rbd: add 'snap_id' sysfs rbd device attribute
Export snap id in sysfs, so tools like multipathd can use it in a uuid.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index c95104a..36ebec1 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -4669,6 +4669,14 @@
return sprintf(buf, "%s\n", rbd_dev->spec->snap_name);
}
+static ssize_t rbd_snap_id_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
+
+ return sprintf(buf, "%llu\n", rbd_dev->spec->snap_id);
+}
+
/*
* For a v2 image, shows the chain of parent images, separated by empty
* lines. For v1 images or if there is no parent, shows "(no parent
@@ -4730,6 +4738,7 @@
static DEVICE_ATTR(image_id, S_IRUGO, rbd_image_id_show, NULL);
static DEVICE_ATTR(refresh, S_IWUSR, NULL, rbd_image_refresh);
static DEVICE_ATTR(current_snap, S_IRUGO, rbd_snap_show, NULL);
+static DEVICE_ATTR(snap_id, S_IRUGO, rbd_snap_id_show, NULL);
static DEVICE_ATTR(parent, S_IRUGO, rbd_parent_show, NULL);
static struct attribute *rbd_attrs[] = {
@@ -4745,6 +4754,7 @@
&dev_attr_name.attr,
&dev_attr_image_id.attr,
&dev_attr_current_snap.attr,
+ &dev_attr_snap_id.attr,
&dev_attr_parent.attr,
&dev_attr_refresh.attr,
NULL