macvtap: Convert to using rtnl lock

[cascardo/linux.git] / drivers / net / macvtap.c

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 5a76f20..efbf2eb 100644 (file)
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -69,7 +69,7 @@ static const struct proto_ops macvtap_socket_ops;
  * RCU usage:
  * The macvtap_queue and the macvlan_dev are loosely coupled, the
  * pointers from one to the other can only be read while rcu_read_lock
- * or macvtap_lock is held.
+ * or rtnl is held.
  *
  * Both the file and the macvlan_dev hold a reference on the macvtap_queue
  * through sock_hold(&q->sk). When the macvlan_dev goes away first,
@@ -81,7 +81,6 @@ static const struct proto_ops macvtap_socket_ops;
  * file or the dev. The data structure is freed through __sk_free
  * when both our references and any pending SKBs are gone.
  */
-static DEFINE_SPINLOCK(macvtap_lock);
 
 static int macvtap_enable_queue(struct net_device *dev, struct file *file,
                                struct macvtap_queue *q)
@@ -89,7 +88,7 @@ static int macvtap_enable_queue(struct net_device *dev, struct file *file,
        struct macvlan_dev *vlan = netdev_priv(dev);
        int err = -EINVAL;
 
-       spin_lock(&macvtap_lock);
+       ASSERT_RTNL();
 
        if (q->enabled)
                goto out;
@@ -101,7 +100,6 @@ static int macvtap_enable_queue(struct net_device *dev, struct file *file,
 
        vlan->numvtaps++;
 out:
-       spin_unlock(&macvtap_lock);
        return err;
 }
 
@@ -111,7 +109,7 @@ static int macvtap_set_queue(struct net_device *dev, struct file *file,
        struct macvlan_dev *vlan = netdev_priv(dev);
        int err = -EBUSY;
 
-       spin_lock(&macvtap_lock);
+       rtnl_lock();
        if (vlan->numqueues == MAX_MACVTAP_QUEUES)
                goto out;
 
@@ -130,26 +128,25 @@ static int macvtap_set_queue(struct net_device *dev, struct file *file,
        vlan->numqueues++;
 
 out:
-       spin_unlock(&macvtap_lock);
+       rtnl_unlock();
        return err;
 }
 
-static int __macvtap_disable_queue(struct macvtap_queue *q)
+static int macvtap_disable_queue(struct macvtap_queue *q)
 {
        struct macvlan_dev *vlan;
        struct macvtap_queue *nq;
 
-       vlan = rcu_dereference_protected(q->vlan,
-                                        lockdep_is_held(&macvtap_lock));
-
+       ASSERT_RTNL();
        if (!q->enabled)
                return -EINVAL;
 
+       vlan = rtnl_dereference(q->vlan);
+
        if (vlan) {
                int index = q->queue_index;
                BUG_ON(index >= vlan->numvtaps);
-               nq = rcu_dereference_protected(vlan->taps[vlan->numvtaps - 1],
-                                              lockdep_is_held(&macvtap_lock));
+               nq = rtnl_dereference(vlan->taps[vlan->numvtaps - 1]);
                nq->queue_index = index;
 
                rcu_assign_pointer(vlan->taps[index], nq);
@@ -162,17 +159,6 @@ static int __macvtap_disable_queue(struct macvtap_queue *q)
        return 0;
 }
 
-static int macvtap_disable_queue(struct macvtap_queue *q)
-{
-       int err;
-
-       spin_lock(&macvtap_lock);
-       err = __macvtap_disable_queue(q);
-       spin_unlock(&macvtap_lock);
-
-       return err;
-}
-
 /*
  * The file owning the queue got closed, give up both
  * the reference that the files holds as well as the
@@ -185,12 +171,12 @@ static void macvtap_put_queue(struct macvtap_queue *q)
 {
        struct macvlan_dev *vlan;
 
-       spin_lock(&macvtap_lock);
-       vlan = rcu_dereference_protected(q->vlan,
-                                        lockdep_is_held(&macvtap_lock));
+       rtnl_lock();
+       vlan = rtnl_dereference(q->vlan);
+
        if (vlan) {
                if (q->enabled)
-                       BUG_ON(__macvtap_disable_queue(q));
+                       BUG_ON(macvtap_disable_queue(q));
 
                vlan->numqueues--;
                RCU_INIT_POINTER(q->vlan, NULL);
@@ -198,7 +184,7 @@ static void macvtap_put_queue(struct macvtap_queue *q)
                list_del_init(&q->next);
        }
 
-       spin_unlock(&macvtap_lock);
+       rtnl_unlock();
 
        synchronize_rcu();
        sock_put(&q->sk);
@@ -260,7 +246,7 @@ static void macvtap_del_queues(struct net_device *dev)
        struct macvtap_queue *q, *tmp, *qlist[MAX_MACVTAP_QUEUES];
        int i, j = 0;
 
-       spin_lock(&macvtap_lock);
+       ASSERT_RTNL();
        list_for_each_entry_safe(q, tmp, &vlan->queue_list, next) {
                list_del_init(&q->next);
                qlist[j++] = q;
@@ -275,9 +261,6 @@ static void macvtap_del_queues(struct net_device *dev)
        BUG_ON(vlan->numqueues);
        /* guarantee that any future macvtap_set_queue will fail */
        vlan->numvtaps = MAX_MACVTAP_QUEUES;
-       spin_unlock(&macvtap_lock);
-
-       synchronize_rcu();
 
        for (--j; j >= 0; j--)
                sock_put(&qlist[j]->sk);
@@ -941,11 +924,10 @@ static struct macvlan_dev *macvtap_get_vlan(struct macvtap_queue *q)
 {
        struct macvlan_dev *vlan;
 
-       rcu_read_lock_bh();
-       vlan = rcu_dereference_bh(q->vlan);
+       ASSERT_RTNL();
+       vlan = rtnl_dereference(q->vlan);
        if (vlan)
                dev_hold(vlan->dev);
-       rcu_read_unlock_bh();
 
        return vlan;
 }
@@ -1008,21 +990,27 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
                return ret;
 
        case TUNGETIFF:
+               rtnl_lock();
                vlan = macvtap_get_vlan(q);
-               if (!vlan)
+               if (!vlan) {
+                       rtnl_unlock();
                        return -ENOLINK;
+               }
 
                ret = 0;
                if (copy_to_user(&ifr->ifr_name, vlan->dev->name, IFNAMSIZ) ||
                    put_user(q->flags, &ifr->ifr_flags))
                        ret = -EFAULT;
                macvtap_put_vlan(vlan);
+               rtnl_unlock();
                return ret;
 
        case TUNSETQUEUE:
                if (get_user(u, &ifr->ifr_flags))
                        return -EFAULT;
-               return macvtap_ioctl_set_queue(file, u);
+               rtnl_lock();
+               ret = macvtap_ioctl_set_queue(file, u);
+               rtnl_unlock();
 
        case TUNGETFEATURES:
                if (put_user(IFF_TAP | IFF_NO_PI | IFF_VNET_HDR |