Commit 92a58671 authored by Mike Christie's avatar Mike Christie Committed by Ilya Dryomov
Browse files

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: default avatarMike Christie <mchristi@redhat.com>
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent 267fb90b

Documentation/ABI/testing/sysfs-bus-rbd

+4 −0
Original line number Diff line number Diff line
@@ -102,6 +102,10 @@ current_snap 


	The current snapshot for which the device is mapped.



snap_id



	The current snapshot's id.  (August 2016, since 4.9.)



parent



	Information identifying the chain of parent images in a layered rbd

drivers/block/rbd.c

+10 −0
Original line number Diff line number Diff line
@@ -4669,6 +4669,14 @@ static ssize_t rbd_snap_show(struct device *dev, 
	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(name, S_IRUGO, rbd_name_show, NULL); 
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 @@ static struct attribute *rbd_attrs[] = { 
	&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