NVMe: Expose ns wwid through single sysfs entry
The method to uniquely identify a namespace depends on the controller's
specification revision level and implemented capabilities. This patch
has the driver figure this out and exports the unique string through a
single 'wwid' attribute so the user doesn't have this burden.
The longest namespace unique identifier is used if available. If not
available, the driver will concat the controller's vendor, serial,
and model with the namespace ID. The specification provides this as a
unique indentifier.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 4304be0..266918b 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -915,6 +915,7 @@
return -EIO;
}
+ ctrl->vid = le16_to_cpu(id->vid);
ctrl->oncs = le16_to_cpup(&id->oncs);
atomic_set(&ctrl->abort_limit, id->acl + 1);
ctrl->vwc = id->vwc;
@@ -1053,6 +1054,30 @@
}
static DEVICE_ATTR(reset_controller, S_IWUSR, NULL, nvme_sysfs_reset);
+static ssize_t wwid_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct nvme_ns *ns = dev_to_disk(dev)->private_data;
+ struct nvme_ctrl *ctrl = ns->ctrl;
+ int serial_len = sizeof(ctrl->serial);
+ int model_len = sizeof(ctrl->model);
+
+ if (memchr_inv(ns->uuid, 0, sizeof(ns->uuid)))
+ return sprintf(buf, "eui.%16phN\n", ns->uuid);
+
+ if (memchr_inv(ns->eui, 0, sizeof(ns->eui)))
+ return sprintf(buf, "eui.%8phN\n", ns->eui);
+
+ while (ctrl->serial[serial_len - 1] == ' ')
+ serial_len--;
+ while (ctrl->model[model_len - 1] == ' ')
+ model_len--;
+
+ return sprintf(buf, "nvme.%04x-%*phN-%*phN-%08x\n", ctrl->vid,
+ serial_len, ctrl->serial, model_len, ctrl->model, ns->ns_id);
+}
+static DEVICE_ATTR(wwid, S_IRUGO, wwid_show, NULL);
+
static ssize_t uuid_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
@@ -1078,6 +1103,7 @@
static DEVICE_ATTR(nsid, S_IRUGO, nsid_show, NULL);
static struct attribute *nvme_ns_attrs[] = {
+ &dev_attr_wwid.attr,
&dev_attr_uuid.attr,
&dev_attr_eui.attr,
&dev_attr_nsid.attr,