afs: add afs_wq and use it instead of the system workqueue

flush_scheduled_work() is going away. afs needs to make sure all the
works it has queued have finished before being unloaded and there can
be arbitrary number of pending works. Add afs_wq and use it as the
flush domain instead of the system workqueue.

Also, convert cancel_delayed_work() + flush_scheduled_work() to
cancel_delayed_work_sync() in afs_mntpt_kill_timer().

Signed-off-by: Tejun Heo <[e-mail]>
Signed-off-by: David Howells <[e-mail]>
Cc: [e-mail]
Signed-off-by: Linus Torvalds <[e-mail]>

fs/afs/cmservice.c

···
 	call->server = server;
 
 	INIT_WORK(&call->work, SRXAFSCB_CallBack);
-	schedule_work(&call->work);
+	queue_work(afs_wq, &call->work);
 	return 0;
 }
 
···
 	call->server = server;
 
 	INIT_WORK(&call->work, SRXAFSCB_InitCallBackState);
-	schedule_work(&call->work);
+	queue_work(afs_wq, &call->work);
 	return 0;
 }
 
···
 	call->server = server;
 
 	INIT_WORK(&call->work, SRXAFSCB_InitCallBackState);
-	schedule_work(&call->work);
+	queue_work(afs_wq, &call->work);
 	return 0;
 }
 
···
 	call->state = AFS_CALL_REPLYING;
 
 	INIT_WORK(&call->work, SRXAFSCB_Probe);
-	schedule_work(&call->work);
+	queue_work(afs_wq, &call->work);
 	return 0;
 }
 
···
 	call->state = AFS_CALL_REPLYING;
 
 	INIT_WORK(&call->work, SRXAFSCB_ProbeUuid);
-	schedule_work(&call->work);
+	queue_work(afs_wq, &call->work);
 	return 0;
 }
 
···
 	call->state = AFS_CALL_REPLYING;
 
 	INIT_WORK(&call->work, SRXAFSCB_TellMeAboutYourself);
-	schedule_work(&call->work);
+	queue_work(afs_wq, &call->work);
 	return 0;
 }

fs/afs/internal.h

···
 /*
  * main.c
  */
+extern struct workqueue_struct *afs_wq;
 extern struct afs_uuid afs_uuid;
 
 /*

fs/afs/main.c

···
 MODULE_PARM_DESC(rootcell, "root AFS cell name and VL server IP addr list");
 
 struct afs_uuid afs_uuid;
+struct workqueue_struct *afs_wq;
 
 /*
  * get a client UUID
···
 	if (ret < 0)
 		return ret;
 
+	/* create workqueue */
+	ret = -ENOMEM;
+	afs_wq = alloc_workqueue("afs", 0, 0);
+	if (!afs_wq)
+		return ret;
+
 	/* register the /proc stuff */
 	ret = afs_proc_init();
 	if (ret < 0)
-		return ret;
+		goto error_proc;
 
 #ifdef CONFIG_AFS_FSCACHE
 	/* we want to be able to cache */
···
 error_cache:
 #endif
 	afs_proc_cleanup();
+error_proc:
+	destroy_workqueue(afs_wq);
 	rcu_barrier();
 	printk(KERN_ERR "kAFS: failed to register: %d\n", ret);
 	return ret;
···
 	afs_purge_servers();
 	afs_callback_update_kill();
 	afs_vlocation_purge();
-	flush_scheduled_work();
+	destroy_workqueue(afs_wq);
 	afs_cell_purge();
 #ifdef CONFIG_AFS_FSCACHE
 	fscache_unregister_netfs(&afs_cache_netfs);

fs/afs/mntpt.c

···
 		path_put(&nd->path);
 		nd->path.mnt = newmnt;
 		nd->path.dentry = dget(newmnt->mnt_root);
-		schedule_delayed_work(&afs_mntpt_expiry_timer,
-				      afs_mntpt_expiry_timeout * HZ);
+		queue_delayed_work(afs_wq, &afs_mntpt_expiry_timer,
+				   afs_mntpt_expiry_timeout * HZ);
 		break;
 	case -EBUSY:
 		/* someone else made a mount here whilst we were busy */
···
 
 	if (!list_empty(&afs_vfsmounts)) {
 		mark_mounts_for_expiry(&afs_vfsmounts);
-		schedule_delayed_work(&afs_mntpt_expiry_timer,
-				      afs_mntpt_expiry_timeout * HZ);
+		queue_delayed_work(afs_wq, &afs_mntpt_expiry_timer,
+				   afs_mntpt_expiry_timeout * HZ);
 	}
 
 	_leave("");
···
 	_enter("");
 
 	ASSERT(list_empty(&afs_vfsmounts));
-	cancel_delayed_work(&afs_mntpt_expiry_timer);
-	flush_scheduled_work();
+	cancel_delayed_work_sync(&afs_mntpt_expiry_timer);
 }

fs/afs/rxrpc.c

···
 	if (!call) {
 		/* its an incoming call for our callback service */
 		skb_queue_tail(&afs_incoming_calls, skb);
-		schedule_work(&afs_collect_incoming_call_work);
+		queue_work(afs_wq, &afs_collect_incoming_call_work);
 	} else {
 		/* route the messages directly to the appropriate call */
 		skb_queue_tail(&call->rx_queue, skb);

fs/afs/server.c

···
 	if (atomic_read(&server->usage) == 0) {
 		list_move_tail(&server->grave, &afs_server_graveyard);
 		server->time_of_death = get_seconds();
-		schedule_delayed_work(&afs_server_reaper,
-				      afs_server_timeout * HZ);
+		queue_delayed_work(afs_wq, &afs_server_reaper,
+				   afs_server_timeout * HZ);
 	}
 	spin_unlock(&afs_server_graveyard_lock);
 	_leave(" [dead]");
···
 		expiry = server->time_of_death + afs_server_timeout;
 		if (expiry > now) {
 			delay = (expiry - now) * HZ;
-			if (!schedule_delayed_work(&afs_server_reaper, delay)) {
+			if (!queue_delayed_work(afs_wq, &afs_server_reaper,
+						delay)) {
 				cancel_delayed_work(&afs_server_reaper);
-				schedule_delayed_work(&afs_server_reaper,
-						      delay);
+				queue_delayed_work(afs_wq, &afs_server_reaper,
+						   delay);
 			}
 			break;
 		}
···
 {
 	afs_server_timeout = 0;
 	cancel_delayed_work(&afs_server_reaper);
-	schedule_delayed_work(&afs_server_reaper, 0);
+	queue_delayed_work(afs_wq, &afs_server_reaper, 0);
 }

fs/afs/vlocation.c

···
 		_debug("buried");
 		list_move_tail(&vl->grave, &afs_vlocation_graveyard);
 		vl->time_of_death = get_seconds();
-		schedule_delayed_work(&afs_vlocation_reap,
-				      afs_vlocation_timeout * HZ);
+		queue_delayed_work(afs_wq, &afs_vlocation_reap,
+				   afs_vlocation_timeout * HZ);
 
 		/* suspend updates on this record */
 		if (!list_empty(&vl->update)) {
···
 		if (expiry > now) {
 			delay = (expiry - now) * HZ;
 			_debug("delay %lu", delay);
-			if (!schedule_delayed_work(&afs_vlocation_reap,
-						   delay)) {
+			if (!queue_delayed_work(afs_wq, &afs_vlocation_reap,
+						delay)) {
 				cancel_delayed_work(&afs_vlocation_reap);
-				schedule_delayed_work(&afs_vlocation_reap,
-						      delay);
+				queue_delayed_work(afs_wq, &afs_vlocation_reap,
+						   delay);
 			}
 			break;
 		}
···
 	destroy_workqueue(afs_vlocation_update_worker);
 
 	cancel_delayed_work(&afs_vlocation_reap);
-	schedule_delayed_work(&afs_vlocation_reap, 0);
+	queue_delayed_work(afs_wq, &afs_vlocation_reap, 0);
 }
 
 /*