Input: use full RCU API

RT guys alerted me to the fact that in their tree spinlocks
are preemptible and it is better to use full RCU API
(rcu_read_lock()/rcu_read_unlock()) to be safe.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 4 insertions, 7 deletions

diff --git a/drivers/input/mousedev.c b/drivers/input/mousedev.c
index cc36edbb912f..79146d6ed2ab 100644
--- a/drivers/input/mousedev.c
+++ b/drivers/input/mousedev.c
@@ -265,6 +265,7 @@ static void mousedev_notify_readers(struct mousedev *mousedev,
         unsigned int new_head;
         int wake_readers = 0;
 
+        rcu_read_lock();
         list_for_each_entry_rcu(client, &mousedev->client_list, node) {
 
                 /* Just acquire the lock, interrupts already disabled */
@@ -309,6 +310,7 @@ static void mousedev_notify_readers(struct mousedev *mousedev,
                         wake_readers = 1;
                 }
         }
+        rcu_read_unlock();
 
         if (wake_readers)
                 wake_up_interruptible(&mousedev->wait);
@@ -499,12 +501,7 @@ static void mousedev_attach_client(struct mousedev *mousedev,
         spin_lock(&mousedev->client_lock);
         list_add_tail_rcu(&client->node, &mousedev->client_list);
         spin_unlock(&mousedev->client_lock);
-        /*
-         * We don't use synchronize_rcu() here because read-side
-         * critical section is protected by a spinlock (dev->event_lock)
-         * instead of rcu_read_lock().
-         */
-        synchronize_sched();
+        synchronize_rcu();
 }
 
 static void mousedev_detach_client(struct mousedev *mousedev,
@@ -513,7 +510,7 @@ static void mousedev_detach_client(struct mousedev *mousedev,
         spin_lock(&mousedev->client_lock);
         list_del_rcu(&client->node);
         spin_unlock(&mousedev->client_lock);
-        synchronize_sched();
+        synchronize_rcu();
 }
 
 static int mousedev_release(struct inode *inode, struct file *file)