upgrades: add helper function to bump SystemDatabaseSchemaVersion

This patch adds a helper function that should be used by upgrades that
create or modify the schema of system tables to bump the schema version
field on the `system` database descriptor.

Release note: None

pkg/upgrade/upgrades/BUILD.bazel

@@ -202,6 +202,7 @@ go_test(
         "//pkg/util/intsets",
         "//pkg/util/leaktest",
         "//pkg/util/log",
+        "//pkg/util/protoutil",
         "//pkg/util/syncutil",
         "//pkg/util/timeutil",
         "@com_github_cockroachdb_cockroach_go_v2//crdb",

pkg/upgrade/upgrades/create_region_liveness.go

@@ -25,7 +25,7 @@ import (
 
 // createRegionLivenessTables creates the system.region_liveness table.
 func createRegionLivenessTables(
-	ctx context.Context, _ clusterversion.ClusterVersion, d upgrade.TenantDeps,
+	ctx context.Context, cs clusterversion.ClusterVersion, d upgrade.TenantDeps,
 ) error {
 	setDBLocality := false
 	// Since this is a re-use of an old key space, invalid data might exists,
@@ -96,5 +96,5 @@ func createRegionLivenessTables(
 		}
 	}
 
-	return nil
+	return bumpSystemDatabaseSchemaVersion(ctx, cs, d)
 }

pkg/upgrade/upgrades/create_region_liveness_test.go

@@ -57,4 +57,6 @@ func TestRegionLivenessTableMigration(t *testing.T) {
 
 	_, err := db.Exec("SELECT * FROM system.region_liveness")
 	assert.NoError(t, err, "system.region_liveness exists")
+
+	upgrades.ValidateSystemDatabaseSchemaVersionBumped(t, db, clusterversion.V23_2_RegionaLivenessTable)
 }

pkg/upgrade/upgrades/helpers_test.go

@@ -18,6 +18,7 @@ import (
 
 	"github.com/cockroachdb/cockroach-go/v2/crdb"
 	"github.com/cockroachdb/cockroach/pkg/clusterversion"
+	"github.com/cockroachdb/cockroach/pkg/keys"
 	"github.com/cockroachdb/cockroach/pkg/roachpb"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/descpb"
@@ -26,6 +27,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/systemschema"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/tabledesc"
 	"github.com/cockroachdb/cockroach/pkg/testutils/serverutils"
+	"github.com/cockroachdb/cockroach/pkg/util/protoutil"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -198,3 +200,29 @@ func ExecForCountInTxns(
 		require.NoError(t, err)
 	}
 }
+
+// ValidateSystemDatabaseSchemaVersionBumped validates that the system database
+// schema version has been bumped to the expected version.
+func ValidateSystemDatabaseSchemaVersionBumped(
+	t *testing.T, sqlDB *gosql.DB, expectedVersion clusterversion.Key,
+) {
+	expectedSchemaVersion := clusterversion.ByKey(expectedVersion)
+
+	var actualSchemaVersionBytes []byte
+	require.NoError(t, sqlDB.QueryRow(
+		`SELECT crdb_internal.json_to_pb(
+    'cockroach.roachpb.Version',
+    crdb_internal.pb_to_json(
+        'cockroach.sql.sqlbase.Descriptor',
+        descriptor,
+        false
+    )->'database'->'systemDatabaseSchemaVersion')
+FROM system.descriptor WHERE id = $1`,
+		keys.SystemDatabaseID,
+	).Scan(&actualSchemaVersionBytes))
+
+	actualSchemaVersion := roachpb.Version{}
+	require.NoError(t, protoutil.Unmarshal(actualSchemaVersionBytes, &actualSchemaVersion))
+
+	require.Equal(t, expectedSchemaVersion, actualSchemaVersion)
+}

pkg/upgrade/upgrades/plan_gist_stmt_diagnostics_requests.go

@@ -76,5 +76,5 @@ func stmtDiagForPlanGistMigration(
 			return err
 		}
 	}
-	return nil
+	return bumpSystemDatabaseSchemaVersion(ctx, cs, d)
 }

pkg/upgrade/upgrades/plan_gist_stmt_diagnostics_requests_test.go

@@ -98,6 +98,8 @@ func TestStmtDiagForPlanGistMigration(t *testing.T) {
 	)
 	// Validate that the table has new schema.
 	validateSchemaExists(true)
+
+	upgrades.ValidateSystemDatabaseSchemaVersionBumped(t, sqlDB, clusterversion.V23_2_StmtDiagForPlanGist)
 }
 
 // getOldStmtDiagReqsDescriptor returns the

pkg/upgrade/upgrades/schema_changes.go

@@ -21,6 +21,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/catpb"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/descpb"
 	"github.com/cockroachdb/cockroach/pkg/sql/catalog/descs"
+	"github.com/cockroachdb/cockroach/pkg/sql/sem/catconstants"
 	"github.com/cockroachdb/cockroach/pkg/sql/sessiondata"
 	"github.com/cockroachdb/cockroach/pkg/upgrade"
 	"github.com/cockroachdb/cockroach/pkg/util/log"
@@ -411,3 +412,28 @@ func onlyHasColumnFamily(
 	}
 	return true, nil
 }
+
+// bumpSystemDatabaseSchemaVersion bumps the SystemDatabaseSchemaVersion
+// field for the system database descriptor. It should be called at the end
+// of any upgrade that creates or modifies the schema of any system table.
+func bumpSystemDatabaseSchemaVersion(
+	ctx context.Context, cs clusterversion.ClusterVersion, d upgrade.TenantDeps,
+) error {
+	return d.DB.DescsTxn(ctx, func(ctx context.Context, txn descs.Txn) error {
+		systemDBDesc, err := txn.Descriptors().MutableByName(txn.KV()).Database(ctx, catconstants.SystemDatabaseName)
+		if err != nil {
+			return err
+		}
+		if sv := systemDBDesc.GetSystemDatabaseSchemaVersion(); sv != nil {
+			if cs.Version.Less(*sv) {
+				return errors.AssertionFailedf(
+					"new system schema version (%#v) is lower than previous system schema version (%#v)",
+					cs.Version,
+					*sv,
+				)
+			}
+		}
+		systemDBDesc.SystemDatabaseSchemaVersion = &cs.Version
+		return txn.Descriptors().WriteDesc(ctx, false /* kvTrace */, systemDBDesc, txn.KV())
+	})
+}