Messages in this thread | | | Date | Fri, 24 Oct 2014 10:13:01 +0800 | Subject | Re: [PATCH] virtio_blk: fix race at module removal | From | Ming Lei <> |
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On Fri, Oct 24, 2014 at 12:12 AM, Michael S. Tsirkin <mst@redhat.com> wrote: > 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.
Yes, there is a tiny race window.
> > To fix, cleanup in reverse order of initialization.
Reviewed-by: Ming Lei <ming.lei@canonical.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > drivers/block/virtio_blk.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > index 56aadbc..adfba9f 100644 > --- a/drivers/block/virtio_blk.c > +++ b/drivers/block/virtio_blk.c > @@ -883,8 +883,8 @@ 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);
Thanks, -- Ming Lei
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