Re: [PATCH V2] xen: export device state to sysfs

[Boris Ostrovsky]

On 08/28/2018 10:56 AM, Joe Jin wrote:
> Export device state to sysfs to allow for easier get device state.
>
> Signed-off-by: Joe Jin <joe.jin@xxxxxxxxxx>
> Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
> Cc: Juergen Gross <jgross@xxxxxxxx>
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> ---
>  Documentation/ABI/stable/sysfs-bus-xen-backend | 9 +++++++++
>  drivers/xen/xenbus/xenbus_probe.c              | 9 +++++++++
>  2 files changed, 18 insertions(+)
>
> diff --git a/Documentation/ABI/stable/sysfs-bus-xen-backend b/Documentation/ABI/stable/sysfs-bus-xen-backend
> index 3d5951c8bf5f..e8b60bd766f7 100644
> --- a/Documentation/ABI/stable/sysfs-bus-xen-backend


Won't this show up in the frontend as well?

-boris

> +++ b/Documentation/ABI/stable/sysfs-bus-xen-backend
> @@ -73,3 +73,12 @@ KernelVersion:	3.0
>  Contact:	Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
>  Description:
>                  Number of sectors written by the frontend.
> +
> +What:		/sys/bus/xen-backend/devices/*/state
> +Date:		August 2018
> +KernelVersion:	4.19
> +Contact:	Joe Jin <joe.jin@xxxxxxxxxx>
> +Description:
> +                The state of the device. One of: 'Unknown',
> +                'Initialising', 'Initialised', 'Connected', 'Closing',
> +                'Closed', 'Reconfiguring', 'Reconfigured'.
> diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
> index f2088838f690..5b471889d723 100644
> --- a/drivers/xen/xenbus/xenbus_probe.c
> +++ b/drivers/xen/xenbus/xenbus_probe.c
> @@ -402,10 +402,19 @@ static ssize_t modalias_show(struct device *dev,
>  }
>  static DEVICE_ATTR_RO(modalias);
>  
> +static ssize_t state_show(struct device *dev,
> +			    struct device_attribute *attr, char *buf)
> +{
> +	return sprintf(buf, "%s\n",
> +			xenbus_strstate(to_xenbus_device(dev)->state));
> +}
> +static DEVICE_ATTR_RO(state);
> +
>  static struct attribute *xenbus_dev_attrs[] = {
>  	&dev_attr_nodename.attr,
>  	&dev_attr_devtype.attr,
>  	&dev_attr_modalias.attr,
> +	&dev_attr_state.attr,
>  	NULL,
>  };
>