Make enum for sync methods available to frontend code.

This commit renames RecoveryInitSyncMethod to DataDirSyncMethod and
moves it to common/file_utils.h.  This is preparatory work for a
follow-up commit that will allow specifying the synchronization
method in frontend utilities such as pg_upgrade and pg_basebackup.

Reviewed-by: Michael Paquier
Discussion: https://postgr.es/m/ZN2ZB4afQ2JbR9TA%40paquier.xyz

src/backend/storage/file/fd.c

@@ -162,7 +162,7 @@ int			max_safe_fds = FD_MINFREE;	/* default if not changed */
 bool		data_sync_retry = false;
 
 /* How SyncDataDirectory() should do its job. */
-int			recovery_init_sync_method = RECOVERY_INIT_SYNC_METHOD_FSYNC;
+int			recovery_init_sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 /* Which kinds of files should be opened with PG_O_DIRECT. */
 int			io_direct_flags;
@@ -3513,7 +3513,7 @@ SyncDataDirectory(void)
 	}
 
 #ifdef HAVE_SYNCFS
-	if (recovery_init_sync_method == RECOVERY_INIT_SYNC_METHOD_SYNCFS)
+	if (recovery_init_sync_method == DATA_DIR_SYNC_METHOD_SYNCFS)
 	{
 		DIR		   *dir;
 		struct dirent *de;

src/backend/utils/misc/guc_tables.c

@@ -41,6 +41,7 @@
 #include "commands/trigger.h"
 #include "commands/user.h"
 #include "commands/vacuum.h"
+#include "common/file_utils.h"
 #include "common/scram-common.h"
 #include "jit/jit.h"
 #include "libpq/auth.h"
@@ -430,9 +431,9 @@ StaticAssertDecl(lengthof(ssl_protocol_versions_info) == (PG_TLS1_3_VERSION + 2)
 				 "array length mismatch");
 
 static const struct config_enum_entry recovery_init_sync_method_options[] = {
-	{"fsync", RECOVERY_INIT_SYNC_METHOD_FSYNC, false},
+	{"fsync", DATA_DIR_SYNC_METHOD_FSYNC, false},
 #ifdef HAVE_SYNCFS
-	{"syncfs", RECOVERY_INIT_SYNC_METHOD_SYNCFS, false},
+	{"syncfs", DATA_DIR_SYNC_METHOD_SYNCFS, false},
 #endif
 	{NULL, 0, false}
 };
@@ -4953,7 +4954,7 @@ struct config_enum ConfigureNamesEnum[] =
 			gettext_noop("Sets the method for synchronizing the data directory before crash recovery."),
 		},
 		&recovery_init_sync_method,
-		RECOVERY_INIT_SYNC_METHOD_FSYNC, recovery_init_sync_method_options,
+		DATA_DIR_SYNC_METHOD_FSYNC, recovery_init_sync_method_options,
 		NULL, NULL, NULL
 	},
 

src/include/common/file_utils.h

@@ -24,6 +24,12 @@ typedef enum PGFileType
 	PGFILETYPE_LNK
 } PGFileType;
 
+typedef enum DataDirSyncMethod
+{
+	DATA_DIR_SYNC_METHOD_FSYNC,
+	DATA_DIR_SYNC_METHOD_SYNCFS
+} DataDirSyncMethod;
+
 struct iovec;					/* avoid including port/pg_iovec.h here */
 
 #ifdef FRONTEND

src/include/storage/fd.h

@@ -46,12 +46,6 @@
 #include <dirent.h>
 #include <fcntl.h>
 
-typedef enum RecoveryInitSyncMethod
-{
-	RECOVERY_INIT_SYNC_METHOD_FSYNC,
-	RECOVERY_INIT_SYNC_METHOD_SYNCFS
-}			RecoveryInitSyncMethod;
-
 typedef int File;
 
 

src/tools/pgindent/typedefs.list

@@ -545,6 +545,7 @@ DR_printtup
 DR_sqlfunction
 DR_transientrel
 DWORD
+DataDirSyncMethod
 DataDumperPtr
 DataPageDeleteStack
 DatabaseInfo