nvme: add spdk_nvme_ns_get_uuid() function

This function retrieves the UUID from a namespace, if available.

Change-Id: I98c55375948b92eaf429b41fb36dfea4e2b780a2
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-on: https://review.gerrithub.io/404734
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>

CHANGELOG.md

@@ -15,6 +15,8 @@ needed; previously, the response was limited to 32 kilobytes.
 EXPERIMENTAL: Adds support for WDS and RDS capable CMBs in NVMe controllers. This support is
 experimental pending a functional allocator to free and reallocate CMB buffers.
 
+spdk_nvme_ns_get_uuid() has been added to allow retrieval of per-namespace UUIDs when available.
+
 ### NVMe-oF Target
 
 Namespaces may now be assigned unique identifiers via new optional "eui64" and "nguid" parameters

include/spdk/nvme.h

@@ -1052,6 +1052,15 @@ enum spdk_nvme_dealloc_logical_block_read_value spdk_nvme_ns_get_dealloc_logical
  */
 uint32_t spdk_nvme_ns_get_optimal_io_boundary(struct spdk_nvme_ns *ns);
 
+/**
+ * Get the UUID for the given namespace.
+ *
+ * \param ns Namespace to query.
+ *
+ * \return Pointer to namespace UUID, or NULL if ns does not have a UUID.
+ */
+const struct spdk_uuid *spdk_nvme_ns_get_uuid(const struct spdk_nvme_ns *ns);
+
 /**
  * \brief Namespace command support flags.
  */

lib/nvme/nvme_internal.h

@@ -302,6 +302,9 @@ struct spdk_nvme_ns {
 	uint32_t			sectors_per_stripe;
 	uint32_t			id;
 	uint16_t			flags;
+
+	/* Namespace Identification Descriptor List (CNS = 03h) */
+	uint8_t				id_desc_list[4096];
 };
 
 /**

lib/nvme/nvme_ns.c

@@ -122,6 +122,30 @@ int nvme_ns_identify_update(struct spdk_nvme_ns *ns)
 		ns->flags |= SPDK_NVME_NS_DPS_PI_SUPPORTED;
 		ns->pi_type = nsdata->dps.pit;
 	}
+
+	memset(ns->id_desc_list, 0, sizeof(ns->id_desc_list));
+	if (ns->ctrlr->cdata.ver.raw >= SPDK_NVME_VERSION(1, 3, 0)) {
+		SPDK_DEBUGLOG(SPDK_LOG_NVME, "Attempting to retrieve NS ID Descriptor List\n");
+		status.done = false;
+		rc = nvme_ctrlr_cmd_identify(ns->ctrlr, SPDK_NVME_IDENTIFY_NS_ID_DESCRIPTOR_LIST, 0, ns->id,
+					     ns->id_desc_list, sizeof(ns->id_desc_list),
+					     nvme_completion_poll_cb, &status);
+		if (rc == 0) {
+			while (status.done == false) {
+				nvme_robust_mutex_lock(&ns->ctrlr->ctrlr_lock);
+				spdk_nvme_qpair_process_completions(ns->ctrlr->adminq, 0);
+				nvme_robust_mutex_unlock(&ns->ctrlr->ctrlr_lock);
+			}
+		}
+
+		if (rc != 0 || spdk_nvme_cpl_is_error(&status.cpl)) {
+			SPDK_WARNLOG("Failed to retrieve NS ID Descriptor List\n");
+			memset(ns->id_desc_list, 0, sizeof(ns->id_desc_list));
+		}
+	} else {
+		SPDK_DEBUGLOG(SPDK_LOG_NVME, "Version < 1.3; not attempting to retrieve NS ID Descriptor List\n");
+	}
+
 	return rc;
 }
 
@@ -223,6 +247,55 @@ spdk_nvme_ns_get_optimal_io_boundary(struct spdk_nvme_ns *ns)
 	return ns->sectors_per_stripe;
 }
 
+static const void *
+_spdk_nvme_ns_find_id_desc(const struct spdk_nvme_ns *ns, enum spdk_nvme_nidt type, size_t *length)
+{
+	const struct spdk_nvme_ns_id_desc *desc;
+	size_t offset;
+
+	offset = 0;
+	while (offset + 4 < sizeof(ns->id_desc_list)) {
+		desc = (const struct spdk_nvme_ns_id_desc *)&ns->id_desc_list[offset];
+
+		if (desc->nidl == 0) {
+			/* End of list */
+			return NULL;
+		}
+
+		/*
+		 * Check if this descriptor fits within the list.
+		 * 4 is the fixed-size descriptor header (not counted in NIDL).
+		 */
+		if (offset + desc->nidl + 4 > sizeof(ns->id_desc_list)) {
+			/* Descriptor longer than remaining space in list (invalid) */
+			return NULL;
+		}
+
+		if (desc->nidt == type) {
+			*length = desc->nidl;
+			return &desc->nid[0];
+		}
+
+		offset += 4 + desc->nidl;
+	}
+
+	return NULL;
+}
+
+const struct spdk_uuid *
+spdk_nvme_ns_get_uuid(const struct spdk_nvme_ns *ns)
+{
+	const struct spdk_uuid *uuid;
+	size_t uuid_size;
+
+	uuid = _spdk_nvme_ns_find_id_desc(ns, SPDK_NVME_NIDT_UUID, &uuid_size);
+	if (uuid == NULL || uuid_size != sizeof(*uuid)) {
+		return NULL;
+	}
+
+	return uuid;
+}
+
 int nvme_ns_construct(struct spdk_nvme_ns *ns, uint32_t id,
 		      struct spdk_nvme_ctrlr *ctrlr)
 {

test/unit/lib/nvme/nvme_ns.c/nvme_ns_ut.c

@@ -71,6 +71,62 @@ test_nvme_ns_construct(void)
 	CU_ASSERT(ns.id == 1);
 }
 
+static void
+test_nvme_ns_uuid(void)
+{
+	struct spdk_nvme_ns ns = {};
+	const struct spdk_uuid *uuid;
+	struct spdk_uuid expected_uuid;
+
+	memset(&expected_uuid, 0xA5, sizeof(expected_uuid));
+
+	/* Empty list - no UUID should be found */
+	memset(ns.id_desc_list, 0, sizeof(ns.id_desc_list));
+	uuid = spdk_nvme_ns_get_uuid(&ns);
+	CU_ASSERT(uuid == NULL);
+
+	/* NGUID only (no UUID in list) */
+	memset(ns.id_desc_list, 0, sizeof(ns.id_desc_list));
+	ns.id_desc_list[0] = 0x02; /* NIDT == NGUID */
+	ns.id_desc_list[1] = 0x10; /* NIDL */
+	memset(&ns.id_desc_list[4], 0xCC, 0x10);
+	uuid = spdk_nvme_ns_get_uuid(&ns);
+	CU_ASSERT(uuid == NULL);
+
+	/* Just UUID in the list */
+	memset(ns.id_desc_list, 0, sizeof(ns.id_desc_list));
+	ns.id_desc_list[0] = 0x03; /* NIDT == UUID */
+	ns.id_desc_list[1] = 0x10; /* NIDL */
+	memcpy(&ns.id_desc_list[4], &expected_uuid, sizeof(expected_uuid));
+	uuid = spdk_nvme_ns_get_uuid(&ns);
+	SPDK_CU_ASSERT_FATAL(uuid != NULL);
+	CU_ASSERT(memcmp(uuid, &expected_uuid, sizeof(*uuid)) == 0);
+
+	/* UUID followed by NGUID */
+	memset(ns.id_desc_list, 0, sizeof(ns.id_desc_list));
+	ns.id_desc_list[0] = 0x03; /* NIDT == UUID */
+	ns.id_desc_list[1] = 0x10; /* NIDL */
+	memcpy(&ns.id_desc_list[4], &expected_uuid, sizeof(expected_uuid));
+	ns.id_desc_list[20] = 0x02; /* NIDT == NGUID */
+	ns.id_desc_list[21] = 0x10; /* NIDL */
+	memset(&ns.id_desc_list[24], 0xCC, 0x10);
+	uuid = spdk_nvme_ns_get_uuid(&ns);
+	SPDK_CU_ASSERT_FATAL(uuid != NULL);
+	CU_ASSERT(memcmp(uuid, &expected_uuid, sizeof(*uuid)) == 0);
+
+	/* NGUID followed by UUID */
+	memset(ns.id_desc_list, 0, sizeof(ns.id_desc_list));
+	ns.id_desc_list[0] = 0x02; /* NIDT == NGUID */
+	ns.id_desc_list[1] = 0x10; /* NIDL */
+	memset(&ns.id_desc_list[4], 0xCC, 0x10);
+	ns.id_desc_list[20] = 0x03; /* NIDT = UUID */
+	ns.id_desc_list[21] = 0x10; /* NIDL */
+	memcpy(&ns.id_desc_list[24], &expected_uuid, sizeof(expected_uuid));
+	uuid = spdk_nvme_ns_get_uuid(&ns);
+	SPDK_CU_ASSERT_FATAL(uuid != NULL);
+	CU_ASSERT(memcmp(uuid, &expected_uuid, sizeof(*uuid)) == 0);
+}
+
 int main(int argc, char **argv)
 {
 	CU_pSuite	suite = NULL;
@@ -87,7 +143,8 @@ int main(int argc, char **argv)
 	}
 
 	if (
-		CU_add_test(suite, "test_nvme_ns", test_nvme_ns_construct) == NULL
+		CU_add_test(suite, "test_nvme_ns", test_nvme_ns_construct) == NULL ||
+		CU_add_test(suite, "test_nvme_ns_uuid", test_nvme_ns_uuid) == NULL
 	) {
 		CU_cleanup_registry();
 		return CU_get_error();