[PATCH v3 1/2] virtio-rng: fix stuck of hot-unplugging busy device

[Amos Kong]

When we try to hot-remove a busy virtio-rng device from QEMU monitor,
the device can't be hot-removed. Because virtio-rng driver hangs at
wait_for_completion_killable().

This patch exits the waiting by completing have_data completion before
unregistering, resets data_avail to avoid the hwrng core use wrong
buffer bytes.

Signed-off-by: Amos Kong 
Cc: sta...@vger.kernel.org
---
 drivers/char/hw_random/virtio-rng.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/char/hw_random/virtio-rng.c 
b/drivers/char/hw_random/virtio-rng.c
index 2e3139e..849b228 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -137,6 +137,8 @@ static void remove_common(struct virtio_device *vdev)
 {
struct virtrng_info *vi = vdev->priv;
 
+   vi->data_avail = 0;
+   complete(&vi->have_data);
vdev->config->reset(vdev);
vi->busy = false;
if (vi->hwrng_register_done)
-- 
1.9.3

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Re: [PATCH v3 1/2] virtio-rng: fix stuck of hot-unplugging busy device

[Amit Shah]

On (Wed) 10 Sep 2014 [14:11:36], Amos Kong wrote:
> When we try to hot-remove a busy virtio-rng device from QEMU monitor,
> the device can't be hot-removed. Because virtio-rng driver hangs at
> wait_for_completion_killable().
> 
> This patch exits the waiting by completing have_data completion before
> unregistering, resets data_avail to avoid the hwrng core use wrong
> buffer bytes.
> 
> Signed-off-by: Amos Kong 
> Cc: sta...@vger.kernel.org

Reviewed-by: Amit Shah 

Amit
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Re: [PATCH v3 1/2] virtio-rng: fix stuck of hot-unplugging busy device

[Rusty Russell]

Amit Shah  writes:
> On (Wed) 10 Sep 2014 [14:11:36], Amos Kong wrote:
>> When we try to hot-remove a busy virtio-rng device from QEMU monitor,
>> the device can't be hot-removed. Because virtio-rng driver hangs at
>> wait_for_completion_killable().
>> 
>> This patch exits the waiting by completing have_data completion before
>> unregistering, resets data_avail to avoid the hwrng core use wrong
>> buffer bytes.
>> 
>> Signed-off-by: Amos Kong 
>> Cc: sta...@vger.kernel.org
>
> Reviewed-by: Amit Shah 

Thanks, applied.

Cheers,
Rusty.
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