On Thu, 3 May 2012 10:20:51 +0800, Asias He <[email protected]> wrote:
> Current index allocation in virtio is based on a monotonically
> increasing variable "index". This means we'll run out of numbers
> after a while. E.g. someone crazy doing this in host side.
>
> while(1) {
> hot-plug a virtio device
> hot-unplug the virito devcie
> }
>
> Signed-off-by: Asias He <[email protected]>
Applied. Nice and simple.
Thanks,
Rusty.
> ---
> drivers/virtio/virtio.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
> index 984c501..f355807 100644
> --- a/drivers/virtio/virtio.c
> +++ b/drivers/virtio/virtio.c
> @@ -2,9 +2,10 @@
> #include <linux/spinlock.h>
> #include <linux/virtio_config.h>
> #include <linux/module.h>
> +#include <linux/idr.h>
>
> /* Unique numbering for virtio devices. */
> -static unsigned int dev_index;
> +static DEFINE_IDA(virtio_index_ida);
>
> static ssize_t device_show(struct device *_d,
> struct device_attribute *attr, char *buf)
> @@ -193,7 +194,11 @@ int register_virtio_device(struct virtio_device *dev)
> dev->dev.bus = &virtio_bus;
>
> /* Assign a unique device index and hence name. */
> - dev->index = dev_index++;
> + err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL);
> + if (err < 0)
> + goto out;
> +
> + dev->index = err;
> dev_set_name(&dev->dev, "virtio%u", dev->index);
>
> /* We always start by resetting the device, in case a previous
> @@ -208,6 +213,7 @@ int register_virtio_device(struct virtio_device *dev)
> /* device_register() causes the bus infrastructure to look for a
> * matching driver. */
> err = device_register(&dev->dev);
> +out:
> if (err)
> add_status(dev, VIRTIO_CONFIG_S_FAILED);
> return err;
> @@ -217,6 +223,7 @@ EXPORT_SYMBOL_GPL(register_virtio_device);
> void unregister_virtio_device(struct virtio_device *dev)
> {
> device_unregister(&dev->dev);
> + ida_simple_remove(&virtio_index_ida, dev->index);
> }
> EXPORT_SYMBOL_GPL(unregister_virtio_device);
>
> --
> 1.7.10
>
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