9p/trans_virtio: fix hot-unplug

[firefly-linux-kernel-4.4.55.git] / net / 9p / trans_virtio.c

diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index d8e376a5f0f13d9eed735f62b81367b7bc685ebe..36a1a739ad68ff57eace5ba4bc4166faf12c485b 100644 (file)
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -658,14 +658,30 @@ p9_virtio_create(struct p9_client *client, const char *devname, char *args)
 static void p9_virtio_remove(struct virtio_device *vdev)
 {
        struct virtio_chan *chan = vdev->priv;
-
-       if (chan->inuse)
-               p9_virtio_close(chan->client);
-       vdev->config->del_vqs(vdev);
+       unsigned long warning_time;
 
        mutex_lock(&virtio_9p_lock);
+
+       /* Remove self from list so we don't get new users. */
        list_del(&chan->chan_list);
+       warning_time = jiffies;
+
+       /* Wait for existing users to close. */
+       while (chan->inuse) {
+               mutex_unlock(&virtio_9p_lock);
+               msleep(250);
+               if (time_after(jiffies, warning_time + 10 * HZ)) {
+                       dev_emerg(&vdev->dev,
+                                 "p9_virtio_remove: waiting for device in use.\n");
+                       warning_time = jiffies;
+               }
+               mutex_lock(&virtio_9p_lock);
+       }
+
        mutex_unlock(&virtio_9p_lock);
+
+       vdev->config->del_vqs(vdev);
+
        sysfs_remove_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr);
        kobject_uevent(&(vdev->dev.kobj), KOBJ_CHANGE);
        kfree(chan->tag);