[3.16 stable PATCH 0/2] virtio-rng: two backports to fix stuck

[3.16 stable PATCH 0/2] virtio-rng: two backports to fix stuck

[Amos Kong]

I received two mails about faile to apply patches to 3.16-stable tree:

FAILED: patch "[PATCH] virtio-rng: skip reading when we start to remove the device" failed to apply to 3.16-stable tree
FAILED: patch "[PATCH] virtio-rng: fix stuck of hot-unplugging busy device" failed to apply to 3.16-stable tree

Amit already backported two patches for 3.16-stable, then cherry-pick
of my two patches works.

Thanks.

Amos Kong (2):
  virtio-rng: fix stuck of hot-unplugging busy device
  virtio-rng: skip reading when we start to remove the device

 drivers/char/hw_random/virtio-rng.c | 7 +++++++
 1 file changed, 7 insertions(+)

-- 
1.9.3

[3.16 stable PATCH 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 <akong@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
(cherry picked from commit 3856e548372513665670ca5db60d9a74b970fe0d)
Signed-off-by: Amos Kong <akong@redhat.com>
---
 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 f1aa13b..b50252c 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

[3.16 stable PATCH 2/2] virtio-rng: skip reading when we start to remove the device

[Amos Kong]

Before we really unregister the hwrng device, reading will get stuck if
the virtio device is reset. We should return error for reading when we
start to remove the device.

Signed-off-by: Amos Kong <akong@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
(cherry picked from commit f49819560f53b7f3a596a8ea2e6764dc86695b62)
Signed-off-by: Amos Kong <akong@redhat.com>
---
 drivers/char/hw_random/virtio-rng.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
index b50252c..cb1688a 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -37,6 +37,7 @@ struct virtrng_info {
 	char name[25];
 	int index;
 	bool hwrng_register_done;
+	bool hwrng_removed;
 };
 
 
@@ -69,6 +70,9 @@ static int virtio_read(struct hwrng *rng, void *buf, size_t size, bool wait)
 	int ret;
 	struct virtrng_info *vi = (struct virtrng_info *)rng->priv;
 
+	if (vi->hwrng_removed)
+		return -ENODEV;
+
 	if (!vi->busy) {
 		vi->busy = true;
 		init_completion(&vi->have_data);
@@ -137,6 +141,7 @@ static void remove_common(struct virtio_device *vdev)
 {
 	struct virtrng_info *vi = vdev->priv;
 
+	vi->hwrng_removed = true;
 	vi->data_avail = 0;
 	complete(&vi->have_data);
 	vdev->config->reset(vdev);
-- 
1.9.3

Re: [3.16 stable PATCH 0/2] virtio-rng: two backports to fix stuck

[Amos Kong]

On Sat, Oct 11, 2014 at 06:51:47AM +0800, Amos Kong wrote:
> I received two mails about faile to apply patches to 3.16-stable tree:
> 
> FAILED: patch "[PATCH] virtio-rng: skip reading when we start to remove the device" failed to apply to 3.16-stable tree
> FAILED: patch "[PATCH] virtio-rng: fix stuck of hot-unplugging busy device" failed to apply to 3.16-stable tree
> 
> Amit already backported two patches for 3.16-stable, then cherry-pick
> of my two patches works.
> 
> Thanks.

Ping Greg, thanks.
 
> Amos Kong (2):
>   virtio-rng: fix stuck of hot-unplugging busy device
>   virtio-rng: skip reading when we start to remove the device
> 
>  drivers/char/hw_random/virtio-rng.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> -- 
> 1.9.3
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

-- 
			Amos.

Re: [3.16 stable PATCH 0/2] virtio-rng: two backports to fix stuck

[Luis Henriques]

Hi Amos

On Tue, Nov 04, 2014 at 12:32:27PM +0800, Amos Kong wrote:
> On Sat, Oct 11, 2014 at 06:51:47AM +0800, Amos Kong wrote:
> > I received two mails about faile to apply patches to 3.16-stable tree:
> > 
> > FAILED: patch "[PATCH] virtio-rng: skip reading when we start to remove the device" failed to apply to 3.16-stable tree
> > FAILED: patch "[PATCH] virtio-rng: fix stuck of hot-unplugging busy device" failed to apply to 3.16-stable tree
> > 
> > Amit already backported two patches for 3.16-stable, then cherry-pick
> > of my two patches works.
> > 
> > Thanks.
> 
> Ping Greg, thanks.
>  

I'm now doing the extended stable maintenance of the 3.16 kernel, as
Greg has EOL'ed it.

Anyway, I will be queuing these 2 patches for the extended 3.16
kernel.  Thank you!

Cheers,
--
Luís

> > Amos Kong (2):
> >   virtio-rng: fix stuck of hot-unplugging busy device
> >   virtio-rng: skip reading when we start to remove the device
> > 
> >  drivers/char/hw_random/virtio-rng.c | 7 +++++++
> >  1 file changed, 7 insertions(+)
> > 
> > -- 
> > 1.9.3
> > 
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > Please read the FAQ at  http://www.tux.org/lkml/
> 
> -- 
> 			Amos.
> --
> To unsubscribe from this list: send the line "unsubscribe stable" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [3.16 stable PATCH 0/2] virtio-rng: two backports to fix stuck

[Amos Kong]

[-- Attachment #1.1: Type: text/plain, Size: 1230 bytes --]

On Wed, Nov 05, 2014 at 04:02:49PM +0000, Luis Henriques wrote:
> Hi Amos
> 
> On Tue, Nov 04, 2014 at 12:32:27PM +0800, Amos Kong wrote:
> > On Sat, Oct 11, 2014 at 06:51:47AM +0800, Amos Kong wrote:
> > > I received two mails about faile to apply patches to 3.16-stable tree:
> > > 
> > > FAILED: patch "[PATCH] virtio-rng: skip reading when we start to remove the device" failed to apply to 3.16-stable tree
> > > FAILED: patch "[PATCH] virtio-rng: fix stuck of hot-unplugging busy device" failed to apply to 3.16-stable tree
> > > 
> > > Amit already backported two patches for 3.16-stable, then cherry-pick
> > > of my two patches works.
> > > 
> > > Thanks.
> > 
> > Ping Greg, thanks.
> >  
> 
> I'm now doing the extended stable maintenance of the 3.16 kernel, as
> Greg has EOL'ed it.
> 
> Anyway, I will be queuing these 2 patches for the extended 3.16
> kernel.  Thank you!

Thanks a lot!
 
> Cheers,
> --
> Luís
> 
> > > Amos Kong (2):
> > >   virtio-rng: fix stuck of hot-unplugging busy device
> > >   virtio-rng: skip reading when we start to remove the device
> > > 
> > >  drivers/char/hw_random/virtio-rng.c | 7 +++++++
> > >  1 file changed, 7 insertions(+)

-- 
			Amos.

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Re: [3.16 stable PATCH 0/2] virtio-rng: two backports to fix stuck

[Greg KH]

On Tue, Nov 04, 2014 at 12:32:27PM +0800, Amos Kong wrote:
> On Sat, Oct 11, 2014 at 06:51:47AM +0800, Amos Kong wrote:
> > I received two mails about faile to apply patches to 3.16-stable tree:
> > 
> > FAILED: patch "[PATCH] virtio-rng: skip reading when we start to remove the device" failed to apply to 3.16-stable tree
> > FAILED: patch "[PATCH] virtio-rng: fix stuck of hot-unplugging busy device" failed to apply to 3.16-stable tree
> > 
> > Amit already backported two patches for 3.16-stable, then cherry-pick
> > of my two patches works.
> > 
> > Thanks.
> 
> Ping Greg, thanks.

Why me?  3.16-stable is end-of-life, I'm no longer maintaining it, so
what can I do here with these patches?

confused,

greg k-h