virtio: fix module/device unloading

The virtio code never hooked through the ->remove callback.  Although
noone supports device removal at the moment, this code is already
needed for module unloading.

This of course also revealed bugs in virtio_blk, virtio_net and lguest
unloading paths.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

4 files changed, 28 insertions, 5 deletions

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 3cf7129d83e6..924ddd8bccd2 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -223,7 +223,7 @@ static int virtblk_probe(struct virtio_device *vdev)
         err = virtio_config_val(vdev, VIRTIO_CONFIG_BLK_F_CAPACITY, &cap);
         if (err) {
                 dev_err(&vdev->dev, "Bad/missing capacity in config\n");
-                goto out_put_disk;
+                goto out_cleanup_queue;
         }
 
         /* If capacity is too big, truncate with warning. */
@@ -239,7 +239,7 @@ static int virtblk_probe(struct virtio_device *vdev)
                 blk_queue_max_segment_size(vblk->disk->queue, v);
         else if (err != -ENOENT) {
                 dev_err(&vdev->dev, "Bad SIZE_MAX in config\n");
-                goto out_put_disk;
+                goto out_cleanup_queue;
         }
 
         err = virtio_config_val(vdev, VIRTIO_CONFIG_BLK_F_SEG_MAX, &v);
@@ -247,12 +247,14 @@ static int virtblk_probe(struct virtio_device *vdev)
                 blk_queue_max_hw_segments(vblk->disk->queue, v);
         else if (err != -ENOENT) {
                 dev_err(&vdev->dev, "Bad SEG_MAX in config\n");
-                goto out_put_disk;
+                goto out_cleanup_queue;
         }
 
         add_disk(vblk->disk);
         return 0;
 
+out_cleanup_queue:
+        blk_cleanup_queue(vblk->disk->queue);
 out_put_disk:
         put_disk(vblk->disk);
 out_unregister_blkdev:
@@ -277,6 +279,8 @@ static void virtblk_remove(struct virtio_device *vdev)
         put_disk(vblk->disk);
         unregister_blkdev(major, "virtblk");
         mempool_destroy(vblk->pool);
+        /* There should be nothing in the queue now, so no need to shutdown */
+        vdev->config->del_vq(vblk->vq);
         kfree(vblk);
 }
 
diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c
index 66f38722253a..e2eec38c83c2 100644
--- a/drivers/lguest/lguest_device.c
+++ b/drivers/lguest/lguest_device.c
@@ -247,6 +247,8 @@ static void lg_del_vq(struct virtqueue *vq)
 {
         struct lguest_vq_info *lvq = vq->priv;
 
+        /* Release the interrupt */
+        free_irq(lvq->config.irq, vq);
         /* Tell virtio_ring.c to free the virtqueue. */
         vring_del_virtqueue(vq);
         /* Unmap the pages containing the ring. */
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index a75be57fb209..d74e6f4aa248 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -404,8 +404,12 @@ free:
 
 static void virtnet_remove(struct virtio_device *vdev)
 {
-        unregister_netdev(vdev->priv);
-        free_netdev(vdev->priv);
+        struct virtnet_info *vi = vdev->priv;
+
+        vdev->config->del_vq(vi->svq);
+        vdev->config->del_vq(vi->rvq);
+        unregister_netdev(vi->dev);
+        free_netdev(vi->dev);
 }
 
 static struct virtio_device_id id_table[] = {
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 15d7787dea87..69d7ea02cd48 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -96,10 +96,23 @@ static int virtio_dev_probe(struct device *_d)
         return err;
 }
 
+static int virtio_dev_remove(struct device *_d)
+{
+        struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
+        struct virtio_driver *drv = container_of(dev->dev.driver,
+                                                 struct virtio_driver, driver);
+
+        dev->config->set_status(dev, dev->config->get_status(dev)
+                                & ~VIRTIO_CONFIG_S_DRIVER);
+        drv->remove(dev);
+        return 0;
+}
+
 int register_virtio_driver(struct virtio_driver *driver)
 {
         driver->driver.bus = &virtio_bus;
         driver->driver.probe = virtio_dev_probe;
+        driver->driver.remove = virtio_dev_remove;
         return driver_register(&driver->driver);
 }
 EXPORT_SYMBOL_GPL(register_virtio_driver);