nvme: get list of namespace descriptors

If a target identifies itself as NVMe 1.3 compliant, try to get the
list of Namespace Identification Descriptors and populate the UUID,
NGUID and EUI64 fileds in the NVMe namespace structure with these
values.
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/host/core.c

@@ -638,6 +638,77 @@ int nvme_identify_ctrl(struct nvme_ctrl *dev, struct nvme_id_ctrl **id)
 	return error;
 }
 
+static int nvme_identify_ns_descs(struct nvme_ns *ns, unsigned nsid)
+{
+	struct nvme_command c = { };
+	int status;
+	void *data;
+	int pos;
+	int len;
+
+	c.identify.opcode = nvme_admin_identify;
+	c.identify.nsid = cpu_to_le32(nsid);
+	c.identify.cns = NVME_ID_CNS_NS_DESC_LIST;
+
+	data = kzalloc(NVME_IDENTIFY_DATA_SIZE, GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	status = nvme_submit_sync_cmd(ns->ctrl->admin_q, &c, data,
+				      NVME_IDENTIFY_DATA_SIZE);
+	if (status)
+		goto free_data;
+
+	for (pos = 0; pos < NVME_IDENTIFY_DATA_SIZE; pos += len) {
+		struct nvme_ns_id_desc *cur = data + pos;
+
+		if (cur->nidl == 0)
+			break;
+
+		switch (cur->nidt) {
+		case NVME_NIDT_EUI64:
+			if (cur->nidl != NVME_NIDT_EUI64_LEN) {
+				dev_warn(ns->ctrl->device,
+					 "ctrl returned bogus length: %d for NVME_NIDT_EUI64\n",
+					 cur->nidl);
+				goto free_data;
+			}
+			len = NVME_NIDT_EUI64_LEN;
+			memcpy(ns->eui, data + pos + sizeof(*cur), len);
+			break;
+		case NVME_NIDT_NGUID:
+			if (cur->nidl != NVME_NIDT_NGUID_LEN) {
+				dev_warn(ns->ctrl->device,
+					 "ctrl returned bogus length: %d for NVME_NIDT_NGUID\n",
+					 cur->nidl);
+				goto free_data;
+			}
+			len = NVME_NIDT_NGUID_LEN;
+			memcpy(ns->nguid, data + pos + sizeof(*cur), len);
+			break;
+		case NVME_NIDT_UUID:
+			if (cur->nidl != NVME_NIDT_UUID_LEN) {
+				dev_warn(ns->ctrl->device,
+					 "ctrl returned bogus length: %d for NVME_NIDT_UUID\n",
+					 cur->nidl);
+				goto free_data;
+			}
+			len = NVME_NIDT_UUID_LEN;
+			uuid_copy(&ns->uuid, data + pos + sizeof(*cur));
+			break;
+		default:
+			/* Skip unnkown types */
+			len = cur->nidl;
+			break;
+		}
+
+		len += sizeof(*cur);
+	}
+free_data:
+	kfree(data);
+	return status;
+}
+
 static int nvme_identify_ns_list(struct nvme_ctrl *dev, unsigned nsid, __le32 *ns_list)
 {
 	struct nvme_command c = { };
@@ -1012,6 +1083,14 @@ static int nvme_revalidate_ns(struct nvme_ns *ns, struct nvme_id_ns **id)
 		memcpy(ns->eui, (*id)->eui64, sizeof(ns->eui));
 	if (ns->ctrl->vs >= NVME_VS(1, 2, 0))
 		memcpy(ns->nguid, (*id)->nguid, sizeof(ns->nguid));
+	if (ns->ctrl->vs >= NVME_VS(1, 3, 0)) {
+		 /* Don't treat error as fatal we potentially
+		  * already have a NGUID or EUI-64
+		  */
+		if (nvme_identify_ns_descs(ns, ns->ns_id))
+			dev_warn(ns->ctrl->device,
+				 "%s: Identify Descriptors failed\n", __func__);
+	}
 
 	return 0;
 }

drivers/nvme/host/nvme.h

@@ -196,6 +196,7 @@ struct nvme_ns {
 
 	u8 eui[8];
 	u8 nguid[16];
+	uuid_t uuid;
 
 	unsigned ns_id;
 	int lba_shift;