unify flush_work/flush_work_keventd and rename it to cancel_work_sync

flush_work(wq, work) doesn't need the first parameter, we can use cwq->wq
(this was possible from the very beginnig, I missed this). So we can unify
flush_work_keventd and flush_work.

Also, rename flush_work() to cancel_work_sync() and fix all callers.
Perhaps this is not the best name, but "flush_work" is really bad.

(akpm: this is why the earlier patches bypassed maintainers)

Signed-off-by: Oleg Nesterov <[e-mail]>
Cc: Jeff Garzik <[e-mail]>
Cc: "David S. Miller" <[e-mail]>
Cc: Jens Axboe <[e-mail]>
Cc: Tejun Heo <[e-mail]>
Cc: Auke Kok <[e-mail]>,
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

block/ll_rw_blk.c

···
 
 void kblockd_flush_work(struct work_struct *work)
 {
-	flush_work(kblockd_workqueue, work);
+	cancel_work_sync(work);
 }
 EXPORT_SYMBOL(kblockd_flush_work);
 

drivers/ata/libata-core.c

···
 	spin_unlock_irqrestore(ap->lock, flags);
 
 	DPRINTK("flush #1\n");
-	flush_work(ata_wq, &ap->port_task.work); /* akpm: seems unneeded */
+	cancel_work_sync(&ap->port_task.work); /* akpm: seems unneeded */
 
 	/*
 	 * At this point, if a task is running, it's guaranteed to see
···
 		if (ata_msg_ctl(ap))
 			ata_port_printk(ap, KERN_DEBUG, "%s: flush #2\n",
 					__FUNCTION__);
-		flush_work(ata_wq, &ap->port_task.work);
+		cancel_work_sync(&ap->port_task.work);
 	}
 
 	spin_lock_irqsave(ap->lock, flags);
···
 	/* Flush hotplug task.  The sequence is similar to
 	 * ata_port_flush_task().
 	 */
-	flush_work(ata_aux_wq, &ap->hotplug_task.work); /* akpm: why? */
+	cancel_work_sync(&ap->hotplug_task.work); /* akpm: why? */
 	cancel_delayed_work(&ap->hotplug_task);
-	flush_work(ata_aux_wq, &ap->hotplug_task.work);
+	cancel_work_sync(&ap->hotplug_task.work);
 
  skip_eh:
 	/* remove the associated SCSI host */

drivers/net/e1000/e1000_main.c

···
 	int i;
 #endif
 
-	flush_work_keventd(&adapter->reset_task);
+	cancel_work_sync(&adapter->reset_task);
 
 	e1000_release_manageability(adapter);
 

drivers/net/phy/phy.c

···
 
 	/*
 	 * Finish any pending work; we might have been scheduled to be called
-	 * from keventd ourselves, but flush_work_keventd() handles that.
+	 * from keventd ourselves, but cancel_work_sync() handles that.
 	 */
-	flush_work_keventd(&phydev->phy_queue);
+	cancel_work_sync(&phydev->phy_queue);
 
 	free_irq(phydev->irq, phydev);
 

drivers/net/tg3.c

···
 {
 	struct tg3 *tp = netdev_priv(dev);
 
-	flush_work_keventd(&tp->reset_task);
+	cancel_work_sync(&tp->reset_task);
 
 	netif_stop_queue(dev);
 

fs/aio.c

···
 		/*
 		 * Ensure we don't leave the ctx on the aio_wq
 		 */
-		flush_work(aio_wq, &ctx->wq.work);
+		cancel_work_sync(&ctx->wq.work);
 
 		if (1 != atomic_read(&ctx->users))
 			printk(KERN_DEBUG
···
 	BUG_ON(ctx->reqs_active);
 
 	cancel_delayed_work(&ctx->wq);
-	flush_work(aio_wq, &ctx->wq.work);
+	cancel_work_sync(&ctx->wq.work);
 	aio_free_ring(ctx);
 	mmdrop(ctx->mm);
 	ctx->mm = NULL;

include/linux/workqueue.h

···
 extern void destroy_workqueue(struct workqueue_struct *wq);
 
 extern int FASTCALL(queue_work(struct workqueue_struct *wq, struct work_struct *work));
-extern int FASTCALL(queue_delayed_work(struct workqueue_struct *wq, struct delayed_work *work, unsigned long delay));
+extern int FASTCALL(queue_delayed_work(struct workqueue_struct *wq,
+			struct delayed_work *work, unsigned long delay));
 extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
-	struct delayed_work *work, unsigned long delay);
+			struct delayed_work *work, unsigned long delay);
+
 extern void FASTCALL(flush_workqueue(struct workqueue_struct *wq));
-extern void flush_work(struct workqueue_struct *wq, struct work_struct *work);
-extern void flush_work_keventd(struct work_struct *work);
+extern void flush_scheduled_work(void);
 
 extern int FASTCALL(schedule_work(struct work_struct *work));
-extern int FASTCALL(schedule_delayed_work(struct delayed_work *work, unsigned long delay));
-
-extern int schedule_delayed_work_on(int cpu, struct delayed_work *work, unsigned long delay);
+extern int FASTCALL(schedule_delayed_work(struct delayed_work *work,
+					unsigned long delay));
+extern int schedule_delayed_work_on(int cpu, struct delayed_work *work,
+					unsigned long delay);
 extern int schedule_on_each_cpu(work_func_t func);
-extern void flush_scheduled_work(void);
 extern int current_is_keventd(void);
 extern int keventd_up(void);
 
 extern void init_workqueues(void);
 int execute_in_process_context(work_func_t fn, struct execute_work *);
 
+extern void cancel_work_sync(struct work_struct *work);
+
 /*
  * Kill off a pending schedule_delayed_work().  Note that the work callback
  * function may still be running on return from cancel_delayed_work(), unless
  * it returns 1 and the work doesn't re-arm itself. Run flush_workqueue() or
- * flush_work() or cancel_work_sync() to wait on it.
+ * cancel_work_sync() to wait on it.
  */
 static inline int cancel_delayed_work(struct delayed_work *work)
 {

kernel/workqueue.c

···
 }
 
 /**
- * flush_work - block until a work_struct's callback has terminated
- * @wq: the workqueue on which the work is queued
+ * cancel_work_sync - block until a work_struct's callback has terminated
  * @work: the work which is to be flushed
  *
- * flush_work() will attempt to cancel the work if it is queued.  If the work's
- * callback appears to be running, flush_work() will block until it has
- * completed.
+ * cancel_work_sync() will attempt to cancel the work if it is queued. If the
+ * work's callback appears to be running, cancel_work_sync() will block until
+ * it has completed.
  *
- * flush_work() is designed to be used when the caller is tearing down data
- * structures which the callback function operates upon.  It is expected that,
- * prior to calling flush_work(), the caller has arranged for the work to not
- * be requeued.
+ * cancel_work_sync() is designed to be used when the caller is tearing down
+ * data structures which the callback function operates upon. It is expected
+ * that, prior to calling cancel_work_sync(), the caller has arranged for the
+ * work to not be requeued.
  */
-void flush_work(struct workqueue_struct *wq, struct work_struct *work)
+void cancel_work_sync(struct work_struct *work)
 {
-	const cpumask_t *cpu_map = wq_cpu_map(wq);
 	struct cpu_workqueue_struct *cwq;
+	struct workqueue_struct *wq;
+	const cpumask_t *cpu_map;
 	int cpu;
 
 	might_sleep();
···
 	work_clear_pending(work);
 	spin_unlock_irq(&cwq->lock);
 
+	wq = cwq->wq;
+	cpu_map = wq_cpu_map(wq);
+
 	for_each_cpu_mask(cpu, *cpu_map)
 		wait_on_work(per_cpu_ptr(wq->cpu_wq, cpu), work);
 }
-EXPORT_SYMBOL_GPL(flush_work);
+EXPORT_SYMBOL_GPL(cancel_work_sync);
 
 
 static struct workqueue_struct *keventd_wq;
···
 }
 EXPORT_SYMBOL(flush_scheduled_work);
 
-void flush_work_keventd(struct work_struct *work)
-{
-	flush_work(keventd_wq, work);
-}
-EXPORT_SYMBOL(flush_work_keventd);
-
 /**
  * cancel_rearming_delayed_work - kill off a delayed work whose handler rearms the delayed work.
  * @dwork: the delayed work struct
  *
  * Note that the work callback function may still be running on return from
- * cancel_delayed_work(). Run flush_workqueue() or flush_work() to wait on it.
+ * cancel_delayed_work(). Run flush_workqueue() or cancel_work_sync() to wait
+ * on it.
  */
 void cancel_rearming_delayed_work(struct delayed_work *dwork)
 {

net/ipv4/ipvs/ip_vs_ctl.c

···
 	EnterFunction(2);
 	ip_vs_trash_cleanup();
 	cancel_rearming_delayed_work(&defense_work);
-	flush_work_keventd(&defense_work.work);
+	cancel_work_sync(&defense_work.work);
 	ip_vs_kill_estimator(&ip_vs_stats);
 	unregister_sysctl_table(sysctl_header);
 	proc_net_remove("ip_vs_stats");