vhost: get rid of vhost_poll_flush() wrapper

vhost_poll_flush() is a simple wrapper around vhost_work_dev_flush().
It gives wrong impression that we are doing some work over vhost_poll,
while in fact it flushes vhost_poll->dev.
It only complicate understanding of the code and leads to mistakes
like flushing the same vhost_dev several times in a row.

Just remove vhost_poll_flush() and call vhost_work_dev_flush() directly.
Signed-off-by: Andrey Ryabinin <arbn@yandex-team.com>
[merge vhost_poll_flush removal from Stefano Garzarella]
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20220517180850.198915-2-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vhost/net.c

@@ -1376,8 +1376,8 @@ static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
 
 static void vhost_net_flush_vq(struct vhost_net *n, int index)
 {
-	vhost_poll_flush(n->poll + index);
-	vhost_poll_flush(&n->vqs[index].vq.poll);
+	vhost_work_dev_flush(n->poll[index].dev);
+	vhost_work_dev_flush(n->vqs[index].vq.poll.dev);
 }
 
 static void vhost_net_flush(struct vhost_net *n)

drivers/vhost/test.c

@@ -146,7 +146,7 @@ static void vhost_test_stop(struct vhost_test *n, void **privatep)
 
 static void vhost_test_flush_vq(struct vhost_test *n, int index)
 {
-	vhost_poll_flush(&n->vqs[index].poll);
+	vhost_work_dev_flush(n->vqs[index].poll.dev);
 }
 
 static void vhost_test_flush(struct vhost_test *n)

drivers/vhost/vhost.c

@@ -245,14 +245,6 @@ void vhost_work_dev_flush(struct vhost_dev *dev)
 }
 EXPORT_SYMBOL_GPL(vhost_work_dev_flush);
 
-/* Flush any work that has been scheduled. When calling this, don't hold any
- * locks that are also used by the callback. */
-void vhost_poll_flush(struct vhost_poll *poll)
-{
-	vhost_work_dev_flush(poll->dev);
-}
-EXPORT_SYMBOL_GPL(vhost_poll_flush);
-
 void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work)
 {
 	if (!dev->worker)
@@ -663,7 +655,7 @@ void vhost_dev_stop(struct vhost_dev *dev)
 	for (i = 0; i < dev->nvqs; ++i) {
 		if (dev->vqs[i]->kick && dev->vqs[i]->handle_kick) {
 			vhost_poll_stop(&dev->vqs[i]->poll);
-			vhost_poll_flush(&dev->vqs[i]->poll);
+			vhost_work_dev_flush(dev->vqs[i]->poll.dev);
 		}
 	}
 }
@@ -1732,7 +1724,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg
 	mutex_unlock(&vq->mutex);
 
 	if (pollstop && vq->handle_kick)
-		vhost_poll_flush(&vq->poll);
+		vhost_work_dev_flush(vq->poll.dev);
 	return r;
 }
 EXPORT_SYMBOL_GPL(vhost_vring_ioctl);

drivers/vhost/vhost.h

@@ -44,7 +44,6 @@ void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
 		     __poll_t mask, struct vhost_dev *dev);
 int vhost_poll_start(struct vhost_poll *poll, struct file *file);
 void vhost_poll_stop(struct vhost_poll *poll);
-void vhost_poll_flush(struct vhost_poll *poll);
 void vhost_poll_queue(struct vhost_poll *poll);
 void vhost_work_dev_flush(struct vhost_dev *dev);
 

drivers/vhost/vsock.c

@@ -709,7 +709,7 @@ static void vhost_vsock_flush(struct vhost_vsock *vsock)
 
 	for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++)
 		if (vsock->vqs[i].handle_kick)
-			vhost_poll_flush(&vsock->vqs[i].poll);
+			vhost_work_dev_flush(vsock->vqs[i].poll.dev);
 	vhost_work_dev_flush(&vsock->dev);
 }