From: Michael S. Tsirkin <mst@redhat.com>
Date: Thu, 23 Oct 2014 15:57:19 +0000 (+0300)
Subject: virtio_blk: fix race at module removal
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=38f37b578f7d62a827d6f42e21d55bf428f9af8e;p=sagit-ice-cold%2Fkernel_xiaomi_msm8998.git

virtio_blk: fix race at module removal

If a device appears while module is being removed,
driver will get a callback after we've given up
on the major number.

In theory this means this major number can get reused
by something else, resulting in a conflict.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 055f3df0b4d0..1f8b111c5dab 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -884,8 +884,8 @@ out_destroy_workqueue:
 
 static void __exit fini(void)
 {
-	unregister_blkdev(major, "virtblk");
 	unregister_virtio_driver(&virtio_blk);
+	unregister_blkdev(major, "virtblk");
 	destroy_workqueue(virtblk_wq);
 }
 module_init(init);