vhost: fix release path lockdep checks

We shouldn't hold any locks on release path. Pass a flag to
vhost_dev_cleanup to use the lockdep info correctly.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Sasha Levin <levinsasha928@gmail.com>

drivers/vhost/net.c

@@ -588,7 +588,7 @@ static int vhost_net_release(struct inode *inode, struct file *f)
 
 	vhost_net_stop(n, &tx_sock, &rx_sock);
 	vhost_net_flush(n);
-	vhost_dev_cleanup(&n->dev);
+	vhost_dev_cleanup(&n->dev, false);
 	if (tx_sock)
 		fput(tx_sock->file);
 	if (rx_sock)

drivers/vhost/vhost.c

@@ -405,7 +405,7 @@ long vhost_dev_reset_owner(struct vhost_dev *dev)
 	if (!memory)
 		return -ENOMEM;
 
-	vhost_dev_cleanup(dev);
+	vhost_dev_cleanup(dev, true);
 
 	memory->nregions = 0;
 	RCU_INIT_POINTER(dev->memory, memory);
@@ -436,8 +436,8 @@ int vhost_zerocopy_signal_used(struct vhost_virtqueue *vq)
 	return j;
 }
 
-/* Caller should have device mutex */
-void vhost_dev_cleanup(struct vhost_dev *dev)
+/* Caller should have device mutex if and only if locked is set */
+void vhost_dev_cleanup(struct vhost_dev *dev, bool locked)
 {
 	int i;
 
@@ -474,6 +474,7 @@ void vhost_dev_cleanup(struct vhost_dev *dev)
 	dev->log_file = NULL;
 	/* No one will access memory at this point */
 	kfree(rcu_dereference_protected(dev->memory,
+					locked ==
 						lockdep_is_held(&dev->mutex)));
 	RCU_INIT_POINTER(dev->memory, NULL);
 	WARN_ON(!list_empty(&dev->work_list));

drivers/vhost/vhost.h

@@ -163,7 +163,7 @@ struct vhost_dev {
 long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue *vqs, int nvqs);
 long vhost_dev_check_owner(struct vhost_dev *);
 long vhost_dev_reset_owner(struct vhost_dev *);
-void vhost_dev_cleanup(struct vhost_dev *);
+void vhost_dev_cleanup(struct vhost_dev *, bool locked);
 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, unsigned long arg);
 int vhost_vq_access_ok(struct vhost_virtqueue *vq);
 int vhost_log_access_ok(struct vhost_dev *);