cifs: remove dnotify thread code

cifs: remove dnotify thread code

Al Viro recently removed the dir_notify code from the kernel along with
the CIFS code that used it. We can also get rid of the dnotify thread
as well.

In actuality, it never had anything to do with dir_notify anyway. All
it did was unnecessarily wake up all the tasks waiting on the response
queues every 15s. Previously that happened to prevent tasks from hanging
indefinitely when the server went unresponsive, but we put those to
sleep with proper timeouts now so there's no reason to keep this around.

Signed-off-by: Jeff Layton <[e-mail]>
Signed-off-by: Steve French <[e-mail]>

fs/cifs/cifsfs.c

···
 extern struct task_struct *oplockThread; /* remove sparse warning */
 struct task_struct *oplockThread = NULL;
 /* extern struct task_struct * dnotifyThread; remove sparse warning */
-#ifdef CONFIG_CIFS_EXPERIMENTAL
-static struct task_struct *dnotifyThread = NULL;
-#endif
 static const struct super_operations cifs_super_ops;
 unsigned int CIFSMaxBufSize = CIFS_MAX_MSGSIZE;
 module_param(CIFSMaxBufSize, int, 0);
···
 	return 0;
 }
 
-#ifdef CONFIG_CIFS_EXPERIMENTAL
-static int cifs_dnotify_thread(void *dummyarg)
-{
-	struct list_head *tmp;
-	struct TCP_Server_Info *server;
-
-	do {
-		if (try_to_freeze())
-			continue;
-		set_current_state(TASK_INTERRUPTIBLE);
-		schedule_timeout(15*HZ);
-		/* check if any stuck requests that need
-		   to be woken up and wakeq so the
-		   thread can wake up and error out */
-		read_lock(&cifs_tcp_ses_lock);
-		list_for_each(tmp, &cifs_tcp_ses_list) {
-			server = list_entry(tmp, struct TCP_Server_Info,
-					 tcp_ses_list);
-			if (atomic_read(&server->inFlight))
-				wake_up_all(&server->response_q);
-		}
-		read_unlock(&cifs_tcp_ses_lock);
-	} while (!kthread_should_stop());
-
-	return 0;
-}
-#endif
-
 static int __init
 init_cifs(void)
 {
···
 		goto out_unregister_dfs_key_type;
 	}
 
-#ifdef CONFIG_CIFS_EXPERIMENTAL
-	dnotifyThread = kthread_run(cifs_dnotify_thread, NULL, "cifsdnotifyd");
-	if (IS_ERR(dnotifyThread)) {
-		rc = PTR_ERR(dnotifyThread);
-		cERROR(1, ("error %d create dnotify thread", rc));
-		goto out_stop_oplock_thread;
-	}
-#endif
-
 	return 0;
 
-#ifdef CONFIG_CIFS_EXPERIMENTAL
- out_stop_oplock_thread:
-#endif
-	kthread_stop(oplockThread);
  out_unregister_dfs_key_type:
 #ifdef CONFIG_CIFS_DFS_UPCALL
 	unregister_key_type(&key_type_dns_resolver);
···
 	cifs_destroy_inodecache();
 	cifs_destroy_mids();
 	cifs_destroy_request_bufs();
-#ifdef CONFIG_CIFS_EXPERIMENTAL
-	kthread_stop(dnotifyThread);
-#endif
 	kthread_stop(oplockThread);
 }