nvme: provide UUID value to userspace
Now that we have a way for getting the UUID from a target, provide it
to userspace as well.
Unfortunately there is already a sysfs attribute called UUID which is
a misnomer as it holds the NGUID value. So instead of creating yet
another wrong name, create a new 'nguid' sysfs attribute for the
NGUID. For the UUID attribute add a check wheter the namespace has a
UUID assigned to it and return this or return the NGUID to maintain
backwards compatibility. This should give userspace a chance to catch
up.
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Sagi Grimberg <sagi@rimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 17118ef..89a7fe4 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1879,11 +1879,28 @@
}
static DEVICE_ATTR(wwid, S_IRUGO, wwid_show, NULL);
+static ssize_t nguid_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct nvme_ns *ns = nvme_get_ns_from_dev(dev);
+ return sprintf(buf, "%pU\n", ns->nguid);
+}
+static DEVICE_ATTR(nguid, S_IRUGO, nguid_show, NULL);
+
static ssize_t uuid_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct nvme_ns *ns = nvme_get_ns_from_dev(dev);
- return sprintf(buf, "%pU\n", ns->nguid);
+
+ /* For backward compatibility expose the NGUID to userspace if
+ * we have no UUID set
+ */
+ if (uuid_is_null(&ns->uuid)) {
+ printk_ratelimited(KERN_WARNING
+ "No UUID available providing old NGUID\n");
+ return sprintf(buf, "%pU\n", ns->nguid);
+ }
+ return sprintf(buf, "%pU\n", &ns->uuid);
}
static DEVICE_ATTR(uuid, S_IRUGO, uuid_show, NULL);
@@ -1906,6 +1923,7 @@
static struct attribute *nvme_ns_attrs[] = {
&dev_attr_wwid.attr,
&dev_attr_uuid.attr,
+ &dev_attr_nguid.attr,
&dev_attr_eui.attr,
&dev_attr_nsid.attr,
NULL,
@@ -1918,6 +1936,11 @@
struct nvme_ns *ns = nvme_get_ns_from_dev(dev);
if (a == &dev_attr_uuid.attr) {
+ if (uuid_is_null(&ns->uuid) ||
+ !memchr_inv(ns->nguid, 0, sizeof(ns->nguid)))
+ return 0;
+ }
+ if (a == &dev_attr_nguid.attr) {
if (!memchr_inv(ns->nguid, 0, sizeof(ns->nguid)))
return 0;
}