayed_work()
  to WARN_ON_ONCE()s so that the kernel doesn't crash even if there are
  more such abuses."

* 'for-3.7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: convert BUG_ON()s in __queue_delayed_work() to WARN_ON_ONCE()s
  megaraid: fix BUG_ON() from incorrect use of delayed work

3 files changed, 9 insertions, 11 deletions

diff --git a/drivers/scsi/megaraid/megaraid_sas.h b/drivers/scsi/megaraid/megaraid_sas.h
index 16b7a72a70c4..3b2365c8eab2 100644
--- a/drivers/scsi/megaraid/megaraid_sas.h
+++ b/drivers/scsi/megaraid/megaraid_sas.h
@@ -1276,7 +1276,7 @@ struct megasas_evt_detail {
 } __attribute__ ((packed));
 
 struct megasas_aen_event {
-	struct work_struct hotplug_work;
+	struct delayed_work hotplug_work;
 	struct megasas_instance *instance;
 };
 
diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index d2c5366aff7f..e4f2baacf1e1 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -2060,9 +2060,9 @@ megasas_service_aen(struct megasas_instance *instance, struct megasas_cmd *cmd)
 		} else {
 			ev->instance = instance;
 			instance->ev = ev;
-			INIT_WORK(&ev->hotplug_work, megasas_aen_polling);
-			schedule_delayed_work(
-				(struct delayed_work *)&ev->hotplug_work, 0);
+			INIT_DELAYED_WORK(&ev->hotplug_work,
+					  megasas_aen_polling);
+			schedule_delayed_work(&ev->hotplug_work, 0);
 		}
 	}
 }
@@ -4352,8 +4352,7 @@ megasas_suspend(struct pci_dev *pdev, pm_message_t state)
 	/* cancel the delayed work if this work still in queue */
 	if (instance->ev != NULL) {
 		struct megasas_aen_event *ev = instance->ev;
-		cancel_delayed_work_sync(
-			(struct delayed_work *)&ev->hotplug_work);
+		cancel_delayed_work_sync(&ev->hotplug_work);
 		instance->ev = NULL;
 	}
 
@@ -4545,8 +4544,7 @@ static void __devexit megasas_detach_one(struct pci_dev *pdev)
 	/* cancel the delayed work if this work still in queue*/
 	if (instance->ev != NULL) {
 		struct megasas_aen_event *ev = instance->ev;
-		cancel_delayed_work_sync(
-			(struct delayed_work *)&ev->hotplug_work);
+		cancel_delayed_work_sync(&ev->hotplug_work);
 		instance->ev = NULL;
 	}
 
@@ -5190,7 +5188,7 @@ static void
 megasas_aen_polling(struct work_struct *work)
 {
 	struct megasas_aen_event *ev =
-		container_of(work, struct megasas_aen_event, hotplug_work);
+		container_of(work, struct megasas_aen_event, hotplug_work.work);
 	struct megasas_instance *instance = ev->instance;
 	union megasas_evt_class_locale class_locale;
 	struct  Scsi_Host *host;
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 084aa47bac82..1dae900df798 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1361,8 +1361,8 @@ static void __queue_delayed_work(int cpu, struct workqueue_struct *wq,
 
 	WARN_ON_ONCE(timer->function != delayed_work_timer_fn ||
 		     timer->data != (unsigned long)dwork);
-	BUG_ON(timer_pending(timer));
-	BUG_ON(!list_empty(&work->entry));
+	WARN_ON_ONCE(timer_pending(timer));
+	WARN_ON_ONCE(!list_empty(&work->entry));
 
 	/*
 	 * If @delay is 0, queue @dwork->work immediately.  This is for