Re: [PATCH] virtio_blk: fix race at module removal
Ming Lei writes: > On Fri, Oct 24, 2014 at 12:12 AM, Michael S. Tsirkin 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. Applied. Thanks, Rusty. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] virtio_blk: fix race at module removal
Ming Lei tom.leim...@gmail.com writes: On Fri, Oct 24, 2014 at 12:12 AM, Michael S. Tsirkin m...@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. Applied. Thanks, Rusty. -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH] virtio_blk: fix race at module removal
On Fri, Oct 24, 2014 at 12:12 AM, Michael S. Tsirkin 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
> Signed-off-by: Michael S. Tsirkin
> ---
> 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(_blk);
> + unregister_blkdev(major, "virtblk");
> destroy_workqueue(virtblk_wq);
> }
> module_init(init);
Thanks,
--
Ming Lei
--
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[PATCH] 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.
To fix, cleanup in reverse order of initialization.
Signed-off-by: Michael S. Tsirkin
---
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(_blk);
+ unregister_blkdev(major, "virtblk");
destroy_workqueue(virtblk_wq);
}
module_init(init);
--
MST
--
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[PATCH] 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.
To fix, cleanup in reverse order of initialization.
Signed-off-by: Michael S. Tsirkin m...@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);
--
MST
--
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Re: [PATCH] virtio_blk: fix race at module removal
On Fri, Oct 24, 2014 at 12:12 AM, Michael S. Tsirkin m...@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@canonical.com
Signed-off-by: Michael S. Tsirkin m...@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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