Re: [PATCH v2 1/2] virtio_console: free unused buffers with port delete

2019-08-08 Thread Pankaj Gupta 


> 
> On Thu, Aug 08, 2019 at 05:06:05PM +0530, Pankaj Gupta wrote:
> >   The commit a7a69ec0d8e4 ("virtio_console: free buffers after reset")
> >   deferred detaching of unused buffer to virtio device unplug time.
> > 
> >   This causes unplug/replug of single port in virtio device with an
> >   error "Error allocating inbufs\n". As we don't free the unused buffers
> >   attached with the port. Re-plug the same port tries to allocate new
> >   buffers in virtqueue and results in this error if queue is full.
> > 
> >   This patch removes the unused buffers in vq's when we unplug the port.
> >   This is the best we can do as we cannot call device_reset because virtio
> >   device is still active.
> 
> Why is this indented?

o.k. will remove the empty lines.

> 
> > 
> > Reported-by: Xiaohui Li 
> > Fixes: b3258ff1d6 ("virtio_console: free buffers after reset")
> 
> Fixes: b3258ff1d608 ("virtio: Decrement avail idx on buffer detach")
> 
> is the correct format to use.

Sorry! for this. Commit it fixes is:
a7a69ec0d8e4 ("virtio_console: free buffers after reset")

> 
> And given that this is from 2.6.39 (and 2.6.38.5), shouldn't it also be
> backported for the stable kernels?

Yes.

Thanks,
Pankaj

> 
> thanks,
> 
> greg k-h
> 
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Re: [PATCH v2 1/2] virtio_console: free unused buffers with port delete

2019-08-08 Thread Greg KH 
On Thu, Aug 08, 2019 at 05:06:05PM +0530, Pankaj Gupta wrote:
>   The commit a7a69ec0d8e4 ("virtio_console: free buffers after reset")
>   deferred detaching of unused buffer to virtio device unplug time.
> 
>   This causes unplug/replug of single port in virtio device with an
>   error "Error allocating inbufs\n". As we don't free the unused buffers
>   attached with the port. Re-plug the same port tries to allocate new
>   buffers in virtqueue and results in this error if queue is full.
> 
>   This patch removes the unused buffers in vq's when we unplug the port.
>   This is the best we can do as we cannot call device_reset because virtio
>   device is still active.

Why is this indented?

> 
> Reported-by: Xiaohui Li 
> Fixes: b3258ff1d6 ("virtio_console: free buffers after reset")

Fixes: b3258ff1d608 ("virtio: Decrement avail idx on buffer detach")

is the correct format to use.

And given that this is from 2.6.39 (and 2.6.38.5), shouldn't it also be
backported for the stable kernels?

thanks,

greg k-h
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[PATCH v2 1/2] virtio_console: free unused buffers with port delete

2019-08-08 Thread Pankaj Gupta 
  The commit a7a69ec0d8e4 ("virtio_console: free buffers after reset")
  deferred detaching of unused buffer to virtio device unplug time.

  This causes unplug/replug of single port in virtio device with an
  error "Error allocating inbufs\n". As we don't free the unused buffers
  attached with the port. Re-plug the same port tries to allocate new
  buffers in virtqueue and results in this error if queue is full.

  This patch removes the unused buffers in vq's when we unplug the port.
  This is the best we can do as we cannot call device_reset because virtio
  device is still active.

Reported-by: Xiaohui Li 
Fixes: b3258ff1d6 ("virtio_console: free buffers after reset")
Signed-off-by: Pankaj Gupta 
---
 drivers/char/virtio_console.c | 14 +++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 7270e7b69262..e8be82f1bae9 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1494,15 +1494,25 @@ static void remove_port(struct kref *kref)
kfree(port);
 }
 
+static void remove_unused_bufs(struct virtqueue *vq)
+{
+   struct port_buffer *buf;
+
+   while ((buf = virtqueue_detach_unused_buf(vq)))
+   free_buf(buf, true);
+}
+
 static void remove_port_data(struct port *port)
 {
spin_lock_irq(>inbuf_lock);
/* Remove unused data this port might have received. */
discard_port_data(port);
+   remove_unused_bufs(port->in_vq);
spin_unlock_irq(>inbuf_lock);
 
spin_lock_irq(>outvq_lock);
reclaim_consumed_buffers(port);
+   remove_unused_bufs(port->out_vq);
spin_unlock_irq(>outvq_lock);
 }
 
@@ -1938,11 +1948,9 @@ static void remove_vqs(struct ports_device *portdev)
struct virtqueue *vq;
 
virtio_device_for_each_vq(portdev->vdev, vq) {
-   struct port_buffer *buf;
 
flush_bufs(vq, true);
-   while ((buf = virtqueue_detach_unused_buf(vq)))
-   free_buf(buf, true);
+   remove_unused_bufs(vq);
}
portdev->vdev->config->del_vqs(portdev->vdev);
kfree(portdev->in_vqs);
-- 
2.21.0

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