bdev_gpt: use unique partition GUID as bdev UUID

In releases of SPDK prior to v23.01, GPT bdevs had a random UUID. This
ended with commit a1c7ae2d3f, which is OK
because a non-persistent UUID is not all that useful.

Per Table 5.6 in Section 5.3.3 of UEFI Spec 2.3, each partition has a
16-byte UniquePartitionGUID:

  GUID that is unique for every partition entry. Every partition ever
  created will have a unique GUID. This GUID must be assigned when the
  GPT Partition Entry is created.  The GPT Partition Entry is created
  whenever the NumberOfPartitionEntries in the GPT Header is increased
  to include a larger range of addresses.

With this change, GPT bdevs use this unique partition GUID as the bdev's
UUID.

Signed-off-by: Mike Gerdts <mgerdts@nvidia.com>
Change-Id: Id8e8aa9e7903d31f199e8cfdb487e45ce1524d7b
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/17351
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Community-CI: Mellanox Build Bot

CHANGELOG.md

@@ -17,6 +17,10 @@ multiple readers.
 
 New function `spdk_env_get_main_core` was added.
 
+### gpt
+
+GPT bdevs now use the GPT Unique Partition ID as the bdev's UUID.
+
 ### lvol
 
 New API `spdk_lvol_iter_immediate_clones` was added to iterate the clones of an lvol.

module/bdev/gpt/vbdev_gpt.c

@@ -219,6 +219,29 @@ vbdev_gpt_submit_request(struct spdk_io_channel *_ch, struct spdk_bdev_io *bdev_
 	}
 }
 
+static void
+gpt_guid_to_uuid(const struct spdk_gpt_guid *guid, struct spdk_uuid *uuid)
+{
+#pragma pack(push, 1)
+	struct tmp_uuid {
+		uint32_t b0;
+		uint16_t b4;
+		uint16_t b6;
+		uint16_t b8;
+		uint16_t b10;
+		uint32_t b12;
+	} *ret = (struct tmp_uuid *)uuid;
+#pragma pack(pop)
+	SPDK_STATIC_ASSERT(sizeof(*ret) == sizeof(*uuid), "wrong size");
+
+	ret->b0 = from_be32(&guid->raw[0]);
+	ret->b4 = from_be16(&guid->raw[4]);
+	ret->b6 = from_be16(&guid->raw[6]);
+	ret->b8 = from_le16(&guid->raw[8]);
+	ret->b10 = from_le16(&guid->raw[10]);
+	ret->b12 = from_le32(&guid->raw[12]);
+}
+
 static void
 write_guid(struct spdk_json_write_ctx *w, const struct spdk_gpt_guid *guid)
 {
@@ -315,6 +338,7 @@ vbdev_gpt_create_bdevs(struct gpt_base *gpt_base)
 		uint64_t lba_start = from_le64(&p->starting_lba);
 		uint64_t lba_end = from_le64(&p->ending_lba);
 		uint64_t partition_size = lba_end - lba_start + 1;
+		struct spdk_bdev_part_construct_opts opts;
 
 		if (lba_start == 0) {
 			continue;
@@ -353,8 +377,10 @@ vbdev_gpt_create_bdevs(struct gpt_base *gpt_base)
 			return -1;
 		}
 
-		rc = spdk_bdev_part_construct(&d->part, gpt_base->part_base, name,
+		spdk_bdev_part_construct_opts_init(&opts, sizeof(opts));
-					      lba_start, partition_size, "GPT Disk");
+		gpt_guid_to_uuid(&p->unique_partition_guid, &opts.uuid);
+		rc = spdk_bdev_part_construct_ext(&d->part, gpt_base->part_base, name, lba_start,
+						  partition_size, "GPT Disk", &opts);
 		free(name);
 		if (rc) {
 			SPDK_ERRLOG("could not construct bdev part\n");

test/bdev/blockdev.sh

@@ -117,13 +117,20 @@ function setup_gpt_conf() {
 		fi
 	done
 	if [[ -n $gpt_nvme ]]; then
+		# These Unique Partition GUIDs were randomly generated for testing and are distinct
+		# from the Partition Type GUIDs (SPDK_GPT_OLD_GUID and SPDK_GPT_GUID) which have
+		# special meaning to SPDK. See section 5.3.3 of UEFI Spec 2.3 for the distinction
+		# between Unique Partition GUID and Partition Type GUID.
+		typeset -g g_unique_partguid=6f89f330-603b-4116-ac73-2ca8eae53030
+		typeset -g g_unique_partguid_old=abf1734f-66e5-4c0f-aa29-4021d4d307df
+
 		# Create gpt partition table
 		parted -s "$gpt_nvme" mklabel gpt mkpart SPDK_TEST_first '0%' '50%' mkpart SPDK_TEST_second '50%' '100%'
 		# Change the partition type GUIDs to SPDK partition type values
 		SPDK_GPT_OLD_GUID=$(get_spdk_gpt_old)
 		SPDK_GPT_GUID=$(get_spdk_gpt)
-		sgdisk -t "1:$SPDK_GPT_GUID" "$gpt_nvme"
+		sgdisk -t "1:$SPDK_GPT_GUID" -u "1:$g_unique_partguid" "$gpt_nvme"
-		sgdisk -t "2:$SPDK_GPT_OLD_GUID" "$gpt_nvme"
+		sgdisk -t "2:$SPDK_GPT_OLD_GUID" -u "2:$g_unique_partguid_old" "$gpt_nvme"
 		"$rootdir/scripts/setup.sh"
 		"$rpc_py" bdev_get_bdevs
 		setup_nvme_conf
@@ -609,6 +616,27 @@ function stat_test_suite() {
 	trap - SIGINT SIGTERM EXIT
 }
 
+function bdev_gpt_uuid() {
+	local bdev
+
+	start_spdk_tgt
+
+	"$rpc_py" load_config -j "$conf_file"
+	"$rpc_py" bdev_wait_for_examine
+
+	bdev=$("$rpc_py" bdev_get_bdevs -b "$g_unique_partguid")
+	[[ "$(jq -r 'length' <<< "$bdev")" == "1" ]]
+	[[ "$(jq -r '.[0].aliases[0]' <<< "$bdev")" == "$g_unique_partguid" ]]
+	[[ "$(jq -r '.[0].driver_specific.gpt.unique_partition_guid' <<< "$bdev")" == "$g_unique_partguid" ]]
+
+	bdev=$("$rpc_py" bdev_get_bdevs -b "$g_unique_partguid_old")
+	[[ "$(jq -r 'length' <<< "$bdev")" == "1" ]]
+	[[ "$(jq -r '.[0].aliases[0]' <<< "$bdev")" == "$g_unique_partguid_old" ]]
+	[[ "$(jq -r '.[0].driver_specific.gpt.unique_partition_guid' <<< "$bdev")" == "$g_unique_partguid_old" ]]
+
+	killprocess "$spdk_tgt_pid"
+}
+
 # Initial bdev creation and configuration
 #-----------------------------------------------------
 QOS_DEV_1="Malloc_0"
@@ -743,6 +771,10 @@ if [[ $test_type == bdev ]]; then
 	run_test "bdev_stat" stat_test_suite "$env_ctx"
 fi
 
+if [[ $test_type == gpt ]]; then
+	run_test "bdev_gpt_uuid" bdev_gpt_uuid
+fi
+
 # Temporarily disabled - infinite loop
 # if [ $RUN_NIGHTLY -eq 1 ]; then
 # run_test "bdev_reset" $rootdir/build/examples/bdevperf --json "$conf_file" -q 16 -w reset -o 4096 -t 60 "$env_ctx"