[PATCH V2] xen: export device state to sysfs

From: Joe Jin
Date: Tue Aug 28 2018 - 10:56:18 EST


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
+++ 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,
};

--
2.15.2 (Apple Git-101.1)