should frontend tools use syncfs() ?

From 4f484cd0268e63da8226d78dd21a8d7e29aa2b78 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Fri, 28 Jul 2023 15:56:24 -0700
Subject: [PATCH v1 1/1] allow syncfs in frontend utilities

---
 src/bin/initdb/initdb.c               | 11 +++-
 src/bin/pg_basebackup/pg_basebackup.c |  8 ++-
 src/bin/pg_checksums/pg_checksums.c   |  8 ++-
 src/bin/pg_rewind/file_ops.c          |  2 +-
 src/bin/pg_rewind/pg_rewind.c         |  8 +++
 src/bin/pg_rewind/pg_rewind.h         |  2 +
 src/bin/pg_upgrade/option.c           | 12 ++++
 src/bin/pg_upgrade/pg_upgrade.c       |  6 +-
 src/bin/pg_upgrade/pg_upgrade.h       |  1 +
 src/common/file_utils.c               | 79 ++++++++++++++++++++++++++-
 src/fe_utils/option_utils.c           | 18 ++++++
 src/include/common/file_utils.h       | 15 ++++-
 src/include/fe_utils/option_utils.h   |  3 +
 src/include/storage/fd.h              |  4 ++
 src/tools/pgindent/typedefs.list      |  1 +
 15 files changed, 168 insertions(+), 10 deletions(-)

diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index 3f4167682a..908263ee62 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -76,6 +76,7 @@
 #include "common/restricted_token.h"
 #include "common/string.h"
 #include "common/username.h"
+#include "fe_utils/option_utils.h"
 #include "fe_utils/string_utils.h"
 #include "getopt_long.h"
 #include "mb/pg_wchar.h"
@@ -165,6 +166,7 @@ static bool data_checksums = false;
 static char *xlog_dir = NULL;
 static char *str_wal_segment_size_mb = NULL;
 static int	wal_segment_size_mb;
+static SyncMethod sync_method = SYNC_METHOD_FSYNC;
 
 
 /* internal vars */
@@ -3106,6 +3108,7 @@ main(int argc, char *argv[])
 		{"locale-provider", required_argument, NULL, 15},
 		{"icu-locale", required_argument, NULL, 16},
 		{"icu-rules", required_argument, NULL, 17},
+		{"sync-method", required_argument, NULL, 18},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -3285,6 +3288,10 @@ main(int argc, char *argv[])
 			case 17:
 				icu_rules = pg_strdup(optarg);
 				break;
+			case 18:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -3332,7 +3339,7 @@ main(int argc, char *argv[])
 
 		fputs(_("syncing data to disk ... "), stdout);
 		fflush(stdout);
-		fsync_pgdata(pg_data, PG_VERSION_NUM);
+		fsync_pgdata(pg_data, PG_VERSION_NUM, sync_method);
 		check_ok();
 		return 0;
 	}
@@ -3409,7 +3416,7 @@ main(int argc, char *argv[])
 	{
 		fputs(_("syncing data to disk ... "), stdout);
 		fflush(stdout);
-		fsync_pgdata(pg_data, PG_VERSION_NUM);
+		fsync_pgdata(pg_data, PG_VERSION_NUM, sync_method);
 		check_ok();
 	}
 	else
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 1dc8efe0cb..548e764b2f 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -148,6 +148,7 @@ static bool verify_checksums = true;
 static bool manifest = true;
 static bool manifest_force_encode = false;
 static char *manifest_checksums = NULL;
+static SyncMethod sync_method = SYNC_METHOD_FSYNC;
 
 static bool success = false;
 static bool made_new_pgdata = false;
@@ -2203,7 +2204,7 @@ BaseBackup(char *compression_algorithm, char *compression_detail,
 		}
 		else
 		{
-			(void) fsync_pgdata(basedir, serverVersion);
+			(void) fsync_pgdata(basedir, serverVersion, sync_method);
 		}
 	}
 
@@ -2281,6 +2282,7 @@ main(int argc, char **argv)
 		{"no-manifest", no_argument, NULL, 5},
 		{"manifest-force-encode", no_argument, NULL, 6},
 		{"manifest-checksums", required_argument, NULL, 7},
+		{"sync-method", required_argument, NULL, 8},
 		{NULL, 0, NULL, 0}
 	};
 	int			c;
@@ -2452,6 +2454,10 @@ main(int argc, char **argv)
 			case 7:
 				manifest_checksums = pg_strdup(optarg);
 				break;
+			case 8:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 19eb67e485..a1dfc51273 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -44,6 +44,7 @@ static char *only_filenode = NULL;
 static bool do_sync = true;
 static bool verbose = false;
 static bool showprogress = false;
+static SyncMethod sync_method = SYNC_METHOD_FSYNC;
 
 typedef enum
 {
@@ -445,6 +446,7 @@ main(int argc, char *argv[])
 		{"no-sync", no_argument, NULL, 'N'},
 		{"progress", no_argument, NULL, 'P'},
 		{"verbose", no_argument, NULL, 'v'},
+		{"sync-method", required_argument, NULL, 1},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -503,6 +505,10 @@ main(int argc, char *argv[])
 			case 'v':
 				verbose = true;
 				break;
+			case 1:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -633,7 +639,7 @@ main(int argc, char *argv[])
 		if (do_sync)
 		{
 			pg_log_info("syncing data directory");
-			fsync_pgdata(DataDir, PG_VERSION_NUM);
+			fsync_pgdata(DataDir, PG_VERSION_NUM, sync_method);
 		}
 
 		pg_log_info("updating control file");
diff --git a/src/bin/pg_rewind/file_ops.c b/src/bin/pg_rewind/file_ops.c
index 25996b4da4..451fb1856e 100644
--- a/src/bin/pg_rewind/file_ops.c
+++ b/src/bin/pg_rewind/file_ops.c
@@ -296,7 +296,7 @@ sync_target_dir(void)
 	if (!do_sync || dry_run)
 		return;
 
-	fsync_pgdata(datadir_target, PG_VERSION_NUM);
+	fsync_pgdata(datadir_target, PG_VERSION_NUM, sync_method);
 }
 
 
diff --git a/src/bin/pg_rewind/pg_rewind.c b/src/bin/pg_rewind/pg_rewind.c
index f7f3b8227f..a424762f1e 100644
--- a/src/bin/pg_rewind/pg_rewind.c
+++ b/src/bin/pg_rewind/pg_rewind.c
@@ -22,6 +22,7 @@
 #include "common/file_perm.h"
 #include "common/restricted_token.h"
 #include "common/string.h"
+#include "fe_utils/option_utils.h"
 #include "fe_utils/recovery_gen.h"
 #include "fe_utils/string_utils.h"
 #include "file_ops.h"
@@ -74,6 +75,7 @@ bool		showprogress = false;
 bool		dry_run = false;
 bool		do_sync = true;
 bool		restore_wal = false;
+SyncMethod	sync_method = SYNC_METHOD_FSYNC;
 
 /* Target history */
 TimeLineHistoryEntry *targetHistory;
@@ -131,6 +133,7 @@ main(int argc, char **argv)
 		{"no-sync", no_argument, NULL, 'N'},
 		{"progress", no_argument, NULL, 'P'},
 		{"debug", no_argument, NULL, 3},
+		{"sync-method", required_argument, NULL, 6},
 		{NULL, 0, NULL, 0}
 	};
 	int			option_index;
@@ -218,6 +221,11 @@ main(int argc, char **argv)
 				config_file = pg_strdup(optarg);
 				break;
 
+			case 6:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_rewind/pg_rewind.h b/src/bin/pg_rewind/pg_rewind.h
index ef8bdc1fbb..a7ce754880 100644
--- a/src/bin/pg_rewind/pg_rewind.h
+++ b/src/bin/pg_rewind/pg_rewind.h
@@ -13,6 +13,7 @@
 
 #include "access/timeline.h"
 #include "common/logging.h"
+#include "common/file_utils.h"
 #include "datapagemap.h"
 #include "libpq-fe.h"
 #include "storage/block.h"
@@ -24,6 +25,7 @@ extern bool showprogress;
 extern bool dry_run;
 extern bool do_sync;
 extern int	WalSegSz;
+extern SyncMethod sync_method;
 
 /* Target history */
 extern TimeLineHistoryEntry *targetHistory;
diff --git a/src/bin/pg_upgrade/option.c b/src/bin/pg_upgrade/option.c
index 640361009e..4f9da8e685 100644
--- a/src/bin/pg_upgrade/option.c
+++ b/src/bin/pg_upgrade/option.c
@@ -14,6 +14,7 @@
 #endif
 
 #include "common/string.h"
+#include "fe_utils/option_utils.h"
 #include "getopt_long.h"
 #include "pg_upgrade.h"
 #include "utils/pidfile.h"
@@ -57,12 +58,14 @@ parseCommandLine(int argc, char *argv[])
 		{"verbose", no_argument, NULL, 'v'},
 		{"clone", no_argument, NULL, 1},
 		{"copy", no_argument, NULL, 2},
+		{"sync-method", required_argument, NULL, 3},
 
 		{NULL, 0, NULL, 0}
 	};
 	int			option;			/* Command line option */
 	int			optindex = 0;	/* used by getopt_long */
 	int			os_user_effective_id;
+	SyncMethod	unused;
 
 	user_opts.do_sync = true;
 	user_opts.transfer_mode = TRANSFER_MODE_COPY;
@@ -199,6 +202,12 @@ parseCommandLine(int argc, char *argv[])
 				user_opts.transfer_mode = TRANSFER_MODE_COPY;
 				break;
 
+			case 3:
+				if (!parse_sync_method(optarg, &unused))
+					exit(1);
+				user_opts.sync_method = pg_strdup(optarg);
+				break;
+
 			default:
 				fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
 						os_info.progname);
@@ -209,6 +218,9 @@ parseCommandLine(int argc, char *argv[])
 	if (optind < argc)
 		pg_fatal("too many command-line arguments (first is \"%s\")", argv[optind]);
 
+	if (!user_opts.sync_method)
+		user_opts.sync_method = pg_strdup("fsync");
+
 	if (log_opts.verbose)
 		pg_log(PG_REPORT, "Running in verbose mode");
 
diff --git a/src/bin/pg_upgrade/pg_upgrade.c b/src/bin/pg_upgrade/pg_upgrade.c
index 4562dafcff..96bfb67167 100644
--- a/src/bin/pg_upgrade/pg_upgrade.c
+++ b/src/bin/pg_upgrade/pg_upgrade.c
@@ -192,8 +192,10 @@ main(int argc, char **argv)
 	{
 		prep_status("Sync data directory to disk");
 		exec_prog(UTILITY_LOG_FILE, NULL, true, true,
-				  "\"%s/initdb\" --sync-only \"%s\"", new_cluster.bindir,
-				  new_cluster.pgdata);
+				  "\"%s/initdb\" --sync-only \"%s\" --sync-method %s",
+				  new_cluster.bindir,
+				  new_cluster.pgdata,
+				  user_opts.sync_method);
 		check_ok();
 	}
 
diff --git a/src/bin/pg_upgrade/pg_upgrade.h b/src/bin/pg_upgrade/pg_upgrade.h
index 3eea0139c7..13457b2f75 100644
--- a/src/bin/pg_upgrade/pg_upgrade.h
+++ b/src/bin/pg_upgrade/pg_upgrade.h
@@ -304,6 +304,7 @@ typedef struct
 	transferMode transfer_mode; /* copy files or link them? */
 	int			jobs;			/* number of processes/threads to use */
 	char	   *socketdir;		/* directory to use for Unix sockets */
+	char	   *sync_method;
 } UserOpts;
 
 typedef struct
diff --git a/src/common/file_utils.c b/src/common/file_utils.c
index 74833c4acb..b3d814d0c4 100644
--- a/src/common/file_utils.c
+++ b/src/common/file_utils.c
@@ -51,6 +51,33 @@ static void walkdir(const char *path,
 					int (*action) (const char *fname, bool isdir),
 					bool process_symlinks);
 
+#ifdef HAVE_SYNCFS
+static void
+do_syncfs(const char *path)
+{
+	int			fd;
+
+	fd = open(path, O_RDONLY | PG_BINARY, 0);
+
+	if (fd < 0)
+	{
+		if (errno == EACCES || errno == EISDIR)
+			return;
+		pg_log_error("could not open file \"%s\": %m", path);
+		return;
+	}
+
+	if (syncfs(fd) < 0)
+	{
+		pg_log_error("could not synchronize file system for file \"%s\": %m", path);
+		(void) close(fd);
+		exit(EXIT_FAILURE);
+	}
+
+	(void) close(fd);
+}
+#endif
+
 /*
  * Issue fsync recursively on PGDATA and all its contents.
  *
@@ -63,7 +90,8 @@ static void walkdir(const char *path,
  */
 void
 fsync_pgdata(const char *pg_data,
-			 int serverVersion)
+			 int serverVersion,
+			 SyncMethod sync_method)
 {
 	bool		xlog_is_symlink;
 	char		pg_wal[MAXPGPATH];
@@ -89,6 +117,55 @@ fsync_pgdata(const char *pg_data,
 			xlog_is_symlink = true;
 	}
 
+#ifdef HAVE_SYNCFS
+	if (sync_method == SYNC_METHOD_SYNCFS)
+	{
+		DIR		   *dir;
+		struct dirent *de;
+
+		/*
+		 * On Linux, we don't have to open every single file one by one.  We
+		 * can use syncfs() to sync whole filesystems.  We only expect
+		 * filesystem boundaries to exist where we tolerate symlinks, namely
+		 * pg_wal and the tablespaces, so we call syncfs() for each of those
+		 * directories.
+		 */
+
+		/* Sync the top level pgdata directory. */
+		do_syncfs(pg_data);
+
+		/* If any tablespaces are configured, sync each of those. */
+		dir = opendir(pg_tblspc);
+		if (dir == NULL)
+			pg_log_error("could not open directory \"%s\": %m", pg_tblspc);
+		else
+		{
+			while (errno = 0, (de = readdir(dir)) != NULL)
+			{
+				char		subpath[MAXPGPATH * 2];
+
+				if (strcmp(de->d_name, ".") == 0 ||
+					strcmp(de->d_name, "..") == 0)
+					continue;
+
+				snprintf(subpath, sizeof(subpath), "%s/%s", pg_tblspc, de->d_name);
+				do_syncfs(subpath);
+			}
+
+			if (errno)
+				pg_log_error("could not read directory \"%s\": %m", pg_tblspc);
+
+			(void) closedir(dir);
+		}
+
+		/* If pg_wal is a symlink, process that too. */
+		if (xlog_is_symlink)
+			do_syncfs(pg_wal);
+
+		return;
+	}
+#endif							/* HAVE_SYNCFS */
+
 	/*
 	 * If possible, hint to the kernel that we're soon going to fsync the data
 	 * directory and its contents.
diff --git a/src/fe_utils/option_utils.c b/src/fe_utils/option_utils.c
index 763c991015..c65aedf8f5 100644
--- a/src/fe_utils/option_utils.c
+++ b/src/fe_utils/option_utils.c
@@ -82,3 +82,21 @@ option_parse_int(const char *optarg, const char *optname,
 		*result = val;
 	return true;
 }
+
+bool
+parse_sync_method(const char *optarg, SyncMethod *sync_method)
+{
+	if (strcmp(optarg, "fsync") == 0)
+		*sync_method = SYNC_METHOD_FSYNC;
+#ifdef HAVE_SYNCFS
+	else if (strcmp(optarg, "syncfs") == 0)
+		*sync_method = SYNC_METHOD_SYNCFS;
+#endif
+	else
+	{
+		pg_log_error("unrecognized sync method: %s", optarg);
+		return false;
+	}
+
+	return true;
+}
diff --git a/src/include/common/file_utils.h b/src/include/common/file_utils.h
index b7efa1226d..fd5162fef1 100644
--- a/src/include/common/file_utils.h
+++ b/src/include/common/file_utils.h
@@ -27,12 +27,23 @@ typedef enum PGFileType
 struct iovec;					/* avoid including port/pg_iovec.h here */
 
 #ifdef FRONTEND
+
+typedef enum SyncMethod
+{
+	SYNC_METHOD_FSYNC,
+#ifdef HAVE_SYNCFS
+	SYNC_METHOD_SYNCFS
+#endif
+} SyncMethod;
+
 extern int	fsync_fname(const char *fname, bool isdir);
-extern void fsync_pgdata(const char *pg_data, int serverVersion);
+extern void fsync_pgdata(const char *pg_data, int serverVersion,
+						 SyncMethod sync_method);
 extern void fsync_dir_recurse(const char *dir);
 extern int	durable_rename(const char *oldfile, const char *newfile);
 extern int	fsync_parent_path(const char *fname);
-#endif
+
+#endif							/* FRONTEND */
 
 extern PGFileType get_dirent_type(const char *path,
 								  const struct dirent *de,
diff --git a/src/include/fe_utils/option_utils.h b/src/include/fe_utils/option_utils.h
index b7b0654cee..3ad8737219 100644
--- a/src/include/fe_utils/option_utils.h
+++ b/src/include/fe_utils/option_utils.h
@@ -14,6 +14,8 @@
 
 #include "postgres_fe.h"
 
+#include "common/file_utils.h"
+
 typedef void (*help_handler) (const char *progname);
 
 extern void handle_help_version_opts(int argc, char *argv[],
@@ -22,5 +24,6 @@ extern void handle_help_version_opts(int argc, char *argv[],
 extern bool option_parse_int(const char *optarg, const char *optname,
 							 int min_range, int max_range,
 							 int *result);
+extern bool parse_sync_method(const char *optarg, SyncMethod *sync_method);
 
 #endif							/* OPTION_UTILS_H */
diff --git a/src/include/storage/fd.h b/src/include/storage/fd.h
index 6791a406fc..196f20e716 100644
--- a/src/include/storage/fd.h
+++ b/src/include/storage/fd.h
@@ -43,6 +43,8 @@
 #ifndef FD_H
 #define FD_H
 
+#ifndef FRONTEND
+
 #include <dirent.h>
 #include <fcntl.h>
 
@@ -195,6 +197,8 @@ extern int	durable_unlink(const char *fname, int elevel);
 extern void SyncDataDirectory(void);
 extern int	data_sync_elevel(int elevel);
 
+#endif							/* ! FRONTEND */
+
 /* Filename components */
 #define PG_TEMP_FILES_DIR "pgsql_tmp"
 #define PG_TEMP_FILE_PREFIX "pgsql_tmp"
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 11d47294cf..3bbf70fdf3 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2678,6 +2678,7 @@ SupportRequestSelectivity
 SupportRequestSimplify
 SupportRequestWFuncMonotonic
 Syn
+SyncMethod
 SyncOps
 SyncRepConfigData
 SyncRepStandbyData
-- 
2.25.1

From 6b65605c90703ee3aebca0b90c771c9f14b59545 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Fri, 28 Jul 2023 15:56:24 -0700
Subject: [PATCH v2 1/1] allow syncfs in frontend utilities

---
 doc/src/sgml/ref/initdb.sgml          | 27 ++++++++
 doc/src/sgml/ref/pg_basebackup.sgml   | 30 +++++++++
 doc/src/sgml/ref/pg_checksums.sgml    | 27 ++++++++
 doc/src/sgml/ref/pg_dump.sgml         | 27 ++++++++
 doc/src/sgml/ref/pg_rewind.sgml       | 27 ++++++++
 doc/src/sgml/ref/pgupgrade.sgml       | 29 +++++++++
 src/bin/initdb/initdb.c               | 11 +++-
 src/bin/pg_basebackup/pg_basebackup.c | 10 ++-
 src/bin/pg_checksums/pg_checksums.c   |  8 ++-
 src/bin/pg_dump/pg_backup.h           |  4 +-
 src/bin/pg_dump/pg_backup_archiver.c  | 13 ++--
 src/bin/pg_dump/pg_backup_archiver.h  |  1 +
 src/bin/pg_dump/pg_backup_directory.c |  2 +-
 src/bin/pg_dump/pg_dump.c             |  9 ++-
 src/bin/pg_rewind/file_ops.c          |  2 +-
 src/bin/pg_rewind/pg_rewind.c         |  8 +++
 src/bin/pg_rewind/pg_rewind.h         |  2 +
 src/bin/pg_upgrade/option.c           | 12 ++++
 src/bin/pg_upgrade/pg_upgrade.c       |  6 +-
 src/bin/pg_upgrade/pg_upgrade.h       |  1 +
 src/common/file_utils.c               | 91 ++++++++++++++++++++++++++-
 src/fe_utils/option_utils.c           | 18 ++++++
 src/include/common/file_utils.h       | 17 ++++-
 src/include/fe_utils/option_utils.h   |  3 +
 src/include/storage/fd.h              |  4 ++
 src/tools/pgindent/typedefs.list      |  1 +
 26 files changed, 369 insertions(+), 21 deletions(-)

diff --git a/doc/src/sgml/ref/initdb.sgml b/doc/src/sgml/ref/initdb.sgml
index 22f1011781..872fef5705 100644
--- a/doc/src/sgml/ref/initdb.sgml
+++ b/doc/src/sgml/ref/initdb.sgml
@@ -365,6 +365,33 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry id="app-initdb-option-sync-method">
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>initdb</command> will recursively open and synchronize all
+        files in the data directory.  The search for files will follow symbolic
+        links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  This may be a lot
+        faster than the <literal>fsync</literal> setting, because it doesn't
+        need to open each file one by one.  On the other hand, it may be slower
+        if a file system is shared by other applications that modify a lot of
+        files, since those files will also be written to disk.  Furthermore, on
+        versions of Linux before 5.8, I/O errors encountered while writing data
+        to disk may not be reported to <command>initdb</command>, and relevant
+        error messages may appear only in kernel logs.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="app-initdb-option-sync-only">
       <term><option>-S</option></term>
       <term><option>--sync-only</option></term>
diff --git a/doc/src/sgml/ref/pg_basebackup.sgml b/doc/src/sgml/ref/pg_basebackup.sgml
index 79d3e657c3..af8eb43251 100644
--- a/doc/src/sgml/ref/pg_basebackup.sgml
+++ b/doc/src/sgml/ref/pg_basebackup.sgml
@@ -594,6 +594,36 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_basebackup</command> will recursively open and synchronize
+        all files in the backup directory.  When the plain format is used, the
+        search for files will follow symbolic links for the WAL directory and
+        each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file system that contains the
+        backup directory.  When the plain format is used,
+        <command>pg_basebackup</command> will also synchronize the file systems
+        that contain the WAL files and each tablespace.  This may be a lot
+        faster than the <literal>fsync</literal> setting, because it doesn't
+        need to open each file one by one.  On the other hand, it may be slower
+        if a file system is shared by other applications that modify a lot of
+        files, since those files will also be written to disk.  Furthermore, on
+        versions of Linux before 5.8, I/O errors encountered while writing data
+        to disk may not be reported to <command>pg_basebackup</command>, and
+        relevant error messages may appear only in kernel logs.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-v</option></term>
       <term><option>--verbose</option></term>
diff --git a/doc/src/sgml/ref/pg_checksums.sgml b/doc/src/sgml/ref/pg_checksums.sgml
index a3d0b0f0a3..70fb65a474 100644
--- a/doc/src/sgml/ref/pg_checksums.sgml
+++ b/doc/src/sgml/ref/pg_checksums.sgml
@@ -139,6 +139,33 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_checksums</command> will recursively open and synchronize
+        all files in the data directory.  The search for files will follow
+        symbolic links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  This may be a lot
+        faster than the <literal>fsync</literal> setting, because it doesn't
+        need to open each file one by one.  On the other hand, it may be slower
+        if a file system is shared by other applications that modify a lot of
+        files, since those files will also be written to disk. Furthermore, on
+        versions of Linux before 5.8, I/O errors encountered while writing data
+        to disk may not be reported to <command>pg_checksums</command>, and
+        relevant error messages may appear only in kernel logs.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-v</option></term>
       <term><option>--verbose</option></term>
diff --git a/doc/src/sgml/ref/pg_dump.sgml b/doc/src/sgml/ref/pg_dump.sgml
index a3cf0608f5..88139a3064 100644
--- a/doc/src/sgml/ref/pg_dump.sgml
+++ b/doc/src/sgml/ref/pg_dump.sgml
@@ -1179,6 +1179,33 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_dump --format=directory</command> will recursively open and
+        synchronize all files in the archive directory.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file system that contains the
+        archive directory.  This may be a lot faster than the
+        <literal>fsync</literal> setting, because it doesn't need to open each
+        file one by one.  On the other hand, it may be slower if the file
+        system is shared by other applications that modify a lot of files,
+        since those files will also be written to disk.  Furthermore, on
+        versions of Linux before 5.8, I/O errors encountered while writing data
+        to disk may not be reported to <command>pg_dump</command>, and relevant
+        error messages may appear only in kernel logs.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used or
+        <option>--format</option> is not set to <literal>directory</literal>.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>--table-and-children=<replaceable class="parameter">pattern</replaceable></option></term>
       <listitem>
diff --git a/doc/src/sgml/ref/pg_rewind.sgml b/doc/src/sgml/ref/pg_rewind.sgml
index 15cddd086b..ed170a4c4c 100644
--- a/doc/src/sgml/ref/pg_rewind.sgml
+++ b/doc/src/sgml/ref/pg_rewind.sgml
@@ -284,6 +284,33 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_rewind</command> will recursively open and synchronize all
+        files in the data directory.  The search for files will follow symbolic
+        links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  This may be a lot
+        faster than the <literal>fsync</literal> setting, because it doesn't
+        need to open each file one by one.  On the other hand, it may be slower
+        if a file system is shared by other applications that modify a lot of
+        files, since those files will also be written to disk.  Furthermore, on
+        versions of Linux before 5.8, I/O errors encountered while writing data
+        to disk may not be reported to <command>pg_rewind</command>, and
+        relevant error messages may appear only in kernel logs.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-V</option></term>
       <term><option>--version</option></term>
diff --git a/doc/src/sgml/ref/pgupgrade.sgml b/doc/src/sgml/ref/pgupgrade.sgml
index 7816b4c685..dd2ae6cbc9 100644
--- a/doc/src/sgml/ref/pgupgrade.sgml
+++ b/doc/src/sgml/ref/pgupgrade.sgml
@@ -190,6 +190,35 @@ PostgreSQL documentation
       variable <envar>PGSOCKETDIR</envar></para></listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_upgrade</command> will recursively open and synchronize all
+        files in the upgraded cluster's data directory.  The search for files
+        will follow symbolic links for the WAL directory and each configured
+        tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        upgrade cluster's data directory, its WAL files, and each tablespace.
+        This may be a lot faster than the <literal>fsync</literal> setting,
+        because it doesn't need to open each file one by one.  On the other
+        hand, it may be slower if a file system is shared by other applications
+        that modify a lot of files, since those files will also be written to
+        disk.  Furthermore, on versions of Linux before 5.8, I/O errors
+        encountered while writing data to disk may not be reported to
+        <command>pg_upgrade</command>, and relevant error messages may appear
+        only in kernel logs.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-U</option> <replaceable>username</replaceable></term>
       <term><option>--username=</option><replaceable>username</replaceable></term>
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index 3f4167682a..908263ee62 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -76,6 +76,7 @@
 #include "common/restricted_token.h"
 #include "common/string.h"
 #include "common/username.h"
+#include "fe_utils/option_utils.h"
 #include "fe_utils/string_utils.h"
 #include "getopt_long.h"
 #include "mb/pg_wchar.h"
@@ -165,6 +166,7 @@ static bool data_checksums = false;
 static char *xlog_dir = NULL;
 static char *str_wal_segment_size_mb = NULL;
 static int	wal_segment_size_mb;
+static SyncMethod sync_method = SYNC_METHOD_FSYNC;
 
 
 /* internal vars */
@@ -3106,6 +3108,7 @@ main(int argc, char *argv[])
 		{"locale-provider", required_argument, NULL, 15},
 		{"icu-locale", required_argument, NULL, 16},
 		{"icu-rules", required_argument, NULL, 17},
+		{"sync-method", required_argument, NULL, 18},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -3285,6 +3288,10 @@ main(int argc, char *argv[])
 			case 17:
 				icu_rules = pg_strdup(optarg);
 				break;
+			case 18:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -3332,7 +3339,7 @@ main(int argc, char *argv[])
 
 		fputs(_("syncing data to disk ... "), stdout);
 		fflush(stdout);
-		fsync_pgdata(pg_data, PG_VERSION_NUM);
+		fsync_pgdata(pg_data, PG_VERSION_NUM, sync_method);
 		check_ok();
 		return 0;
 	}
@@ -3409,7 +3416,7 @@ main(int argc, char *argv[])
 	{
 		fputs(_("syncing data to disk ... "), stdout);
 		fflush(stdout);
-		fsync_pgdata(pg_data, PG_VERSION_NUM);
+		fsync_pgdata(pg_data, PG_VERSION_NUM, sync_method);
 		check_ok();
 	}
 	else
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 1dc8efe0cb..3443a91956 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -148,6 +148,7 @@ static bool verify_checksums = true;
 static bool manifest = true;
 static bool manifest_force_encode = false;
 static char *manifest_checksums = NULL;
+static SyncMethod sync_method = SYNC_METHOD_FSYNC;
 
 static bool success = false;
 static bool made_new_pgdata = false;
@@ -2199,11 +2200,11 @@ BaseBackup(char *compression_algorithm, char *compression_detail,
 		if (format == 't')
 		{
 			if (strcmp(basedir, "-") != 0)
-				(void) fsync_dir_recurse(basedir);
+				(void) fsync_dir_recurse(basedir, sync_method);
 		}
 		else
 		{
-			(void) fsync_pgdata(basedir, serverVersion);
+			(void) fsync_pgdata(basedir, serverVersion, sync_method);
 		}
 	}
 
@@ -2281,6 +2282,7 @@ main(int argc, char **argv)
 		{"no-manifest", no_argument, NULL, 5},
 		{"manifest-force-encode", no_argument, NULL, 6},
 		{"manifest-checksums", required_argument, NULL, 7},
+		{"sync-method", required_argument, NULL, 8},
 		{NULL, 0, NULL, 0}
 	};
 	int			c;
@@ -2452,6 +2454,10 @@ main(int argc, char **argv)
 			case 7:
 				manifest_checksums = pg_strdup(optarg);
 				break;
+			case 8:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 19eb67e485..a1dfc51273 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -44,6 +44,7 @@ static char *only_filenode = NULL;
 static bool do_sync = true;
 static bool verbose = false;
 static bool showprogress = false;
+static SyncMethod sync_method = SYNC_METHOD_FSYNC;
 
 typedef enum
 {
@@ -445,6 +446,7 @@ main(int argc, char *argv[])
 		{"no-sync", no_argument, NULL, 'N'},
 		{"progress", no_argument, NULL, 'P'},
 		{"verbose", no_argument, NULL, 'v'},
+		{"sync-method", required_argument, NULL, 1},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -503,6 +505,10 @@ main(int argc, char *argv[])
 			case 'v':
 				verbose = true;
 				break;
+			case 1:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -633,7 +639,7 @@ main(int argc, char *argv[])
 		if (do_sync)
 		{
 			pg_log_info("syncing data directory");
-			fsync_pgdata(DataDir, PG_VERSION_NUM);
+			fsync_pgdata(DataDir, PG_VERSION_NUM, sync_method);
 		}
 
 		pg_log_info("updating control file");
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index aba780ef4b..7a2bb92938 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -24,6 +24,7 @@
 #define PG_BACKUP_H
 
 #include "common/compression.h"
+#include "common/file_utils.h"
 #include "fe_utils/simple_list.h"
 #include "libpq-fe.h"
 
@@ -307,7 +308,8 @@ extern Archive *OpenArchive(const char *FileSpec, const ArchiveFormat fmt);
 extern Archive *CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 							  const pg_compress_specification compression_spec,
 							  bool dosync, ArchiveMode mode,
-							  SetupWorkerPtrType setupDumpWorker);
+							  SetupWorkerPtrType setupDumpWorker,
+							  SyncMethod sync_method);
 
 /* The --list option */
 extern void PrintTOCSummary(Archive *AHX);
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index 39ebcfec32..979db4bba6 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -66,7 +66,8 @@ typedef struct _parallelReadyList
 static ArchiveHandle *_allocAH(const char *FileSpec, const ArchiveFormat fmt,
 							   const pg_compress_specification compression_spec,
 							   bool dosync, ArchiveMode mode,
-							   SetupWorkerPtrType setupWorkerPtr);
+							   SetupWorkerPtrType setupWorkerPtr,
+							   SyncMethod sync_method);
 static void _getObjectDescription(PQExpBuffer buf, const TocEntry *te);
 static void _printTocEntry(ArchiveHandle *AH, TocEntry *te, bool isData);
 static char *sanitize_line(const char *str, bool want_hyphen);
@@ -238,11 +239,12 @@ Archive *
 CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 			  const pg_compress_specification compression_spec,
 			  bool dosync, ArchiveMode mode,
-			  SetupWorkerPtrType setupDumpWorker)
+			  SetupWorkerPtrType setupDumpWorker,
+			  SyncMethod sync_method)
 
 {
 	ArchiveHandle *AH = _allocAH(FileSpec, fmt, compression_spec,
-								 dosync, mode, setupDumpWorker);
+								 dosync, mode, setupDumpWorker, sync_method);
 
 	return (Archive *) AH;
 }
@@ -257,7 +259,7 @@ OpenArchive(const char *FileSpec, const ArchiveFormat fmt)
 
 	compression_spec.algorithm = PG_COMPRESSION_NONE;
 	AH = _allocAH(FileSpec, fmt, compression_spec, true,
-				  archModeRead, setupRestoreWorker);
+				  archModeRead, setupRestoreWorker, SYNC_METHOD_FSYNC);
 
 	return (Archive *) AH;
 }
@@ -2233,7 +2235,7 @@ static ArchiveHandle *
 _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 		 const pg_compress_specification compression_spec,
 		 bool dosync, ArchiveMode mode,
-		 SetupWorkerPtrType setupWorkerPtr)
+		 SetupWorkerPtrType setupWorkerPtr, SyncMethod sync_method)
 {
 	ArchiveHandle *AH;
 	CompressFileHandle *CFH;
@@ -2287,6 +2289,7 @@ _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 	AH->mode = mode;
 	AH->compression_spec = compression_spec;
 	AH->dosync = dosync;
+	AH->sync_method = sync_method;
 
 	memset(&(AH->sqlparse), 0, sizeof(AH->sqlparse));
 
diff --git a/src/bin/pg_dump/pg_backup_archiver.h b/src/bin/pg_dump/pg_backup_archiver.h
index 18b38c17ab..e32e00547b 100644
--- a/src/bin/pg_dump/pg_backup_archiver.h
+++ b/src/bin/pg_dump/pg_backup_archiver.h
@@ -312,6 +312,7 @@ struct _archiveHandle
 	pg_compress_specification compression_spec; /* Requested specification for
 												 * compression */
 	bool		dosync;			/* data requested to be synced on sight */
+	SyncMethod	sync_method;
 	ArchiveMode mode;			/* File mode - r or w */
 	void	   *formatData;		/* Header data specific to file format */
 
diff --git a/src/bin/pg_dump/pg_backup_directory.c b/src/bin/pg_dump/pg_backup_directory.c
index 7f2ac7c7fd..6faa3a511f 100644
--- a/src/bin/pg_dump/pg_backup_directory.c
+++ b/src/bin/pg_dump/pg_backup_directory.c
@@ -613,7 +613,7 @@ _CloseArchive(ArchiveHandle *AH)
 		 * individually. Just recurse once through all the files generated.
 		 */
 		if (AH->dosync)
-			fsync_dir_recurse(ctx->directory);
+			fsync_dir_recurse(ctx->directory, AH->sync_method);
 	}
 	AH->FH = NULL;
 }
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 5dab1ba9ea..fec1b6b3a9 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -357,6 +357,7 @@ main(int argc, char **argv)
 	char	   *compression_algorithm_str = "none";
 	char	   *error_detail = NULL;
 	bool		user_compression_defined = false;
+	SyncMethod	sync_method = SYNC_METHOD_FSYNC;
 
 	static DumpOptions dopt;
 
@@ -431,6 +432,7 @@ main(int argc, char **argv)
 		{"table-and-children", required_argument, NULL, 12},
 		{"exclude-table-and-children", required_argument, NULL, 13},
 		{"exclude-table-data-and-children", required_argument, NULL, 14},
+		{"sync-method", required_argument, NULL, 15},
 
 		{NULL, 0, NULL, 0}
 	};
@@ -657,6 +659,11 @@ main(int argc, char **argv)
 										  optarg);
 				break;
 
+			case 15:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit_nicely(1);
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -777,7 +784,7 @@ main(int argc, char **argv)
 
 	/* Open the output file */
 	fout = CreateArchive(filename, archiveFormat, compression_spec,
-						 dosync, archiveMode, setupDumpWorker);
+						 dosync, archiveMode, setupDumpWorker, sync_method);
 
 	/* Make dump options accessible right away */
 	SetArchiveOptions(fout, &dopt, NULL);
diff --git a/src/bin/pg_rewind/file_ops.c b/src/bin/pg_rewind/file_ops.c
index 25996b4da4..451fb1856e 100644
--- a/src/bin/pg_rewind/file_ops.c
+++ b/src/bin/pg_rewind/file_ops.c
@@ -296,7 +296,7 @@ sync_target_dir(void)
 	if (!do_sync || dry_run)
 		return;
 
-	fsync_pgdata(datadir_target, PG_VERSION_NUM);
+	fsync_pgdata(datadir_target, PG_VERSION_NUM, sync_method);
 }
 
 
diff --git a/src/bin/pg_rewind/pg_rewind.c b/src/bin/pg_rewind/pg_rewind.c
index f7f3b8227f..a424762f1e 100644
--- a/src/bin/pg_rewind/pg_rewind.c
+++ b/src/bin/pg_rewind/pg_rewind.c
@@ -22,6 +22,7 @@
 #include "common/file_perm.h"
 #include "common/restricted_token.h"
 #include "common/string.h"
+#include "fe_utils/option_utils.h"
 #include "fe_utils/recovery_gen.h"
 #include "fe_utils/string_utils.h"
 #include "file_ops.h"
@@ -74,6 +75,7 @@ bool		showprogress = false;
 bool		dry_run = false;
 bool		do_sync = true;
 bool		restore_wal = false;
+SyncMethod	sync_method = SYNC_METHOD_FSYNC;
 
 /* Target history */
 TimeLineHistoryEntry *targetHistory;
@@ -131,6 +133,7 @@ main(int argc, char **argv)
 		{"no-sync", no_argument, NULL, 'N'},
 		{"progress", no_argument, NULL, 'P'},
 		{"debug", no_argument, NULL, 3},
+		{"sync-method", required_argument, NULL, 6},
 		{NULL, 0, NULL, 0}
 	};
 	int			option_index;
@@ -218,6 +221,11 @@ main(int argc, char **argv)
 				config_file = pg_strdup(optarg);
 				break;
 
+			case 6:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_rewind/pg_rewind.h b/src/bin/pg_rewind/pg_rewind.h
index ef8bdc1fbb..a7ce754880 100644
--- a/src/bin/pg_rewind/pg_rewind.h
+++ b/src/bin/pg_rewind/pg_rewind.h
@@ -13,6 +13,7 @@
 
 #include "access/timeline.h"
 #include "common/logging.h"
+#include "common/file_utils.h"
 #include "datapagemap.h"
 #include "libpq-fe.h"
 #include "storage/block.h"
@@ -24,6 +25,7 @@ extern bool showprogress;
 extern bool dry_run;
 extern bool do_sync;
 extern int	WalSegSz;
+extern SyncMethod sync_method;
 
 /* Target history */
 extern TimeLineHistoryEntry *targetHistory;
diff --git a/src/bin/pg_upgrade/option.c b/src/bin/pg_upgrade/option.c
index 640361009e..4f9da8e685 100644
--- a/src/bin/pg_upgrade/option.c
+++ b/src/bin/pg_upgrade/option.c
@@ -14,6 +14,7 @@
 #endif
 
 #include "common/string.h"
+#include "fe_utils/option_utils.h"
 #include "getopt_long.h"
 #include "pg_upgrade.h"
 #include "utils/pidfile.h"
@@ -57,12 +58,14 @@ parseCommandLine(int argc, char *argv[])
 		{"verbose", no_argument, NULL, 'v'},
 		{"clone", no_argument, NULL, 1},
 		{"copy", no_argument, NULL, 2},
+		{"sync-method", required_argument, NULL, 3},
 
 		{NULL, 0, NULL, 0}
 	};
 	int			option;			/* Command line option */
 	int			optindex = 0;	/* used by getopt_long */
 	int			os_user_effective_id;
+	SyncMethod	unused;
 
 	user_opts.do_sync = true;
 	user_opts.transfer_mode = TRANSFER_MODE_COPY;
@@ -199,6 +202,12 @@ parseCommandLine(int argc, char *argv[])
 				user_opts.transfer_mode = TRANSFER_MODE_COPY;
 				break;
 
+			case 3:
+				if (!parse_sync_method(optarg, &unused))
+					exit(1);
+				user_opts.sync_method = pg_strdup(optarg);
+				break;
+
 			default:
 				fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
 						os_info.progname);
@@ -209,6 +218,9 @@ parseCommandLine(int argc, char *argv[])
 	if (optind < argc)
 		pg_fatal("too many command-line arguments (first is \"%s\")", argv[optind]);
 
+	if (!user_opts.sync_method)
+		user_opts.sync_method = pg_strdup("fsync");
+
 	if (log_opts.verbose)
 		pg_log(PG_REPORT, "Running in verbose mode");
 
diff --git a/src/bin/pg_upgrade/pg_upgrade.c b/src/bin/pg_upgrade/pg_upgrade.c
index 4562dafcff..96bfb67167 100644
--- a/src/bin/pg_upgrade/pg_upgrade.c
+++ b/src/bin/pg_upgrade/pg_upgrade.c
@@ -192,8 +192,10 @@ main(int argc, char **argv)
 	{
 		prep_status("Sync data directory to disk");
 		exec_prog(UTILITY_LOG_FILE, NULL, true, true,
-				  "\"%s/initdb\" --sync-only \"%s\"", new_cluster.bindir,
-				  new_cluster.pgdata);
+				  "\"%s/initdb\" --sync-only \"%s\" --sync-method %s",
+				  new_cluster.bindir,
+				  new_cluster.pgdata,
+				  user_opts.sync_method);
 		check_ok();
 	}
 
diff --git a/src/bin/pg_upgrade/pg_upgrade.h b/src/bin/pg_upgrade/pg_upgrade.h
index 3eea0139c7..13457b2f75 100644
--- a/src/bin/pg_upgrade/pg_upgrade.h
+++ b/src/bin/pg_upgrade/pg_upgrade.h
@@ -304,6 +304,7 @@ typedef struct
 	transferMode transfer_mode; /* copy files or link them? */
 	int			jobs;			/* number of processes/threads to use */
 	char	   *socketdir;		/* directory to use for Unix sockets */
+	char	   *sync_method;
 } UserOpts;
 
 typedef struct
diff --git a/src/common/file_utils.c b/src/common/file_utils.c
index 74833c4acb..8aa7784b5f 100644
--- a/src/common/file_utils.c
+++ b/src/common/file_utils.c
@@ -51,6 +51,31 @@ static void walkdir(const char *path,
 					int (*action) (const char *fname, bool isdir),
 					bool process_symlinks);
 
+#ifdef HAVE_SYNCFS
+static void
+do_syncfs(const char *path)
+{
+	int			fd;
+
+	fd = open(path, O_RDONLY, 0);
+
+	if (fd < 0)
+	{
+		pg_log_error("could not open file \"%s\": %m", path);
+		return;
+	}
+
+	if (syncfs(fd) < 0)
+	{
+		pg_log_error("could not synchronize file system for file \"%s\": %m", path);
+		(void) close(fd);
+		exit(EXIT_FAILURE);
+	}
+
+	(void) close(fd);
+}
+#endif
+
 /*
  * Issue fsync recursively on PGDATA and all its contents.
  *
@@ -63,7 +88,8 @@ static void walkdir(const char *path,
  */
 void
 fsync_pgdata(const char *pg_data,
-			 int serverVersion)
+			 int serverVersion,
+			 SyncMethod sync_method)
 {
 	bool		xlog_is_symlink;
 	char		pg_wal[MAXPGPATH];
@@ -89,6 +115,55 @@ fsync_pgdata(const char *pg_data,
 			xlog_is_symlink = true;
 	}
 
+#ifdef HAVE_SYNCFS
+	if (sync_method == SYNC_METHOD_SYNCFS)
+	{
+		DIR		   *dir;
+		struct dirent *de;
+
+		/*
+		 * On Linux, we don't have to open every single file one by one.  We
+		 * can use syncfs() to sync whole filesystems.  We only expect
+		 * filesystem boundaries to exist where we tolerate symlinks, namely
+		 * pg_wal and the tablespaces, so we call syncfs() for each of those
+		 * directories.
+		 */
+
+		/* Sync the top level pgdata directory. */
+		do_syncfs(pg_data);
+
+		/* If any tablespaces are configured, sync each of those. */
+		dir = opendir(pg_tblspc);
+		if (dir == NULL)
+			pg_log_error("could not open directory \"%s\": %m", pg_tblspc);
+		else
+		{
+			while (errno = 0, (de = readdir(dir)) != NULL)
+			{
+				char		subpath[MAXPGPATH * 2];
+
+				if (strcmp(de->d_name, ".") == 0 ||
+					strcmp(de->d_name, "..") == 0)
+					continue;
+
+				snprintf(subpath, sizeof(subpath), "%s/%s", pg_tblspc, de->d_name);
+				do_syncfs(subpath);
+			}
+
+			if (errno)
+				pg_log_error("could not read directory \"%s\": %m", pg_tblspc);
+
+			(void) closedir(dir);
+		}
+
+		/* If pg_wal is a symlink, process that too. */
+		if (xlog_is_symlink)
+			do_syncfs(pg_wal);
+
+		return;
+	}
+#endif							/* HAVE_SYNCFS */
+
 	/*
 	 * If possible, hint to the kernel that we're soon going to fsync the data
 	 * directory and its contents.
@@ -121,8 +196,20 @@ fsync_pgdata(const char *pg_data,
  * This is a convenient wrapper on top of walkdir().
  */
 void
-fsync_dir_recurse(const char *dir)
+fsync_dir_recurse(const char *dir, SyncMethod sync_method)
 {
+#ifdef HAVE_SYNCFS
+	if (sync_method == SYNC_METHOD_SYNCFS)
+	{
+		/*
+		 * On Linux, we don't have to open every single file one by one.  We
+		 * can use syncfs() to sync the whole filesystem.
+		 */
+		do_syncfs(dir);
+		return;
+	}
+#endif							/* HAVE_SYNCFS */
+
 	/*
 	 * If possible, hint to the kernel that we're soon going to fsync the data
 	 * directory and its contents.
diff --git a/src/fe_utils/option_utils.c b/src/fe_utils/option_utils.c
index 763c991015..c65aedf8f5 100644
--- a/src/fe_utils/option_utils.c
+++ b/src/fe_utils/option_utils.c
@@ -82,3 +82,21 @@ option_parse_int(const char *optarg, const char *optname,
 		*result = val;
 	return true;
 }
+
+bool
+parse_sync_method(const char *optarg, SyncMethod *sync_method)
+{
+	if (strcmp(optarg, "fsync") == 0)
+		*sync_method = SYNC_METHOD_FSYNC;
+#ifdef HAVE_SYNCFS
+	else if (strcmp(optarg, "syncfs") == 0)
+		*sync_method = SYNC_METHOD_SYNCFS;
+#endif
+	else
+	{
+		pg_log_error("unrecognized sync method: %s", optarg);
+		return false;
+	}
+
+	return true;
+}
diff --git a/src/include/common/file_utils.h b/src/include/common/file_utils.h
index b7efa1226d..3044f7f742 100644
--- a/src/include/common/file_utils.h
+++ b/src/include/common/file_utils.h
@@ -27,12 +27,23 @@ typedef enum PGFileType
 struct iovec;					/* avoid including port/pg_iovec.h here */
 
 #ifdef FRONTEND
+
+typedef enum SyncMethod
+{
+	SYNC_METHOD_FSYNC,
+#ifdef HAVE_SYNCFS
+	SYNC_METHOD_SYNCFS
+#endif
+} SyncMethod;
+
 extern int	fsync_fname(const char *fname, bool isdir);
-extern void fsync_pgdata(const char *pg_data, int serverVersion);
-extern void fsync_dir_recurse(const char *dir);
+extern void fsync_pgdata(const char *pg_data, int serverVersion,
+						 SyncMethod sync_method);
+extern void fsync_dir_recurse(const char *dir, SyncMethod sync_method);
 extern int	durable_rename(const char *oldfile, const char *newfile);
 extern int	fsync_parent_path(const char *fname);
-#endif
+
+#endif							/* FRONTEND */
 
 extern PGFileType get_dirent_type(const char *path,
 								  const struct dirent *de,
diff --git a/src/include/fe_utils/option_utils.h b/src/include/fe_utils/option_utils.h
index b7b0654cee..3ad8737219 100644
--- a/src/include/fe_utils/option_utils.h
+++ b/src/include/fe_utils/option_utils.h
@@ -14,6 +14,8 @@
 
 #include "postgres_fe.h"
 
+#include "common/file_utils.h"
+
 typedef void (*help_handler) (const char *progname);
 
 extern void handle_help_version_opts(int argc, char *argv[],
@@ -22,5 +24,6 @@ extern void handle_help_version_opts(int argc, char *argv[],
 extern bool option_parse_int(const char *optarg, const char *optname,
 							 int min_range, int max_range,
 							 int *result);
+extern bool parse_sync_method(const char *optarg, SyncMethod *sync_method);
 
 #endif							/* OPTION_UTILS_H */
diff --git a/src/include/storage/fd.h b/src/include/storage/fd.h
index 6791a406fc..196f20e716 100644
--- a/src/include/storage/fd.h
+++ b/src/include/storage/fd.h
@@ -43,6 +43,8 @@
 #ifndef FD_H
 #define FD_H
 
+#ifndef FRONTEND
+
 #include <dirent.h>
 #include <fcntl.h>
 
@@ -195,6 +197,8 @@ extern int	durable_unlink(const char *fname, int elevel);
 extern void SyncDataDirectory(void);
 extern int	data_sync_elevel(int elevel);
 
+#endif							/* ! FRONTEND */
+
 /* Filename components */
 #define PG_TEMP_FILES_DIR "pgsql_tmp"
 #define PG_TEMP_FILE_PREFIX "pgsql_tmp"
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index ab97f1794a..0635ce4a87 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2678,6 +2678,7 @@ SupportRequestSelectivity
 SupportRequestSimplify
 SupportRequestWFuncMonotonic
 Syn
+SyncMethod
 SyncOps
 SyncRepConfigData
 SyncRepStandbyData
-- 
2.25.1

From be52e4625754fa36703423e8b67d2f6cd2a16a09 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Fri, 28 Jul 2023 15:56:24 -0700
Subject: [PATCH v3 1/1] allow syncfs in frontend utilities

---
 doc/src/sgml/ref/initdb.sgml          | 27 ++++++++
 doc/src/sgml/ref/pg_basebackup.sgml   | 30 +++++++++
 doc/src/sgml/ref/pg_checksums.sgml    | 27 ++++++++
 doc/src/sgml/ref/pg_dump.sgml         | 27 ++++++++
 doc/src/sgml/ref/pg_rewind.sgml       | 27 ++++++++
 doc/src/sgml/ref/pgupgrade.sgml       | 29 +++++++++
 src/bin/initdb/initdb.c               | 12 +++-
 src/bin/pg_basebackup/pg_basebackup.c | 12 +++-
 src/bin/pg_checksums/pg_checksums.c   |  9 ++-
 src/bin/pg_dump/pg_backup.h           |  4 +-
 src/bin/pg_dump/pg_backup_archiver.c  | 13 ++--
 src/bin/pg_dump/pg_backup_archiver.h  |  1 +
 src/bin/pg_dump/pg_backup_directory.c |  2 +-
 src/bin/pg_dump/pg_dump.c             | 10 ++-
 src/bin/pg_rewind/file_ops.c          |  2 +-
 src/bin/pg_rewind/pg_rewind.c         |  9 +++
 src/bin/pg_rewind/pg_rewind.h         |  2 +
 src/bin/pg_upgrade/option.c           | 13 ++++
 src/bin/pg_upgrade/pg_upgrade.c       |  6 +-
 src/bin/pg_upgrade/pg_upgrade.h       |  1 +
 src/common/file_utils.c               | 91 ++++++++++++++++++++++++++-
 src/fe_utils/option_utils.c           | 18 ++++++
 src/include/common/file_utils.h       | 17 ++++-
 src/include/fe_utils/option_utils.h   |  3 +
 src/include/storage/fd.h              |  4 ++
 src/tools/pgindent/typedefs.list      |  1 +
 26 files changed, 376 insertions(+), 21 deletions(-)

diff --git a/doc/src/sgml/ref/initdb.sgml b/doc/src/sgml/ref/initdb.sgml
index 22f1011781..872fef5705 100644
--- a/doc/src/sgml/ref/initdb.sgml
+++ b/doc/src/sgml/ref/initdb.sgml
@@ -365,6 +365,33 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry id="app-initdb-option-sync-method">
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>initdb</command> will recursively open and synchronize all
+        files in the data directory.  The search for files will follow symbolic
+        links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  This may be a lot
+        faster than the <literal>fsync</literal> setting, because it doesn't
+        need to open each file one by one.  On the other hand, it may be slower
+        if a file system is shared by other applications that modify a lot of
+        files, since those files will also be written to disk.  Furthermore, on
+        versions of Linux before 5.8, I/O errors encountered while writing data
+        to disk may not be reported to <command>initdb</command>, and relevant
+        error messages may appear only in kernel logs.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="app-initdb-option-sync-only">
       <term><option>-S</option></term>
       <term><option>--sync-only</option></term>
diff --git a/doc/src/sgml/ref/pg_basebackup.sgml b/doc/src/sgml/ref/pg_basebackup.sgml
index 79d3e657c3..af8eb43251 100644
--- a/doc/src/sgml/ref/pg_basebackup.sgml
+++ b/doc/src/sgml/ref/pg_basebackup.sgml
@@ -594,6 +594,36 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_basebackup</command> will recursively open and synchronize
+        all files in the backup directory.  When the plain format is used, the
+        search for files will follow symbolic links for the WAL directory and
+        each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file system that contains the
+        backup directory.  When the plain format is used,
+        <command>pg_basebackup</command> will also synchronize the file systems
+        that contain the WAL files and each tablespace.  This may be a lot
+        faster than the <literal>fsync</literal> setting, because it doesn't
+        need to open each file one by one.  On the other hand, it may be slower
+        if a file system is shared by other applications that modify a lot of
+        files, since those files will also be written to disk.  Furthermore, on
+        versions of Linux before 5.8, I/O errors encountered while writing data
+        to disk may not be reported to <command>pg_basebackup</command>, and
+        relevant error messages may appear only in kernel logs.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-v</option></term>
       <term><option>--verbose</option></term>
diff --git a/doc/src/sgml/ref/pg_checksums.sgml b/doc/src/sgml/ref/pg_checksums.sgml
index a3d0b0f0a3..70fb65a474 100644
--- a/doc/src/sgml/ref/pg_checksums.sgml
+++ b/doc/src/sgml/ref/pg_checksums.sgml
@@ -139,6 +139,33 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_checksums</command> will recursively open and synchronize
+        all files in the data directory.  The search for files will follow
+        symbolic links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  This may be a lot
+        faster than the <literal>fsync</literal> setting, because it doesn't
+        need to open each file one by one.  On the other hand, it may be slower
+        if a file system is shared by other applications that modify a lot of
+        files, since those files will also be written to disk. Furthermore, on
+        versions of Linux before 5.8, I/O errors encountered while writing data
+        to disk may not be reported to <command>pg_checksums</command>, and
+        relevant error messages may appear only in kernel logs.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-v</option></term>
       <term><option>--verbose</option></term>
diff --git a/doc/src/sgml/ref/pg_dump.sgml b/doc/src/sgml/ref/pg_dump.sgml
index a3cf0608f5..88139a3064 100644
--- a/doc/src/sgml/ref/pg_dump.sgml
+++ b/doc/src/sgml/ref/pg_dump.sgml
@@ -1179,6 +1179,33 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_dump --format=directory</command> will recursively open and
+        synchronize all files in the archive directory.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file system that contains the
+        archive directory.  This may be a lot faster than the
+        <literal>fsync</literal> setting, because it doesn't need to open each
+        file one by one.  On the other hand, it may be slower if the file
+        system is shared by other applications that modify a lot of files,
+        since those files will also be written to disk.  Furthermore, on
+        versions of Linux before 5.8, I/O errors encountered while writing data
+        to disk may not be reported to <command>pg_dump</command>, and relevant
+        error messages may appear only in kernel logs.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used or
+        <option>--format</option> is not set to <literal>directory</literal>.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>--table-and-children=<replaceable class="parameter">pattern</replaceable></option></term>
       <listitem>
diff --git a/doc/src/sgml/ref/pg_rewind.sgml b/doc/src/sgml/ref/pg_rewind.sgml
index 15cddd086b..ed170a4c4c 100644
--- a/doc/src/sgml/ref/pg_rewind.sgml
+++ b/doc/src/sgml/ref/pg_rewind.sgml
@@ -284,6 +284,33 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_rewind</command> will recursively open and synchronize all
+        files in the data directory.  The search for files will follow symbolic
+        links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  This may be a lot
+        faster than the <literal>fsync</literal> setting, because it doesn't
+        need to open each file one by one.  On the other hand, it may be slower
+        if a file system is shared by other applications that modify a lot of
+        files, since those files will also be written to disk.  Furthermore, on
+        versions of Linux before 5.8, I/O errors encountered while writing data
+        to disk may not be reported to <command>pg_rewind</command>, and
+        relevant error messages may appear only in kernel logs.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-V</option></term>
       <term><option>--version</option></term>
diff --git a/doc/src/sgml/ref/pgupgrade.sgml b/doc/src/sgml/ref/pgupgrade.sgml
index 7816b4c685..dd2ae6cbc9 100644
--- a/doc/src/sgml/ref/pgupgrade.sgml
+++ b/doc/src/sgml/ref/pgupgrade.sgml
@@ -190,6 +190,35 @@ PostgreSQL documentation
       variable <envar>PGSOCKETDIR</envar></para></listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_upgrade</command> will recursively open and synchronize all
+        files in the upgraded cluster's data directory.  The search for files
+        will follow symbolic links for the WAL directory and each configured
+        tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        upgrade cluster's data directory, its WAL files, and each tablespace.
+        This may be a lot faster than the <literal>fsync</literal> setting,
+        because it doesn't need to open each file one by one.  On the other
+        hand, it may be slower if a file system is shared by other applications
+        that modify a lot of files, since those files will also be written to
+        disk.  Furthermore, on versions of Linux before 5.8, I/O errors
+        encountered while writing data to disk may not be reported to
+        <command>pg_upgrade</command>, and relevant error messages may appear
+        only in kernel logs.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-U</option> <replaceable>username</replaceable></term>
       <term><option>--username=</option><replaceable>username</replaceable></term>
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index 3f4167682a..bfbe5bd3fd 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -76,6 +76,7 @@
 #include "common/restricted_token.h"
 #include "common/string.h"
 #include "common/username.h"
+#include "fe_utils/option_utils.h"
 #include "fe_utils/string_utils.h"
 #include "getopt_long.h"
 #include "mb/pg_wchar.h"
@@ -165,6 +166,7 @@ static bool data_checksums = false;
 static char *xlog_dir = NULL;
 static char *str_wal_segment_size_mb = NULL;
 static int	wal_segment_size_mb;
+static SyncMethod sync_method = SYNC_METHOD_FSYNC;
 
 
 /* internal vars */
@@ -2466,6 +2468,7 @@ usage(const char *progname)
 	printf(_("  -N, --no-sync             do not wait for changes to be written safely to disk\n"));
 	printf(_("      --no-instructions     do not print instructions for next steps\n"));
 	printf(_("  -s, --show                show internal settings\n"));
+	printf(_("      --sync-method=METHOD  set method for syncing files to disk\n"));
 	printf(_("  -S, --sync-only           only sync database files to disk, then exit\n"));
 	printf(_("\nOther options:\n"));
 	printf(_("  -V, --version             output version information, then exit\n"));
@@ -3106,6 +3109,7 @@ main(int argc, char *argv[])
 		{"locale-provider", required_argument, NULL, 15},
 		{"icu-locale", required_argument, NULL, 16},
 		{"icu-rules", required_argument, NULL, 17},
+		{"sync-method", required_argument, NULL, 18},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -3285,6 +3289,10 @@ main(int argc, char *argv[])
 			case 17:
 				icu_rules = pg_strdup(optarg);
 				break;
+			case 18:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -3332,7 +3340,7 @@ main(int argc, char *argv[])
 
 		fputs(_("syncing data to disk ... "), stdout);
 		fflush(stdout);
-		fsync_pgdata(pg_data, PG_VERSION_NUM);
+		fsync_pgdata(pg_data, PG_VERSION_NUM, sync_method);
 		check_ok();
 		return 0;
 	}
@@ -3409,7 +3417,7 @@ main(int argc, char *argv[])
 	{
 		fputs(_("syncing data to disk ... "), stdout);
 		fflush(stdout);
-		fsync_pgdata(pg_data, PG_VERSION_NUM);
+		fsync_pgdata(pg_data, PG_VERSION_NUM, sync_method);
 		check_ok();
 	}
 	else
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 1dc8efe0cb..51f29f83fd 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -148,6 +148,7 @@ static bool verify_checksums = true;
 static bool manifest = true;
 static bool manifest_force_encode = false;
 static char *manifest_checksums = NULL;
+static SyncMethod sync_method = SYNC_METHOD_FSYNC;
 
 static bool success = false;
 static bool made_new_pgdata = false;
@@ -424,6 +425,8 @@ usage(void)
 	printf(_("      --no-slot          prevent creation of temporary replication slot\n"));
 	printf(_("      --no-verify-checksums\n"
 			 "                         do not verify checksums\n"));
+	printf(_("      --sync-method=METHOD\n"
+			 "                         set method for syncing files to disk\n"));
 	printf(_("  -?, --help             show this help, then exit\n"));
 	printf(_("\nConnection options:\n"));
 	printf(_("  -d, --dbname=CONNSTR   connection string\n"));
@@ -2199,11 +2202,11 @@ BaseBackup(char *compression_algorithm, char *compression_detail,
 		if (format == 't')
 		{
 			if (strcmp(basedir, "-") != 0)
-				(void) fsync_dir_recurse(basedir);
+				(void) fsync_dir_recurse(basedir, sync_method);
 		}
 		else
 		{
-			(void) fsync_pgdata(basedir, serverVersion);
+			(void) fsync_pgdata(basedir, serverVersion, sync_method);
 		}
 	}
 
@@ -2281,6 +2284,7 @@ main(int argc, char **argv)
 		{"no-manifest", no_argument, NULL, 5},
 		{"manifest-force-encode", no_argument, NULL, 6},
 		{"manifest-checksums", required_argument, NULL, 7},
+		{"sync-method", required_argument, NULL, 8},
 		{NULL, 0, NULL, 0}
 	};
 	int			c;
@@ -2452,6 +2456,10 @@ main(int argc, char **argv)
 			case 7:
 				manifest_checksums = pg_strdup(optarg);
 				break;
+			case 8:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 19eb67e485..3ddbffd471 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -44,6 +44,7 @@ static char *only_filenode = NULL;
 static bool do_sync = true;
 static bool verbose = false;
 static bool showprogress = false;
+static SyncMethod sync_method = SYNC_METHOD_FSYNC;
 
 typedef enum
 {
@@ -87,6 +88,7 @@ usage(void)
 	printf(_("  -f, --filenode=FILENODE  check only relation with specified filenode\n"));
 	printf(_("  -N, --no-sync            do not wait for changes to be written safely to disk\n"));
 	printf(_("  -P, --progress           show progress information\n"));
+	printf(_("      --sync-method=METHOD set method for syncing files to disk\n"));
 	printf(_("  -v, --verbose            output verbose messages\n"));
 	printf(_("  -V, --version            output version information, then exit\n"));
 	printf(_("  -?, --help               show this help, then exit\n"));
@@ -445,6 +447,7 @@ main(int argc, char *argv[])
 		{"no-sync", no_argument, NULL, 'N'},
 		{"progress", no_argument, NULL, 'P'},
 		{"verbose", no_argument, NULL, 'v'},
+		{"sync-method", required_argument, NULL, 1},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -503,6 +506,10 @@ main(int argc, char *argv[])
 			case 'v':
 				verbose = true;
 				break;
+			case 1:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -633,7 +640,7 @@ main(int argc, char *argv[])
 		if (do_sync)
 		{
 			pg_log_info("syncing data directory");
-			fsync_pgdata(DataDir, PG_VERSION_NUM);
+			fsync_pgdata(DataDir, PG_VERSION_NUM, sync_method);
 		}
 
 		pg_log_info("updating control file");
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index aba780ef4b..7a2bb92938 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -24,6 +24,7 @@
 #define PG_BACKUP_H
 
 #include "common/compression.h"
+#include "common/file_utils.h"
 #include "fe_utils/simple_list.h"
 #include "libpq-fe.h"
 
@@ -307,7 +308,8 @@ extern Archive *OpenArchive(const char *FileSpec, const ArchiveFormat fmt);
 extern Archive *CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 							  const pg_compress_specification compression_spec,
 							  bool dosync, ArchiveMode mode,
-							  SetupWorkerPtrType setupDumpWorker);
+							  SetupWorkerPtrType setupDumpWorker,
+							  SyncMethod sync_method);
 
 /* The --list option */
 extern void PrintTOCSummary(Archive *AHX);
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index 39ebcfec32..979db4bba6 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -66,7 +66,8 @@ typedef struct _parallelReadyList
 static ArchiveHandle *_allocAH(const char *FileSpec, const ArchiveFormat fmt,
 							   const pg_compress_specification compression_spec,
 							   bool dosync, ArchiveMode mode,
-							   SetupWorkerPtrType setupWorkerPtr);
+							   SetupWorkerPtrType setupWorkerPtr,
+							   SyncMethod sync_method);
 static void _getObjectDescription(PQExpBuffer buf, const TocEntry *te);
 static void _printTocEntry(ArchiveHandle *AH, TocEntry *te, bool isData);
 static char *sanitize_line(const char *str, bool want_hyphen);
@@ -238,11 +239,12 @@ Archive *
 CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 			  const pg_compress_specification compression_spec,
 			  bool dosync, ArchiveMode mode,
-			  SetupWorkerPtrType setupDumpWorker)
+			  SetupWorkerPtrType setupDumpWorker,
+			  SyncMethod sync_method)
 
 {
 	ArchiveHandle *AH = _allocAH(FileSpec, fmt, compression_spec,
-								 dosync, mode, setupDumpWorker);
+								 dosync, mode, setupDumpWorker, sync_method);
 
 	return (Archive *) AH;
 }
@@ -257,7 +259,7 @@ OpenArchive(const char *FileSpec, const ArchiveFormat fmt)
 
 	compression_spec.algorithm = PG_COMPRESSION_NONE;
 	AH = _allocAH(FileSpec, fmt, compression_spec, true,
-				  archModeRead, setupRestoreWorker);
+				  archModeRead, setupRestoreWorker, SYNC_METHOD_FSYNC);
 
 	return (Archive *) AH;
 }
@@ -2233,7 +2235,7 @@ static ArchiveHandle *
 _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 		 const pg_compress_specification compression_spec,
 		 bool dosync, ArchiveMode mode,
-		 SetupWorkerPtrType setupWorkerPtr)
+		 SetupWorkerPtrType setupWorkerPtr, SyncMethod sync_method)
 {
 	ArchiveHandle *AH;
 	CompressFileHandle *CFH;
@@ -2287,6 +2289,7 @@ _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 	AH->mode = mode;
 	AH->compression_spec = compression_spec;
 	AH->dosync = dosync;
+	AH->sync_method = sync_method;
 
 	memset(&(AH->sqlparse), 0, sizeof(AH->sqlparse));
 
diff --git a/src/bin/pg_dump/pg_backup_archiver.h b/src/bin/pg_dump/pg_backup_archiver.h
index 18b38c17ab..e32e00547b 100644
--- a/src/bin/pg_dump/pg_backup_archiver.h
+++ b/src/bin/pg_dump/pg_backup_archiver.h
@@ -312,6 +312,7 @@ struct _archiveHandle
 	pg_compress_specification compression_spec; /* Requested specification for
 												 * compression */
 	bool		dosync;			/* data requested to be synced on sight */
+	SyncMethod	sync_method;
 	ArchiveMode mode;			/* File mode - r or w */
 	void	   *formatData;		/* Header data specific to file format */
 
diff --git a/src/bin/pg_dump/pg_backup_directory.c b/src/bin/pg_dump/pg_backup_directory.c
index 7f2ac7c7fd..6faa3a511f 100644
--- a/src/bin/pg_dump/pg_backup_directory.c
+++ b/src/bin/pg_dump/pg_backup_directory.c
@@ -613,7 +613,7 @@ _CloseArchive(ArchiveHandle *AH)
 		 * individually. Just recurse once through all the files generated.
 		 */
 		if (AH->dosync)
-			fsync_dir_recurse(ctx->directory);
+			fsync_dir_recurse(ctx->directory, AH->sync_method);
 	}
 	AH->FH = NULL;
 }
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 5dab1ba9ea..b8117fe536 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -357,6 +357,7 @@ main(int argc, char **argv)
 	char	   *compression_algorithm_str = "none";
 	char	   *error_detail = NULL;
 	bool		user_compression_defined = false;
+	SyncMethod	sync_method = SYNC_METHOD_FSYNC;
 
 	static DumpOptions dopt;
 
@@ -431,6 +432,7 @@ main(int argc, char **argv)
 		{"table-and-children", required_argument, NULL, 12},
 		{"exclude-table-and-children", required_argument, NULL, 13},
 		{"exclude-table-data-and-children", required_argument, NULL, 14},
+		{"sync-method", required_argument, NULL, 15},
 
 		{NULL, 0, NULL, 0}
 	};
@@ -657,6 +659,11 @@ main(int argc, char **argv)
 										  optarg);
 				break;
 
+			case 15:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit_nicely(1);
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -777,7 +784,7 @@ main(int argc, char **argv)
 
 	/* Open the output file */
 	fout = CreateArchive(filename, archiveFormat, compression_spec,
-						 dosync, archiveMode, setupDumpWorker);
+						 dosync, archiveMode, setupDumpWorker, sync_method);
 
 	/* Make dump options accessible right away */
 	SetArchiveOptions(fout, &dopt, NULL);
@@ -1068,6 +1075,7 @@ help(const char *progname)
 			 "                               compress as specified\n"));
 	printf(_("  --lock-wait-timeout=TIMEOUT  fail after waiting TIMEOUT for a table lock\n"));
 	printf(_("  --no-sync                    do not wait for changes to be written safely to disk\n"));
+	printf(_("  --sync-method=METHOD         set method for syncing files to disk\n"));
 	printf(_("  -?, --help                   show this help, then exit\n"));
 
 	printf(_("\nOptions controlling the output content:\n"));
diff --git a/src/bin/pg_rewind/file_ops.c b/src/bin/pg_rewind/file_ops.c
index 25996b4da4..451fb1856e 100644
--- a/src/bin/pg_rewind/file_ops.c
+++ b/src/bin/pg_rewind/file_ops.c
@@ -296,7 +296,7 @@ sync_target_dir(void)
 	if (!do_sync || dry_run)
 		return;
 
-	fsync_pgdata(datadir_target, PG_VERSION_NUM);
+	fsync_pgdata(datadir_target, PG_VERSION_NUM, sync_method);
 }
 
 
diff --git a/src/bin/pg_rewind/pg_rewind.c b/src/bin/pg_rewind/pg_rewind.c
index f7f3b8227f..25cffb897d 100644
--- a/src/bin/pg_rewind/pg_rewind.c
+++ b/src/bin/pg_rewind/pg_rewind.c
@@ -22,6 +22,7 @@
 #include "common/file_perm.h"
 #include "common/restricted_token.h"
 #include "common/string.h"
+#include "fe_utils/option_utils.h"
 #include "fe_utils/recovery_gen.h"
 #include "fe_utils/string_utils.h"
 #include "file_ops.h"
@@ -74,6 +75,7 @@ bool		showprogress = false;
 bool		dry_run = false;
 bool		do_sync = true;
 bool		restore_wal = false;
+SyncMethod	sync_method = SYNC_METHOD_FSYNC;
 
 /* Target history */
 TimeLineHistoryEntry *targetHistory;
@@ -107,6 +109,7 @@ usage(const char *progname)
 			 "                                 file when running target cluster\n"));
 	printf(_("      --debug                    write a lot of debug messages\n"));
 	printf(_("      --no-ensure-shutdown       do not automatically fix unclean shutdown\n"));
+	printf(_("      --sync-method=METHOD       set method for syncing files to disk\n"));
 	printf(_("  -V, --version                  output version information, then exit\n"));
 	printf(_("  -?, --help                     show this help, then exit\n"));
 	printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
@@ -131,6 +134,7 @@ main(int argc, char **argv)
 		{"no-sync", no_argument, NULL, 'N'},
 		{"progress", no_argument, NULL, 'P'},
 		{"debug", no_argument, NULL, 3},
+		{"sync-method", required_argument, NULL, 6},
 		{NULL, 0, NULL, 0}
 	};
 	int			option_index;
@@ -218,6 +222,11 @@ main(int argc, char **argv)
 				config_file = pg_strdup(optarg);
 				break;
 
+			case 6:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_rewind/pg_rewind.h b/src/bin/pg_rewind/pg_rewind.h
index ef8bdc1fbb..a7ce754880 100644
--- a/src/bin/pg_rewind/pg_rewind.h
+++ b/src/bin/pg_rewind/pg_rewind.h
@@ -13,6 +13,7 @@
 
 #include "access/timeline.h"
 #include "common/logging.h"
+#include "common/file_utils.h"
 #include "datapagemap.h"
 #include "libpq-fe.h"
 #include "storage/block.h"
@@ -24,6 +25,7 @@ extern bool showprogress;
 extern bool dry_run;
 extern bool do_sync;
 extern int	WalSegSz;
+extern SyncMethod sync_method;
 
 /* Target history */
 extern TimeLineHistoryEntry *targetHistory;
diff --git a/src/bin/pg_upgrade/option.c b/src/bin/pg_upgrade/option.c
index 640361009e..44675131a2 100644
--- a/src/bin/pg_upgrade/option.c
+++ b/src/bin/pg_upgrade/option.c
@@ -14,6 +14,7 @@
 #endif
 
 #include "common/string.h"
+#include "fe_utils/option_utils.h"
 #include "getopt_long.h"
 #include "pg_upgrade.h"
 #include "utils/pidfile.h"
@@ -57,12 +58,14 @@ parseCommandLine(int argc, char *argv[])
 		{"verbose", no_argument, NULL, 'v'},
 		{"clone", no_argument, NULL, 1},
 		{"copy", no_argument, NULL, 2},
+		{"sync-method", required_argument, NULL, 3},
 
 		{NULL, 0, NULL, 0}
 	};
 	int			option;			/* Command line option */
 	int			optindex = 0;	/* used by getopt_long */
 	int			os_user_effective_id;
+	SyncMethod	unused;
 
 	user_opts.do_sync = true;
 	user_opts.transfer_mode = TRANSFER_MODE_COPY;
@@ -199,6 +202,12 @@ parseCommandLine(int argc, char *argv[])
 				user_opts.transfer_mode = TRANSFER_MODE_COPY;
 				break;
 
+			case 3:
+				if (!parse_sync_method(optarg, &unused))
+					exit(1);
+				user_opts.sync_method = pg_strdup(optarg);
+				break;
+
 			default:
 				fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
 						os_info.progname);
@@ -209,6 +218,9 @@ parseCommandLine(int argc, char *argv[])
 	if (optind < argc)
 		pg_fatal("too many command-line arguments (first is \"%s\")", argv[optind]);
 
+	if (!user_opts.sync_method)
+		user_opts.sync_method = pg_strdup("fsync");
+
 	if (log_opts.verbose)
 		pg_log(PG_REPORT, "Running in verbose mode");
 
@@ -289,6 +301,7 @@ usage(void)
 	printf(_("  -V, --version                 display version information, then exit\n"));
 	printf(_("  --clone                       clone instead of copying files to new cluster\n"));
 	printf(_("  --copy                        copy files to new cluster (default)\n"));
+	printf(_("  --sync-method=METHOD          set method for syncing files to disk\n"));
 	printf(_("  -?, --help                    show this help, then exit\n"));
 	printf(_("\n"
 			 "Before running pg_upgrade you must:\n"
diff --git a/src/bin/pg_upgrade/pg_upgrade.c b/src/bin/pg_upgrade/pg_upgrade.c
index 4562dafcff..96bfb67167 100644
--- a/src/bin/pg_upgrade/pg_upgrade.c
+++ b/src/bin/pg_upgrade/pg_upgrade.c
@@ -192,8 +192,10 @@ main(int argc, char **argv)
 	{
 		prep_status("Sync data directory to disk");
 		exec_prog(UTILITY_LOG_FILE, NULL, true, true,
-				  "\"%s/initdb\" --sync-only \"%s\"", new_cluster.bindir,
-				  new_cluster.pgdata);
+				  "\"%s/initdb\" --sync-only \"%s\" --sync-method %s",
+				  new_cluster.bindir,
+				  new_cluster.pgdata,
+				  user_opts.sync_method);
 		check_ok();
 	}
 
diff --git a/src/bin/pg_upgrade/pg_upgrade.h b/src/bin/pg_upgrade/pg_upgrade.h
index 3eea0139c7..13457b2f75 100644
--- a/src/bin/pg_upgrade/pg_upgrade.h
+++ b/src/bin/pg_upgrade/pg_upgrade.h
@@ -304,6 +304,7 @@ typedef struct
 	transferMode transfer_mode; /* copy files or link them? */
 	int			jobs;			/* number of processes/threads to use */
 	char	   *socketdir;		/* directory to use for Unix sockets */
+	char	   *sync_method;
 } UserOpts;
 
 typedef struct
diff --git a/src/common/file_utils.c b/src/common/file_utils.c
index 74833c4acb..8aa7784b5f 100644
--- a/src/common/file_utils.c
+++ b/src/common/file_utils.c
@@ -51,6 +51,31 @@ static void walkdir(const char *path,
 					int (*action) (const char *fname, bool isdir),
 					bool process_symlinks);
 
+#ifdef HAVE_SYNCFS
+static void
+do_syncfs(const char *path)
+{
+	int			fd;
+
+	fd = open(path, O_RDONLY, 0);
+
+	if (fd < 0)
+	{
+		pg_log_error("could not open file \"%s\": %m", path);
+		return;
+	}
+
+	if (syncfs(fd) < 0)
+	{
+		pg_log_error("could not synchronize file system for file \"%s\": %m", path);
+		(void) close(fd);
+		exit(EXIT_FAILURE);
+	}
+
+	(void) close(fd);
+}
+#endif
+
 /*
  * Issue fsync recursively on PGDATA and all its contents.
  *
@@ -63,7 +88,8 @@ static void walkdir(const char *path,
  */
 void
 fsync_pgdata(const char *pg_data,
-			 int serverVersion)
+			 int serverVersion,
+			 SyncMethod sync_method)
 {
 	bool		xlog_is_symlink;
 	char		pg_wal[MAXPGPATH];
@@ -89,6 +115,55 @@ fsync_pgdata(const char *pg_data,
 			xlog_is_symlink = true;
 	}
 
+#ifdef HAVE_SYNCFS
+	if (sync_method == SYNC_METHOD_SYNCFS)
+	{
+		DIR		   *dir;
+		struct dirent *de;
+
+		/*
+		 * On Linux, we don't have to open every single file one by one.  We
+		 * can use syncfs() to sync whole filesystems.  We only expect
+		 * filesystem boundaries to exist where we tolerate symlinks, namely
+		 * pg_wal and the tablespaces, so we call syncfs() for each of those
+		 * directories.
+		 */
+
+		/* Sync the top level pgdata directory. */
+		do_syncfs(pg_data);
+
+		/* If any tablespaces are configured, sync each of those. */
+		dir = opendir(pg_tblspc);
+		if (dir == NULL)
+			pg_log_error("could not open directory \"%s\": %m", pg_tblspc);
+		else
+		{
+			while (errno = 0, (de = readdir(dir)) != NULL)
+			{
+				char		subpath[MAXPGPATH * 2];
+
+				if (strcmp(de->d_name, ".") == 0 ||
+					strcmp(de->d_name, "..") == 0)
+					continue;
+
+				snprintf(subpath, sizeof(subpath), "%s/%s", pg_tblspc, de->d_name);
+				do_syncfs(subpath);
+			}
+
+			if (errno)
+				pg_log_error("could not read directory \"%s\": %m", pg_tblspc);
+
+			(void) closedir(dir);
+		}
+
+		/* If pg_wal is a symlink, process that too. */
+		if (xlog_is_symlink)
+			do_syncfs(pg_wal);
+
+		return;
+	}
+#endif							/* HAVE_SYNCFS */
+
 	/*
 	 * If possible, hint to the kernel that we're soon going to fsync the data
 	 * directory and its contents.
@@ -121,8 +196,20 @@ fsync_pgdata(const char *pg_data,
  * This is a convenient wrapper on top of walkdir().
  */
 void
-fsync_dir_recurse(const char *dir)
+fsync_dir_recurse(const char *dir, SyncMethod sync_method)
 {
+#ifdef HAVE_SYNCFS
+	if (sync_method == SYNC_METHOD_SYNCFS)
+	{
+		/*
+		 * On Linux, we don't have to open every single file one by one.  We
+		 * can use syncfs() to sync the whole filesystem.
+		 */
+		do_syncfs(dir);
+		return;
+	}
+#endif							/* HAVE_SYNCFS */
+
 	/*
 	 * If possible, hint to the kernel that we're soon going to fsync the data
 	 * directory and its contents.
diff --git a/src/fe_utils/option_utils.c b/src/fe_utils/option_utils.c
index 763c991015..c65aedf8f5 100644
--- a/src/fe_utils/option_utils.c
+++ b/src/fe_utils/option_utils.c
@@ -82,3 +82,21 @@ option_parse_int(const char *optarg, const char *optname,
 		*result = val;
 	return true;
 }
+
+bool
+parse_sync_method(const char *optarg, SyncMethod *sync_method)
+{
+	if (strcmp(optarg, "fsync") == 0)
+		*sync_method = SYNC_METHOD_FSYNC;
+#ifdef HAVE_SYNCFS
+	else if (strcmp(optarg, "syncfs") == 0)
+		*sync_method = SYNC_METHOD_SYNCFS;
+#endif
+	else
+	{
+		pg_log_error("unrecognized sync method: %s", optarg);
+		return false;
+	}
+
+	return true;
+}
diff --git a/src/include/common/file_utils.h b/src/include/common/file_utils.h
index b7efa1226d..3044f7f742 100644
--- a/src/include/common/file_utils.h
+++ b/src/include/common/file_utils.h
@@ -27,12 +27,23 @@ typedef enum PGFileType
 struct iovec;					/* avoid including port/pg_iovec.h here */
 
 #ifdef FRONTEND
+
+typedef enum SyncMethod
+{
+	SYNC_METHOD_FSYNC,
+#ifdef HAVE_SYNCFS
+	SYNC_METHOD_SYNCFS
+#endif
+} SyncMethod;
+
 extern int	fsync_fname(const char *fname, bool isdir);
-extern void fsync_pgdata(const char *pg_data, int serverVersion);
-extern void fsync_dir_recurse(const char *dir);
+extern void fsync_pgdata(const char *pg_data, int serverVersion,
+						 SyncMethod sync_method);
+extern void fsync_dir_recurse(const char *dir, SyncMethod sync_method);
 extern int	durable_rename(const char *oldfile, const char *newfile);
 extern int	fsync_parent_path(const char *fname);
-#endif
+
+#endif							/* FRONTEND */
 
 extern PGFileType get_dirent_type(const char *path,
 								  const struct dirent *de,
diff --git a/src/include/fe_utils/option_utils.h b/src/include/fe_utils/option_utils.h
index b7b0654cee..3ad8737219 100644
--- a/src/include/fe_utils/option_utils.h
+++ b/src/include/fe_utils/option_utils.h
@@ -14,6 +14,8 @@
 
 #include "postgres_fe.h"
 
+#include "common/file_utils.h"
+
 typedef void (*help_handler) (const char *progname);
 
 extern void handle_help_version_opts(int argc, char *argv[],
@@ -22,5 +24,6 @@ extern void handle_help_version_opts(int argc, char *argv[],
 extern bool option_parse_int(const char *optarg, const char *optname,
 							 int min_range, int max_range,
 							 int *result);
+extern bool parse_sync_method(const char *optarg, SyncMethod *sync_method);
 
 #endif							/* OPTION_UTILS_H */
diff --git a/src/include/storage/fd.h b/src/include/storage/fd.h
index 6791a406fc..196f20e716 100644
--- a/src/include/storage/fd.h
+++ b/src/include/storage/fd.h
@@ -43,6 +43,8 @@
 #ifndef FD_H
 #define FD_H
 
+#ifndef FRONTEND
+
 #include <dirent.h>
 #include <fcntl.h>
 
@@ -195,6 +197,8 @@ extern int	durable_unlink(const char *fname, int elevel);
 extern void SyncDataDirectory(void);
 extern int	data_sync_elevel(int elevel);
 
+#endif							/* ! FRONTEND */
+
 /* Filename components */
 #define PG_TEMP_FILES_DIR "pgsql_tmp"
 #define PG_TEMP_FILE_PREFIX "pgsql_tmp"
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 66823bc2a7..bebb2b8e49 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2677,6 +2677,7 @@ SupportRequestSelectivity
 SupportRequestSimplify
 SupportRequestWFuncMonotonic
 Syn
+SyncMethod
 SyncOps
 SyncRepConfigData
 SyncRepStandbyData
-- 
2.25.1

From 5edd4b4570617a897043086cf203af57a5596e11 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Fri, 28 Jul 2023 15:56:24 -0700
Subject: [PATCH v4 1/1] allow syncfs in frontend utilities

---
 doc/src/sgml/ref/initdb.sgml          | 27 ++++++++
 doc/src/sgml/ref/pg_basebackup.sgml   | 30 +++++++++
 doc/src/sgml/ref/pg_checksums.sgml    | 27 ++++++++
 doc/src/sgml/ref/pg_dump.sgml         | 27 ++++++++
 doc/src/sgml/ref/pg_rewind.sgml       | 27 ++++++++
 doc/src/sgml/ref/pgupgrade.sgml       | 29 +++++++++
 src/backend/storage/file/fd.c         |  4 +-
 src/backend/utils/misc/guc_tables.c   |  7 ++-
 src/bin/initdb/initdb.c               | 12 +++-
 src/bin/pg_basebackup/pg_basebackup.c | 12 +++-
 src/bin/pg_checksums/pg_checksums.c   |  9 ++-
 src/bin/pg_dump/pg_backup.h           |  4 +-
 src/bin/pg_dump/pg_backup_archiver.c  | 14 +++--
 src/bin/pg_dump/pg_backup_archiver.h  |  1 +
 src/bin/pg_dump/pg_backup_directory.c |  2 +-
 src/bin/pg_dump/pg_dump.c             | 10 ++-
 src/bin/pg_rewind/file_ops.c          |  2 +-
 src/bin/pg_rewind/pg_rewind.c         |  9 +++
 src/bin/pg_rewind/pg_rewind.h         |  2 +
 src/bin/pg_upgrade/option.c           | 13 ++++
 src/bin/pg_upgrade/pg_upgrade.c       |  6 +-
 src/bin/pg_upgrade/pg_upgrade.h       |  1 +
 src/common/file_utils.c               | 91 ++++++++++++++++++++++++++-
 src/fe_utils/option_utils.c           | 24 +++++++
 src/include/common/file_utils.h       | 15 ++++-
 src/include/fe_utils/option_utils.h   |  4 ++
 src/include/storage/fd.h              | 10 ++-
 src/tools/pgindent/typedefs.list      |  1 +
 28 files changed, 388 insertions(+), 32 deletions(-)

diff --git a/doc/src/sgml/ref/initdb.sgml b/doc/src/sgml/ref/initdb.sgml
index 22f1011781..872fef5705 100644
--- a/doc/src/sgml/ref/initdb.sgml
+++ b/doc/src/sgml/ref/initdb.sgml
@@ -365,6 +365,33 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry id="app-initdb-option-sync-method">
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>initdb</command> will recursively open and synchronize all
+        files in the data directory.  The search for files will follow symbolic
+        links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  This may be a lot
+        faster than the <literal>fsync</literal> setting, because it doesn't
+        need to open each file one by one.  On the other hand, it may be slower
+        if a file system is shared by other applications that modify a lot of
+        files, since those files will also be written to disk.  Furthermore, on
+        versions of Linux before 5.8, I/O errors encountered while writing data
+        to disk may not be reported to <command>initdb</command>, and relevant
+        error messages may appear only in kernel logs.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="app-initdb-option-sync-only">
       <term><option>-S</option></term>
       <term><option>--sync-only</option></term>
diff --git a/doc/src/sgml/ref/pg_basebackup.sgml b/doc/src/sgml/ref/pg_basebackup.sgml
index 79d3e657c3..af8eb43251 100644
--- a/doc/src/sgml/ref/pg_basebackup.sgml
+++ b/doc/src/sgml/ref/pg_basebackup.sgml
@@ -594,6 +594,36 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_basebackup</command> will recursively open and synchronize
+        all files in the backup directory.  When the plain format is used, the
+        search for files will follow symbolic links for the WAL directory and
+        each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file system that contains the
+        backup directory.  When the plain format is used,
+        <command>pg_basebackup</command> will also synchronize the file systems
+        that contain the WAL files and each tablespace.  This may be a lot
+        faster than the <literal>fsync</literal> setting, because it doesn't
+        need to open each file one by one.  On the other hand, it may be slower
+        if a file system is shared by other applications that modify a lot of
+        files, since those files will also be written to disk.  Furthermore, on
+        versions of Linux before 5.8, I/O errors encountered while writing data
+        to disk may not be reported to <command>pg_basebackup</command>, and
+        relevant error messages may appear only in kernel logs.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-v</option></term>
       <term><option>--verbose</option></term>
diff --git a/doc/src/sgml/ref/pg_checksums.sgml b/doc/src/sgml/ref/pg_checksums.sgml
index a3d0b0f0a3..70fb65a474 100644
--- a/doc/src/sgml/ref/pg_checksums.sgml
+++ b/doc/src/sgml/ref/pg_checksums.sgml
@@ -139,6 +139,33 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_checksums</command> will recursively open and synchronize
+        all files in the data directory.  The search for files will follow
+        symbolic links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  This may be a lot
+        faster than the <literal>fsync</literal> setting, because it doesn't
+        need to open each file one by one.  On the other hand, it may be slower
+        if a file system is shared by other applications that modify a lot of
+        files, since those files will also be written to disk. Furthermore, on
+        versions of Linux before 5.8, I/O errors encountered while writing data
+        to disk may not be reported to <command>pg_checksums</command>, and
+        relevant error messages may appear only in kernel logs.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-v</option></term>
       <term><option>--verbose</option></term>
diff --git a/doc/src/sgml/ref/pg_dump.sgml b/doc/src/sgml/ref/pg_dump.sgml
index a3cf0608f5..88139a3064 100644
--- a/doc/src/sgml/ref/pg_dump.sgml
+++ b/doc/src/sgml/ref/pg_dump.sgml
@@ -1179,6 +1179,33 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_dump --format=directory</command> will recursively open and
+        synchronize all files in the archive directory.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file system that contains the
+        archive directory.  This may be a lot faster than the
+        <literal>fsync</literal> setting, because it doesn't need to open each
+        file one by one.  On the other hand, it may be slower if the file
+        system is shared by other applications that modify a lot of files,
+        since those files will also be written to disk.  Furthermore, on
+        versions of Linux before 5.8, I/O errors encountered while writing data
+        to disk may not be reported to <command>pg_dump</command>, and relevant
+        error messages may appear only in kernel logs.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used or
+        <option>--format</option> is not set to <literal>directory</literal>.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>--table-and-children=<replaceable class="parameter">pattern</replaceable></option></term>
       <listitem>
diff --git a/doc/src/sgml/ref/pg_rewind.sgml b/doc/src/sgml/ref/pg_rewind.sgml
index 15cddd086b..ed170a4c4c 100644
--- a/doc/src/sgml/ref/pg_rewind.sgml
+++ b/doc/src/sgml/ref/pg_rewind.sgml
@@ -284,6 +284,33 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_rewind</command> will recursively open and synchronize all
+        files in the data directory.  The search for files will follow symbolic
+        links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  This may be a lot
+        faster than the <literal>fsync</literal> setting, because it doesn't
+        need to open each file one by one.  On the other hand, it may be slower
+        if a file system is shared by other applications that modify a lot of
+        files, since those files will also be written to disk.  Furthermore, on
+        versions of Linux before 5.8, I/O errors encountered while writing data
+        to disk may not be reported to <command>pg_rewind</command>, and
+        relevant error messages may appear only in kernel logs.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-V</option></term>
       <term><option>--version</option></term>
diff --git a/doc/src/sgml/ref/pgupgrade.sgml b/doc/src/sgml/ref/pgupgrade.sgml
index 7816b4c685..dd2ae6cbc9 100644
--- a/doc/src/sgml/ref/pgupgrade.sgml
+++ b/doc/src/sgml/ref/pgupgrade.sgml
@@ -190,6 +190,35 @@ PostgreSQL documentation
       variable <envar>PGSOCKETDIR</envar></para></listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_upgrade</command> will recursively open and synchronize all
+        files in the upgraded cluster's data directory.  The search for files
+        will follow symbolic links for the WAL directory and each configured
+        tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        upgrade cluster's data directory, its WAL files, and each tablespace.
+        This may be a lot faster than the <literal>fsync</literal> setting,
+        because it doesn't need to open each file one by one.  On the other
+        hand, it may be slower if a file system is shared by other applications
+        that modify a lot of files, since those files will also be written to
+        disk.  Furthermore, on versions of Linux before 5.8, I/O errors
+        encountered while writing data to disk may not be reported to
+        <command>pg_upgrade</command>, and relevant error messages may appear
+        only in kernel logs.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-U</option> <replaceable>username</replaceable></term>
       <term><option>--username=</option><replaceable>username</replaceable></term>
diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index a027a8aabc..206db91217 100644
--- a/src/backend/storage/file/fd.c
+++ b/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;
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index f9dba43b8c..331f65cbe6 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/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}
 };
@@ -4964,7 +4965,7 @@ 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
 	},
 
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index 3f4167682a..6d7d10cffb 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -76,6 +76,7 @@
 #include "common/restricted_token.h"
 #include "common/string.h"
 #include "common/username.h"
+#include "fe_utils/option_utils.h"
 #include "fe_utils/string_utils.h"
 #include "getopt_long.h"
 #include "mb/pg_wchar.h"
@@ -165,6 +166,7 @@ static bool data_checksums = false;
 static char *xlog_dir = NULL;
 static char *str_wal_segment_size_mb = NULL;
 static int	wal_segment_size_mb;
+static DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 
 /* internal vars */
@@ -2466,6 +2468,7 @@ usage(const char *progname)
 	printf(_("  -N, --no-sync             do not wait for changes to be written safely to disk\n"));
 	printf(_("      --no-instructions     do not print instructions for next steps\n"));
 	printf(_("  -s, --show                show internal settings\n"));
+	printf(_("      --sync-method=METHOD  set method for syncing files to disk\n"));
 	printf(_("  -S, --sync-only           only sync database files to disk, then exit\n"));
 	printf(_("\nOther options:\n"));
 	printf(_("  -V, --version             output version information, then exit\n"));
@@ -3106,6 +3109,7 @@ main(int argc, char *argv[])
 		{"locale-provider", required_argument, NULL, 15},
 		{"icu-locale", required_argument, NULL, 16},
 		{"icu-rules", required_argument, NULL, 17},
+		{"sync-method", required_argument, NULL, 18},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -3285,6 +3289,10 @@ main(int argc, char *argv[])
 			case 17:
 				icu_rules = pg_strdup(optarg);
 				break;
+			case 18:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -3332,7 +3340,7 @@ main(int argc, char *argv[])
 
 		fputs(_("syncing data to disk ... "), stdout);
 		fflush(stdout);
-		fsync_pgdata(pg_data, PG_VERSION_NUM);
+		fsync_pgdata(pg_data, PG_VERSION_NUM, sync_method);
 		check_ok();
 		return 0;
 	}
@@ -3409,7 +3417,7 @@ main(int argc, char *argv[])
 	{
 		fputs(_("syncing data to disk ... "), stdout);
 		fflush(stdout);
-		fsync_pgdata(pg_data, PG_VERSION_NUM);
+		fsync_pgdata(pg_data, PG_VERSION_NUM, sync_method);
 		check_ok();
 	}
 	else
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 1dc8efe0cb..977c793a67 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -148,6 +148,7 @@ static bool verify_checksums = true;
 static bool manifest = true;
 static bool manifest_force_encode = false;
 static char *manifest_checksums = NULL;
+static DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 static bool success = false;
 static bool made_new_pgdata = false;
@@ -424,6 +425,8 @@ usage(void)
 	printf(_("      --no-slot          prevent creation of temporary replication slot\n"));
 	printf(_("      --no-verify-checksums\n"
 			 "                         do not verify checksums\n"));
+	printf(_("      --sync-method=METHOD\n"
+			 "                         set method for syncing files to disk\n"));
 	printf(_("  -?, --help             show this help, then exit\n"));
 	printf(_("\nConnection options:\n"));
 	printf(_("  -d, --dbname=CONNSTR   connection string\n"));
@@ -2199,11 +2202,11 @@ BaseBackup(char *compression_algorithm, char *compression_detail,
 		if (format == 't')
 		{
 			if (strcmp(basedir, "-") != 0)
-				(void) fsync_dir_recurse(basedir);
+				(void) fsync_dir_recurse(basedir, sync_method);
 		}
 		else
 		{
-			(void) fsync_pgdata(basedir, serverVersion);
+			(void) fsync_pgdata(basedir, serverVersion, sync_method);
 		}
 	}
 
@@ -2281,6 +2284,7 @@ main(int argc, char **argv)
 		{"no-manifest", no_argument, NULL, 5},
 		{"manifest-force-encode", no_argument, NULL, 6},
 		{"manifest-checksums", required_argument, NULL, 7},
+		{"sync-method", required_argument, NULL, 8},
 		{NULL, 0, NULL, 0}
 	};
 	int			c;
@@ -2452,6 +2456,10 @@ main(int argc, char **argv)
 			case 7:
 				manifest_checksums = pg_strdup(optarg);
 				break;
+			case 8:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 19eb67e485..adcc767b0f 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -44,6 +44,7 @@ static char *only_filenode = NULL;
 static bool do_sync = true;
 static bool verbose = false;
 static bool showprogress = false;
+static DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 typedef enum
 {
@@ -87,6 +88,7 @@ usage(void)
 	printf(_("  -f, --filenode=FILENODE  check only relation with specified filenode\n"));
 	printf(_("  -N, --no-sync            do not wait for changes to be written safely to disk\n"));
 	printf(_("  -P, --progress           show progress information\n"));
+	printf(_("      --sync-method=METHOD set method for syncing files to disk\n"));
 	printf(_("  -v, --verbose            output verbose messages\n"));
 	printf(_("  -V, --version            output version information, then exit\n"));
 	printf(_("  -?, --help               show this help, then exit\n"));
@@ -445,6 +447,7 @@ main(int argc, char *argv[])
 		{"no-sync", no_argument, NULL, 'N'},
 		{"progress", no_argument, NULL, 'P'},
 		{"verbose", no_argument, NULL, 'v'},
+		{"sync-method", required_argument, NULL, 1},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -503,6 +506,10 @@ main(int argc, char *argv[])
 			case 'v':
 				verbose = true;
 				break;
+			case 1:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -633,7 +640,7 @@ main(int argc, char *argv[])
 		if (do_sync)
 		{
 			pg_log_info("syncing data directory");
-			fsync_pgdata(DataDir, PG_VERSION_NUM);
+			fsync_pgdata(DataDir, PG_VERSION_NUM, sync_method);
 		}
 
 		pg_log_info("updating control file");
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index aba780ef4b..3a57cdd97d 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -24,6 +24,7 @@
 #define PG_BACKUP_H
 
 #include "common/compression.h"
+#include "common/file_utils.h"
 #include "fe_utils/simple_list.h"
 #include "libpq-fe.h"
 
@@ -307,7 +308,8 @@ extern Archive *OpenArchive(const char *FileSpec, const ArchiveFormat fmt);
 extern Archive *CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 							  const pg_compress_specification compression_spec,
 							  bool dosync, ArchiveMode mode,
-							  SetupWorkerPtrType setupDumpWorker);
+							  SetupWorkerPtrType setupDumpWorker,
+							  DataDirSyncMethod sync_method);
 
 /* The --list option */
 extern void PrintTOCSummary(Archive *AHX);
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index 39ebcfec32..4d83381d84 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -66,7 +66,8 @@ typedef struct _parallelReadyList
 static ArchiveHandle *_allocAH(const char *FileSpec, const ArchiveFormat fmt,
 							   const pg_compress_specification compression_spec,
 							   bool dosync, ArchiveMode mode,
-							   SetupWorkerPtrType setupWorkerPtr);
+							   SetupWorkerPtrType setupWorkerPtr,
+							   DataDirSyncMethod sync_method);
 static void _getObjectDescription(PQExpBuffer buf, const TocEntry *te);
 static void _printTocEntry(ArchiveHandle *AH, TocEntry *te, bool isData);
 static char *sanitize_line(const char *str, bool want_hyphen);
@@ -238,11 +239,12 @@ Archive *
 CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 			  const pg_compress_specification compression_spec,
 			  bool dosync, ArchiveMode mode,
-			  SetupWorkerPtrType setupDumpWorker)
+			  SetupWorkerPtrType setupDumpWorker,
+			  DataDirSyncMethod sync_method)
 
 {
 	ArchiveHandle *AH = _allocAH(FileSpec, fmt, compression_spec,
-								 dosync, mode, setupDumpWorker);
+								 dosync, mode, setupDumpWorker, sync_method);
 
 	return (Archive *) AH;
 }
@@ -257,7 +259,8 @@ OpenArchive(const char *FileSpec, const ArchiveFormat fmt)
 
 	compression_spec.algorithm = PG_COMPRESSION_NONE;
 	AH = _allocAH(FileSpec, fmt, compression_spec, true,
-				  archModeRead, setupRestoreWorker);
+				  archModeRead, setupRestoreWorker,
+				  DATA_DIR_SYNC_METHOD_FSYNC);
 
 	return (Archive *) AH;
 }
@@ -2233,7 +2236,7 @@ static ArchiveHandle *
 _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 		 const pg_compress_specification compression_spec,
 		 bool dosync, ArchiveMode mode,
-		 SetupWorkerPtrType setupWorkerPtr)
+		 SetupWorkerPtrType setupWorkerPtr, DataDirSyncMethod sync_method)
 {
 	ArchiveHandle *AH;
 	CompressFileHandle *CFH;
@@ -2287,6 +2290,7 @@ _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 	AH->mode = mode;
 	AH->compression_spec = compression_spec;
 	AH->dosync = dosync;
+	AH->sync_method = sync_method;
 
 	memset(&(AH->sqlparse), 0, sizeof(AH->sqlparse));
 
diff --git a/src/bin/pg_dump/pg_backup_archiver.h b/src/bin/pg_dump/pg_backup_archiver.h
index 18b38c17ab..b07673933d 100644
--- a/src/bin/pg_dump/pg_backup_archiver.h
+++ b/src/bin/pg_dump/pg_backup_archiver.h
@@ -312,6 +312,7 @@ struct _archiveHandle
 	pg_compress_specification compression_spec; /* Requested specification for
 												 * compression */
 	bool		dosync;			/* data requested to be synced on sight */
+	DataDirSyncMethod sync_method;
 	ArchiveMode mode;			/* File mode - r or w */
 	void	   *formatData;		/* Header data specific to file format */
 
diff --git a/src/bin/pg_dump/pg_backup_directory.c b/src/bin/pg_dump/pg_backup_directory.c
index 7f2ac7c7fd..6faa3a511f 100644
--- a/src/bin/pg_dump/pg_backup_directory.c
+++ b/src/bin/pg_dump/pg_backup_directory.c
@@ -613,7 +613,7 @@ _CloseArchive(ArchiveHandle *AH)
 		 * individually. Just recurse once through all the files generated.
 		 */
 		if (AH->dosync)
-			fsync_dir_recurse(ctx->directory);
+			fsync_dir_recurse(ctx->directory, AH->sync_method);
 	}
 	AH->FH = NULL;
 }
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 5dab1ba9ea..895360dac7 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -357,6 +357,7 @@ main(int argc, char **argv)
 	char	   *compression_algorithm_str = "none";
 	char	   *error_detail = NULL;
 	bool		user_compression_defined = false;
+	DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 	static DumpOptions dopt;
 
@@ -431,6 +432,7 @@ main(int argc, char **argv)
 		{"table-and-children", required_argument, NULL, 12},
 		{"exclude-table-and-children", required_argument, NULL, 13},
 		{"exclude-table-data-and-children", required_argument, NULL, 14},
+		{"sync-method", required_argument, NULL, 15},
 
 		{NULL, 0, NULL, 0}
 	};
@@ -657,6 +659,11 @@ main(int argc, char **argv)
 										  optarg);
 				break;
 
+			case 15:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit_nicely(1);
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -777,7 +784,7 @@ main(int argc, char **argv)
 
 	/* Open the output file */
 	fout = CreateArchive(filename, archiveFormat, compression_spec,
-						 dosync, archiveMode, setupDumpWorker);
+						 dosync, archiveMode, setupDumpWorker, sync_method);
 
 	/* Make dump options accessible right away */
 	SetArchiveOptions(fout, &dopt, NULL);
@@ -1068,6 +1075,7 @@ help(const char *progname)
 			 "                               compress as specified\n"));
 	printf(_("  --lock-wait-timeout=TIMEOUT  fail after waiting TIMEOUT for a table lock\n"));
 	printf(_("  --no-sync                    do not wait for changes to be written safely to disk\n"));
+	printf(_("  --sync-method=METHOD         set method for syncing files to disk\n"));
 	printf(_("  -?, --help                   show this help, then exit\n"));
 
 	printf(_("\nOptions controlling the output content:\n"));
diff --git a/src/bin/pg_rewind/file_ops.c b/src/bin/pg_rewind/file_ops.c
index 25996b4da4..451fb1856e 100644
--- a/src/bin/pg_rewind/file_ops.c
+++ b/src/bin/pg_rewind/file_ops.c
@@ -296,7 +296,7 @@ sync_target_dir(void)
 	if (!do_sync || dry_run)
 		return;
 
-	fsync_pgdata(datadir_target, PG_VERSION_NUM);
+	fsync_pgdata(datadir_target, PG_VERSION_NUM, sync_method);
 }
 
 
diff --git a/src/bin/pg_rewind/pg_rewind.c b/src/bin/pg_rewind/pg_rewind.c
index f7f3b8227f..64a7469f22 100644
--- a/src/bin/pg_rewind/pg_rewind.c
+++ b/src/bin/pg_rewind/pg_rewind.c
@@ -22,6 +22,7 @@
 #include "common/file_perm.h"
 #include "common/restricted_token.h"
 #include "common/string.h"
+#include "fe_utils/option_utils.h"
 #include "fe_utils/recovery_gen.h"
 #include "fe_utils/string_utils.h"
 #include "file_ops.h"
@@ -74,6 +75,7 @@ bool		showprogress = false;
 bool		dry_run = false;
 bool		do_sync = true;
 bool		restore_wal = false;
+DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 /* Target history */
 TimeLineHistoryEntry *targetHistory;
@@ -107,6 +109,7 @@ usage(const char *progname)
 			 "                                 file when running target cluster\n"));
 	printf(_("      --debug                    write a lot of debug messages\n"));
 	printf(_("      --no-ensure-shutdown       do not automatically fix unclean shutdown\n"));
+	printf(_("      --sync-method=METHOD       set method for syncing files to disk\n"));
 	printf(_("  -V, --version                  output version information, then exit\n"));
 	printf(_("  -?, --help                     show this help, then exit\n"));
 	printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
@@ -131,6 +134,7 @@ main(int argc, char **argv)
 		{"no-sync", no_argument, NULL, 'N'},
 		{"progress", no_argument, NULL, 'P'},
 		{"debug", no_argument, NULL, 3},
+		{"sync-method", required_argument, NULL, 6},
 		{NULL, 0, NULL, 0}
 	};
 	int			option_index;
@@ -218,6 +222,11 @@ main(int argc, char **argv)
 				config_file = pg_strdup(optarg);
 				break;
 
+			case 6:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_rewind/pg_rewind.h b/src/bin/pg_rewind/pg_rewind.h
index ef8bdc1fbb..05729adfef 100644
--- a/src/bin/pg_rewind/pg_rewind.h
+++ b/src/bin/pg_rewind/pg_rewind.h
@@ -13,6 +13,7 @@
 
 #include "access/timeline.h"
 #include "common/logging.h"
+#include "common/file_utils.h"
 #include "datapagemap.h"
 #include "libpq-fe.h"
 #include "storage/block.h"
@@ -24,6 +25,7 @@ extern bool showprogress;
 extern bool dry_run;
 extern bool do_sync;
 extern int	WalSegSz;
+extern DataDirSyncMethod sync_method;
 
 /* Target history */
 extern TimeLineHistoryEntry *targetHistory;
diff --git a/src/bin/pg_upgrade/option.c b/src/bin/pg_upgrade/option.c
index 640361009e..b9d900d0db 100644
--- a/src/bin/pg_upgrade/option.c
+++ b/src/bin/pg_upgrade/option.c
@@ -14,6 +14,7 @@
 #endif
 
 #include "common/string.h"
+#include "fe_utils/option_utils.h"
 #include "getopt_long.h"
 #include "pg_upgrade.h"
 #include "utils/pidfile.h"
@@ -57,12 +58,14 @@ parseCommandLine(int argc, char *argv[])
 		{"verbose", no_argument, NULL, 'v'},
 		{"clone", no_argument, NULL, 1},
 		{"copy", no_argument, NULL, 2},
+		{"sync-method", required_argument, NULL, 3},
 
 		{NULL, 0, NULL, 0}
 	};
 	int			option;			/* Command line option */
 	int			optindex = 0;	/* used by getopt_long */
 	int			os_user_effective_id;
+	DataDirSyncMethod unused;
 
 	user_opts.do_sync = true;
 	user_opts.transfer_mode = TRANSFER_MODE_COPY;
@@ -199,6 +202,12 @@ parseCommandLine(int argc, char *argv[])
 				user_opts.transfer_mode = TRANSFER_MODE_COPY;
 				break;
 
+			case 3:
+				if (!parse_sync_method(optarg, &unused))
+					exit(1);
+				user_opts.sync_method = pg_strdup(optarg);
+				break;
+
 			default:
 				fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
 						os_info.progname);
@@ -209,6 +218,9 @@ parseCommandLine(int argc, char *argv[])
 	if (optind < argc)
 		pg_fatal("too many command-line arguments (first is \"%s\")", argv[optind]);
 
+	if (!user_opts.sync_method)
+		user_opts.sync_method = pg_strdup("fsync");
+
 	if (log_opts.verbose)
 		pg_log(PG_REPORT, "Running in verbose mode");
 
@@ -289,6 +301,7 @@ usage(void)
 	printf(_("  -V, --version                 display version information, then exit\n"));
 	printf(_("  --clone                       clone instead of copying files to new cluster\n"));
 	printf(_("  --copy                        copy files to new cluster (default)\n"));
+	printf(_("  --sync-method=METHOD          set method for syncing files to disk\n"));
 	printf(_("  -?, --help                    show this help, then exit\n"));
 	printf(_("\n"
 			 "Before running pg_upgrade you must:\n"
diff --git a/src/bin/pg_upgrade/pg_upgrade.c b/src/bin/pg_upgrade/pg_upgrade.c
index 4562dafcff..96bfb67167 100644
--- a/src/bin/pg_upgrade/pg_upgrade.c
+++ b/src/bin/pg_upgrade/pg_upgrade.c
@@ -192,8 +192,10 @@ main(int argc, char **argv)
 	{
 		prep_status("Sync data directory to disk");
 		exec_prog(UTILITY_LOG_FILE, NULL, true, true,
-				  "\"%s/initdb\" --sync-only \"%s\"", new_cluster.bindir,
-				  new_cluster.pgdata);
+				  "\"%s/initdb\" --sync-only \"%s\" --sync-method %s",
+				  new_cluster.bindir,
+				  new_cluster.pgdata,
+				  user_opts.sync_method);
 		check_ok();
 	}
 
diff --git a/src/bin/pg_upgrade/pg_upgrade.h b/src/bin/pg_upgrade/pg_upgrade.h
index 3eea0139c7..13457b2f75 100644
--- a/src/bin/pg_upgrade/pg_upgrade.h
+++ b/src/bin/pg_upgrade/pg_upgrade.h
@@ -304,6 +304,7 @@ typedef struct
 	transferMode transfer_mode; /* copy files or link them? */
 	int			jobs;			/* number of processes/threads to use */
 	char	   *socketdir;		/* directory to use for Unix sockets */
+	char	   *sync_method;
 } UserOpts;
 
 typedef struct
diff --git a/src/common/file_utils.c b/src/common/file_utils.c
index 74833c4acb..c977c990ad 100644
--- a/src/common/file_utils.c
+++ b/src/common/file_utils.c
@@ -51,6 +51,31 @@ static void walkdir(const char *path,
 					int (*action) (const char *fname, bool isdir),
 					bool process_symlinks);
 
+#ifdef HAVE_SYNCFS
+static void
+do_syncfs(const char *path)
+{
+	int			fd;
+
+	fd = open(path, O_RDONLY, 0);
+
+	if (fd < 0)
+	{
+		pg_log_error("could not open file \"%s\": %m", path);
+		return;
+	}
+
+	if (syncfs(fd) < 0)
+	{
+		pg_log_error("could not synchronize file system for file \"%s\": %m", path);
+		(void) close(fd);
+		exit(EXIT_FAILURE);
+	}
+
+	(void) close(fd);
+}
+#endif
+
 /*
  * Issue fsync recursively on PGDATA and all its contents.
  *
@@ -63,7 +88,8 @@ static void walkdir(const char *path,
  */
 void
 fsync_pgdata(const char *pg_data,
-			 int serverVersion)
+			 int serverVersion,
+			 DataDirSyncMethod sync_method)
 {
 	bool		xlog_is_symlink;
 	char		pg_wal[MAXPGPATH];
@@ -89,6 +115,55 @@ fsync_pgdata(const char *pg_data,
 			xlog_is_symlink = true;
 	}
 
+#ifdef HAVE_SYNCFS
+	if (sync_method == DATA_DIR_SYNC_METHOD_SYNCFS)
+	{
+		DIR		   *dir;
+		struct dirent *de;
+
+		/*
+		 * On Linux, we don't have to open every single file one by one.  We
+		 * can use syncfs() to sync whole filesystems.  We only expect
+		 * filesystem boundaries to exist where we tolerate symlinks, namely
+		 * pg_wal and the tablespaces, so we call syncfs() for each of those
+		 * directories.
+		 */
+
+		/* Sync the top level pgdata directory. */
+		do_syncfs(pg_data);
+
+		/* If any tablespaces are configured, sync each of those. */
+		dir = opendir(pg_tblspc);
+		if (dir == NULL)
+			pg_log_error("could not open directory \"%s\": %m", pg_tblspc);
+		else
+		{
+			while (errno = 0, (de = readdir(dir)) != NULL)
+			{
+				char		subpath[MAXPGPATH * 2];
+
+				if (strcmp(de->d_name, ".") == 0 ||
+					strcmp(de->d_name, "..") == 0)
+					continue;
+
+				snprintf(subpath, sizeof(subpath), "%s/%s", pg_tblspc, de->d_name);
+				do_syncfs(subpath);
+			}
+
+			if (errno)
+				pg_log_error("could not read directory \"%s\": %m", pg_tblspc);
+
+			(void) closedir(dir);
+		}
+
+		/* If pg_wal is a symlink, process that too. */
+		if (xlog_is_symlink)
+			do_syncfs(pg_wal);
+
+		return;
+	}
+#endif							/* HAVE_SYNCFS */
+
 	/*
 	 * If possible, hint to the kernel that we're soon going to fsync the data
 	 * directory and its contents.
@@ -121,8 +196,20 @@ fsync_pgdata(const char *pg_data,
  * This is a convenient wrapper on top of walkdir().
  */
 void
-fsync_dir_recurse(const char *dir)
+fsync_dir_recurse(const char *dir, DataDirSyncMethod sync_method)
 {
+#ifdef HAVE_SYNCFS
+	if (sync_method == DATA_DIR_SYNC_METHOD_SYNCFS)
+	{
+		/*
+		 * On Linux, we don't have to open every single file one by one.  We
+		 * can use syncfs() to sync the whole filesystem.
+		 */
+		do_syncfs(dir);
+		return;
+	}
+#endif							/* HAVE_SYNCFS */
+
 	/*
 	 * If possible, hint to the kernel that we're soon going to fsync the data
 	 * directory and its contents.
diff --git a/src/fe_utils/option_utils.c b/src/fe_utils/option_utils.c
index 763c991015..36ac689964 100644
--- a/src/fe_utils/option_utils.c
+++ b/src/fe_utils/option_utils.c
@@ -82,3 +82,27 @@ option_parse_int(const char *optarg, const char *optname,
 		*result = val;
 	return true;
 }
+
+bool
+parse_sync_method(const char *optarg, DataDirSyncMethod *sync_method)
+{
+	if (strcmp(optarg, "fsync") == 0)
+		*sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
+	else if (strcmp(optarg, "syncfs") == 0)
+	{
+#ifdef HAVE_SYNCFS
+		*sync_method = DATA_DIR_SYNC_METHOD_SYNCFS;
+#else
+		pg_log_error("this build does not support sync method \"%s\"",
+					 "syncfs");
+		return false;
+#endif
+	}
+	else
+	{
+		pg_log_error("unrecognized sync method: %s", optarg);
+		return false;
+	}
+
+	return true;
+}
diff --git a/src/include/common/file_utils.h b/src/include/common/file_utils.h
index b7efa1226d..93aa5bdaf8 100644
--- a/src/include/common/file_utils.h
+++ b/src/include/common/file_utils.h
@@ -26,13 +26,22 @@ typedef enum PGFileType
 
 struct iovec;					/* avoid including port/pg_iovec.h here */
 
+typedef enum DataDirSyncMethod
+{
+	DATA_DIR_SYNC_METHOD_FSYNC,
+	DATA_DIR_SYNC_METHOD_SYNCFS
+} DataDirSyncMethod;
+
 #ifdef FRONTEND
+
 extern int	fsync_fname(const char *fname, bool isdir);
-extern void fsync_pgdata(const char *pg_data, int serverVersion);
-extern void fsync_dir_recurse(const char *dir);
+extern void fsync_pgdata(const char *pg_data, int serverVersion,
+						 DataDirSyncMethod sync_method);
+extern void fsync_dir_recurse(const char *dir, DataDirSyncMethod sync_method);
 extern int	durable_rename(const char *oldfile, const char *newfile);
 extern int	fsync_parent_path(const char *fname);
-#endif
+
+#endif							/* FRONTEND */
 
 extern PGFileType get_dirent_type(const char *path,
 								  const struct dirent *de,
diff --git a/src/include/fe_utils/option_utils.h b/src/include/fe_utils/option_utils.h
index b7b0654cee..6f3a965916 100644
--- a/src/include/fe_utils/option_utils.h
+++ b/src/include/fe_utils/option_utils.h
@@ -14,6 +14,8 @@
 
 #include "postgres_fe.h"
 
+#include "common/file_utils.h"
+
 typedef void (*help_handler) (const char *progname);
 
 extern void handle_help_version_opts(int argc, char *argv[],
@@ -22,5 +24,7 @@ extern void handle_help_version_opts(int argc, char *argv[],
 extern bool option_parse_int(const char *optarg, const char *optname,
 							 int min_range, int max_range,
 							 int *result);
+extern bool parse_sync_method(const char *optarg,
+							  DataDirSyncMethod *sync_method);
 
 #endif							/* OPTION_UTILS_H */
diff --git a/src/include/storage/fd.h b/src/include/storage/fd.h
index 6791a406fc..dedb773304 100644
--- a/src/include/storage/fd.h
+++ b/src/include/storage/fd.h
@@ -43,15 +43,11 @@
 #ifndef FD_H
 #define FD_H
 
+#ifndef FRONTEND
+
 #include <dirent.h>
 #include <fcntl.h>
 
-typedef enum RecoveryInitSyncMethod
-{
-	RECOVERY_INIT_SYNC_METHOD_FSYNC,
-	RECOVERY_INIT_SYNC_METHOD_SYNCFS
-}			RecoveryInitSyncMethod;
-
 typedef int File;
 
 
@@ -195,6 +191,8 @@ extern int	durable_unlink(const char *fname, int elevel);
 extern void SyncDataDirectory(void);
 extern int	data_sync_elevel(int elevel);
 
+#endif							/* ! FRONTEND */
+
 /* Filename components */
 #define PG_TEMP_FILES_DIR "pgsql_tmp"
 #define PG_TEMP_FILE_PREFIX "pgsql_tmp"
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 51b7951ad8..07387ed251 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2678,6 +2678,7 @@ SupportRequestSelectivity
 SupportRequestSimplify
 SupportRequestWFuncMonotonic
 Syn
+DataDirSyncMethod
 SyncOps
 SyncRepConfigData
 SyncRepStandbyData
-- 
2.25.1

From af40f64933b5d8829b7e1641ce57e4ef8fd5a2c2 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Mon, 21 Aug 2023 19:05:14 -0700
Subject: [PATCH 1/1] move PG_TEMP_FILE* macros to file_utils.h

---
 src/backend/backup/basebackup.c     |  2 +-
 src/backend/storage/file/fileset.c  |  1 +
 src/bin/pg_checksums/pg_checksums.c | 10 ----------
 src/bin/pg_rewind/filemap.c         |  2 +-
 src/include/common/file_utils.h     |  4 ++++
 src/include/storage/fd.h            |  4 ----
 6 files changed, 7 insertions(+), 16 deletions(-)

diff --git a/src/backend/backup/basebackup.c b/src/backend/backup/basebackup.c
index 45be21131c..5d66014499 100644
--- a/src/backend/backup/basebackup.c
+++ b/src/backend/backup/basebackup.c
@@ -25,6 +25,7 @@
 #include "commands/defrem.h"
 #include "common/compression.h"
 #include "common/file_perm.h"
+#include "common/file_utils.h"
 #include "lib/stringinfo.h"
 #include "miscadmin.h"
 #include "nodes/pg_list.h"
@@ -37,7 +38,6 @@
 #include "storage/bufpage.h"
 #include "storage/checksum.h"
 #include "storage/dsm_impl.h"
-#include "storage/fd.h"
 #include "storage/ipc.h"
 #include "storage/reinit.h"
 #include "utils/builtins.h"
diff --git a/src/backend/storage/file/fileset.c b/src/backend/storage/file/fileset.c
index e9951b0269..84cae32548 100644
--- a/src/backend/storage/file/fileset.c
+++ b/src/backend/storage/file/fileset.c
@@ -25,6 +25,7 @@
 
 #include "catalog/pg_tablespace.h"
 #include "commands/tablespace.h"
+#include "common/file_utils.h"
 #include "common/hashfn.h"
 #include "miscadmin.h"
 #include "storage/ipc.h"
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 19eb67e485..9011a19b4e 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -52,16 +52,6 @@ typedef enum
 	PG_MODE_ENABLE
 } PgChecksumMode;
 
-/*
- * Filename components.
- *
- * XXX: fd.h is not declared here as frontend side code is not able to
- * interact with the backend-side definitions for the various fsync
- * wrappers.
- */
-#define PG_TEMP_FILES_DIR "pgsql_tmp"
-#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
-
 static PgChecksumMode mode = PG_MODE_CHECK;
 
 static const char *progname;
diff --git a/src/bin/pg_rewind/filemap.c b/src/bin/pg_rewind/filemap.c
index bd5c598e20..58280d9abc 100644
--- a/src/bin/pg_rewind/filemap.c
+++ b/src/bin/pg_rewind/filemap.c
@@ -27,12 +27,12 @@
 #include <unistd.h>
 
 #include "catalog/pg_tablespace_d.h"
+#include "common/file_utils.h"
 #include "common/hashfn.h"
 #include "common/string.h"
 #include "datapagemap.h"
 #include "filemap.h"
 #include "pg_rewind.h"
-#include "storage/fd.h"
 
 /*
  * Define a hash table which we can use to store information about the files
diff --git a/src/include/common/file_utils.h b/src/include/common/file_utils.h
index b7efa1226d..dd1532bcb0 100644
--- a/src/include/common/file_utils.h
+++ b/src/include/common/file_utils.h
@@ -46,4 +46,8 @@ extern ssize_t pg_pwritev_with_retry(int fd,
 
 extern ssize_t pg_pwrite_zeros(int fd, size_t size, off_t offset);
 
+/* Filename components */
+#define PG_TEMP_FILES_DIR "pgsql_tmp"
+#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
+
 #endif							/* FILE_UTILS_H */
diff --git a/src/include/storage/fd.h b/src/include/storage/fd.h
index 6791a406fc..aea30c0622 100644
--- a/src/include/storage/fd.h
+++ b/src/include/storage/fd.h
@@ -195,8 +195,4 @@ extern int	durable_unlink(const char *fname, int elevel);
 extern void SyncDataDirectory(void);
 extern int	data_sync_elevel(int elevel);
 
-/* Filename components */
-#define PG_TEMP_FILES_DIR "pgsql_tmp"
-#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
-
 #endif							/* FD_H */
-- 
2.25.1

From 25357aefb8956e12b4555881346c5b4a73c1f4e5 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Mon, 21 Aug 2023 19:05:14 -0700
Subject: [PATCH v5 1/2] move PG_TEMP_FILE* macros to file_utils.h

---
 src/backend/backup/basebackup.c     |  2 +-
 src/backend/postmaster/postmaster.c |  1 +
 src/backend/storage/file/fileset.c  |  1 +
 src/bin/pg_checksums/pg_checksums.c | 10 ----------
 src/bin/pg_rewind/filemap.c         |  2 +-
 src/include/common/file_utils.h     |  4 ++++
 src/include/storage/fd.h            |  4 ----
 7 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/src/backend/backup/basebackup.c b/src/backend/backup/basebackup.c
index 45be21131c..5d66014499 100644
--- a/src/backend/backup/basebackup.c
+++ b/src/backend/backup/basebackup.c
@@ -25,6 +25,7 @@
 #include "commands/defrem.h"
 #include "common/compression.h"
 #include "common/file_perm.h"
+#include "common/file_utils.h"
 #include "lib/stringinfo.h"
 #include "miscadmin.h"
 #include "nodes/pg_list.h"
@@ -37,7 +38,6 @@
 #include "storage/bufpage.h"
 #include "storage/checksum.h"
 #include "storage/dsm_impl.h"
-#include "storage/fd.h"
 #include "storage/ipc.h"
 #include "storage/reinit.h"
 #include "utils/builtins.h"
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 9c8ec779f9..d375dcb795 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -94,6 +94,7 @@
 #include "access/xlogrecovery.h"
 #include "catalog/pg_control.h"
 #include "common/file_perm.h"
+#include "common/file_utils.h"
 #include "common/ip.h"
 #include "common/pg_prng.h"
 #include "common/string.h"
diff --git a/src/backend/storage/file/fileset.c b/src/backend/storage/file/fileset.c
index e9951b0269..84cae32548 100644
--- a/src/backend/storage/file/fileset.c
+++ b/src/backend/storage/file/fileset.c
@@ -25,6 +25,7 @@
 
 #include "catalog/pg_tablespace.h"
 #include "commands/tablespace.h"
+#include "common/file_utils.h"
 #include "common/hashfn.h"
 #include "miscadmin.h"
 #include "storage/ipc.h"
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 19eb67e485..9011a19b4e 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -52,16 +52,6 @@ typedef enum
 	PG_MODE_ENABLE
 } PgChecksumMode;
 
-/*
- * Filename components.
- *
- * XXX: fd.h is not declared here as frontend side code is not able to
- * interact with the backend-side definitions for the various fsync
- * wrappers.
- */
-#define PG_TEMP_FILES_DIR "pgsql_tmp"
-#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
-
 static PgChecksumMode mode = PG_MODE_CHECK;
 
 static const char *progname;
diff --git a/src/bin/pg_rewind/filemap.c b/src/bin/pg_rewind/filemap.c
index bd5c598e20..58280d9abc 100644
--- a/src/bin/pg_rewind/filemap.c
+++ b/src/bin/pg_rewind/filemap.c
@@ -27,12 +27,12 @@
 #include <unistd.h>
 
 #include "catalog/pg_tablespace_d.h"
+#include "common/file_utils.h"
 #include "common/hashfn.h"
 #include "common/string.h"
 #include "datapagemap.h"
 #include "filemap.h"
 #include "pg_rewind.h"
-#include "storage/fd.h"
 
 /*
  * Define a hash table which we can use to store information about the files
diff --git a/src/include/common/file_utils.h b/src/include/common/file_utils.h
index b7efa1226d..dd1532bcb0 100644
--- a/src/include/common/file_utils.h
+++ b/src/include/common/file_utils.h
@@ -46,4 +46,8 @@ extern ssize_t pg_pwritev_with_retry(int fd,
 
 extern ssize_t pg_pwrite_zeros(int fd, size_t size, off_t offset);
 
+/* Filename components */
+#define PG_TEMP_FILES_DIR "pgsql_tmp"
+#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
+
 #endif							/* FILE_UTILS_H */
diff --git a/src/include/storage/fd.h b/src/include/storage/fd.h
index 6791a406fc..aea30c0622 100644
--- a/src/include/storage/fd.h
+++ b/src/include/storage/fd.h
@@ -195,8 +195,4 @@ extern int	durable_unlink(const char *fname, int elevel);
 extern void SyncDataDirectory(void);
 extern int	data_sync_elevel(int elevel);
 
-/* Filename components */
-#define PG_TEMP_FILES_DIR "pgsql_tmp"
-#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
-
 #endif							/* FD_H */
-- 
2.25.1

From 4cc8395720a3af1916f3baada04826177783ec80 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Fri, 28 Jul 2023 15:56:24 -0700
Subject: [PATCH v5 2/2] allow syncfs in frontend utilities

---
 doc/src/sgml/config.sgml              | 12 +---
 doc/src/sgml/filelist.sgml            |  1 +
 doc/src/sgml/postgres.sgml            |  1 +
 doc/src/sgml/ref/initdb.sgml          | 22 +++++++
 doc/src/sgml/ref/pg_basebackup.sgml   | 25 ++++++++
 doc/src/sgml/ref/pg_checksums.sgml    | 22 +++++++
 doc/src/sgml/ref/pg_dump.sgml         | 21 +++++++
 doc/src/sgml/ref/pg_rewind.sgml       | 22 +++++++
 doc/src/sgml/ref/pgupgrade.sgml       | 23 +++++++
 doc/src/sgml/syncfs.sgml              | 36 +++++++++++
 src/backend/storage/file/fd.c         |  4 +-
 src/backend/utils/misc/guc_tables.c   |  7 ++-
 src/bin/initdb/initdb.c               | 12 +++-
 src/bin/pg_basebackup/pg_basebackup.c | 12 +++-
 src/bin/pg_checksums/pg_checksums.c   |  9 ++-
 src/bin/pg_dump/pg_backup.h           |  4 +-
 src/bin/pg_dump/pg_backup_archiver.c  | 14 +++--
 src/bin/pg_dump/pg_backup_archiver.h  |  1 +
 src/bin/pg_dump/pg_backup_directory.c |  2 +-
 src/bin/pg_dump/pg_dump.c             | 10 ++-
 src/bin/pg_rewind/file_ops.c          |  2 +-
 src/bin/pg_rewind/pg_rewind.c         |  9 +++
 src/bin/pg_rewind/pg_rewind.h         |  2 +
 src/bin/pg_upgrade/option.c           | 13 ++++
 src/bin/pg_upgrade/pg_upgrade.c       |  6 +-
 src/bin/pg_upgrade/pg_upgrade.h       |  1 +
 src/common/file_utils.c               | 91 ++++++++++++++++++++++++++-
 src/fe_utils/option_utils.c           | 24 +++++++
 src/include/common/file_utils.h       | 11 +++-
 src/include/fe_utils/option_utils.h   |  4 ++
 src/include/storage/fd.h              |  6 --
 src/tools/pgindent/typedefs.list      |  1 +
 32 files changed, 390 insertions(+), 40 deletions(-)
 create mode 100644 doc/src/sgml/syncfs.sgml

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 11251fa05e..77b008b854 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -10580,15 +10580,9 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
         On Linux, <literal>syncfs</literal> may be used instead, to ask the
         operating system to synchronize the whole file systems that contain the
         data directory, the WAL files and each tablespace (but not any other
-        file systems that may be reachable through symbolic links).  This may
-        be a lot faster than the <literal>fsync</literal> setting, because it
-        doesn't need to open each file one by one.  On the other hand, it may
-        be slower if a file system is shared by other applications that
-        modify a lot of files, since those files will also be written to disk.
-        Furthermore, on versions of Linux before 5.8, I/O errors encountered
-        while writing data to disk may not be reported to
-        <productname>PostgreSQL</productname>, and relevant error messages may
-        appear only in kernel logs.
+        file systems that may be reachable through symbolic links).  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
        </para>
        <para>
         This parameter can only be set in the
diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
index 63b0fc2a46..df5d7c3025 100644
--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -184,6 +184,7 @@
 <!ENTITY acronyms   SYSTEM "acronyms.sgml">
 <!ENTITY glossary   SYSTEM "glossary.sgml">
 <!ENTITY color      SYSTEM "color.sgml">
+<!ENTITY syncfs     SYSTEM "syncfs.sgml">
 
 <!ENTITY features-supported   SYSTEM "features-supported.sgml">
 <!ENTITY features-unsupported SYSTEM "features-unsupported.sgml">
diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml
index 2e271862fc..f629524be0 100644
--- a/doc/src/sgml/postgres.sgml
+++ b/doc/src/sgml/postgres.sgml
@@ -294,6 +294,7 @@ break is not needed in a wider output rendering.
   &acronyms;
   &glossary;
   &color;
+  &syncfs;
   &obsolete;
 
  </part>
diff --git a/doc/src/sgml/ref/initdb.sgml b/doc/src/sgml/ref/initdb.sgml
index 22f1011781..8a09c5c438 100644
--- a/doc/src/sgml/ref/initdb.sgml
+++ b/doc/src/sgml/ref/initdb.sgml
@@ -365,6 +365,28 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry id="app-initdb-option-sync-method">
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>initdb</command> will recursively open and synchronize all
+        files in the data directory.  The search for files will follow symbolic
+        links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="app-initdb-option-sync-only">
       <term><option>-S</option></term>
       <term><option>--sync-only</option></term>
diff --git a/doc/src/sgml/ref/pg_basebackup.sgml b/doc/src/sgml/ref/pg_basebackup.sgml
index 79d3e657c3..d2b8ddd200 100644
--- a/doc/src/sgml/ref/pg_basebackup.sgml
+++ b/doc/src/sgml/ref/pg_basebackup.sgml
@@ -594,6 +594,31 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_basebackup</command> will recursively open and synchronize
+        all files in the backup directory.  When the plain format is used, the
+        search for files will follow symbolic links for the WAL directory and
+        each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file system that contains the
+        backup directory.  When the plain format is used,
+        <command>pg_basebackup</command> will also synchronize the file systems
+        that contain the WAL files and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-v</option></term>
       <term><option>--verbose</option></term>
diff --git a/doc/src/sgml/ref/pg_checksums.sgml b/doc/src/sgml/ref/pg_checksums.sgml
index a3d0b0f0a3..7b44ba71cf 100644
--- a/doc/src/sgml/ref/pg_checksums.sgml
+++ b/doc/src/sgml/ref/pg_checksums.sgml
@@ -139,6 +139,28 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_checksums</command> will recursively open and synchronize
+        all files in the data directory.  The search for files will follow
+        symbolic links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-v</option></term>
       <term><option>--verbose</option></term>
diff --git a/doc/src/sgml/ref/pg_dump.sgml b/doc/src/sgml/ref/pg_dump.sgml
index a3cf0608f5..c1e2220b3c 100644
--- a/doc/src/sgml/ref/pg_dump.sgml
+++ b/doc/src/sgml/ref/pg_dump.sgml
@@ -1179,6 +1179,27 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_dump --format=directory</command> will recursively open and
+        synchronize all files in the archive directory.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file system that contains the
+        archive directory.  See <xref linkend="syncfs"/> for more information
+        about using <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used or
+        <option>--format</option> is not set to <literal>directory</literal>.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>--table-and-children=<replaceable class="parameter">pattern</replaceable></option></term>
       <listitem>
diff --git a/doc/src/sgml/ref/pg_rewind.sgml b/doc/src/sgml/ref/pg_rewind.sgml
index 15cddd086b..80dff16168 100644
--- a/doc/src/sgml/ref/pg_rewind.sgml
+++ b/doc/src/sgml/ref/pg_rewind.sgml
@@ -284,6 +284,28 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_rewind</command> will recursively open and synchronize all
+        files in the data directory.  The search for files will follow symbolic
+        links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-V</option></term>
       <term><option>--version</option></term>
diff --git a/doc/src/sgml/ref/pgupgrade.sgml b/doc/src/sgml/ref/pgupgrade.sgml
index 7816b4c685..6c033485ea 100644
--- a/doc/src/sgml/ref/pgupgrade.sgml
+++ b/doc/src/sgml/ref/pgupgrade.sgml
@@ -190,6 +190,29 @@ PostgreSQL documentation
       variable <envar>PGSOCKETDIR</envar></para></listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_upgrade</command> will recursively open and synchronize all
+        files in the upgraded cluster's data directory.  The search for files
+        will follow symbolic links for the WAL directory and each configured
+        tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        upgrade cluster's data directory, its WAL files, and each tablespace.
+        See <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-U</option> <replaceable>username</replaceable></term>
       <term><option>--username=</option><replaceable>username</replaceable></term>
diff --git a/doc/src/sgml/syncfs.sgml b/doc/src/sgml/syncfs.sgml
new file mode 100644
index 0000000000..00457d2457
--- /dev/null
+++ b/doc/src/sgml/syncfs.sgml
@@ -0,0 +1,36 @@
+<!-- doc/src/sgml/syncfs.sgml -->
+
+<appendix id="syncfs">
+ <title><function>syncfs()</function> Caveats</title>
+
+ <indexterm zone="syncfs">
+  <primary>syncfs</primary>
+ </indexterm>
+
+ <para>
+  On Linux <function>syncfs()</function> may be specified for some
+  configuration parameters (e.g.,
+  <xref linkend="guc-recovery-init-sync-method"/>), server applications (e.g.,
+  <application>pg_upgrade</application>), and client applications (e.g.,
+  <application>pg_basebackup</application>) that involve synchronizing many
+  files to disk.  <function>syncfs()</function> is advantageous in many cases,
+  but there are some trade-offs to keep in mind.
+ </para>
+
+ <para>
+  Since <function>syncfs()</function> instructs the operating system to
+  synchronize a whole file system, it typically requires many fewer system
+  calls than using <function>fsync()</function> to synchronize each file one by
+  one.  Therefore, using <function>syncfs()</function> may be a lot faster than
+  using <function>fsync()</function>.  However, it may be slower if a file
+  system is shared by other applications that modify a lot of files, since
+  those files will also be written to disk.
+ </para>
+
+ <para>
+  Furthermore, on versions of Linux before 5.8, I/O errors encountered while
+  writing data to disk may not be reported to the calling program, and relevant
+  error messages may appear only in kernel logs.
+ </para>
+
+</appendix>
diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index a027a8aabc..206db91217 100644
--- a/src/backend/storage/file/fd.c
+++ b/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;
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index f9dba43b8c..331f65cbe6 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/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}
 };
@@ -4964,7 +4965,7 @@ 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
 	},
 
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index 3f4167682a..6d7d10cffb 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -76,6 +76,7 @@
 #include "common/restricted_token.h"
 #include "common/string.h"
 #include "common/username.h"
+#include "fe_utils/option_utils.h"
 #include "fe_utils/string_utils.h"
 #include "getopt_long.h"
 #include "mb/pg_wchar.h"
@@ -165,6 +166,7 @@ static bool data_checksums = false;
 static char *xlog_dir = NULL;
 static char *str_wal_segment_size_mb = NULL;
 static int	wal_segment_size_mb;
+static DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 
 /* internal vars */
@@ -2466,6 +2468,7 @@ usage(const char *progname)
 	printf(_("  -N, --no-sync             do not wait for changes to be written safely to disk\n"));
 	printf(_("      --no-instructions     do not print instructions for next steps\n"));
 	printf(_("  -s, --show                show internal settings\n"));
+	printf(_("      --sync-method=METHOD  set method for syncing files to disk\n"));
 	printf(_("  -S, --sync-only           only sync database files to disk, then exit\n"));
 	printf(_("\nOther options:\n"));
 	printf(_("  -V, --version             output version information, then exit\n"));
@@ -3106,6 +3109,7 @@ main(int argc, char *argv[])
 		{"locale-provider", required_argument, NULL, 15},
 		{"icu-locale", required_argument, NULL, 16},
 		{"icu-rules", required_argument, NULL, 17},
+		{"sync-method", required_argument, NULL, 18},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -3285,6 +3289,10 @@ main(int argc, char *argv[])
 			case 17:
 				icu_rules = pg_strdup(optarg);
 				break;
+			case 18:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -3332,7 +3340,7 @@ main(int argc, char *argv[])
 
 		fputs(_("syncing data to disk ... "), stdout);
 		fflush(stdout);
-		fsync_pgdata(pg_data, PG_VERSION_NUM);
+		fsync_pgdata(pg_data, PG_VERSION_NUM, sync_method);
 		check_ok();
 		return 0;
 	}
@@ -3409,7 +3417,7 @@ main(int argc, char *argv[])
 	{
 		fputs(_("syncing data to disk ... "), stdout);
 		fflush(stdout);
-		fsync_pgdata(pg_data, PG_VERSION_NUM);
+		fsync_pgdata(pg_data, PG_VERSION_NUM, sync_method);
 		check_ok();
 	}
 	else
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 1dc8efe0cb..977c793a67 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -148,6 +148,7 @@ static bool verify_checksums = true;
 static bool manifest = true;
 static bool manifest_force_encode = false;
 static char *manifest_checksums = NULL;
+static DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 static bool success = false;
 static bool made_new_pgdata = false;
@@ -424,6 +425,8 @@ usage(void)
 	printf(_("      --no-slot          prevent creation of temporary replication slot\n"));
 	printf(_("      --no-verify-checksums\n"
 			 "                         do not verify checksums\n"));
+	printf(_("      --sync-method=METHOD\n"
+			 "                         set method for syncing files to disk\n"));
 	printf(_("  -?, --help             show this help, then exit\n"));
 	printf(_("\nConnection options:\n"));
 	printf(_("  -d, --dbname=CONNSTR   connection string\n"));
@@ -2199,11 +2202,11 @@ BaseBackup(char *compression_algorithm, char *compression_detail,
 		if (format == 't')
 		{
 			if (strcmp(basedir, "-") != 0)
-				(void) fsync_dir_recurse(basedir);
+				(void) fsync_dir_recurse(basedir, sync_method);
 		}
 		else
 		{
-			(void) fsync_pgdata(basedir, serverVersion);
+			(void) fsync_pgdata(basedir, serverVersion, sync_method);
 		}
 	}
 
@@ -2281,6 +2284,7 @@ main(int argc, char **argv)
 		{"no-manifest", no_argument, NULL, 5},
 		{"manifest-force-encode", no_argument, NULL, 6},
 		{"manifest-checksums", required_argument, NULL, 7},
+		{"sync-method", required_argument, NULL, 8},
 		{NULL, 0, NULL, 0}
 	};
 	int			c;
@@ -2452,6 +2456,10 @@ main(int argc, char **argv)
 			case 7:
 				manifest_checksums = pg_strdup(optarg);
 				break;
+			case 8:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 9011a19b4e..9fb2c5b3c7 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -44,6 +44,7 @@ static char *only_filenode = NULL;
 static bool do_sync = true;
 static bool verbose = false;
 static bool showprogress = false;
+static DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 typedef enum
 {
@@ -77,6 +78,7 @@ usage(void)
 	printf(_("  -f, --filenode=FILENODE  check only relation with specified filenode\n"));
 	printf(_("  -N, --no-sync            do not wait for changes to be written safely to disk\n"));
 	printf(_("  -P, --progress           show progress information\n"));
+	printf(_("      --sync-method=METHOD set method for syncing files to disk\n"));
 	printf(_("  -v, --verbose            output verbose messages\n"));
 	printf(_("  -V, --version            output version information, then exit\n"));
 	printf(_("  -?, --help               show this help, then exit\n"));
@@ -435,6 +437,7 @@ main(int argc, char *argv[])
 		{"no-sync", no_argument, NULL, 'N'},
 		{"progress", no_argument, NULL, 'P'},
 		{"verbose", no_argument, NULL, 'v'},
+		{"sync-method", required_argument, NULL, 1},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -493,6 +496,10 @@ main(int argc, char *argv[])
 			case 'v':
 				verbose = true;
 				break;
+			case 1:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -623,7 +630,7 @@ main(int argc, char *argv[])
 		if (do_sync)
 		{
 			pg_log_info("syncing data directory");
-			fsync_pgdata(DataDir, PG_VERSION_NUM);
+			fsync_pgdata(DataDir, PG_VERSION_NUM, sync_method);
 		}
 
 		pg_log_info("updating control file");
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index aba780ef4b..3a57cdd97d 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -24,6 +24,7 @@
 #define PG_BACKUP_H
 
 #include "common/compression.h"
+#include "common/file_utils.h"
 #include "fe_utils/simple_list.h"
 #include "libpq-fe.h"
 
@@ -307,7 +308,8 @@ extern Archive *OpenArchive(const char *FileSpec, const ArchiveFormat fmt);
 extern Archive *CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 							  const pg_compress_specification compression_spec,
 							  bool dosync, ArchiveMode mode,
-							  SetupWorkerPtrType setupDumpWorker);
+							  SetupWorkerPtrType setupDumpWorker,
+							  DataDirSyncMethod sync_method);
 
 /* The --list option */
 extern void PrintTOCSummary(Archive *AHX);
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index 39ebcfec32..4d83381d84 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -66,7 +66,8 @@ typedef struct _parallelReadyList
 static ArchiveHandle *_allocAH(const char *FileSpec, const ArchiveFormat fmt,
 							   const pg_compress_specification compression_spec,
 							   bool dosync, ArchiveMode mode,
-							   SetupWorkerPtrType setupWorkerPtr);
+							   SetupWorkerPtrType setupWorkerPtr,
+							   DataDirSyncMethod sync_method);
 static void _getObjectDescription(PQExpBuffer buf, const TocEntry *te);
 static void _printTocEntry(ArchiveHandle *AH, TocEntry *te, bool isData);
 static char *sanitize_line(const char *str, bool want_hyphen);
@@ -238,11 +239,12 @@ Archive *
 CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 			  const pg_compress_specification compression_spec,
 			  bool dosync, ArchiveMode mode,
-			  SetupWorkerPtrType setupDumpWorker)
+			  SetupWorkerPtrType setupDumpWorker,
+			  DataDirSyncMethod sync_method)
 
 {
 	ArchiveHandle *AH = _allocAH(FileSpec, fmt, compression_spec,
-								 dosync, mode, setupDumpWorker);
+								 dosync, mode, setupDumpWorker, sync_method);
 
 	return (Archive *) AH;
 }
@@ -257,7 +259,8 @@ OpenArchive(const char *FileSpec, const ArchiveFormat fmt)
 
 	compression_spec.algorithm = PG_COMPRESSION_NONE;
 	AH = _allocAH(FileSpec, fmt, compression_spec, true,
-				  archModeRead, setupRestoreWorker);
+				  archModeRead, setupRestoreWorker,
+				  DATA_DIR_SYNC_METHOD_FSYNC);
 
 	return (Archive *) AH;
 }
@@ -2233,7 +2236,7 @@ static ArchiveHandle *
 _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 		 const pg_compress_specification compression_spec,
 		 bool dosync, ArchiveMode mode,
-		 SetupWorkerPtrType setupWorkerPtr)
+		 SetupWorkerPtrType setupWorkerPtr, DataDirSyncMethod sync_method)
 {
 	ArchiveHandle *AH;
 	CompressFileHandle *CFH;
@@ -2287,6 +2290,7 @@ _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 	AH->mode = mode;
 	AH->compression_spec = compression_spec;
 	AH->dosync = dosync;
+	AH->sync_method = sync_method;
 
 	memset(&(AH->sqlparse), 0, sizeof(AH->sqlparse));
 
diff --git a/src/bin/pg_dump/pg_backup_archiver.h b/src/bin/pg_dump/pg_backup_archiver.h
index 18b38c17ab..b07673933d 100644
--- a/src/bin/pg_dump/pg_backup_archiver.h
+++ b/src/bin/pg_dump/pg_backup_archiver.h
@@ -312,6 +312,7 @@ struct _archiveHandle
 	pg_compress_specification compression_spec; /* Requested specification for
 												 * compression */
 	bool		dosync;			/* data requested to be synced on sight */
+	DataDirSyncMethod sync_method;
 	ArchiveMode mode;			/* File mode - r or w */
 	void	   *formatData;		/* Header data specific to file format */
 
diff --git a/src/bin/pg_dump/pg_backup_directory.c b/src/bin/pg_dump/pg_backup_directory.c
index 7f2ac7c7fd..6faa3a511f 100644
--- a/src/bin/pg_dump/pg_backup_directory.c
+++ b/src/bin/pg_dump/pg_backup_directory.c
@@ -613,7 +613,7 @@ _CloseArchive(ArchiveHandle *AH)
 		 * individually. Just recurse once through all the files generated.
 		 */
 		if (AH->dosync)
-			fsync_dir_recurse(ctx->directory);
+			fsync_dir_recurse(ctx->directory, AH->sync_method);
 	}
 	AH->FH = NULL;
 }
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 5dab1ba9ea..895360dac7 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -357,6 +357,7 @@ main(int argc, char **argv)
 	char	   *compression_algorithm_str = "none";
 	char	   *error_detail = NULL;
 	bool		user_compression_defined = false;
+	DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 	static DumpOptions dopt;
 
@@ -431,6 +432,7 @@ main(int argc, char **argv)
 		{"table-and-children", required_argument, NULL, 12},
 		{"exclude-table-and-children", required_argument, NULL, 13},
 		{"exclude-table-data-and-children", required_argument, NULL, 14},
+		{"sync-method", required_argument, NULL, 15},
 
 		{NULL, 0, NULL, 0}
 	};
@@ -657,6 +659,11 @@ main(int argc, char **argv)
 										  optarg);
 				break;
 
+			case 15:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit_nicely(1);
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -777,7 +784,7 @@ main(int argc, char **argv)
 
 	/* Open the output file */
 	fout = CreateArchive(filename, archiveFormat, compression_spec,
-						 dosync, archiveMode, setupDumpWorker);
+						 dosync, archiveMode, setupDumpWorker, sync_method);
 
 	/* Make dump options accessible right away */
 	SetArchiveOptions(fout, &dopt, NULL);
@@ -1068,6 +1075,7 @@ help(const char *progname)
 			 "                               compress as specified\n"));
 	printf(_("  --lock-wait-timeout=TIMEOUT  fail after waiting TIMEOUT for a table lock\n"));
 	printf(_("  --no-sync                    do not wait for changes to be written safely to disk\n"));
+	printf(_("  --sync-method=METHOD         set method for syncing files to disk\n"));
 	printf(_("  -?, --help                   show this help, then exit\n"));
 
 	printf(_("\nOptions controlling the output content:\n"));
diff --git a/src/bin/pg_rewind/file_ops.c b/src/bin/pg_rewind/file_ops.c
index 25996b4da4..451fb1856e 100644
--- a/src/bin/pg_rewind/file_ops.c
+++ b/src/bin/pg_rewind/file_ops.c
@@ -296,7 +296,7 @@ sync_target_dir(void)
 	if (!do_sync || dry_run)
 		return;
 
-	fsync_pgdata(datadir_target, PG_VERSION_NUM);
+	fsync_pgdata(datadir_target, PG_VERSION_NUM, sync_method);
 }
 
 
diff --git a/src/bin/pg_rewind/pg_rewind.c b/src/bin/pg_rewind/pg_rewind.c
index f7f3b8227f..64a7469f22 100644
--- a/src/bin/pg_rewind/pg_rewind.c
+++ b/src/bin/pg_rewind/pg_rewind.c
@@ -22,6 +22,7 @@
 #include "common/file_perm.h"
 #include "common/restricted_token.h"
 #include "common/string.h"
+#include "fe_utils/option_utils.h"
 #include "fe_utils/recovery_gen.h"
 #include "fe_utils/string_utils.h"
 #include "file_ops.h"
@@ -74,6 +75,7 @@ bool		showprogress = false;
 bool		dry_run = false;
 bool		do_sync = true;
 bool		restore_wal = false;
+DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 /* Target history */
 TimeLineHistoryEntry *targetHistory;
@@ -107,6 +109,7 @@ usage(const char *progname)
 			 "                                 file when running target cluster\n"));
 	printf(_("      --debug                    write a lot of debug messages\n"));
 	printf(_("      --no-ensure-shutdown       do not automatically fix unclean shutdown\n"));
+	printf(_("      --sync-method=METHOD       set method for syncing files to disk\n"));
 	printf(_("  -V, --version                  output version information, then exit\n"));
 	printf(_("  -?, --help                     show this help, then exit\n"));
 	printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
@@ -131,6 +134,7 @@ main(int argc, char **argv)
 		{"no-sync", no_argument, NULL, 'N'},
 		{"progress", no_argument, NULL, 'P'},
 		{"debug", no_argument, NULL, 3},
+		{"sync-method", required_argument, NULL, 6},
 		{NULL, 0, NULL, 0}
 	};
 	int			option_index;
@@ -218,6 +222,11 @@ main(int argc, char **argv)
 				config_file = pg_strdup(optarg);
 				break;
 
+			case 6:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_rewind/pg_rewind.h b/src/bin/pg_rewind/pg_rewind.h
index ef8bdc1fbb..05729adfef 100644
--- a/src/bin/pg_rewind/pg_rewind.h
+++ b/src/bin/pg_rewind/pg_rewind.h
@@ -13,6 +13,7 @@
 
 #include "access/timeline.h"
 #include "common/logging.h"
+#include "common/file_utils.h"
 #include "datapagemap.h"
 #include "libpq-fe.h"
 #include "storage/block.h"
@@ -24,6 +25,7 @@ extern bool showprogress;
 extern bool dry_run;
 extern bool do_sync;
 extern int	WalSegSz;
+extern DataDirSyncMethod sync_method;
 
 /* Target history */
 extern TimeLineHistoryEntry *targetHistory;
diff --git a/src/bin/pg_upgrade/option.c b/src/bin/pg_upgrade/option.c
index 640361009e..b9d900d0db 100644
--- a/src/bin/pg_upgrade/option.c
+++ b/src/bin/pg_upgrade/option.c
@@ -14,6 +14,7 @@
 #endif
 
 #include "common/string.h"
+#include "fe_utils/option_utils.h"
 #include "getopt_long.h"
 #include "pg_upgrade.h"
 #include "utils/pidfile.h"
@@ -57,12 +58,14 @@ parseCommandLine(int argc, char *argv[])
 		{"verbose", no_argument, NULL, 'v'},
 		{"clone", no_argument, NULL, 1},
 		{"copy", no_argument, NULL, 2},
+		{"sync-method", required_argument, NULL, 3},
 
 		{NULL, 0, NULL, 0}
 	};
 	int			option;			/* Command line option */
 	int			optindex = 0;	/* used by getopt_long */
 	int			os_user_effective_id;
+	DataDirSyncMethod unused;
 
 	user_opts.do_sync = true;
 	user_opts.transfer_mode = TRANSFER_MODE_COPY;
@@ -199,6 +202,12 @@ parseCommandLine(int argc, char *argv[])
 				user_opts.transfer_mode = TRANSFER_MODE_COPY;
 				break;
 
+			case 3:
+				if (!parse_sync_method(optarg, &unused))
+					exit(1);
+				user_opts.sync_method = pg_strdup(optarg);
+				break;
+
 			default:
 				fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
 						os_info.progname);
@@ -209,6 +218,9 @@ parseCommandLine(int argc, char *argv[])
 	if (optind < argc)
 		pg_fatal("too many command-line arguments (first is \"%s\")", argv[optind]);
 
+	if (!user_opts.sync_method)
+		user_opts.sync_method = pg_strdup("fsync");
+
 	if (log_opts.verbose)
 		pg_log(PG_REPORT, "Running in verbose mode");
 
@@ -289,6 +301,7 @@ usage(void)
 	printf(_("  -V, --version                 display version information, then exit\n"));
 	printf(_("  --clone                       clone instead of copying files to new cluster\n"));
 	printf(_("  --copy                        copy files to new cluster (default)\n"));
+	printf(_("  --sync-method=METHOD          set method for syncing files to disk\n"));
 	printf(_("  -?, --help                    show this help, then exit\n"));
 	printf(_("\n"
 			 "Before running pg_upgrade you must:\n"
diff --git a/src/bin/pg_upgrade/pg_upgrade.c b/src/bin/pg_upgrade/pg_upgrade.c
index 4562dafcff..96bfb67167 100644
--- a/src/bin/pg_upgrade/pg_upgrade.c
+++ b/src/bin/pg_upgrade/pg_upgrade.c
@@ -192,8 +192,10 @@ main(int argc, char **argv)
 	{
 		prep_status("Sync data directory to disk");
 		exec_prog(UTILITY_LOG_FILE, NULL, true, true,
-				  "\"%s/initdb\" --sync-only \"%s\"", new_cluster.bindir,
-				  new_cluster.pgdata);
+				  "\"%s/initdb\" --sync-only \"%s\" --sync-method %s",
+				  new_cluster.bindir,
+				  new_cluster.pgdata,
+				  user_opts.sync_method);
 		check_ok();
 	}
 
diff --git a/src/bin/pg_upgrade/pg_upgrade.h b/src/bin/pg_upgrade/pg_upgrade.h
index 3eea0139c7..13457b2f75 100644
--- a/src/bin/pg_upgrade/pg_upgrade.h
+++ b/src/bin/pg_upgrade/pg_upgrade.h
@@ -304,6 +304,7 @@ typedef struct
 	transferMode transfer_mode; /* copy files or link them? */
 	int			jobs;			/* number of processes/threads to use */
 	char	   *socketdir;		/* directory to use for Unix sockets */
+	char	   *sync_method;
 } UserOpts;
 
 typedef struct
diff --git a/src/common/file_utils.c b/src/common/file_utils.c
index 74833c4acb..c977c990ad 100644
--- a/src/common/file_utils.c
+++ b/src/common/file_utils.c
@@ -51,6 +51,31 @@ static void walkdir(const char *path,
 					int (*action) (const char *fname, bool isdir),
 					bool process_symlinks);
 
+#ifdef HAVE_SYNCFS
+static void
+do_syncfs(const char *path)
+{
+	int			fd;
+
+	fd = open(path, O_RDONLY, 0);
+
+	if (fd < 0)
+	{
+		pg_log_error("could not open file \"%s\": %m", path);
+		return;
+	}
+
+	if (syncfs(fd) < 0)
+	{
+		pg_log_error("could not synchronize file system for file \"%s\": %m", path);
+		(void) close(fd);
+		exit(EXIT_FAILURE);
+	}
+
+	(void) close(fd);
+}
+#endif
+
 /*
  * Issue fsync recursively on PGDATA and all its contents.
  *
@@ -63,7 +88,8 @@ static void walkdir(const char *path,
  */
 void
 fsync_pgdata(const char *pg_data,
-			 int serverVersion)
+			 int serverVersion,
+			 DataDirSyncMethod sync_method)
 {
 	bool		xlog_is_symlink;
 	char		pg_wal[MAXPGPATH];
@@ -89,6 +115,55 @@ fsync_pgdata(const char *pg_data,
 			xlog_is_symlink = true;
 	}
 
+#ifdef HAVE_SYNCFS
+	if (sync_method == DATA_DIR_SYNC_METHOD_SYNCFS)
+	{
+		DIR		   *dir;
+		struct dirent *de;
+
+		/*
+		 * On Linux, we don't have to open every single file one by one.  We
+		 * can use syncfs() to sync whole filesystems.  We only expect
+		 * filesystem boundaries to exist where we tolerate symlinks, namely
+		 * pg_wal and the tablespaces, so we call syncfs() for each of those
+		 * directories.
+		 */
+
+		/* Sync the top level pgdata directory. */
+		do_syncfs(pg_data);
+
+		/* If any tablespaces are configured, sync each of those. */
+		dir = opendir(pg_tblspc);
+		if (dir == NULL)
+			pg_log_error("could not open directory \"%s\": %m", pg_tblspc);
+		else
+		{
+			while (errno = 0, (de = readdir(dir)) != NULL)
+			{
+				char		subpath[MAXPGPATH * 2];
+
+				if (strcmp(de->d_name, ".") == 0 ||
+					strcmp(de->d_name, "..") == 0)
+					continue;
+
+				snprintf(subpath, sizeof(subpath), "%s/%s", pg_tblspc, de->d_name);
+				do_syncfs(subpath);
+			}
+
+			if (errno)
+				pg_log_error("could not read directory \"%s\": %m", pg_tblspc);
+
+			(void) closedir(dir);
+		}
+
+		/* If pg_wal is a symlink, process that too. */
+		if (xlog_is_symlink)
+			do_syncfs(pg_wal);
+
+		return;
+	}
+#endif							/* HAVE_SYNCFS */
+
 	/*
 	 * If possible, hint to the kernel that we're soon going to fsync the data
 	 * directory and its contents.
@@ -121,8 +196,20 @@ fsync_pgdata(const char *pg_data,
  * This is a convenient wrapper on top of walkdir().
  */
 void
-fsync_dir_recurse(const char *dir)
+fsync_dir_recurse(const char *dir, DataDirSyncMethod sync_method)
 {
+#ifdef HAVE_SYNCFS
+	if (sync_method == DATA_DIR_SYNC_METHOD_SYNCFS)
+	{
+		/*
+		 * On Linux, we don't have to open every single file one by one.  We
+		 * can use syncfs() to sync the whole filesystem.
+		 */
+		do_syncfs(dir);
+		return;
+	}
+#endif							/* HAVE_SYNCFS */
+
 	/*
 	 * If possible, hint to the kernel that we're soon going to fsync the data
 	 * directory and its contents.
diff --git a/src/fe_utils/option_utils.c b/src/fe_utils/option_utils.c
index 763c991015..36ac689964 100644
--- a/src/fe_utils/option_utils.c
+++ b/src/fe_utils/option_utils.c
@@ -82,3 +82,27 @@ option_parse_int(const char *optarg, const char *optname,
 		*result = val;
 	return true;
 }
+
+bool
+parse_sync_method(const char *optarg, DataDirSyncMethod *sync_method)
+{
+	if (strcmp(optarg, "fsync") == 0)
+		*sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
+	else if (strcmp(optarg, "syncfs") == 0)
+	{
+#ifdef HAVE_SYNCFS
+		*sync_method = DATA_DIR_SYNC_METHOD_SYNCFS;
+#else
+		pg_log_error("this build does not support sync method \"%s\"",
+					 "syncfs");
+		return false;
+#endif
+	}
+	else
+	{
+		pg_log_error("unrecognized sync method: %s", optarg);
+		return false;
+	}
+
+	return true;
+}
diff --git a/src/include/common/file_utils.h b/src/include/common/file_utils.h
index dd1532bcb0..09d1e5d561 100644
--- a/src/include/common/file_utils.h
+++ b/src/include/common/file_utils.h
@@ -26,10 +26,17 @@ typedef enum PGFileType
 
 struct iovec;					/* avoid including port/pg_iovec.h here */
 
+typedef enum DataDirSyncMethod
+{
+	DATA_DIR_SYNC_METHOD_FSYNC,
+	DATA_DIR_SYNC_METHOD_SYNCFS
+} DataDirSyncMethod;
+
 #ifdef FRONTEND
 extern int	fsync_fname(const char *fname, bool isdir);
-extern void fsync_pgdata(const char *pg_data, int serverVersion);
-extern void fsync_dir_recurse(const char *dir);
+extern void fsync_pgdata(const char *pg_data, int serverVersion,
+						 DataDirSyncMethod sync_method);
+extern void fsync_dir_recurse(const char *dir, DataDirSyncMethod sync_method);
 extern int	durable_rename(const char *oldfile, const char *newfile);
 extern int	fsync_parent_path(const char *fname);
 #endif
diff --git a/src/include/fe_utils/option_utils.h b/src/include/fe_utils/option_utils.h
index b7b0654cee..6f3a965916 100644
--- a/src/include/fe_utils/option_utils.h
+++ b/src/include/fe_utils/option_utils.h
@@ -14,6 +14,8 @@
 
 #include "postgres_fe.h"
 
+#include "common/file_utils.h"
+
 typedef void (*help_handler) (const char *progname);
 
 extern void handle_help_version_opts(int argc, char *argv[],
@@ -22,5 +24,7 @@ extern void handle_help_version_opts(int argc, char *argv[],
 extern bool option_parse_int(const char *optarg, const char *optname,
 							 int min_range, int max_range,
 							 int *result);
+extern bool parse_sync_method(const char *optarg,
+							  DataDirSyncMethod *sync_method);
 
 #endif							/* OPTION_UTILS_H */
diff --git a/src/include/storage/fd.h b/src/include/storage/fd.h
index aea30c0622..d9d5d9da5f 100644
--- a/src/include/storage/fd.h
+++ b/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;
 
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 51b7951ad8..46c916ae24 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -544,6 +544,7 @@ DR_printtup
 DR_sqlfunction
 DR_transientrel
 DWORD
+DataDirSyncMethod
 DataDumperPtr
 DataPageDeleteStack
 DatabaseInfo
-- 
2.25.1

From 1bb28cfe5d40670386ae663e14c8854dc1b5486d Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Mon, 21 Aug 2023 19:05:14 -0700
Subject: [PATCH v6 1/2] move PG_TEMP_FILE* macros to file_utils.h

---
 src/backend/backup/basebackup.c     |  2 +-
 src/backend/postmaster/postmaster.c |  1 +
 src/backend/storage/file/fileset.c  |  1 +
 src/bin/pg_checksums/pg_checksums.c | 10 ----------
 src/bin/pg_rewind/filemap.c         |  2 +-
 src/include/common/file_utils.h     |  4 ++++
 src/include/storage/fd.h            |  4 ----
 7 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/src/backend/backup/basebackup.c b/src/backend/backup/basebackup.c
index 45be21131c..5d66014499 100644
--- a/src/backend/backup/basebackup.c
+++ b/src/backend/backup/basebackup.c
@@ -25,6 +25,7 @@
 #include "commands/defrem.h"
 #include "common/compression.h"
 #include "common/file_perm.h"
+#include "common/file_utils.h"
 #include "lib/stringinfo.h"
 #include "miscadmin.h"
 #include "nodes/pg_list.h"
@@ -37,7 +38,6 @@
 #include "storage/bufpage.h"
 #include "storage/checksum.h"
 #include "storage/dsm_impl.h"
-#include "storage/fd.h"
 #include "storage/ipc.h"
 #include "storage/reinit.h"
 #include "utils/builtins.h"
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index d7bfb28ff3..54e9bfb8c4 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -94,6 +94,7 @@
 #include "access/xlogrecovery.h"
 #include "catalog/pg_control.h"
 #include "common/file_perm.h"
+#include "common/file_utils.h"
 #include "common/ip.h"
 #include "common/pg_prng.h"
 #include "common/string.h"
diff --git a/src/backend/storage/file/fileset.c b/src/backend/storage/file/fileset.c
index e9951b0269..84cae32548 100644
--- a/src/backend/storage/file/fileset.c
+++ b/src/backend/storage/file/fileset.c
@@ -25,6 +25,7 @@
 
 #include "catalog/pg_tablespace.h"
 #include "commands/tablespace.h"
+#include "common/file_utils.h"
 #include "common/hashfn.h"
 #include "miscadmin.h"
 #include "storage/ipc.h"
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 19eb67e485..9011a19b4e 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -52,16 +52,6 @@ typedef enum
 	PG_MODE_ENABLE
 } PgChecksumMode;
 
-/*
- * Filename components.
- *
- * XXX: fd.h is not declared here as frontend side code is not able to
- * interact with the backend-side definitions for the various fsync
- * wrappers.
- */
-#define PG_TEMP_FILES_DIR "pgsql_tmp"
-#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
-
 static PgChecksumMode mode = PG_MODE_CHECK;
 
 static const char *progname;
diff --git a/src/bin/pg_rewind/filemap.c b/src/bin/pg_rewind/filemap.c
index bd5c598e20..58280d9abc 100644
--- a/src/bin/pg_rewind/filemap.c
+++ b/src/bin/pg_rewind/filemap.c
@@ -27,12 +27,12 @@
 #include <unistd.h>
 
 #include "catalog/pg_tablespace_d.h"
+#include "common/file_utils.h"
 #include "common/hashfn.h"
 #include "common/string.h"
 #include "datapagemap.h"
 #include "filemap.h"
 #include "pg_rewind.h"
-#include "storage/fd.h"
 
 /*
  * Define a hash table which we can use to store information about the files
diff --git a/src/include/common/file_utils.h b/src/include/common/file_utils.h
index b7efa1226d..dd1532bcb0 100644
--- a/src/include/common/file_utils.h
+++ b/src/include/common/file_utils.h
@@ -46,4 +46,8 @@ extern ssize_t pg_pwritev_with_retry(int fd,
 
 extern ssize_t pg_pwrite_zeros(int fd, size_t size, off_t offset);
 
+/* Filename components */
+#define PG_TEMP_FILES_DIR "pgsql_tmp"
+#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
+
 #endif							/* FILE_UTILS_H */
diff --git a/src/include/storage/fd.h b/src/include/storage/fd.h
index 6791a406fc..aea30c0622 100644
--- a/src/include/storage/fd.h
+++ b/src/include/storage/fd.h
@@ -195,8 +195,4 @@ extern int	durable_unlink(const char *fname, int elevel);
 extern void SyncDataDirectory(void);
 extern int	data_sync_elevel(int elevel);
 
-/* Filename components */
-#define PG_TEMP_FILES_DIR "pgsql_tmp"
-#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
-
 #endif							/* FD_H */
-- 
2.25.1

From 81e87db711bb90f4641b41b4f863f1f5064eb05d Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Fri, 28 Jul 2023 15:56:24 -0700
Subject: [PATCH v6 2/2] allow syncfs in frontend utilities

---
 doc/src/sgml/config.sgml              | 12 +---
 doc/src/sgml/filelist.sgml            |  1 +
 doc/src/sgml/postgres.sgml            |  1 +
 doc/src/sgml/ref/initdb.sgml          | 22 +++++++
 doc/src/sgml/ref/pg_basebackup.sgml   | 25 ++++++++
 doc/src/sgml/ref/pg_checksums.sgml    | 22 +++++++
 doc/src/sgml/ref/pg_dump.sgml         | 21 +++++++
 doc/src/sgml/ref/pg_rewind.sgml       | 22 +++++++
 doc/src/sgml/ref/pgupgrade.sgml       | 23 +++++++
 doc/src/sgml/syncfs.sgml              | 36 +++++++++++
 src/backend/storage/file/fd.c         |  4 +-
 src/backend/utils/misc/guc_tables.c   |  7 ++-
 src/bin/initdb/initdb.c               | 11 +++-
 src/bin/pg_basebackup/pg_basebackup.c | 12 +++-
 src/bin/pg_checksums/pg_checksums.c   |  9 ++-
 src/bin/pg_dump/pg_backup.h           |  4 +-
 src/bin/pg_dump/pg_backup_archiver.c  | 14 +++--
 src/bin/pg_dump/pg_backup_archiver.h  |  1 +
 src/bin/pg_dump/pg_backup_directory.c |  2 +-
 src/bin/pg_dump/pg_dump.c             | 10 ++-
 src/bin/pg_rewind/file_ops.c          |  2 +-
 src/bin/pg_rewind/pg_rewind.c         |  9 +++
 src/bin/pg_rewind/pg_rewind.h         |  2 +
 src/bin/pg_upgrade/option.c           | 13 ++++
 src/bin/pg_upgrade/pg_upgrade.c       |  6 +-
 src/bin/pg_upgrade/pg_upgrade.h       |  1 +
 src/common/file_utils.c               | 91 ++++++++++++++++++++++++++-
 src/fe_utils/option_utils.c           | 24 +++++++
 src/include/common/file_utils.h       | 11 +++-
 src/include/fe_utils/option_utils.h   |  4 ++
 src/include/storage/fd.h              |  6 --
 src/tools/pgindent/typedefs.list      |  1 +
 32 files changed, 389 insertions(+), 40 deletions(-)
 create mode 100644 doc/src/sgml/syncfs.sgml

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 694d667bf9..2c7d9f1262 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -10580,15 +10580,9 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
         On Linux, <literal>syncfs</literal> may be used instead, to ask the
         operating system to synchronize the whole file systems that contain the
         data directory, the WAL files and each tablespace (but not any other
-        file systems that may be reachable through symbolic links).  This may
-        be a lot faster than the <literal>fsync</literal> setting, because it
-        doesn't need to open each file one by one.  On the other hand, it may
-        be slower if a file system is shared by other applications that
-        modify a lot of files, since those files will also be written to disk.
-        Furthermore, on versions of Linux before 5.8, I/O errors encountered
-        while writing data to disk may not be reported to
-        <productname>PostgreSQL</productname>, and relevant error messages may
-        appear only in kernel logs.
+        file systems that may be reachable through symbolic links).  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
        </para>
        <para>
         This parameter can only be set in the
diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
index 63b0fc2a46..df5d7c3025 100644
--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -184,6 +184,7 @@
 <!ENTITY acronyms   SYSTEM "acronyms.sgml">
 <!ENTITY glossary   SYSTEM "glossary.sgml">
 <!ENTITY color      SYSTEM "color.sgml">
+<!ENTITY syncfs     SYSTEM "syncfs.sgml">
 
 <!ENTITY features-supported   SYSTEM "features-supported.sgml">
 <!ENTITY features-unsupported SYSTEM "features-unsupported.sgml">
diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml
index 2e271862fc..f629524be0 100644
--- a/doc/src/sgml/postgres.sgml
+++ b/doc/src/sgml/postgres.sgml
@@ -294,6 +294,7 @@ break is not needed in a wider output rendering.
   &acronyms;
   &glossary;
   &color;
+  &syncfs;
   &obsolete;
 
  </part>
diff --git a/doc/src/sgml/ref/initdb.sgml b/doc/src/sgml/ref/initdb.sgml
index 22f1011781..8a09c5c438 100644
--- a/doc/src/sgml/ref/initdb.sgml
+++ b/doc/src/sgml/ref/initdb.sgml
@@ -365,6 +365,28 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry id="app-initdb-option-sync-method">
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>initdb</command> will recursively open and synchronize all
+        files in the data directory.  The search for files will follow symbolic
+        links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="app-initdb-option-sync-only">
       <term><option>-S</option></term>
       <term><option>--sync-only</option></term>
diff --git a/doc/src/sgml/ref/pg_basebackup.sgml b/doc/src/sgml/ref/pg_basebackup.sgml
index 79d3e657c3..d2b8ddd200 100644
--- a/doc/src/sgml/ref/pg_basebackup.sgml
+++ b/doc/src/sgml/ref/pg_basebackup.sgml
@@ -594,6 +594,31 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_basebackup</command> will recursively open and synchronize
+        all files in the backup directory.  When the plain format is used, the
+        search for files will follow symbolic links for the WAL directory and
+        each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file system that contains the
+        backup directory.  When the plain format is used,
+        <command>pg_basebackup</command> will also synchronize the file systems
+        that contain the WAL files and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-v</option></term>
       <term><option>--verbose</option></term>
diff --git a/doc/src/sgml/ref/pg_checksums.sgml b/doc/src/sgml/ref/pg_checksums.sgml
index a3d0b0f0a3..7b44ba71cf 100644
--- a/doc/src/sgml/ref/pg_checksums.sgml
+++ b/doc/src/sgml/ref/pg_checksums.sgml
@@ -139,6 +139,28 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_checksums</command> will recursively open and synchronize
+        all files in the data directory.  The search for files will follow
+        symbolic links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-v</option></term>
       <term><option>--verbose</option></term>
diff --git a/doc/src/sgml/ref/pg_dump.sgml b/doc/src/sgml/ref/pg_dump.sgml
index a3cf0608f5..c1e2220b3c 100644
--- a/doc/src/sgml/ref/pg_dump.sgml
+++ b/doc/src/sgml/ref/pg_dump.sgml
@@ -1179,6 +1179,27 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_dump --format=directory</command> will recursively open and
+        synchronize all files in the archive directory.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file system that contains the
+        archive directory.  See <xref linkend="syncfs"/> for more information
+        about using <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used or
+        <option>--format</option> is not set to <literal>directory</literal>.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>--table-and-children=<replaceable class="parameter">pattern</replaceable></option></term>
       <listitem>
diff --git a/doc/src/sgml/ref/pg_rewind.sgml b/doc/src/sgml/ref/pg_rewind.sgml
index 15cddd086b..80dff16168 100644
--- a/doc/src/sgml/ref/pg_rewind.sgml
+++ b/doc/src/sgml/ref/pg_rewind.sgml
@@ -284,6 +284,28 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_rewind</command> will recursively open and synchronize all
+        files in the data directory.  The search for files will follow symbolic
+        links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-V</option></term>
       <term><option>--version</option></term>
diff --git a/doc/src/sgml/ref/pgupgrade.sgml b/doc/src/sgml/ref/pgupgrade.sgml
index 7816b4c685..6c033485ea 100644
--- a/doc/src/sgml/ref/pgupgrade.sgml
+++ b/doc/src/sgml/ref/pgupgrade.sgml
@@ -190,6 +190,29 @@ PostgreSQL documentation
       variable <envar>PGSOCKETDIR</envar></para></listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_upgrade</command> will recursively open and synchronize all
+        files in the upgraded cluster's data directory.  The search for files
+        will follow symbolic links for the WAL directory and each configured
+        tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        upgrade cluster's data directory, its WAL files, and each tablespace.
+        See <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-U</option> <replaceable>username</replaceable></term>
       <term><option>--username=</option><replaceable>username</replaceable></term>
diff --git a/doc/src/sgml/syncfs.sgml b/doc/src/sgml/syncfs.sgml
new file mode 100644
index 0000000000..00457d2457
--- /dev/null
+++ b/doc/src/sgml/syncfs.sgml
@@ -0,0 +1,36 @@
+<!-- doc/src/sgml/syncfs.sgml -->
+
+<appendix id="syncfs">
+ <title><function>syncfs()</function> Caveats</title>
+
+ <indexterm zone="syncfs">
+  <primary>syncfs</primary>
+ </indexterm>
+
+ <para>
+  On Linux <function>syncfs()</function> may be specified for some
+  configuration parameters (e.g.,
+  <xref linkend="guc-recovery-init-sync-method"/>), server applications (e.g.,
+  <application>pg_upgrade</application>), and client applications (e.g.,
+  <application>pg_basebackup</application>) that involve synchronizing many
+  files to disk.  <function>syncfs()</function> is advantageous in many cases,
+  but there are some trade-offs to keep in mind.
+ </para>
+
+ <para>
+  Since <function>syncfs()</function> instructs the operating system to
+  synchronize a whole file system, it typically requires many fewer system
+  calls than using <function>fsync()</function> to synchronize each file one by
+  one.  Therefore, using <function>syncfs()</function> may be a lot faster than
+  using <function>fsync()</function>.  However, it may be slower if a file
+  system is shared by other applications that modify a lot of files, since
+  those files will also be written to disk.
+ </para>
+
+ <para>
+  Furthermore, on versions of Linux before 5.8, I/O errors encountered while
+  writing data to disk may not be reported to the calling program, and relevant
+  error messages may appear only in kernel logs.
+ </para>
+
+</appendix>
diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index b490a76ba7..3fed475c38 100644
--- a/src/backend/storage/file/fd.c
+++ b/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;
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index e565a3092f..5abebe9a9c 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/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}
 };
@@ -4964,7 +4965,7 @@ 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
 	},
 
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index 905b979947..543927b8b4 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -165,6 +165,7 @@ static bool show_setting = false;
 static bool data_checksums = false;
 static char *xlog_dir = NULL;
 static int	wal_segment_size_mb = (DEFAULT_XLOG_SEG_SIZE) / (1024 * 1024);
+static DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 
 /* internal vars */
@@ -2466,6 +2467,7 @@ usage(const char *progname)
 	printf(_("  -N, --no-sync             do not wait for changes to be written safely to disk\n"));
 	printf(_("      --no-instructions     do not print instructions for next steps\n"));
 	printf(_("  -s, --show                show internal settings\n"));
+	printf(_("      --sync-method=METHOD  set method for syncing files to disk\n"));
 	printf(_("  -S, --sync-only           only sync database files to disk, then exit\n"));
 	printf(_("\nOther options:\n"));
 	printf(_("  -V, --version             output version information, then exit\n"));
@@ -3106,6 +3108,7 @@ main(int argc, char *argv[])
 		{"locale-provider", required_argument, NULL, 15},
 		{"icu-locale", required_argument, NULL, 16},
 		{"icu-rules", required_argument, NULL, 17},
+		{"sync-method", required_argument, NULL, 18},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -3286,6 +3289,10 @@ main(int argc, char *argv[])
 			case 17:
 				icu_rules = pg_strdup(optarg);
 				break;
+			case 18:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -3333,7 +3340,7 @@ main(int argc, char *argv[])
 
 		fputs(_("syncing data to disk ... "), stdout);
 		fflush(stdout);
-		fsync_pgdata(pg_data, PG_VERSION_NUM);
+		fsync_pgdata(pg_data, PG_VERSION_NUM, sync_method);
 		check_ok();
 		return 0;
 	}
@@ -3396,7 +3403,7 @@ main(int argc, char *argv[])
 	{
 		fputs(_("syncing data to disk ... "), stdout);
 		fflush(stdout);
-		fsync_pgdata(pg_data, PG_VERSION_NUM);
+		fsync_pgdata(pg_data, PG_VERSION_NUM, sync_method);
 		check_ok();
 	}
 	else
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 1dc8efe0cb..977c793a67 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -148,6 +148,7 @@ static bool verify_checksums = true;
 static bool manifest = true;
 static bool manifest_force_encode = false;
 static char *manifest_checksums = NULL;
+static DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 static bool success = false;
 static bool made_new_pgdata = false;
@@ -424,6 +425,8 @@ usage(void)
 	printf(_("      --no-slot          prevent creation of temporary replication slot\n"));
 	printf(_("      --no-verify-checksums\n"
 			 "                         do not verify checksums\n"));
+	printf(_("      --sync-method=METHOD\n"
+			 "                         set method for syncing files to disk\n"));
 	printf(_("  -?, --help             show this help, then exit\n"));
 	printf(_("\nConnection options:\n"));
 	printf(_("  -d, --dbname=CONNSTR   connection string\n"));
@@ -2199,11 +2202,11 @@ BaseBackup(char *compression_algorithm, char *compression_detail,
 		if (format == 't')
 		{
 			if (strcmp(basedir, "-") != 0)
-				(void) fsync_dir_recurse(basedir);
+				(void) fsync_dir_recurse(basedir, sync_method);
 		}
 		else
 		{
-			(void) fsync_pgdata(basedir, serverVersion);
+			(void) fsync_pgdata(basedir, serverVersion, sync_method);
 		}
 	}
 
@@ -2281,6 +2284,7 @@ main(int argc, char **argv)
 		{"no-manifest", no_argument, NULL, 5},
 		{"manifest-force-encode", no_argument, NULL, 6},
 		{"manifest-checksums", required_argument, NULL, 7},
+		{"sync-method", required_argument, NULL, 8},
 		{NULL, 0, NULL, 0}
 	};
 	int			c;
@@ -2452,6 +2456,10 @@ main(int argc, char **argv)
 			case 7:
 				manifest_checksums = pg_strdup(optarg);
 				break;
+			case 8:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 9011a19b4e..9fb2c5b3c7 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -44,6 +44,7 @@ static char *only_filenode = NULL;
 static bool do_sync = true;
 static bool verbose = false;
 static bool showprogress = false;
+static DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 typedef enum
 {
@@ -77,6 +78,7 @@ usage(void)
 	printf(_("  -f, --filenode=FILENODE  check only relation with specified filenode\n"));
 	printf(_("  -N, --no-sync            do not wait for changes to be written safely to disk\n"));
 	printf(_("  -P, --progress           show progress information\n"));
+	printf(_("      --sync-method=METHOD set method for syncing files to disk\n"));
 	printf(_("  -v, --verbose            output verbose messages\n"));
 	printf(_("  -V, --version            output version information, then exit\n"));
 	printf(_("  -?, --help               show this help, then exit\n"));
@@ -435,6 +437,7 @@ main(int argc, char *argv[])
 		{"no-sync", no_argument, NULL, 'N'},
 		{"progress", no_argument, NULL, 'P'},
 		{"verbose", no_argument, NULL, 'v'},
+		{"sync-method", required_argument, NULL, 1},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -493,6 +496,10 @@ main(int argc, char *argv[])
 			case 'v':
 				verbose = true;
 				break;
+			case 1:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -623,7 +630,7 @@ main(int argc, char *argv[])
 		if (do_sync)
 		{
 			pg_log_info("syncing data directory");
-			fsync_pgdata(DataDir, PG_VERSION_NUM);
+			fsync_pgdata(DataDir, PG_VERSION_NUM, sync_method);
 		}
 
 		pg_log_info("updating control file");
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index aba780ef4b..3a57cdd97d 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -24,6 +24,7 @@
 #define PG_BACKUP_H
 
 #include "common/compression.h"
+#include "common/file_utils.h"
 #include "fe_utils/simple_list.h"
 #include "libpq-fe.h"
 
@@ -307,7 +308,8 @@ extern Archive *OpenArchive(const char *FileSpec, const ArchiveFormat fmt);
 extern Archive *CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 							  const pg_compress_specification compression_spec,
 							  bool dosync, ArchiveMode mode,
-							  SetupWorkerPtrType setupDumpWorker);
+							  SetupWorkerPtrType setupDumpWorker,
+							  DataDirSyncMethod sync_method);
 
 /* The --list option */
 extern void PrintTOCSummary(Archive *AHX);
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index 39ebcfec32..4d83381d84 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -66,7 +66,8 @@ typedef struct _parallelReadyList
 static ArchiveHandle *_allocAH(const char *FileSpec, const ArchiveFormat fmt,
 							   const pg_compress_specification compression_spec,
 							   bool dosync, ArchiveMode mode,
-							   SetupWorkerPtrType setupWorkerPtr);
+							   SetupWorkerPtrType setupWorkerPtr,
+							   DataDirSyncMethod sync_method);
 static void _getObjectDescription(PQExpBuffer buf, const TocEntry *te);
 static void _printTocEntry(ArchiveHandle *AH, TocEntry *te, bool isData);
 static char *sanitize_line(const char *str, bool want_hyphen);
@@ -238,11 +239,12 @@ Archive *
 CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 			  const pg_compress_specification compression_spec,
 			  bool dosync, ArchiveMode mode,
-			  SetupWorkerPtrType setupDumpWorker)
+			  SetupWorkerPtrType setupDumpWorker,
+			  DataDirSyncMethod sync_method)
 
 {
 	ArchiveHandle *AH = _allocAH(FileSpec, fmt, compression_spec,
-								 dosync, mode, setupDumpWorker);
+								 dosync, mode, setupDumpWorker, sync_method);
 
 	return (Archive *) AH;
 }
@@ -257,7 +259,8 @@ OpenArchive(const char *FileSpec, const ArchiveFormat fmt)
 
 	compression_spec.algorithm = PG_COMPRESSION_NONE;
 	AH = _allocAH(FileSpec, fmt, compression_spec, true,
-				  archModeRead, setupRestoreWorker);
+				  archModeRead, setupRestoreWorker,
+				  DATA_DIR_SYNC_METHOD_FSYNC);
 
 	return (Archive *) AH;
 }
@@ -2233,7 +2236,7 @@ static ArchiveHandle *
 _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 		 const pg_compress_specification compression_spec,
 		 bool dosync, ArchiveMode mode,
-		 SetupWorkerPtrType setupWorkerPtr)
+		 SetupWorkerPtrType setupWorkerPtr, DataDirSyncMethod sync_method)
 {
 	ArchiveHandle *AH;
 	CompressFileHandle *CFH;
@@ -2287,6 +2290,7 @@ _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 	AH->mode = mode;
 	AH->compression_spec = compression_spec;
 	AH->dosync = dosync;
+	AH->sync_method = sync_method;
 
 	memset(&(AH->sqlparse), 0, sizeof(AH->sqlparse));
 
diff --git a/src/bin/pg_dump/pg_backup_archiver.h b/src/bin/pg_dump/pg_backup_archiver.h
index 18b38c17ab..b07673933d 100644
--- a/src/bin/pg_dump/pg_backup_archiver.h
+++ b/src/bin/pg_dump/pg_backup_archiver.h
@@ -312,6 +312,7 @@ struct _archiveHandle
 	pg_compress_specification compression_spec; /* Requested specification for
 												 * compression */
 	bool		dosync;			/* data requested to be synced on sight */
+	DataDirSyncMethod sync_method;
 	ArchiveMode mode;			/* File mode - r or w */
 	void	   *formatData;		/* Header data specific to file format */
 
diff --git a/src/bin/pg_dump/pg_backup_directory.c b/src/bin/pg_dump/pg_backup_directory.c
index 7f2ac7c7fd..6faa3a511f 100644
--- a/src/bin/pg_dump/pg_backup_directory.c
+++ b/src/bin/pg_dump/pg_backup_directory.c
@@ -613,7 +613,7 @@ _CloseArchive(ArchiveHandle *AH)
 		 * individually. Just recurse once through all the files generated.
 		 */
 		if (AH->dosync)
-			fsync_dir_recurse(ctx->directory);
+			fsync_dir_recurse(ctx->directory, AH->sync_method);
 	}
 	AH->FH = NULL;
 }
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 65f64c282d..dc4a28e81e 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -357,6 +357,7 @@ main(int argc, char **argv)
 	char	   *compression_algorithm_str = "none";
 	char	   *error_detail = NULL;
 	bool		user_compression_defined = false;
+	DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 	static DumpOptions dopt;
 
@@ -431,6 +432,7 @@ main(int argc, char **argv)
 		{"table-and-children", required_argument, NULL, 12},
 		{"exclude-table-and-children", required_argument, NULL, 13},
 		{"exclude-table-data-and-children", required_argument, NULL, 14},
+		{"sync-method", required_argument, NULL, 15},
 
 		{NULL, 0, NULL, 0}
 	};
@@ -657,6 +659,11 @@ main(int argc, char **argv)
 										  optarg);
 				break;
 
+			case 15:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit_nicely(1);
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -777,7 +784,7 @@ main(int argc, char **argv)
 
 	/* Open the output file */
 	fout = CreateArchive(filename, archiveFormat, compression_spec,
-						 dosync, archiveMode, setupDumpWorker);
+						 dosync, archiveMode, setupDumpWorker, sync_method);
 
 	/* Make dump options accessible right away */
 	SetArchiveOptions(fout, &dopt, NULL);
@@ -1068,6 +1075,7 @@ help(const char *progname)
 			 "                               compress as specified\n"));
 	printf(_("  --lock-wait-timeout=TIMEOUT  fail after waiting TIMEOUT for a table lock\n"));
 	printf(_("  --no-sync                    do not wait for changes to be written safely to disk\n"));
+	printf(_("  --sync-method=METHOD         set method for syncing files to disk\n"));
 	printf(_("  -?, --help                   show this help, then exit\n"));
 
 	printf(_("\nOptions controlling the output content:\n"));
diff --git a/src/bin/pg_rewind/file_ops.c b/src/bin/pg_rewind/file_ops.c
index 25996b4da4..451fb1856e 100644
--- a/src/bin/pg_rewind/file_ops.c
+++ b/src/bin/pg_rewind/file_ops.c
@@ -296,7 +296,7 @@ sync_target_dir(void)
 	if (!do_sync || dry_run)
 		return;
 
-	fsync_pgdata(datadir_target, PG_VERSION_NUM);
+	fsync_pgdata(datadir_target, PG_VERSION_NUM, sync_method);
 }
 
 
diff --git a/src/bin/pg_rewind/pg_rewind.c b/src/bin/pg_rewind/pg_rewind.c
index 7f69f02441..bfd44a284e 100644
--- a/src/bin/pg_rewind/pg_rewind.c
+++ b/src/bin/pg_rewind/pg_rewind.c
@@ -22,6 +22,7 @@
 #include "common/file_perm.h"
 #include "common/restricted_token.h"
 #include "common/string.h"
+#include "fe_utils/option_utils.h"
 #include "fe_utils/recovery_gen.h"
 #include "fe_utils/string_utils.h"
 #include "file_ops.h"
@@ -74,6 +75,7 @@ bool		showprogress = false;
 bool		dry_run = false;
 bool		do_sync = true;
 bool		restore_wal = false;
+DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 /* Target history */
 TimeLineHistoryEntry *targetHistory;
@@ -107,6 +109,7 @@ usage(const char *progname)
 			 "                                 file when running target cluster\n"));
 	printf(_("      --debug                    write a lot of debug messages\n"));
 	printf(_("      --no-ensure-shutdown       do not automatically fix unclean shutdown\n"));
+	printf(_("      --sync-method=METHOD       set method for syncing files to disk\n"));
 	printf(_("  -V, --version                  output version information, then exit\n"));
 	printf(_("  -?, --help                     show this help, then exit\n"));
 	printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
@@ -131,6 +134,7 @@ main(int argc, char **argv)
 		{"no-sync", no_argument, NULL, 'N'},
 		{"progress", no_argument, NULL, 'P'},
 		{"debug", no_argument, NULL, 3},
+		{"sync-method", required_argument, NULL, 6},
 		{NULL, 0, NULL, 0}
 	};
 	int			option_index;
@@ -218,6 +222,11 @@ main(int argc, char **argv)
 				config_file = pg_strdup(optarg);
 				break;
 
+			case 6:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_rewind/pg_rewind.h b/src/bin/pg_rewind/pg_rewind.h
index ef8bdc1fbb..05729adfef 100644
--- a/src/bin/pg_rewind/pg_rewind.h
+++ b/src/bin/pg_rewind/pg_rewind.h
@@ -13,6 +13,7 @@
 
 #include "access/timeline.h"
 #include "common/logging.h"
+#include "common/file_utils.h"
 #include "datapagemap.h"
 #include "libpq-fe.h"
 #include "storage/block.h"
@@ -24,6 +25,7 @@ extern bool showprogress;
 extern bool dry_run;
 extern bool do_sync;
 extern int	WalSegSz;
+extern DataDirSyncMethod sync_method;
 
 /* Target history */
 extern TimeLineHistoryEntry *targetHistory;
diff --git a/src/bin/pg_upgrade/option.c b/src/bin/pg_upgrade/option.c
index 640361009e..b9d900d0db 100644
--- a/src/bin/pg_upgrade/option.c
+++ b/src/bin/pg_upgrade/option.c
@@ -14,6 +14,7 @@
 #endif
 
 #include "common/string.h"
+#include "fe_utils/option_utils.h"
 #include "getopt_long.h"
 #include "pg_upgrade.h"
 #include "utils/pidfile.h"
@@ -57,12 +58,14 @@ parseCommandLine(int argc, char *argv[])
 		{"verbose", no_argument, NULL, 'v'},
 		{"clone", no_argument, NULL, 1},
 		{"copy", no_argument, NULL, 2},
+		{"sync-method", required_argument, NULL, 3},
 
 		{NULL, 0, NULL, 0}
 	};
 	int			option;			/* Command line option */
 	int			optindex = 0;	/* used by getopt_long */
 	int			os_user_effective_id;
+	DataDirSyncMethod unused;
 
 	user_opts.do_sync = true;
 	user_opts.transfer_mode = TRANSFER_MODE_COPY;
@@ -199,6 +202,12 @@ parseCommandLine(int argc, char *argv[])
 				user_opts.transfer_mode = TRANSFER_MODE_COPY;
 				break;
 
+			case 3:
+				if (!parse_sync_method(optarg, &unused))
+					exit(1);
+				user_opts.sync_method = pg_strdup(optarg);
+				break;
+
 			default:
 				fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
 						os_info.progname);
@@ -209,6 +218,9 @@ parseCommandLine(int argc, char *argv[])
 	if (optind < argc)
 		pg_fatal("too many command-line arguments (first is \"%s\")", argv[optind]);
 
+	if (!user_opts.sync_method)
+		user_opts.sync_method = pg_strdup("fsync");
+
 	if (log_opts.verbose)
 		pg_log(PG_REPORT, "Running in verbose mode");
 
@@ -289,6 +301,7 @@ usage(void)
 	printf(_("  -V, --version                 display version information, then exit\n"));
 	printf(_("  --clone                       clone instead of copying files to new cluster\n"));
 	printf(_("  --copy                        copy files to new cluster (default)\n"));
+	printf(_("  --sync-method=METHOD          set method for syncing files to disk\n"));
 	printf(_("  -?, --help                    show this help, then exit\n"));
 	printf(_("\n"
 			 "Before running pg_upgrade you must:\n"
diff --git a/src/bin/pg_upgrade/pg_upgrade.c b/src/bin/pg_upgrade/pg_upgrade.c
index 4562dafcff..96bfb67167 100644
--- a/src/bin/pg_upgrade/pg_upgrade.c
+++ b/src/bin/pg_upgrade/pg_upgrade.c
@@ -192,8 +192,10 @@ main(int argc, char **argv)
 	{
 		prep_status("Sync data directory to disk");
 		exec_prog(UTILITY_LOG_FILE, NULL, true, true,
-				  "\"%s/initdb\" --sync-only \"%s\"", new_cluster.bindir,
-				  new_cluster.pgdata);
+				  "\"%s/initdb\" --sync-only \"%s\" --sync-method %s",
+				  new_cluster.bindir,
+				  new_cluster.pgdata,
+				  user_opts.sync_method);
 		check_ok();
 	}
 
diff --git a/src/bin/pg_upgrade/pg_upgrade.h b/src/bin/pg_upgrade/pg_upgrade.h
index 7afa96716e..842f3b6cd3 100644
--- a/src/bin/pg_upgrade/pg_upgrade.h
+++ b/src/bin/pg_upgrade/pg_upgrade.h
@@ -304,6 +304,7 @@ typedef struct
 	transferMode transfer_mode; /* copy files or link them? */
 	int			jobs;			/* number of processes/threads to use */
 	char	   *socketdir;		/* directory to use for Unix sockets */
+	char	   *sync_method;
 } UserOpts;
 
 typedef struct
diff --git a/src/common/file_utils.c b/src/common/file_utils.c
index 74833c4acb..c977c990ad 100644
--- a/src/common/file_utils.c
+++ b/src/common/file_utils.c
@@ -51,6 +51,31 @@ static void walkdir(const char *path,
 					int (*action) (const char *fname, bool isdir),
 					bool process_symlinks);
 
+#ifdef HAVE_SYNCFS
+static void
+do_syncfs(const char *path)
+{
+	int			fd;
+
+	fd = open(path, O_RDONLY, 0);
+
+	if (fd < 0)
+	{
+		pg_log_error("could not open file \"%s\": %m", path);
+		return;
+	}
+
+	if (syncfs(fd) < 0)
+	{
+		pg_log_error("could not synchronize file system for file \"%s\": %m", path);
+		(void) close(fd);
+		exit(EXIT_FAILURE);
+	}
+
+	(void) close(fd);
+}
+#endif
+
 /*
  * Issue fsync recursively on PGDATA and all its contents.
  *
@@ -63,7 +88,8 @@ static void walkdir(const char *path,
  */
 void
 fsync_pgdata(const char *pg_data,
-			 int serverVersion)
+			 int serverVersion,
+			 DataDirSyncMethod sync_method)
 {
 	bool		xlog_is_symlink;
 	char		pg_wal[MAXPGPATH];
@@ -89,6 +115,55 @@ fsync_pgdata(const char *pg_data,
 			xlog_is_symlink = true;
 	}
 
+#ifdef HAVE_SYNCFS
+	if (sync_method == DATA_DIR_SYNC_METHOD_SYNCFS)
+	{
+		DIR		   *dir;
+		struct dirent *de;
+
+		/*
+		 * On Linux, we don't have to open every single file one by one.  We
+		 * can use syncfs() to sync whole filesystems.  We only expect
+		 * filesystem boundaries to exist where we tolerate symlinks, namely
+		 * pg_wal and the tablespaces, so we call syncfs() for each of those
+		 * directories.
+		 */
+
+		/* Sync the top level pgdata directory. */
+		do_syncfs(pg_data);
+
+		/* If any tablespaces are configured, sync each of those. */
+		dir = opendir(pg_tblspc);
+		if (dir == NULL)
+			pg_log_error("could not open directory \"%s\": %m", pg_tblspc);
+		else
+		{
+			while (errno = 0, (de = readdir(dir)) != NULL)
+			{
+				char		subpath[MAXPGPATH * 2];
+
+				if (strcmp(de->d_name, ".") == 0 ||
+					strcmp(de->d_name, "..") == 0)
+					continue;
+
+				snprintf(subpath, sizeof(subpath), "%s/%s", pg_tblspc, de->d_name);
+				do_syncfs(subpath);
+			}
+
+			if (errno)
+				pg_log_error("could not read directory \"%s\": %m", pg_tblspc);
+
+			(void) closedir(dir);
+		}
+
+		/* If pg_wal is a symlink, process that too. */
+		if (xlog_is_symlink)
+			do_syncfs(pg_wal);
+
+		return;
+	}
+#endif							/* HAVE_SYNCFS */
+
 	/*
 	 * If possible, hint to the kernel that we're soon going to fsync the data
 	 * directory and its contents.
@@ -121,8 +196,20 @@ fsync_pgdata(const char *pg_data,
  * This is a convenient wrapper on top of walkdir().
  */
 void
-fsync_dir_recurse(const char *dir)
+fsync_dir_recurse(const char *dir, DataDirSyncMethod sync_method)
 {
+#ifdef HAVE_SYNCFS
+	if (sync_method == DATA_DIR_SYNC_METHOD_SYNCFS)
+	{
+		/*
+		 * On Linux, we don't have to open every single file one by one.  We
+		 * can use syncfs() to sync the whole filesystem.
+		 */
+		do_syncfs(dir);
+		return;
+	}
+#endif							/* HAVE_SYNCFS */
+
 	/*
 	 * If possible, hint to the kernel that we're soon going to fsync the data
 	 * directory and its contents.
diff --git a/src/fe_utils/option_utils.c b/src/fe_utils/option_utils.c
index 763c991015..36ac689964 100644
--- a/src/fe_utils/option_utils.c
+++ b/src/fe_utils/option_utils.c
@@ -82,3 +82,27 @@ option_parse_int(const char *optarg, const char *optname,
 		*result = val;
 	return true;
 }
+
+bool
+parse_sync_method(const char *optarg, DataDirSyncMethod *sync_method)
+{
+	if (strcmp(optarg, "fsync") == 0)
+		*sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
+	else if (strcmp(optarg, "syncfs") == 0)
+	{
+#ifdef HAVE_SYNCFS
+		*sync_method = DATA_DIR_SYNC_METHOD_SYNCFS;
+#else
+		pg_log_error("this build does not support sync method \"%s\"",
+					 "syncfs");
+		return false;
+#endif
+	}
+	else
+	{
+		pg_log_error("unrecognized sync method: %s", optarg);
+		return false;
+	}
+
+	return true;
+}
diff --git a/src/include/common/file_utils.h b/src/include/common/file_utils.h
index dd1532bcb0..09d1e5d561 100644
--- a/src/include/common/file_utils.h
+++ b/src/include/common/file_utils.h
@@ -26,10 +26,17 @@ typedef enum PGFileType
 
 struct iovec;					/* avoid including port/pg_iovec.h here */
 
+typedef enum DataDirSyncMethod
+{
+	DATA_DIR_SYNC_METHOD_FSYNC,
+	DATA_DIR_SYNC_METHOD_SYNCFS
+} DataDirSyncMethod;
+
 #ifdef FRONTEND
 extern int	fsync_fname(const char *fname, bool isdir);
-extern void fsync_pgdata(const char *pg_data, int serverVersion);
-extern void fsync_dir_recurse(const char *dir);
+extern void fsync_pgdata(const char *pg_data, int serverVersion,
+						 DataDirSyncMethod sync_method);
+extern void fsync_dir_recurse(const char *dir, DataDirSyncMethod sync_method);
 extern int	durable_rename(const char *oldfile, const char *newfile);
 extern int	fsync_parent_path(const char *fname);
 #endif
diff --git a/src/include/fe_utils/option_utils.h b/src/include/fe_utils/option_utils.h
index b7b0654cee..6f3a965916 100644
--- a/src/include/fe_utils/option_utils.h
+++ b/src/include/fe_utils/option_utils.h
@@ -14,6 +14,8 @@
 
 #include "postgres_fe.h"
 
+#include "common/file_utils.h"
+
 typedef void (*help_handler) (const char *progname);
 
 extern void handle_help_version_opts(int argc, char *argv[],
@@ -22,5 +24,7 @@ extern void handle_help_version_opts(int argc, char *argv[],
 extern bool option_parse_int(const char *optarg, const char *optname,
 							 int min_range, int max_range,
 							 int *result);
+extern bool parse_sync_method(const char *optarg,
+							  DataDirSyncMethod *sync_method);
 
 #endif							/* OPTION_UTILS_H */
diff --git a/src/include/storage/fd.h b/src/include/storage/fd.h
index aea30c0622..d9d5d9da5f 100644
--- a/src/include/storage/fd.h
+++ b/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;
 
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 49a33c0387..fe571c6265 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -545,6 +545,7 @@ DR_printtup
 DR_sqlfunction
 DR_transientrel
 DWORD
+DataDirSyncMethod
 DataDumperPtr
 DataPageDeleteStack
 DatabaseInfo
-- 
2.25.1

From f5ecb3c8b5d397c94a9f8ab9a053b3a0cfd7f854 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Mon, 21 Aug 2023 19:05:14 -0700
Subject: [PATCH v7 1/2] move PG_TEMP_FILE* macros to file_utils.h

---
 src/backend/backup/basebackup.c     |  2 +-
 src/backend/postmaster/postmaster.c |  1 +
 src/backend/storage/file/fileset.c  |  1 +
 src/bin/pg_checksums/pg_checksums.c | 10 ----------
 src/bin/pg_rewind/filemap.c         |  2 +-
 src/include/common/file_utils.h     |  4 ++++
 src/include/storage/fd.h            |  4 ----
 7 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/src/backend/backup/basebackup.c b/src/backend/backup/basebackup.c
index 45be21131c..5d66014499 100644
--- a/src/backend/backup/basebackup.c
+++ b/src/backend/backup/basebackup.c
@@ -25,6 +25,7 @@
 #include "commands/defrem.h"
 #include "common/compression.h"
 #include "common/file_perm.h"
+#include "common/file_utils.h"
 #include "lib/stringinfo.h"
 #include "miscadmin.h"
 #include "nodes/pg_list.h"
@@ -37,7 +38,6 @@
 #include "storage/bufpage.h"
 #include "storage/checksum.h"
 #include "storage/dsm_impl.h"
-#include "storage/fd.h"
 #include "storage/ipc.h"
 #include "storage/reinit.h"
 #include "utils/builtins.h"
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index d7bfb28ff3..54e9bfb8c4 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -94,6 +94,7 @@
 #include "access/xlogrecovery.h"
 #include "catalog/pg_control.h"
 #include "common/file_perm.h"
+#include "common/file_utils.h"
 #include "common/ip.h"
 #include "common/pg_prng.h"
 #include "common/string.h"
diff --git a/src/backend/storage/file/fileset.c b/src/backend/storage/file/fileset.c
index e9951b0269..84cae32548 100644
--- a/src/backend/storage/file/fileset.c
+++ b/src/backend/storage/file/fileset.c
@@ -25,6 +25,7 @@
 
 #include "catalog/pg_tablespace.h"
 #include "commands/tablespace.h"
+#include "common/file_utils.h"
 #include "common/hashfn.h"
 #include "miscadmin.h"
 #include "storage/ipc.h"
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 19eb67e485..9011a19b4e 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -52,16 +52,6 @@ typedef enum
 	PG_MODE_ENABLE
 } PgChecksumMode;
 
-/*
- * Filename components.
- *
- * XXX: fd.h is not declared here as frontend side code is not able to
- * interact with the backend-side definitions for the various fsync
- * wrappers.
- */
-#define PG_TEMP_FILES_DIR "pgsql_tmp"
-#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
-
 static PgChecksumMode mode = PG_MODE_CHECK;
 
 static const char *progname;
diff --git a/src/bin/pg_rewind/filemap.c b/src/bin/pg_rewind/filemap.c
index bd5c598e20..58280d9abc 100644
--- a/src/bin/pg_rewind/filemap.c
+++ b/src/bin/pg_rewind/filemap.c
@@ -27,12 +27,12 @@
 #include <unistd.h>
 
 #include "catalog/pg_tablespace_d.h"
+#include "common/file_utils.h"
 #include "common/hashfn.h"
 #include "common/string.h"
 #include "datapagemap.h"
 #include "filemap.h"
 #include "pg_rewind.h"
-#include "storage/fd.h"
 
 /*
  * Define a hash table which we can use to store information about the files
diff --git a/src/include/common/file_utils.h b/src/include/common/file_utils.h
index b7efa1226d..dd1532bcb0 100644
--- a/src/include/common/file_utils.h
+++ b/src/include/common/file_utils.h
@@ -46,4 +46,8 @@ extern ssize_t pg_pwritev_with_retry(int fd,
 
 extern ssize_t pg_pwrite_zeros(int fd, size_t size, off_t offset);
 
+/* Filename components */
+#define PG_TEMP_FILES_DIR "pgsql_tmp"
+#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
+
 #endif							/* FILE_UTILS_H */
diff --git a/src/include/storage/fd.h b/src/include/storage/fd.h
index 6791a406fc..aea30c0622 100644
--- a/src/include/storage/fd.h
+++ b/src/include/storage/fd.h
@@ -195,8 +195,4 @@ extern int	durable_unlink(const char *fname, int elevel);
 extern void SyncDataDirectory(void);
 extern int	data_sync_elevel(int elevel);
 
-/* Filename components */
-#define PG_TEMP_FILES_DIR "pgsql_tmp"
-#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
-
 #endif							/* FD_H */
-- 
2.25.1

From 77f0843a9a4d795cc82693990bede3ec2cbc3824 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Fri, 28 Jul 2023 15:56:24 -0700
Subject: [PATCH v7 2/2] allow syncfs in frontend utilities

---
 doc/src/sgml/config.sgml              |  12 +-
 doc/src/sgml/filelist.sgml            |   1 +
 doc/src/sgml/postgres.sgml            |   1 +
 doc/src/sgml/ref/initdb.sgml          |  22 ++++
 doc/src/sgml/ref/pg_basebackup.sgml   |  25 ++++
 doc/src/sgml/ref/pg_checksums.sgml    |  22 ++++
 doc/src/sgml/ref/pg_dump.sgml         |  21 ++++
 doc/src/sgml/ref/pg_rewind.sgml       |  22 ++++
 doc/src/sgml/ref/pgupgrade.sgml       |  23 ++++
 doc/src/sgml/syncfs.sgml              |  36 ++++++
 src/backend/storage/file/fd.c         |   4 +-
 src/backend/utils/misc/guc_tables.c   |   7 +-
 src/bin/initdb/initdb.c               |  11 +-
 src/bin/pg_basebackup/pg_basebackup.c |  12 +-
 src/bin/pg_checksums/pg_checksums.c   |   9 +-
 src/bin/pg_dump/pg_backup.h           |   4 +-
 src/bin/pg_dump/pg_backup_archiver.c  |  14 ++-
 src/bin/pg_dump/pg_backup_archiver.h  |   1 +
 src/bin/pg_dump/pg_backup_directory.c |   2 +-
 src/bin/pg_dump/pg_dump.c             |  10 +-
 src/bin/pg_rewind/file_ops.c          |   2 +-
 src/bin/pg_rewind/pg_rewind.c         |   9 ++
 src/bin/pg_rewind/pg_rewind.h         |   2 +
 src/bin/pg_upgrade/option.c           |  13 ++
 src/bin/pg_upgrade/pg_upgrade.c       |   6 +-
 src/bin/pg_upgrade/pg_upgrade.h       |   1 +
 src/common/file_utils.c               | 170 +++++++++++++++++++++-----
 src/fe_utils/option_utils.c           |  24 ++++
 src/include/common/file_utils.h       |  11 +-
 src/include/fe_utils/option_utils.h   |   4 +
 src/include/storage/fd.h              |   6 -
 src/tools/pgindent/typedefs.list      |   1 +
 32 files changed, 441 insertions(+), 67 deletions(-)
 create mode 100644 doc/src/sgml/syncfs.sgml

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 694d667bf9..2c7d9f1262 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -10580,15 +10580,9 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
         On Linux, <literal>syncfs</literal> may be used instead, to ask the
         operating system to synchronize the whole file systems that contain the
         data directory, the WAL files and each tablespace (but not any other
-        file systems that may be reachable through symbolic links).  This may
-        be a lot faster than the <literal>fsync</literal> setting, because it
-        doesn't need to open each file one by one.  On the other hand, it may
-        be slower if a file system is shared by other applications that
-        modify a lot of files, since those files will also be written to disk.
-        Furthermore, on versions of Linux before 5.8, I/O errors encountered
-        while writing data to disk may not be reported to
-        <productname>PostgreSQL</productname>, and relevant error messages may
-        appear only in kernel logs.
+        file systems that may be reachable through symbolic links).  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
        </para>
        <para>
         This parameter can only be set in the
diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
index 63b0fc2a46..df5d7c3025 100644
--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -184,6 +184,7 @@
 <!ENTITY acronyms   SYSTEM "acronyms.sgml">
 <!ENTITY glossary   SYSTEM "glossary.sgml">
 <!ENTITY color      SYSTEM "color.sgml">
+<!ENTITY syncfs     SYSTEM "syncfs.sgml">
 
 <!ENTITY features-supported   SYSTEM "features-supported.sgml">
 <!ENTITY features-unsupported SYSTEM "features-unsupported.sgml">
diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml
index 2e271862fc..f629524be0 100644
--- a/doc/src/sgml/postgres.sgml
+++ b/doc/src/sgml/postgres.sgml
@@ -294,6 +294,7 @@ break is not needed in a wider output rendering.
   &acronyms;
   &glossary;
   &color;
+  &syncfs;
   &obsolete;
 
  </part>
diff --git a/doc/src/sgml/ref/initdb.sgml b/doc/src/sgml/ref/initdb.sgml
index 22f1011781..8a09c5c438 100644
--- a/doc/src/sgml/ref/initdb.sgml
+++ b/doc/src/sgml/ref/initdb.sgml
@@ -365,6 +365,28 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry id="app-initdb-option-sync-method">
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>initdb</command> will recursively open and synchronize all
+        files in the data directory.  The search for files will follow symbolic
+        links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="app-initdb-option-sync-only">
       <term><option>-S</option></term>
       <term><option>--sync-only</option></term>
diff --git a/doc/src/sgml/ref/pg_basebackup.sgml b/doc/src/sgml/ref/pg_basebackup.sgml
index 79d3e657c3..d2b8ddd200 100644
--- a/doc/src/sgml/ref/pg_basebackup.sgml
+++ b/doc/src/sgml/ref/pg_basebackup.sgml
@@ -594,6 +594,31 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_basebackup</command> will recursively open and synchronize
+        all files in the backup directory.  When the plain format is used, the
+        search for files will follow symbolic links for the WAL directory and
+        each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file system that contains the
+        backup directory.  When the plain format is used,
+        <command>pg_basebackup</command> will also synchronize the file systems
+        that contain the WAL files and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-v</option></term>
       <term><option>--verbose</option></term>
diff --git a/doc/src/sgml/ref/pg_checksums.sgml b/doc/src/sgml/ref/pg_checksums.sgml
index a3d0b0f0a3..7b44ba71cf 100644
--- a/doc/src/sgml/ref/pg_checksums.sgml
+++ b/doc/src/sgml/ref/pg_checksums.sgml
@@ -139,6 +139,28 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_checksums</command> will recursively open and synchronize
+        all files in the data directory.  The search for files will follow
+        symbolic links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-v</option></term>
       <term><option>--verbose</option></term>
diff --git a/doc/src/sgml/ref/pg_dump.sgml b/doc/src/sgml/ref/pg_dump.sgml
index a3cf0608f5..c1e2220b3c 100644
--- a/doc/src/sgml/ref/pg_dump.sgml
+++ b/doc/src/sgml/ref/pg_dump.sgml
@@ -1179,6 +1179,27 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_dump --format=directory</command> will recursively open and
+        synchronize all files in the archive directory.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file system that contains the
+        archive directory.  See <xref linkend="syncfs"/> for more information
+        about using <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used or
+        <option>--format</option> is not set to <literal>directory</literal>.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>--table-and-children=<replaceable class="parameter">pattern</replaceable></option></term>
       <listitem>
diff --git a/doc/src/sgml/ref/pg_rewind.sgml b/doc/src/sgml/ref/pg_rewind.sgml
index 15cddd086b..80dff16168 100644
--- a/doc/src/sgml/ref/pg_rewind.sgml
+++ b/doc/src/sgml/ref/pg_rewind.sgml
@@ -284,6 +284,28 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_rewind</command> will recursively open and synchronize all
+        files in the data directory.  The search for files will follow symbolic
+        links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-V</option></term>
       <term><option>--version</option></term>
diff --git a/doc/src/sgml/ref/pgupgrade.sgml b/doc/src/sgml/ref/pgupgrade.sgml
index 7816b4c685..6c033485ea 100644
--- a/doc/src/sgml/ref/pgupgrade.sgml
+++ b/doc/src/sgml/ref/pgupgrade.sgml
@@ -190,6 +190,29 @@ PostgreSQL documentation
       variable <envar>PGSOCKETDIR</envar></para></listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_upgrade</command> will recursively open and synchronize all
+        files in the upgraded cluster's data directory.  The search for files
+        will follow symbolic links for the WAL directory and each configured
+        tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        upgrade cluster's data directory, its WAL files, and each tablespace.
+        See <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-U</option> <replaceable>username</replaceable></term>
       <term><option>--username=</option><replaceable>username</replaceable></term>
diff --git a/doc/src/sgml/syncfs.sgml b/doc/src/sgml/syncfs.sgml
new file mode 100644
index 0000000000..00457d2457
--- /dev/null
+++ b/doc/src/sgml/syncfs.sgml
@@ -0,0 +1,36 @@
+<!-- doc/src/sgml/syncfs.sgml -->
+
+<appendix id="syncfs">
+ <title><function>syncfs()</function> Caveats</title>
+
+ <indexterm zone="syncfs">
+  <primary>syncfs</primary>
+ </indexterm>
+
+ <para>
+  On Linux <function>syncfs()</function> may be specified for some
+  configuration parameters (e.g.,
+  <xref linkend="guc-recovery-init-sync-method"/>), server applications (e.g.,
+  <application>pg_upgrade</application>), and client applications (e.g.,
+  <application>pg_basebackup</application>) that involve synchronizing many
+  files to disk.  <function>syncfs()</function> is advantageous in many cases,
+  but there are some trade-offs to keep in mind.
+ </para>
+
+ <para>
+  Since <function>syncfs()</function> instructs the operating system to
+  synchronize a whole file system, it typically requires many fewer system
+  calls than using <function>fsync()</function> to synchronize each file one by
+  one.  Therefore, using <function>syncfs()</function> may be a lot faster than
+  using <function>fsync()</function>.  However, it may be slower if a file
+  system is shared by other applications that modify a lot of files, since
+  those files will also be written to disk.
+ </para>
+
+ <para>
+  Furthermore, on versions of Linux before 5.8, I/O errors encountered while
+  writing data to disk may not be reported to the calling program, and relevant
+  error messages may appear only in kernel logs.
+ </para>
+
+</appendix>
diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index b490a76ba7..3fed475c38 100644
--- a/src/backend/storage/file/fd.c
+++ b/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;
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index e565a3092f..5abebe9a9c 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/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}
 };
@@ -4964,7 +4965,7 @@ 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
 	},
 
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index 905b979947..543927b8b4 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -165,6 +165,7 @@ static bool show_setting = false;
 static bool data_checksums = false;
 static char *xlog_dir = NULL;
 static int	wal_segment_size_mb = (DEFAULT_XLOG_SEG_SIZE) / (1024 * 1024);
+static DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 
 /* internal vars */
@@ -2466,6 +2467,7 @@ usage(const char *progname)
 	printf(_("  -N, --no-sync             do not wait for changes to be written safely to disk\n"));
 	printf(_("      --no-instructions     do not print instructions for next steps\n"));
 	printf(_("  -s, --show                show internal settings\n"));
+	printf(_("      --sync-method=METHOD  set method for syncing files to disk\n"));
 	printf(_("  -S, --sync-only           only sync database files to disk, then exit\n"));
 	printf(_("\nOther options:\n"));
 	printf(_("  -V, --version             output version information, then exit\n"));
@@ -3106,6 +3108,7 @@ main(int argc, char *argv[])
 		{"locale-provider", required_argument, NULL, 15},
 		{"icu-locale", required_argument, NULL, 16},
 		{"icu-rules", required_argument, NULL, 17},
+		{"sync-method", required_argument, NULL, 18},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -3286,6 +3289,10 @@ main(int argc, char *argv[])
 			case 17:
 				icu_rules = pg_strdup(optarg);
 				break;
+			case 18:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -3333,7 +3340,7 @@ main(int argc, char *argv[])
 
 		fputs(_("syncing data to disk ... "), stdout);
 		fflush(stdout);
-		fsync_pgdata(pg_data, PG_VERSION_NUM);
+		fsync_pgdata(pg_data, PG_VERSION_NUM, sync_method);
 		check_ok();
 		return 0;
 	}
@@ -3396,7 +3403,7 @@ main(int argc, char *argv[])
 	{
 		fputs(_("syncing data to disk ... "), stdout);
 		fflush(stdout);
-		fsync_pgdata(pg_data, PG_VERSION_NUM);
+		fsync_pgdata(pg_data, PG_VERSION_NUM, sync_method);
 		check_ok();
 	}
 	else
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 1dc8efe0cb..977c793a67 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -148,6 +148,7 @@ static bool verify_checksums = true;
 static bool manifest = true;
 static bool manifest_force_encode = false;
 static char *manifest_checksums = NULL;
+static DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 static bool success = false;
 static bool made_new_pgdata = false;
@@ -424,6 +425,8 @@ usage(void)
 	printf(_("      --no-slot          prevent creation of temporary replication slot\n"));
 	printf(_("      --no-verify-checksums\n"
 			 "                         do not verify checksums\n"));
+	printf(_("      --sync-method=METHOD\n"
+			 "                         set method for syncing files to disk\n"));
 	printf(_("  -?, --help             show this help, then exit\n"));
 	printf(_("\nConnection options:\n"));
 	printf(_("  -d, --dbname=CONNSTR   connection string\n"));
@@ -2199,11 +2202,11 @@ BaseBackup(char *compression_algorithm, char *compression_detail,
 		if (format == 't')
 		{
 			if (strcmp(basedir, "-") != 0)
-				(void) fsync_dir_recurse(basedir);
+				(void) fsync_dir_recurse(basedir, sync_method);
 		}
 		else
 		{
-			(void) fsync_pgdata(basedir, serverVersion);
+			(void) fsync_pgdata(basedir, serverVersion, sync_method);
 		}
 	}
 
@@ -2281,6 +2284,7 @@ main(int argc, char **argv)
 		{"no-manifest", no_argument, NULL, 5},
 		{"manifest-force-encode", no_argument, NULL, 6},
 		{"manifest-checksums", required_argument, NULL, 7},
+		{"sync-method", required_argument, NULL, 8},
 		{NULL, 0, NULL, 0}
 	};
 	int			c;
@@ -2452,6 +2456,10 @@ main(int argc, char **argv)
 			case 7:
 				manifest_checksums = pg_strdup(optarg);
 				break;
+			case 8:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 9011a19b4e..9fb2c5b3c7 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -44,6 +44,7 @@ static char *only_filenode = NULL;
 static bool do_sync = true;
 static bool verbose = false;
 static bool showprogress = false;
+static DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 typedef enum
 {
@@ -77,6 +78,7 @@ usage(void)
 	printf(_("  -f, --filenode=FILENODE  check only relation with specified filenode\n"));
 	printf(_("  -N, --no-sync            do not wait for changes to be written safely to disk\n"));
 	printf(_("  -P, --progress           show progress information\n"));
+	printf(_("      --sync-method=METHOD set method for syncing files to disk\n"));
 	printf(_("  -v, --verbose            output verbose messages\n"));
 	printf(_("  -V, --version            output version information, then exit\n"));
 	printf(_("  -?, --help               show this help, then exit\n"));
@@ -435,6 +437,7 @@ main(int argc, char *argv[])
 		{"no-sync", no_argument, NULL, 'N'},
 		{"progress", no_argument, NULL, 'P'},
 		{"verbose", no_argument, NULL, 'v'},
+		{"sync-method", required_argument, NULL, 1},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -493,6 +496,10 @@ main(int argc, char *argv[])
 			case 'v':
 				verbose = true;
 				break;
+			case 1:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -623,7 +630,7 @@ main(int argc, char *argv[])
 		if (do_sync)
 		{
 			pg_log_info("syncing data directory");
-			fsync_pgdata(DataDir, PG_VERSION_NUM);
+			fsync_pgdata(DataDir, PG_VERSION_NUM, sync_method);
 		}
 
 		pg_log_info("updating control file");
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index aba780ef4b..3a57cdd97d 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -24,6 +24,7 @@
 #define PG_BACKUP_H
 
 #include "common/compression.h"
+#include "common/file_utils.h"
 #include "fe_utils/simple_list.h"
 #include "libpq-fe.h"
 
@@ -307,7 +308,8 @@ extern Archive *OpenArchive(const char *FileSpec, const ArchiveFormat fmt);
 extern Archive *CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 							  const pg_compress_specification compression_spec,
 							  bool dosync, ArchiveMode mode,
-							  SetupWorkerPtrType setupDumpWorker);
+							  SetupWorkerPtrType setupDumpWorker,
+							  DataDirSyncMethod sync_method);
 
 /* The --list option */
 extern void PrintTOCSummary(Archive *AHX);
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index 39ebcfec32..4d83381d84 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -66,7 +66,8 @@ typedef struct _parallelReadyList
 static ArchiveHandle *_allocAH(const char *FileSpec, const ArchiveFormat fmt,
 							   const pg_compress_specification compression_spec,
 							   bool dosync, ArchiveMode mode,
-							   SetupWorkerPtrType setupWorkerPtr);
+							   SetupWorkerPtrType setupWorkerPtr,
+							   DataDirSyncMethod sync_method);
 static void _getObjectDescription(PQExpBuffer buf, const TocEntry *te);
 static void _printTocEntry(ArchiveHandle *AH, TocEntry *te, bool isData);
 static char *sanitize_line(const char *str, bool want_hyphen);
@@ -238,11 +239,12 @@ Archive *
 CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 			  const pg_compress_specification compression_spec,
 			  bool dosync, ArchiveMode mode,
-			  SetupWorkerPtrType setupDumpWorker)
+			  SetupWorkerPtrType setupDumpWorker,
+			  DataDirSyncMethod sync_method)
 
 {
 	ArchiveHandle *AH = _allocAH(FileSpec, fmt, compression_spec,
-								 dosync, mode, setupDumpWorker);
+								 dosync, mode, setupDumpWorker, sync_method);
 
 	return (Archive *) AH;
 }
@@ -257,7 +259,8 @@ OpenArchive(const char *FileSpec, const ArchiveFormat fmt)
 
 	compression_spec.algorithm = PG_COMPRESSION_NONE;
 	AH = _allocAH(FileSpec, fmt, compression_spec, true,
-				  archModeRead, setupRestoreWorker);
+				  archModeRead, setupRestoreWorker,
+				  DATA_DIR_SYNC_METHOD_FSYNC);
 
 	return (Archive *) AH;
 }
@@ -2233,7 +2236,7 @@ static ArchiveHandle *
 _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 		 const pg_compress_specification compression_spec,
 		 bool dosync, ArchiveMode mode,
-		 SetupWorkerPtrType setupWorkerPtr)
+		 SetupWorkerPtrType setupWorkerPtr, DataDirSyncMethod sync_method)
 {
 	ArchiveHandle *AH;
 	CompressFileHandle *CFH;
@@ -2287,6 +2290,7 @@ _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 	AH->mode = mode;
 	AH->compression_spec = compression_spec;
 	AH->dosync = dosync;
+	AH->sync_method = sync_method;
 
 	memset(&(AH->sqlparse), 0, sizeof(AH->sqlparse));
 
diff --git a/src/bin/pg_dump/pg_backup_archiver.h b/src/bin/pg_dump/pg_backup_archiver.h
index 18b38c17ab..b07673933d 100644
--- a/src/bin/pg_dump/pg_backup_archiver.h
+++ b/src/bin/pg_dump/pg_backup_archiver.h
@@ -312,6 +312,7 @@ struct _archiveHandle
 	pg_compress_specification compression_spec; /* Requested specification for
 												 * compression */
 	bool		dosync;			/* data requested to be synced on sight */
+	DataDirSyncMethod sync_method;
 	ArchiveMode mode;			/* File mode - r or w */
 	void	   *formatData;		/* Header data specific to file format */
 
diff --git a/src/bin/pg_dump/pg_backup_directory.c b/src/bin/pg_dump/pg_backup_directory.c
index 7f2ac7c7fd..6faa3a511f 100644
--- a/src/bin/pg_dump/pg_backup_directory.c
+++ b/src/bin/pg_dump/pg_backup_directory.c
@@ -613,7 +613,7 @@ _CloseArchive(ArchiveHandle *AH)
 		 * individually. Just recurse once through all the files generated.
 		 */
 		if (AH->dosync)
-			fsync_dir_recurse(ctx->directory);
+			fsync_dir_recurse(ctx->directory, AH->sync_method);
 	}
 	AH->FH = NULL;
 }
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 65f64c282d..dc4a28e81e 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -357,6 +357,7 @@ main(int argc, char **argv)
 	char	   *compression_algorithm_str = "none";
 	char	   *error_detail = NULL;
 	bool		user_compression_defined = false;
+	DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 	static DumpOptions dopt;
 
@@ -431,6 +432,7 @@ main(int argc, char **argv)
 		{"table-and-children", required_argument, NULL, 12},
 		{"exclude-table-and-children", required_argument, NULL, 13},
 		{"exclude-table-data-and-children", required_argument, NULL, 14},
+		{"sync-method", required_argument, NULL, 15},
 
 		{NULL, 0, NULL, 0}
 	};
@@ -657,6 +659,11 @@ main(int argc, char **argv)
 										  optarg);
 				break;
 
+			case 15:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit_nicely(1);
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -777,7 +784,7 @@ main(int argc, char **argv)
 
 	/* Open the output file */
 	fout = CreateArchive(filename, archiveFormat, compression_spec,
-						 dosync, archiveMode, setupDumpWorker);
+						 dosync, archiveMode, setupDumpWorker, sync_method);
 
 	/* Make dump options accessible right away */
 	SetArchiveOptions(fout, &dopt, NULL);
@@ -1068,6 +1075,7 @@ help(const char *progname)
 			 "                               compress as specified\n"));
 	printf(_("  --lock-wait-timeout=TIMEOUT  fail after waiting TIMEOUT for a table lock\n"));
 	printf(_("  --no-sync                    do not wait for changes to be written safely to disk\n"));
+	printf(_("  --sync-method=METHOD         set method for syncing files to disk\n"));
 	printf(_("  -?, --help                   show this help, then exit\n"));
 
 	printf(_("\nOptions controlling the output content:\n"));
diff --git a/src/bin/pg_rewind/file_ops.c b/src/bin/pg_rewind/file_ops.c
index 25996b4da4..451fb1856e 100644
--- a/src/bin/pg_rewind/file_ops.c
+++ b/src/bin/pg_rewind/file_ops.c
@@ -296,7 +296,7 @@ sync_target_dir(void)
 	if (!do_sync || dry_run)
 		return;
 
-	fsync_pgdata(datadir_target, PG_VERSION_NUM);
+	fsync_pgdata(datadir_target, PG_VERSION_NUM, sync_method);
 }
 
 
diff --git a/src/bin/pg_rewind/pg_rewind.c b/src/bin/pg_rewind/pg_rewind.c
index 7f69f02441..bfd44a284e 100644
--- a/src/bin/pg_rewind/pg_rewind.c
+++ b/src/bin/pg_rewind/pg_rewind.c
@@ -22,6 +22,7 @@
 #include "common/file_perm.h"
 #include "common/restricted_token.h"
 #include "common/string.h"
+#include "fe_utils/option_utils.h"
 #include "fe_utils/recovery_gen.h"
 #include "fe_utils/string_utils.h"
 #include "file_ops.h"
@@ -74,6 +75,7 @@ bool		showprogress = false;
 bool		dry_run = false;
 bool		do_sync = true;
 bool		restore_wal = false;
+DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 /* Target history */
 TimeLineHistoryEntry *targetHistory;
@@ -107,6 +109,7 @@ usage(const char *progname)
 			 "                                 file when running target cluster\n"));
 	printf(_("      --debug                    write a lot of debug messages\n"));
 	printf(_("      --no-ensure-shutdown       do not automatically fix unclean shutdown\n"));
+	printf(_("      --sync-method=METHOD       set method for syncing files to disk\n"));
 	printf(_("  -V, --version                  output version information, then exit\n"));
 	printf(_("  -?, --help                     show this help, then exit\n"));
 	printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
@@ -131,6 +134,7 @@ main(int argc, char **argv)
 		{"no-sync", no_argument, NULL, 'N'},
 		{"progress", no_argument, NULL, 'P'},
 		{"debug", no_argument, NULL, 3},
+		{"sync-method", required_argument, NULL, 6},
 		{NULL, 0, NULL, 0}
 	};
 	int			option_index;
@@ -218,6 +222,11 @@ main(int argc, char **argv)
 				config_file = pg_strdup(optarg);
 				break;
 
+			case 6:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_rewind/pg_rewind.h b/src/bin/pg_rewind/pg_rewind.h
index ef8bdc1fbb..05729adfef 100644
--- a/src/bin/pg_rewind/pg_rewind.h
+++ b/src/bin/pg_rewind/pg_rewind.h
@@ -13,6 +13,7 @@
 
 #include "access/timeline.h"
 #include "common/logging.h"
+#include "common/file_utils.h"
 #include "datapagemap.h"
 #include "libpq-fe.h"
 #include "storage/block.h"
@@ -24,6 +25,7 @@ extern bool showprogress;
 extern bool dry_run;
 extern bool do_sync;
 extern int	WalSegSz;
+extern DataDirSyncMethod sync_method;
 
 /* Target history */
 extern TimeLineHistoryEntry *targetHistory;
diff --git a/src/bin/pg_upgrade/option.c b/src/bin/pg_upgrade/option.c
index 640361009e..b9d900d0db 100644
--- a/src/bin/pg_upgrade/option.c
+++ b/src/bin/pg_upgrade/option.c
@@ -14,6 +14,7 @@
 #endif
 
 #include "common/string.h"
+#include "fe_utils/option_utils.h"
 #include "getopt_long.h"
 #include "pg_upgrade.h"
 #include "utils/pidfile.h"
@@ -57,12 +58,14 @@ parseCommandLine(int argc, char *argv[])
 		{"verbose", no_argument, NULL, 'v'},
 		{"clone", no_argument, NULL, 1},
 		{"copy", no_argument, NULL, 2},
+		{"sync-method", required_argument, NULL, 3},
 
 		{NULL, 0, NULL, 0}
 	};
 	int			option;			/* Command line option */
 	int			optindex = 0;	/* used by getopt_long */
 	int			os_user_effective_id;
+	DataDirSyncMethod unused;
 
 	user_opts.do_sync = true;
 	user_opts.transfer_mode = TRANSFER_MODE_COPY;
@@ -199,6 +202,12 @@ parseCommandLine(int argc, char *argv[])
 				user_opts.transfer_mode = TRANSFER_MODE_COPY;
 				break;
 
+			case 3:
+				if (!parse_sync_method(optarg, &unused))
+					exit(1);
+				user_opts.sync_method = pg_strdup(optarg);
+				break;
+
 			default:
 				fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
 						os_info.progname);
@@ -209,6 +218,9 @@ parseCommandLine(int argc, char *argv[])
 	if (optind < argc)
 		pg_fatal("too many command-line arguments (first is \"%s\")", argv[optind]);
 
+	if (!user_opts.sync_method)
+		user_opts.sync_method = pg_strdup("fsync");
+
 	if (log_opts.verbose)
 		pg_log(PG_REPORT, "Running in verbose mode");
 
@@ -289,6 +301,7 @@ usage(void)
 	printf(_("  -V, --version                 display version information, then exit\n"));
 	printf(_("  --clone                       clone instead of copying files to new cluster\n"));
 	printf(_("  --copy                        copy files to new cluster (default)\n"));
+	printf(_("  --sync-method=METHOD          set method for syncing files to disk\n"));
 	printf(_("  -?, --help                    show this help, then exit\n"));
 	printf(_("\n"
 			 "Before running pg_upgrade you must:\n"
diff --git a/src/bin/pg_upgrade/pg_upgrade.c b/src/bin/pg_upgrade/pg_upgrade.c
index 4562dafcff..96bfb67167 100644
--- a/src/bin/pg_upgrade/pg_upgrade.c
+++ b/src/bin/pg_upgrade/pg_upgrade.c
@@ -192,8 +192,10 @@ main(int argc, char **argv)
 	{
 		prep_status("Sync data directory to disk");
 		exec_prog(UTILITY_LOG_FILE, NULL, true, true,
-				  "\"%s/initdb\" --sync-only \"%s\"", new_cluster.bindir,
-				  new_cluster.pgdata);
+				  "\"%s/initdb\" --sync-only \"%s\" --sync-method %s",
+				  new_cluster.bindir,
+				  new_cluster.pgdata,
+				  user_opts.sync_method);
 		check_ok();
 	}
 
diff --git a/src/bin/pg_upgrade/pg_upgrade.h b/src/bin/pg_upgrade/pg_upgrade.h
index 7afa96716e..842f3b6cd3 100644
--- a/src/bin/pg_upgrade/pg_upgrade.h
+++ b/src/bin/pg_upgrade/pg_upgrade.h
@@ -304,6 +304,7 @@ typedef struct
 	transferMode transfer_mode; /* copy files or link them? */
 	int			jobs;			/* number of processes/threads to use */
 	char	   *socketdir;		/* directory to use for Unix sockets */
+	char	   *sync_method;
 } UserOpts;
 
 typedef struct
diff --git a/src/common/file_utils.c b/src/common/file_utils.c
index 74833c4acb..05c73c0bb7 100644
--- a/src/common/file_utils.c
+++ b/src/common/file_utils.c
@@ -51,6 +51,31 @@ static void walkdir(const char *path,
 					int (*action) (const char *fname, bool isdir),
 					bool process_symlinks);
 
+#ifdef HAVE_SYNCFS
+static void
+do_syncfs(const char *path)
+{
+	int			fd;
+
+	fd = open(path, O_RDONLY, 0);
+
+	if (fd < 0)
+	{
+		pg_log_error("could not open file \"%s\": %m", path);
+		return;
+	}
+
+	if (syncfs(fd) < 0)
+	{
+		pg_log_error("could not synchronize file system for file \"%s\": %m", path);
+		(void) close(fd);
+		exit(EXIT_FAILURE);
+	}
+
+	(void) close(fd);
+}
+#endif
+
 /*
  * Issue fsync recursively on PGDATA and all its contents.
  *
@@ -63,7 +88,8 @@ static void walkdir(const char *path,
  */
 void
 fsync_pgdata(const char *pg_data,
-			 int serverVersion)
+			 int serverVersion,
+			 DataDirSyncMethod sync_method)
 {
 	bool		xlog_is_symlink;
 	char		pg_wal[MAXPGPATH];
@@ -89,30 +115,93 @@ fsync_pgdata(const char *pg_data,
 			xlog_is_symlink = true;
 	}
 
-	/*
-	 * If possible, hint to the kernel that we're soon going to fsync the data
-	 * directory and its contents.
-	 */
+	switch (sync_method)
+	{
+		case DATA_DIR_SYNC_METHOD_SYNCFS:
+			{
+#ifndef HAVE_SYNCFS
+				pg_log_error("this build does not support sync method \"%s\"",
+							 "syncfs");
+				exit(EXIT_FAILURE);
+#else
+				DIR		   *dir;
+				struct dirent *de;
+
+				/*
+				 * On Linux, we don't have to open every single file one by
+				 * one.  We can use syncfs() to sync whole filesystems.  We
+				 * only expect filesystem boundaries to exist where we
+				 * tolerate symlinks, namely pg_wal and the tablespaces, so we
+				 * call syncfs() for each of those directories.
+				 */
+
+				/* Sync the top level pgdata directory. */
+				do_syncfs(pg_data);
+
+				/* If any tablespaces are configured, sync each of those. */
+				dir = opendir(pg_tblspc);
+				if (dir == NULL)
+					pg_log_error("could not open directory \"%s\": %m",
+								 pg_tblspc);
+				else
+				{
+					while (errno = 0, (de = readdir(dir)) != NULL)
+					{
+						char		subpath[MAXPGPATH * 2];
+
+						if (strcmp(de->d_name, ".") == 0 ||
+							strcmp(de->d_name, "..") == 0)
+							continue;
+
+						snprintf(subpath, sizeof(subpath), "%s/%s",
+								 pg_tblspc, de->d_name);
+						do_syncfs(subpath);
+					}
+
+					if (errno)
+						pg_log_error("could not read directory \"%s\": %m",
+									 pg_tblspc);
+
+					(void) closedir(dir);
+				}
+
+				/* If pg_wal is a symlink, process that too. */
+				if (xlog_is_symlink)
+					do_syncfs(pg_wal);
+#endif							/* HAVE_SYNCFS */
+			}
+			break;
+
+		case DATA_DIR_SYNC_METHOD_FSYNC:
+			{
+				/*
+				 * If possible, hint to the kernel that we're soon going to
+				 * fsync the data directory and its contents.
+				 */
 #ifdef PG_FLUSH_DATA_WORKS
-	walkdir(pg_data, pre_sync_fname, false);
-	if (xlog_is_symlink)
-		walkdir(pg_wal, pre_sync_fname, false);
-	walkdir(pg_tblspc, pre_sync_fname, true);
+				walkdir(pg_data, pre_sync_fname, false);
+				if (xlog_is_symlink)
+					walkdir(pg_wal, pre_sync_fname, false);
+				walkdir(pg_tblspc, pre_sync_fname, true);
 #endif
 
-	/*
-	 * Now we do the fsync()s in the same order.
-	 *
-	 * The main call ignores symlinks, so in addition to specially processing
-	 * pg_wal if it's a symlink, pg_tblspc has to be visited separately with
-	 * process_symlinks = true.  Note that if there are any plain directories
-	 * in pg_tblspc, they'll get fsync'd twice.  That's not an expected case
-	 * so we don't worry about optimizing it.
-	 */
-	walkdir(pg_data, fsync_fname, false);
-	if (xlog_is_symlink)
-		walkdir(pg_wal, fsync_fname, false);
-	walkdir(pg_tblspc, fsync_fname, true);
+				/*
+				 * Now we do the fsync()s in the same order.
+				 *
+				 * The main call ignores symlinks, so in addition to specially
+				 * processing pg_wal if it's a symlink, pg_tblspc has to be
+				 * visited separately with process_symlinks = true.  Note that
+				 * if there are any plain directories in pg_tblspc, they'll
+				 * get fsync'd twice. That's not an expected case so we don't
+				 * worry about optimizing it.
+				 */
+				walkdir(pg_data, fsync_fname, false);
+				if (xlog_is_symlink)
+					walkdir(pg_wal, fsync_fname, false);
+				walkdir(pg_tblspc, fsync_fname, true);
+			}
+			break;
+	}
 }
 
 /*
@@ -121,17 +210,40 @@ fsync_pgdata(const char *pg_data,
  * This is a convenient wrapper on top of walkdir().
  */
 void
-fsync_dir_recurse(const char *dir)
+fsync_dir_recurse(const char *dir, DataDirSyncMethod sync_method)
 {
-	/*
-	 * If possible, hint to the kernel that we're soon going to fsync the data
-	 * directory and its contents.
-	 */
+	switch (sync_method)
+	{
+		case DATA_DIR_SYNC_METHOD_SYNCFS:
+			{
+#ifndef HAVE_SYNCFS
+				pg_log_error("this build does not support sync method \"%s\"",
+							 "syncfs");
+				exit(EXIT_FAILURE);
+#else
+				/*
+				 * On Linux, we don't have to open every single file one by
+				 * one.  We can use syncfs() to sync the whole filesystem.
+				 */
+				do_syncfs(dir);
+#endif							/* HAVE_SYNCFS */
+			}
+			break;
+
+		case DATA_DIR_SYNC_METHOD_FSYNC:
+			{
+				/*
+				 * If possible, hint to the kernel that we're soon going to
+				 * fsync the data directory and its contents.
+				 */
 #ifdef PG_FLUSH_DATA_WORKS
-	walkdir(dir, pre_sync_fname, false);
+				walkdir(dir, pre_sync_fname, false);
 #endif
 
-	walkdir(dir, fsync_fname, false);
+				walkdir(dir, fsync_fname, false);
+			}
+			break;
+	}
 }
 
 /*
diff --git a/src/fe_utils/option_utils.c b/src/fe_utils/option_utils.c
index 763c991015..36ac689964 100644
--- a/src/fe_utils/option_utils.c
+++ b/src/fe_utils/option_utils.c
@@ -82,3 +82,27 @@ option_parse_int(const char *optarg, const char *optname,
 		*result = val;
 	return true;
 }
+
+bool
+parse_sync_method(const char *optarg, DataDirSyncMethod *sync_method)
+{
+	if (strcmp(optarg, "fsync") == 0)
+		*sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
+	else if (strcmp(optarg, "syncfs") == 0)
+	{
+#ifdef HAVE_SYNCFS
+		*sync_method = DATA_DIR_SYNC_METHOD_SYNCFS;
+#else
+		pg_log_error("this build does not support sync method \"%s\"",
+					 "syncfs");
+		return false;
+#endif
+	}
+	else
+	{
+		pg_log_error("unrecognized sync method: %s", optarg);
+		return false;
+	}
+
+	return true;
+}
diff --git a/src/include/common/file_utils.h b/src/include/common/file_utils.h
index dd1532bcb0..09d1e5d561 100644
--- a/src/include/common/file_utils.h
+++ b/src/include/common/file_utils.h
@@ -26,10 +26,17 @@ typedef enum PGFileType
 
 struct iovec;					/* avoid including port/pg_iovec.h here */
 
+typedef enum DataDirSyncMethod
+{
+	DATA_DIR_SYNC_METHOD_FSYNC,
+	DATA_DIR_SYNC_METHOD_SYNCFS
+} DataDirSyncMethod;
+
 #ifdef FRONTEND
 extern int	fsync_fname(const char *fname, bool isdir);
-extern void fsync_pgdata(const char *pg_data, int serverVersion);
-extern void fsync_dir_recurse(const char *dir);
+extern void fsync_pgdata(const char *pg_data, int serverVersion,
+						 DataDirSyncMethod sync_method);
+extern void fsync_dir_recurse(const char *dir, DataDirSyncMethod sync_method);
 extern int	durable_rename(const char *oldfile, const char *newfile);
 extern int	fsync_parent_path(const char *fname);
 #endif
diff --git a/src/include/fe_utils/option_utils.h b/src/include/fe_utils/option_utils.h
index b7b0654cee..6f3a965916 100644
--- a/src/include/fe_utils/option_utils.h
+++ b/src/include/fe_utils/option_utils.h
@@ -14,6 +14,8 @@
 
 #include "postgres_fe.h"
 
+#include "common/file_utils.h"
+
 typedef void (*help_handler) (const char *progname);
 
 extern void handle_help_version_opts(int argc, char *argv[],
@@ -22,5 +24,7 @@ extern void handle_help_version_opts(int argc, char *argv[],
 extern bool option_parse_int(const char *optarg, const char *optname,
 							 int min_range, int max_range,
 							 int *result);
+extern bool parse_sync_method(const char *optarg,
+							  DataDirSyncMethod *sync_method);
 
 #endif							/* OPTION_UTILS_H */
diff --git a/src/include/storage/fd.h b/src/include/storage/fd.h
index aea30c0622..d9d5d9da5f 100644
--- a/src/include/storage/fd.h
+++ b/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;
 
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 49a33c0387..fe571c6265 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -545,6 +545,7 @@ DR_printtup
 DR_sqlfunction
 DR_transientrel
 DWORD
+DataDirSyncMethod
 DataDumperPtr
 DataPageDeleteStack
 DatabaseInfo
-- 
2.25.1

From e627b8ea4dcc01ac9e2fe3a21e3b3cc109b815e4 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Mon, 21 Aug 2023 19:05:14 -0700
Subject: [PATCH v8 1/4] move PG_TEMP_FILE* macros to file_utils.h

---
 src/backend/backup/basebackup.c     |  2 +-
 src/backend/postmaster/postmaster.c |  1 +
 src/backend/storage/file/fileset.c  |  1 +
 src/bin/pg_checksums/pg_checksums.c | 10 ----------
 src/bin/pg_rewind/filemap.c         |  2 +-
 src/include/common/file_utils.h     |  4 ++++
 src/include/storage/fd.h            |  4 ----
 7 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/src/backend/backup/basebackup.c b/src/backend/backup/basebackup.c
index 45be21131c..5d66014499 100644
--- a/src/backend/backup/basebackup.c
+++ b/src/backend/backup/basebackup.c
@@ -25,6 +25,7 @@
 #include "commands/defrem.h"
 #include "common/compression.h"
 #include "common/file_perm.h"
+#include "common/file_utils.h"
 #include "lib/stringinfo.h"
 #include "miscadmin.h"
 #include "nodes/pg_list.h"
@@ -37,7 +38,6 @@
 #include "storage/bufpage.h"
 #include "storage/checksum.h"
 #include "storage/dsm_impl.h"
-#include "storage/fd.h"
 #include "storage/ipc.h"
 #include "storage/reinit.h"
 #include "utils/builtins.h"
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index d7bfb28ff3..54e9bfb8c4 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -94,6 +94,7 @@
 #include "access/xlogrecovery.h"
 #include "catalog/pg_control.h"
 #include "common/file_perm.h"
+#include "common/file_utils.h"
 #include "common/ip.h"
 #include "common/pg_prng.h"
 #include "common/string.h"
diff --git a/src/backend/storage/file/fileset.c b/src/backend/storage/file/fileset.c
index e9951b0269..84cae32548 100644
--- a/src/backend/storage/file/fileset.c
+++ b/src/backend/storage/file/fileset.c
@@ -25,6 +25,7 @@
 
 #include "catalog/pg_tablespace.h"
 #include "commands/tablespace.h"
+#include "common/file_utils.h"
 #include "common/hashfn.h"
 #include "miscadmin.h"
 #include "storage/ipc.h"
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 19eb67e485..9011a19b4e 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -52,16 +52,6 @@ typedef enum
 	PG_MODE_ENABLE
 } PgChecksumMode;
 
-/*
- * Filename components.
- *
- * XXX: fd.h is not declared here as frontend side code is not able to
- * interact with the backend-side definitions for the various fsync
- * wrappers.
- */
-#define PG_TEMP_FILES_DIR "pgsql_tmp"
-#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
-
 static PgChecksumMode mode = PG_MODE_CHECK;
 
 static const char *progname;
diff --git a/src/bin/pg_rewind/filemap.c b/src/bin/pg_rewind/filemap.c
index bd5c598e20..58280d9abc 100644
--- a/src/bin/pg_rewind/filemap.c
+++ b/src/bin/pg_rewind/filemap.c
@@ -27,12 +27,12 @@
 #include <unistd.h>
 
 #include "catalog/pg_tablespace_d.h"
+#include "common/file_utils.h"
 #include "common/hashfn.h"
 #include "common/string.h"
 #include "datapagemap.h"
 #include "filemap.h"
 #include "pg_rewind.h"
-#include "storage/fd.h"
 
 /*
  * Define a hash table which we can use to store information about the files
diff --git a/src/include/common/file_utils.h b/src/include/common/file_utils.h
index b7efa1226d..dd1532bcb0 100644
--- a/src/include/common/file_utils.h
+++ b/src/include/common/file_utils.h
@@ -46,4 +46,8 @@ extern ssize_t pg_pwritev_with_retry(int fd,
 
 extern ssize_t pg_pwrite_zeros(int fd, size_t size, off_t offset);
 
+/* Filename components */
+#define PG_TEMP_FILES_DIR "pgsql_tmp"
+#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
+
 #endif							/* FILE_UTILS_H */
diff --git a/src/include/storage/fd.h b/src/include/storage/fd.h
index 6791a406fc..aea30c0622 100644
--- a/src/include/storage/fd.h
+++ b/src/include/storage/fd.h
@@ -195,8 +195,4 @@ extern int	durable_unlink(const char *fname, int elevel);
 extern void SyncDataDirectory(void);
 extern int	data_sync_elevel(int elevel);
 
-/* Filename components */
-#define PG_TEMP_FILES_DIR "pgsql_tmp"
-#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
-
 #endif							/* FD_H */
-- 
2.25.1

From 9145faf587249cbb1d3ab54e296542cf7c71eefc Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Thu, 31 Aug 2023 07:38:42 -0700
Subject: [PATCH v8 2/4] make common enum for sync methods

---
 src/backend/storage/file/fd.c       | 4 ++--
 src/backend/utils/misc/guc_tables.c | 7 ++++---
 src/include/common/file_utils.h     | 6 ++++++
 src/include/storage/fd.h            | 6 ------
 src/tools/pgindent/typedefs.list    | 1 +
 5 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index b490a76ba7..3fed475c38 100644
--- a/src/backend/storage/file/fd.c
+++ b/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;
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index e565a3092f..5abebe9a9c 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/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}
 };
@@ -4964,7 +4965,7 @@ 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
 	},
 
diff --git a/src/include/common/file_utils.h b/src/include/common/file_utils.h
index dd1532bcb0..7da21f15e6 100644
--- a/src/include/common/file_utils.h
+++ b/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
diff --git a/src/include/storage/fd.h b/src/include/storage/fd.h
index aea30c0622..d9d5d9da5f 100644
--- a/src/include/storage/fd.h
+++ b/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;
 
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 49a33c0387..fe571c6265 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -545,6 +545,7 @@ DR_printtup
 DR_sqlfunction
 DR_transientrel
 DWORD
+DataDirSyncMethod
 DataDumperPtr
 DataPageDeleteStack
 DatabaseInfo
-- 
2.25.1

From c5bc205b3d7d645356ecd27924fdd164ffa90ce3 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Thu, 31 Aug 2023 07:59:52 -0700
Subject: [PATCH v8 3/4] add support for syncfs in frontend support functions

---
 src/bin/initdb/initdb.c               |   5 +-
 src/bin/pg_basebackup/pg_basebackup.c |   5 +-
 src/bin/pg_checksums/pg_checksums.c   |   3 +-
 src/bin/pg_dump/pg_backup.h           |   4 +-
 src/bin/pg_dump/pg_backup_archiver.c  |  14 ++-
 src/bin/pg_dump/pg_backup_archiver.h  |   1 +
 src/bin/pg_dump/pg_backup_directory.c |   2 +-
 src/bin/pg_dump/pg_dump.c             |   3 +-
 src/bin/pg_rewind/file_ops.c          |   2 +-
 src/bin/pg_rewind/pg_rewind.c         |   1 +
 src/bin/pg_rewind/pg_rewind.h         |   2 +
 src/common/file_utils.c               | 170 +++++++++++++++++++++-----
 src/include/common/file_utils.h       |   5 +-
 13 files changed, 172 insertions(+), 45 deletions(-)

diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index 905b979947..bbea1e412b 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -165,6 +165,7 @@ static bool show_setting = false;
 static bool data_checksums = false;
 static char *xlog_dir = NULL;
 static int	wal_segment_size_mb = (DEFAULT_XLOG_SEG_SIZE) / (1024 * 1024);
+static DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 
 /* internal vars */
@@ -3333,7 +3334,7 @@ main(int argc, char *argv[])
 
 		fputs(_("syncing data to disk ... "), stdout);
 		fflush(stdout);
-		fsync_pgdata(pg_data, PG_VERSION_NUM);
+		fsync_pgdata(pg_data, PG_VERSION_NUM, sync_method);
 		check_ok();
 		return 0;
 	}
@@ -3396,7 +3397,7 @@ main(int argc, char *argv[])
 	{
 		fputs(_("syncing data to disk ... "), stdout);
 		fflush(stdout);
-		fsync_pgdata(pg_data, PG_VERSION_NUM);
+		fsync_pgdata(pg_data, PG_VERSION_NUM, sync_method);
 		check_ok();
 	}
 	else
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 1dc8efe0cb..1a6eacf6d5 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -148,6 +148,7 @@ static bool verify_checksums = true;
 static bool manifest = true;
 static bool manifest_force_encode = false;
 static char *manifest_checksums = NULL;
+static DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 static bool success = false;
 static bool made_new_pgdata = false;
@@ -2199,11 +2200,11 @@ BaseBackup(char *compression_algorithm, char *compression_detail,
 		if (format == 't')
 		{
 			if (strcmp(basedir, "-") != 0)
-				(void) fsync_dir_recurse(basedir);
+				(void) fsync_dir_recurse(basedir, sync_method);
 		}
 		else
 		{
-			(void) fsync_pgdata(basedir, serverVersion);
+			(void) fsync_pgdata(basedir, serverVersion, sync_method);
 		}
 	}
 
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 9011a19b4e..123450f483 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -44,6 +44,7 @@ static char *only_filenode = NULL;
 static bool do_sync = true;
 static bool verbose = false;
 static bool showprogress = false;
+static DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 typedef enum
 {
@@ -623,7 +624,7 @@ main(int argc, char *argv[])
 		if (do_sync)
 		{
 			pg_log_info("syncing data directory");
-			fsync_pgdata(DataDir, PG_VERSION_NUM);
+			fsync_pgdata(DataDir, PG_VERSION_NUM, sync_method);
 		}
 
 		pg_log_info("updating control file");
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index aba780ef4b..3a57cdd97d 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -24,6 +24,7 @@
 #define PG_BACKUP_H
 
 #include "common/compression.h"
+#include "common/file_utils.h"
 #include "fe_utils/simple_list.h"
 #include "libpq-fe.h"
 
@@ -307,7 +308,8 @@ extern Archive *OpenArchive(const char *FileSpec, const ArchiveFormat fmt);
 extern Archive *CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 							  const pg_compress_specification compression_spec,
 							  bool dosync, ArchiveMode mode,
-							  SetupWorkerPtrType setupDumpWorker);
+							  SetupWorkerPtrType setupDumpWorker,
+							  DataDirSyncMethod sync_method);
 
 /* The --list option */
 extern void PrintTOCSummary(Archive *AHX);
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index 39ebcfec32..4d83381d84 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -66,7 +66,8 @@ typedef struct _parallelReadyList
 static ArchiveHandle *_allocAH(const char *FileSpec, const ArchiveFormat fmt,
 							   const pg_compress_specification compression_spec,
 							   bool dosync, ArchiveMode mode,
-							   SetupWorkerPtrType setupWorkerPtr);
+							   SetupWorkerPtrType setupWorkerPtr,
+							   DataDirSyncMethod sync_method);
 static void _getObjectDescription(PQExpBuffer buf, const TocEntry *te);
 static void _printTocEntry(ArchiveHandle *AH, TocEntry *te, bool isData);
 static char *sanitize_line(const char *str, bool want_hyphen);
@@ -238,11 +239,12 @@ Archive *
 CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 			  const pg_compress_specification compression_spec,
 			  bool dosync, ArchiveMode mode,
-			  SetupWorkerPtrType setupDumpWorker)
+			  SetupWorkerPtrType setupDumpWorker,
+			  DataDirSyncMethod sync_method)
 
 {
 	ArchiveHandle *AH = _allocAH(FileSpec, fmt, compression_spec,
-								 dosync, mode, setupDumpWorker);
+								 dosync, mode, setupDumpWorker, sync_method);
 
 	return (Archive *) AH;
 }
@@ -257,7 +259,8 @@ OpenArchive(const char *FileSpec, const ArchiveFormat fmt)
 
 	compression_spec.algorithm = PG_COMPRESSION_NONE;
 	AH = _allocAH(FileSpec, fmt, compression_spec, true,
-				  archModeRead, setupRestoreWorker);
+				  archModeRead, setupRestoreWorker,
+				  DATA_DIR_SYNC_METHOD_FSYNC);
 
 	return (Archive *) AH;
 }
@@ -2233,7 +2236,7 @@ static ArchiveHandle *
 _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 		 const pg_compress_specification compression_spec,
 		 bool dosync, ArchiveMode mode,
-		 SetupWorkerPtrType setupWorkerPtr)
+		 SetupWorkerPtrType setupWorkerPtr, DataDirSyncMethod sync_method)
 {
 	ArchiveHandle *AH;
 	CompressFileHandle *CFH;
@@ -2287,6 +2290,7 @@ _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 	AH->mode = mode;
 	AH->compression_spec = compression_spec;
 	AH->dosync = dosync;
+	AH->sync_method = sync_method;
 
 	memset(&(AH->sqlparse), 0, sizeof(AH->sqlparse));
 
diff --git a/src/bin/pg_dump/pg_backup_archiver.h b/src/bin/pg_dump/pg_backup_archiver.h
index 18b38c17ab..b07673933d 100644
--- a/src/bin/pg_dump/pg_backup_archiver.h
+++ b/src/bin/pg_dump/pg_backup_archiver.h
@@ -312,6 +312,7 @@ struct _archiveHandle
 	pg_compress_specification compression_spec; /* Requested specification for
 												 * compression */
 	bool		dosync;			/* data requested to be synced on sight */
+	DataDirSyncMethod sync_method;
 	ArchiveMode mode;			/* File mode - r or w */
 	void	   *formatData;		/* Header data specific to file format */
 
diff --git a/src/bin/pg_dump/pg_backup_directory.c b/src/bin/pg_dump/pg_backup_directory.c
index 7f2ac7c7fd..6faa3a511f 100644
--- a/src/bin/pg_dump/pg_backup_directory.c
+++ b/src/bin/pg_dump/pg_backup_directory.c
@@ -613,7 +613,7 @@ _CloseArchive(ArchiveHandle *AH)
 		 * individually. Just recurse once through all the files generated.
 		 */
 		if (AH->dosync)
-			fsync_dir_recurse(ctx->directory);
+			fsync_dir_recurse(ctx->directory, AH->sync_method);
 	}
 	AH->FH = NULL;
 }
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 65f64c282d..39a468b131 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -357,6 +357,7 @@ main(int argc, char **argv)
 	char	   *compression_algorithm_str = "none";
 	char	   *error_detail = NULL;
 	bool		user_compression_defined = false;
+	DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 	static DumpOptions dopt;
 
@@ -777,7 +778,7 @@ main(int argc, char **argv)
 
 	/* Open the output file */
 	fout = CreateArchive(filename, archiveFormat, compression_spec,
-						 dosync, archiveMode, setupDumpWorker);
+						 dosync, archiveMode, setupDumpWorker, sync_method);
 
 	/* Make dump options accessible right away */
 	SetArchiveOptions(fout, &dopt, NULL);
diff --git a/src/bin/pg_rewind/file_ops.c b/src/bin/pg_rewind/file_ops.c
index 25996b4da4..451fb1856e 100644
--- a/src/bin/pg_rewind/file_ops.c
+++ b/src/bin/pg_rewind/file_ops.c
@@ -296,7 +296,7 @@ sync_target_dir(void)
 	if (!do_sync || dry_run)
 		return;
 
-	fsync_pgdata(datadir_target, PG_VERSION_NUM);
+	fsync_pgdata(datadir_target, PG_VERSION_NUM, sync_method);
 }
 
 
diff --git a/src/bin/pg_rewind/pg_rewind.c b/src/bin/pg_rewind/pg_rewind.c
index 7f69f02441..bdfacf3263 100644
--- a/src/bin/pg_rewind/pg_rewind.c
+++ b/src/bin/pg_rewind/pg_rewind.c
@@ -74,6 +74,7 @@ bool		showprogress = false;
 bool		dry_run = false;
 bool		do_sync = true;
 bool		restore_wal = false;
+DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 /* Target history */
 TimeLineHistoryEntry *targetHistory;
diff --git a/src/bin/pg_rewind/pg_rewind.h b/src/bin/pg_rewind/pg_rewind.h
index ef8bdc1fbb..05729adfef 100644
--- a/src/bin/pg_rewind/pg_rewind.h
+++ b/src/bin/pg_rewind/pg_rewind.h
@@ -13,6 +13,7 @@
 
 #include "access/timeline.h"
 #include "common/logging.h"
+#include "common/file_utils.h"
 #include "datapagemap.h"
 #include "libpq-fe.h"
 #include "storage/block.h"
@@ -24,6 +25,7 @@ extern bool showprogress;
 extern bool dry_run;
 extern bool do_sync;
 extern int	WalSegSz;
+extern DataDirSyncMethod sync_method;
 
 /* Target history */
 extern TimeLineHistoryEntry *targetHistory;
diff --git a/src/common/file_utils.c b/src/common/file_utils.c
index 74833c4acb..05c73c0bb7 100644
--- a/src/common/file_utils.c
+++ b/src/common/file_utils.c
@@ -51,6 +51,31 @@ static void walkdir(const char *path,
 					int (*action) (const char *fname, bool isdir),
 					bool process_symlinks);
 
+#ifdef HAVE_SYNCFS
+static void
+do_syncfs(const char *path)
+{
+	int			fd;
+
+	fd = open(path, O_RDONLY, 0);
+
+	if (fd < 0)
+	{
+		pg_log_error("could not open file \"%s\": %m", path);
+		return;
+	}
+
+	if (syncfs(fd) < 0)
+	{
+		pg_log_error("could not synchronize file system for file \"%s\": %m", path);
+		(void) close(fd);
+		exit(EXIT_FAILURE);
+	}
+
+	(void) close(fd);
+}
+#endif
+
 /*
  * Issue fsync recursively on PGDATA and all its contents.
  *
@@ -63,7 +88,8 @@ static void walkdir(const char *path,
  */
 void
 fsync_pgdata(const char *pg_data,
-			 int serverVersion)
+			 int serverVersion,
+			 DataDirSyncMethod sync_method)
 {
 	bool		xlog_is_symlink;
 	char		pg_wal[MAXPGPATH];
@@ -89,30 +115,93 @@ fsync_pgdata(const char *pg_data,
 			xlog_is_symlink = true;
 	}
 
-	/*
-	 * If possible, hint to the kernel that we're soon going to fsync the data
-	 * directory and its contents.
-	 */
+	switch (sync_method)
+	{
+		case DATA_DIR_SYNC_METHOD_SYNCFS:
+			{
+#ifndef HAVE_SYNCFS
+				pg_log_error("this build does not support sync method \"%s\"",
+							 "syncfs");
+				exit(EXIT_FAILURE);
+#else
+				DIR		   *dir;
+				struct dirent *de;
+
+				/*
+				 * On Linux, we don't have to open every single file one by
+				 * one.  We can use syncfs() to sync whole filesystems.  We
+				 * only expect filesystem boundaries to exist where we
+				 * tolerate symlinks, namely pg_wal and the tablespaces, so we
+				 * call syncfs() for each of those directories.
+				 */
+
+				/* Sync the top level pgdata directory. */
+				do_syncfs(pg_data);
+
+				/* If any tablespaces are configured, sync each of those. */
+				dir = opendir(pg_tblspc);
+				if (dir == NULL)
+					pg_log_error("could not open directory \"%s\": %m",
+								 pg_tblspc);
+				else
+				{
+					while (errno = 0, (de = readdir(dir)) != NULL)
+					{
+						char		subpath[MAXPGPATH * 2];
+
+						if (strcmp(de->d_name, ".") == 0 ||
+							strcmp(de->d_name, "..") == 0)
+							continue;
+
+						snprintf(subpath, sizeof(subpath), "%s/%s",
+								 pg_tblspc, de->d_name);
+						do_syncfs(subpath);
+					}
+
+					if (errno)
+						pg_log_error("could not read directory \"%s\": %m",
+									 pg_tblspc);
+
+					(void) closedir(dir);
+				}
+
+				/* If pg_wal is a symlink, process that too. */
+				if (xlog_is_symlink)
+					do_syncfs(pg_wal);
+#endif							/* HAVE_SYNCFS */
+			}
+			break;
+
+		case DATA_DIR_SYNC_METHOD_FSYNC:
+			{
+				/*
+				 * If possible, hint to the kernel that we're soon going to
+				 * fsync the data directory and its contents.
+				 */
 #ifdef PG_FLUSH_DATA_WORKS
-	walkdir(pg_data, pre_sync_fname, false);
-	if (xlog_is_symlink)
-		walkdir(pg_wal, pre_sync_fname, false);
-	walkdir(pg_tblspc, pre_sync_fname, true);
+				walkdir(pg_data, pre_sync_fname, false);
+				if (xlog_is_symlink)
+					walkdir(pg_wal, pre_sync_fname, false);
+				walkdir(pg_tblspc, pre_sync_fname, true);
 #endif
 
-	/*
-	 * Now we do the fsync()s in the same order.
-	 *
-	 * The main call ignores symlinks, so in addition to specially processing
-	 * pg_wal if it's a symlink, pg_tblspc has to be visited separately with
-	 * process_symlinks = true.  Note that if there are any plain directories
-	 * in pg_tblspc, they'll get fsync'd twice.  That's not an expected case
-	 * so we don't worry about optimizing it.
-	 */
-	walkdir(pg_data, fsync_fname, false);
-	if (xlog_is_symlink)
-		walkdir(pg_wal, fsync_fname, false);
-	walkdir(pg_tblspc, fsync_fname, true);
+				/*
+				 * Now we do the fsync()s in the same order.
+				 *
+				 * The main call ignores symlinks, so in addition to specially
+				 * processing pg_wal if it's a symlink, pg_tblspc has to be
+				 * visited separately with process_symlinks = true.  Note that
+				 * if there are any plain directories in pg_tblspc, they'll
+				 * get fsync'd twice. That's not an expected case so we don't
+				 * worry about optimizing it.
+				 */
+				walkdir(pg_data, fsync_fname, false);
+				if (xlog_is_symlink)
+					walkdir(pg_wal, fsync_fname, false);
+				walkdir(pg_tblspc, fsync_fname, true);
+			}
+			break;
+	}
 }
 
 /*
@@ -121,17 +210,40 @@ fsync_pgdata(const char *pg_data,
  * This is a convenient wrapper on top of walkdir().
  */
 void
-fsync_dir_recurse(const char *dir)
+fsync_dir_recurse(const char *dir, DataDirSyncMethod sync_method)
 {
-	/*
-	 * If possible, hint to the kernel that we're soon going to fsync the data
-	 * directory and its contents.
-	 */
+	switch (sync_method)
+	{
+		case DATA_DIR_SYNC_METHOD_SYNCFS:
+			{
+#ifndef HAVE_SYNCFS
+				pg_log_error("this build does not support sync method \"%s\"",
+							 "syncfs");
+				exit(EXIT_FAILURE);
+#else
+				/*
+				 * On Linux, we don't have to open every single file one by
+				 * one.  We can use syncfs() to sync the whole filesystem.
+				 */
+				do_syncfs(dir);
+#endif							/* HAVE_SYNCFS */
+			}
+			break;
+
+		case DATA_DIR_SYNC_METHOD_FSYNC:
+			{
+				/*
+				 * If possible, hint to the kernel that we're soon going to
+				 * fsync the data directory and its contents.
+				 */
 #ifdef PG_FLUSH_DATA_WORKS
-	walkdir(dir, pre_sync_fname, false);
+				walkdir(dir, pre_sync_fname, false);
 #endif
 
-	walkdir(dir, fsync_fname, false);
+				walkdir(dir, fsync_fname, false);
+			}
+			break;
+	}
 }
 
 /*
diff --git a/src/include/common/file_utils.h b/src/include/common/file_utils.h
index 7da21f15e6..cae6159bf6 100644
--- a/src/include/common/file_utils.h
+++ b/src/include/common/file_utils.h
@@ -34,8 +34,9 @@ struct iovec;					/* avoid including port/pg_iovec.h here */
 
 #ifdef FRONTEND
 extern int	fsync_fname(const char *fname, bool isdir);
-extern void fsync_pgdata(const char *pg_data, int serverVersion);
-extern void fsync_dir_recurse(const char *dir);
+extern void fsync_pgdata(const char *pg_data, int serverVersion,
+						 DataDirSyncMethod sync_method);
+extern void fsync_dir_recurse(const char *dir, DataDirSyncMethod sync_method);
 extern int	durable_rename(const char *oldfile, const char *newfile);
 extern int	fsync_parent_path(const char *fname);
 #endif
-- 
2.25.1

From 49a47f48b247acb33cb1538108b641b4cb8131ee Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Fri, 28 Jul 2023 15:56:24 -0700
Subject: [PATCH v8 4/4] allow syncfs in frontend utilities

---
 doc/src/sgml/config.sgml              | 12 +++------
 doc/src/sgml/filelist.sgml            |  1 +
 doc/src/sgml/postgres.sgml            |  1 +
 doc/src/sgml/ref/initdb.sgml          | 22 ++++++++++++++++
 doc/src/sgml/ref/pg_basebackup.sgml   | 25 +++++++++++++++++++
 doc/src/sgml/ref/pg_checksums.sgml    | 22 ++++++++++++++++
 doc/src/sgml/ref/pg_dump.sgml         | 21 ++++++++++++++++
 doc/src/sgml/ref/pg_rewind.sgml       | 22 ++++++++++++++++
 doc/src/sgml/ref/pgupgrade.sgml       | 23 +++++++++++++++++
 doc/src/sgml/syncfs.sgml              | 36 +++++++++++++++++++++++++++
 src/bin/initdb/initdb.c               |  6 +++++
 src/bin/initdb/t/001_initdb.pl        | 14 +++++++++++
 src/bin/pg_basebackup/pg_basebackup.c |  7 ++++++
 src/bin/pg_checksums/pg_checksums.c   |  6 +++++
 src/bin/pg_dump/pg_dump.c             |  7 ++++++
 src/bin/pg_rewind/pg_rewind.c         |  8 ++++++
 src/bin/pg_upgrade/option.c           | 13 ++++++++++
 src/bin/pg_upgrade/pg_upgrade.c       |  6 +++--
 src/bin/pg_upgrade/pg_upgrade.h       |  1 +
 src/fe_utils/option_utils.c           | 24 ++++++++++++++++++
 src/include/fe_utils/option_utils.h   |  4 +++
 21 files changed, 270 insertions(+), 11 deletions(-)
 create mode 100644 doc/src/sgml/syncfs.sgml

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 694d667bf9..2c7d9f1262 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -10580,15 +10580,9 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
         On Linux, <literal>syncfs</literal> may be used instead, to ask the
         operating system to synchronize the whole file systems that contain the
         data directory, the WAL files and each tablespace (but not any other
-        file systems that may be reachable through symbolic links).  This may
-        be a lot faster than the <literal>fsync</literal> setting, because it
-        doesn't need to open each file one by one.  On the other hand, it may
-        be slower if a file system is shared by other applications that
-        modify a lot of files, since those files will also be written to disk.
-        Furthermore, on versions of Linux before 5.8, I/O errors encountered
-        while writing data to disk may not be reported to
-        <productname>PostgreSQL</productname>, and relevant error messages may
-        appear only in kernel logs.
+        file systems that may be reachable through symbolic links).  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
        </para>
        <para>
         This parameter can only be set in the
diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
index 63b0fc2a46..df5d7c3025 100644
--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -184,6 +184,7 @@
 <!ENTITY acronyms   SYSTEM "acronyms.sgml">
 <!ENTITY glossary   SYSTEM "glossary.sgml">
 <!ENTITY color      SYSTEM "color.sgml">
+<!ENTITY syncfs     SYSTEM "syncfs.sgml">
 
 <!ENTITY features-supported   SYSTEM "features-supported.sgml">
 <!ENTITY features-unsupported SYSTEM "features-unsupported.sgml">
diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml
index 2e271862fc..f629524be0 100644
--- a/doc/src/sgml/postgres.sgml
+++ b/doc/src/sgml/postgres.sgml
@@ -294,6 +294,7 @@ break is not needed in a wider output rendering.
   &acronyms;
   &glossary;
   &color;
+  &syncfs;
   &obsolete;
 
  </part>
diff --git a/doc/src/sgml/ref/initdb.sgml b/doc/src/sgml/ref/initdb.sgml
index 22f1011781..8a09c5c438 100644
--- a/doc/src/sgml/ref/initdb.sgml
+++ b/doc/src/sgml/ref/initdb.sgml
@@ -365,6 +365,28 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry id="app-initdb-option-sync-method">
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>initdb</command> will recursively open and synchronize all
+        files in the data directory.  The search for files will follow symbolic
+        links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="app-initdb-option-sync-only">
       <term><option>-S</option></term>
       <term><option>--sync-only</option></term>
diff --git a/doc/src/sgml/ref/pg_basebackup.sgml b/doc/src/sgml/ref/pg_basebackup.sgml
index 79d3e657c3..d2b8ddd200 100644
--- a/doc/src/sgml/ref/pg_basebackup.sgml
+++ b/doc/src/sgml/ref/pg_basebackup.sgml
@@ -594,6 +594,31 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_basebackup</command> will recursively open and synchronize
+        all files in the backup directory.  When the plain format is used, the
+        search for files will follow symbolic links for the WAL directory and
+        each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file system that contains the
+        backup directory.  When the plain format is used,
+        <command>pg_basebackup</command> will also synchronize the file systems
+        that contain the WAL files and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-v</option></term>
       <term><option>--verbose</option></term>
diff --git a/doc/src/sgml/ref/pg_checksums.sgml b/doc/src/sgml/ref/pg_checksums.sgml
index a3d0b0f0a3..7b44ba71cf 100644
--- a/doc/src/sgml/ref/pg_checksums.sgml
+++ b/doc/src/sgml/ref/pg_checksums.sgml
@@ -139,6 +139,28 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_checksums</command> will recursively open and synchronize
+        all files in the data directory.  The search for files will follow
+        symbolic links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-v</option></term>
       <term><option>--verbose</option></term>
diff --git a/doc/src/sgml/ref/pg_dump.sgml b/doc/src/sgml/ref/pg_dump.sgml
index a3cf0608f5..c1e2220b3c 100644
--- a/doc/src/sgml/ref/pg_dump.sgml
+++ b/doc/src/sgml/ref/pg_dump.sgml
@@ -1179,6 +1179,27 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_dump --format=directory</command> will recursively open and
+        synchronize all files in the archive directory.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file system that contains the
+        archive directory.  See <xref linkend="syncfs"/> for more information
+        about using <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used or
+        <option>--format</option> is not set to <literal>directory</literal>.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>--table-and-children=<replaceable class="parameter">pattern</replaceable></option></term>
       <listitem>
diff --git a/doc/src/sgml/ref/pg_rewind.sgml b/doc/src/sgml/ref/pg_rewind.sgml
index 15cddd086b..80dff16168 100644
--- a/doc/src/sgml/ref/pg_rewind.sgml
+++ b/doc/src/sgml/ref/pg_rewind.sgml
@@ -284,6 +284,28 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_rewind</command> will recursively open and synchronize all
+        files in the data directory.  The search for files will follow symbolic
+        links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-V</option></term>
       <term><option>--version</option></term>
diff --git a/doc/src/sgml/ref/pgupgrade.sgml b/doc/src/sgml/ref/pgupgrade.sgml
index 7816b4c685..6c033485ea 100644
--- a/doc/src/sgml/ref/pgupgrade.sgml
+++ b/doc/src/sgml/ref/pgupgrade.sgml
@@ -190,6 +190,29 @@ PostgreSQL documentation
       variable <envar>PGSOCKETDIR</envar></para></listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_upgrade</command> will recursively open and synchronize all
+        files in the upgraded cluster's data directory.  The search for files
+        will follow symbolic links for the WAL directory and each configured
+        tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        upgrade cluster's data directory, its WAL files, and each tablespace.
+        See <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-U</option> <replaceable>username</replaceable></term>
       <term><option>--username=</option><replaceable>username</replaceable></term>
diff --git a/doc/src/sgml/syncfs.sgml b/doc/src/sgml/syncfs.sgml
new file mode 100644
index 0000000000..00457d2457
--- /dev/null
+++ b/doc/src/sgml/syncfs.sgml
@@ -0,0 +1,36 @@
+<!-- doc/src/sgml/syncfs.sgml -->
+
+<appendix id="syncfs">
+ <title><function>syncfs()</function> Caveats</title>
+
+ <indexterm zone="syncfs">
+  <primary>syncfs</primary>
+ </indexterm>
+
+ <para>
+  On Linux <function>syncfs()</function> may be specified for some
+  configuration parameters (e.g.,
+  <xref linkend="guc-recovery-init-sync-method"/>), server applications (e.g.,
+  <application>pg_upgrade</application>), and client applications (e.g.,
+  <application>pg_basebackup</application>) that involve synchronizing many
+  files to disk.  <function>syncfs()</function> is advantageous in many cases,
+  but there are some trade-offs to keep in mind.
+ </para>
+
+ <para>
+  Since <function>syncfs()</function> instructs the operating system to
+  synchronize a whole file system, it typically requires many fewer system
+  calls than using <function>fsync()</function> to synchronize each file one by
+  one.  Therefore, using <function>syncfs()</function> may be a lot faster than
+  using <function>fsync()</function>.  However, it may be slower if a file
+  system is shared by other applications that modify a lot of files, since
+  those files will also be written to disk.
+ </para>
+
+ <para>
+  Furthermore, on versions of Linux before 5.8, I/O errors encountered while
+  writing data to disk may not be reported to the calling program, and relevant
+  error messages may appear only in kernel logs.
+ </para>
+
+</appendix>
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index bbea1e412b..543927b8b4 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -2467,6 +2467,7 @@ usage(const char *progname)
 	printf(_("  -N, --no-sync             do not wait for changes to be written safely to disk\n"));
 	printf(_("      --no-instructions     do not print instructions for next steps\n"));
 	printf(_("  -s, --show                show internal settings\n"));
+	printf(_("      --sync-method=METHOD  set method for syncing files to disk\n"));
 	printf(_("  -S, --sync-only           only sync database files to disk, then exit\n"));
 	printf(_("\nOther options:\n"));
 	printf(_("  -V, --version             output version information, then exit\n"));
@@ -3107,6 +3108,7 @@ main(int argc, char *argv[])
 		{"locale-provider", required_argument, NULL, 15},
 		{"icu-locale", required_argument, NULL, 16},
 		{"icu-rules", required_argument, NULL, 17},
+		{"sync-method", required_argument, NULL, 18},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -3287,6 +3289,10 @@ main(int argc, char *argv[])
 			case 17:
 				icu_rules = pg_strdup(optarg);
 				break;
+			case 18:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/initdb/t/001_initdb.pl b/src/bin/initdb/t/001_initdb.pl
index 2d7469d2fc..2f2c3faba0 100644
--- a/src/bin/initdb/t/001_initdb.pl
+++ b/src/bin/initdb/t/001_initdb.pl
@@ -16,6 +16,7 @@ use Test::More;
 my $tempdir = PostgreSQL::Test::Utils::tempdir;
 my $xlogdir = "$tempdir/pgxlog";
 my $datadir = "$tempdir/data";
+my $supports_syncfs = check_pg_config("#define HAVE_SYNCFS 1");
 
 program_help_ok('initdb');
 program_version_ok('initdb');
@@ -82,6 +83,19 @@ command_fails([ 'pg_checksums', '-D', $datadir ],
 command_ok([ 'initdb', '-S', $datadir ], 'sync only');
 command_fails([ 'initdb', $datadir ], 'existing data directory');
 
+command_ok([ 'initdb', '-S', $datadir, '--sync-method', 'fsync' ],
+	'sync method fsync');
+if ($supports_syncfs)
+{
+	command_ok([ 'initdb', '-S', $datadir, '--sync-method', 'syncfs' ],
+		'sync method syncfs');
+}
+else
+{
+	command_fails([ 'initdb', '-S', $datadir, '--sync-method', 'syncfs' ],
+		'sync method syncfs');
+}
+
 # Check group access on PGDATA
 SKIP:
 {
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 1a6eacf6d5..977c793a67 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -425,6 +425,8 @@ usage(void)
 	printf(_("      --no-slot          prevent creation of temporary replication slot\n"));
 	printf(_("      --no-verify-checksums\n"
 			 "                         do not verify checksums\n"));
+	printf(_("      --sync-method=METHOD\n"
+			 "                         set method for syncing files to disk\n"));
 	printf(_("  -?, --help             show this help, then exit\n"));
 	printf(_("\nConnection options:\n"));
 	printf(_("  -d, --dbname=CONNSTR   connection string\n"));
@@ -2282,6 +2284,7 @@ main(int argc, char **argv)
 		{"no-manifest", no_argument, NULL, 5},
 		{"manifest-force-encode", no_argument, NULL, 6},
 		{"manifest-checksums", required_argument, NULL, 7},
+		{"sync-method", required_argument, NULL, 8},
 		{NULL, 0, NULL, 0}
 	};
 	int			c;
@@ -2453,6 +2456,10 @@ main(int argc, char **argv)
 			case 7:
 				manifest_checksums = pg_strdup(optarg);
 				break;
+			case 8:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 123450f483..9fb2c5b3c7 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -78,6 +78,7 @@ usage(void)
 	printf(_("  -f, --filenode=FILENODE  check only relation with specified filenode\n"));
 	printf(_("  -N, --no-sync            do not wait for changes to be written safely to disk\n"));
 	printf(_("  -P, --progress           show progress information\n"));
+	printf(_("      --sync-method=METHOD set method for syncing files to disk\n"));
 	printf(_("  -v, --verbose            output verbose messages\n"));
 	printf(_("  -V, --version            output version information, then exit\n"));
 	printf(_("  -?, --help               show this help, then exit\n"));
@@ -436,6 +437,7 @@ main(int argc, char *argv[])
 		{"no-sync", no_argument, NULL, 'N'},
 		{"progress", no_argument, NULL, 'P'},
 		{"verbose", no_argument, NULL, 'v'},
+		{"sync-method", required_argument, NULL, 1},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -494,6 +496,10 @@ main(int argc, char *argv[])
 			case 'v':
 				verbose = true;
 				break;
+			case 1:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 39a468b131..dc4a28e81e 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -432,6 +432,7 @@ main(int argc, char **argv)
 		{"table-and-children", required_argument, NULL, 12},
 		{"exclude-table-and-children", required_argument, NULL, 13},
 		{"exclude-table-data-and-children", required_argument, NULL, 14},
+		{"sync-method", required_argument, NULL, 15},
 
 		{NULL, 0, NULL, 0}
 	};
@@ -658,6 +659,11 @@ main(int argc, char **argv)
 										  optarg);
 				break;
 
+			case 15:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit_nicely(1);
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -1069,6 +1075,7 @@ help(const char *progname)
 			 "                               compress as specified\n"));
 	printf(_("  --lock-wait-timeout=TIMEOUT  fail after waiting TIMEOUT for a table lock\n"));
 	printf(_("  --no-sync                    do not wait for changes to be written safely to disk\n"));
+	printf(_("  --sync-method=METHOD         set method for syncing files to disk\n"));
 	printf(_("  -?, --help                   show this help, then exit\n"));
 
 	printf(_("\nOptions controlling the output content:\n"));
diff --git a/src/bin/pg_rewind/pg_rewind.c b/src/bin/pg_rewind/pg_rewind.c
index bdfacf3263..bfd44a284e 100644
--- a/src/bin/pg_rewind/pg_rewind.c
+++ b/src/bin/pg_rewind/pg_rewind.c
@@ -22,6 +22,7 @@
 #include "common/file_perm.h"
 #include "common/restricted_token.h"
 #include "common/string.h"
+#include "fe_utils/option_utils.h"
 #include "fe_utils/recovery_gen.h"
 #include "fe_utils/string_utils.h"
 #include "file_ops.h"
@@ -108,6 +109,7 @@ usage(const char *progname)
 			 "                                 file when running target cluster\n"));
 	printf(_("      --debug                    write a lot of debug messages\n"));
 	printf(_("      --no-ensure-shutdown       do not automatically fix unclean shutdown\n"));
+	printf(_("      --sync-method=METHOD       set method for syncing files to disk\n"));
 	printf(_("  -V, --version                  output version information, then exit\n"));
 	printf(_("  -?, --help                     show this help, then exit\n"));
 	printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
@@ -132,6 +134,7 @@ main(int argc, char **argv)
 		{"no-sync", no_argument, NULL, 'N'},
 		{"progress", no_argument, NULL, 'P'},
 		{"debug", no_argument, NULL, 3},
+		{"sync-method", required_argument, NULL, 6},
 		{NULL, 0, NULL, 0}
 	};
 	int			option_index;
@@ -219,6 +222,11 @@ main(int argc, char **argv)
 				config_file = pg_strdup(optarg);
 				break;
 
+			case 6:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_upgrade/option.c b/src/bin/pg_upgrade/option.c
index 640361009e..b9d900d0db 100644
--- a/src/bin/pg_upgrade/option.c
+++ b/src/bin/pg_upgrade/option.c
@@ -14,6 +14,7 @@
 #endif
 
 #include "common/string.h"
+#include "fe_utils/option_utils.h"
 #include "getopt_long.h"
 #include "pg_upgrade.h"
 #include "utils/pidfile.h"
@@ -57,12 +58,14 @@ parseCommandLine(int argc, char *argv[])
 		{"verbose", no_argument, NULL, 'v'},
 		{"clone", no_argument, NULL, 1},
 		{"copy", no_argument, NULL, 2},
+		{"sync-method", required_argument, NULL, 3},
 
 		{NULL, 0, NULL, 0}
 	};
 	int			option;			/* Command line option */
 	int			optindex = 0;	/* used by getopt_long */
 	int			os_user_effective_id;
+	DataDirSyncMethod unused;
 
 	user_opts.do_sync = true;
 	user_opts.transfer_mode = TRANSFER_MODE_COPY;
@@ -199,6 +202,12 @@ parseCommandLine(int argc, char *argv[])
 				user_opts.transfer_mode = TRANSFER_MODE_COPY;
 				break;
 
+			case 3:
+				if (!parse_sync_method(optarg, &unused))
+					exit(1);
+				user_opts.sync_method = pg_strdup(optarg);
+				break;
+
 			default:
 				fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
 						os_info.progname);
@@ -209,6 +218,9 @@ parseCommandLine(int argc, char *argv[])
 	if (optind < argc)
 		pg_fatal("too many command-line arguments (first is \"%s\")", argv[optind]);
 
+	if (!user_opts.sync_method)
+		user_opts.sync_method = pg_strdup("fsync");
+
 	if (log_opts.verbose)
 		pg_log(PG_REPORT, "Running in verbose mode");
 
@@ -289,6 +301,7 @@ usage(void)
 	printf(_("  -V, --version                 display version information, then exit\n"));
 	printf(_("  --clone                       clone instead of copying files to new cluster\n"));
 	printf(_("  --copy                        copy files to new cluster (default)\n"));
+	printf(_("  --sync-method=METHOD          set method for syncing files to disk\n"));
 	printf(_("  -?, --help                    show this help, then exit\n"));
 	printf(_("\n"
 			 "Before running pg_upgrade you must:\n"
diff --git a/src/bin/pg_upgrade/pg_upgrade.c b/src/bin/pg_upgrade/pg_upgrade.c
index 4562dafcff..96bfb67167 100644
--- a/src/bin/pg_upgrade/pg_upgrade.c
+++ b/src/bin/pg_upgrade/pg_upgrade.c
@@ -192,8 +192,10 @@ main(int argc, char **argv)
 	{
 		prep_status("Sync data directory to disk");
 		exec_prog(UTILITY_LOG_FILE, NULL, true, true,
-				  "\"%s/initdb\" --sync-only \"%s\"", new_cluster.bindir,
-				  new_cluster.pgdata);
+				  "\"%s/initdb\" --sync-only \"%s\" --sync-method %s",
+				  new_cluster.bindir,
+				  new_cluster.pgdata,
+				  user_opts.sync_method);
 		check_ok();
 	}
 
diff --git a/src/bin/pg_upgrade/pg_upgrade.h b/src/bin/pg_upgrade/pg_upgrade.h
index 7afa96716e..842f3b6cd3 100644
--- a/src/bin/pg_upgrade/pg_upgrade.h
+++ b/src/bin/pg_upgrade/pg_upgrade.h
@@ -304,6 +304,7 @@ typedef struct
 	transferMode transfer_mode; /* copy files or link them? */
 	int			jobs;			/* number of processes/threads to use */
 	char	   *socketdir;		/* directory to use for Unix sockets */
+	char	   *sync_method;
 } UserOpts;
 
 typedef struct
diff --git a/src/fe_utils/option_utils.c b/src/fe_utils/option_utils.c
index 763c991015..36ac689964 100644
--- a/src/fe_utils/option_utils.c
+++ b/src/fe_utils/option_utils.c
@@ -82,3 +82,27 @@ option_parse_int(const char *optarg, const char *optname,
 		*result = val;
 	return true;
 }
+
+bool
+parse_sync_method(const char *optarg, DataDirSyncMethod *sync_method)
+{
+	if (strcmp(optarg, "fsync") == 0)
+		*sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
+	else if (strcmp(optarg, "syncfs") == 0)
+	{
+#ifdef HAVE_SYNCFS
+		*sync_method = DATA_DIR_SYNC_METHOD_SYNCFS;
+#else
+		pg_log_error("this build does not support sync method \"%s\"",
+					 "syncfs");
+		return false;
+#endif
+	}
+	else
+	{
+		pg_log_error("unrecognized sync method: %s", optarg);
+		return false;
+	}
+
+	return true;
+}
diff --git a/src/include/fe_utils/option_utils.h b/src/include/fe_utils/option_utils.h
index b7b0654cee..6f3a965916 100644
--- a/src/include/fe_utils/option_utils.h
+++ b/src/include/fe_utils/option_utils.h
@@ -14,6 +14,8 @@
 
 #include "postgres_fe.h"
 
+#include "common/file_utils.h"
+
 typedef void (*help_handler) (const char *progname);
 
 extern void handle_help_version_opts(int argc, char *argv[],
@@ -22,5 +24,7 @@ extern void handle_help_version_opts(int argc, char *argv[],
 extern bool option_parse_int(const char *optarg, const char *optname,
 							 int min_range, int max_range,
 							 int *result);
+extern bool parse_sync_method(const char *optarg,
+							  DataDirSyncMethod *sync_method);
 
 #endif							/* OPTION_UTILS_H */
-- 
2.25.1

From bc2210a3cee0a852b65f74b544a0c0d23c59b78f Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Mon, 21 Aug 2023 19:05:14 -0700
Subject: [PATCH v9 1/4] move PG_TEMP_FILE* macros to file_utils.h

---
 src/backend/backup/basebackup.c     |  2 +-
 src/backend/postmaster/postmaster.c |  1 +
 src/backend/storage/file/fileset.c  |  1 +
 src/bin/pg_checksums/pg_checksums.c | 10 ----------
 src/bin/pg_rewind/filemap.c         |  2 +-
 src/include/common/file_utils.h     |  4 ++++
 src/include/storage/fd.h            |  4 ----
 7 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/src/backend/backup/basebackup.c b/src/backend/backup/basebackup.c
index 45be21131c..5d66014499 100644
--- a/src/backend/backup/basebackup.c
+++ b/src/backend/backup/basebackup.c
@@ -25,6 +25,7 @@
 #include "commands/defrem.h"
 #include "common/compression.h"
 #include "common/file_perm.h"
+#include "common/file_utils.h"
 #include "lib/stringinfo.h"
 #include "miscadmin.h"
 #include "nodes/pg_list.h"
@@ -37,7 +38,6 @@
 #include "storage/bufpage.h"
 #include "storage/checksum.h"
 #include "storage/dsm_impl.h"
-#include "storage/fd.h"
 #include "storage/ipc.h"
 #include "storage/reinit.h"
 #include "utils/builtins.h"
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index d7bfb28ff3..54e9bfb8c4 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -94,6 +94,7 @@
 #include "access/xlogrecovery.h"
 #include "catalog/pg_control.h"
 #include "common/file_perm.h"
+#include "common/file_utils.h"
 #include "common/ip.h"
 #include "common/pg_prng.h"
 #include "common/string.h"
diff --git a/src/backend/storage/file/fileset.c b/src/backend/storage/file/fileset.c
index e9951b0269..84cae32548 100644
--- a/src/backend/storage/file/fileset.c
+++ b/src/backend/storage/file/fileset.c
@@ -25,6 +25,7 @@
 
 #include "catalog/pg_tablespace.h"
 #include "commands/tablespace.h"
+#include "common/file_utils.h"
 #include "common/hashfn.h"
 #include "miscadmin.h"
 #include "storage/ipc.h"
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 19eb67e485..9011a19b4e 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -52,16 +52,6 @@ typedef enum
 	PG_MODE_ENABLE
 } PgChecksumMode;
 
-/*
- * Filename components.
- *
- * XXX: fd.h is not declared here as frontend side code is not able to
- * interact with the backend-side definitions for the various fsync
- * wrappers.
- */
-#define PG_TEMP_FILES_DIR "pgsql_tmp"
-#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
-
 static PgChecksumMode mode = PG_MODE_CHECK;
 
 static const char *progname;
diff --git a/src/bin/pg_rewind/filemap.c b/src/bin/pg_rewind/filemap.c
index bd5c598e20..58280d9abc 100644
--- a/src/bin/pg_rewind/filemap.c
+++ b/src/bin/pg_rewind/filemap.c
@@ -27,12 +27,12 @@
 #include <unistd.h>
 
 #include "catalog/pg_tablespace_d.h"
+#include "common/file_utils.h"
 #include "common/hashfn.h"
 #include "common/string.h"
 #include "datapagemap.h"
 #include "filemap.h"
 #include "pg_rewind.h"
-#include "storage/fd.h"
 
 /*
  * Define a hash table which we can use to store information about the files
diff --git a/src/include/common/file_utils.h b/src/include/common/file_utils.h
index b7efa1226d..dd1532bcb0 100644
--- a/src/include/common/file_utils.h
+++ b/src/include/common/file_utils.h
@@ -46,4 +46,8 @@ extern ssize_t pg_pwritev_with_retry(int fd,
 
 extern ssize_t pg_pwrite_zeros(int fd, size_t size, off_t offset);
 
+/* Filename components */
+#define PG_TEMP_FILES_DIR "pgsql_tmp"
+#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
+
 #endif							/* FILE_UTILS_H */
diff --git a/src/include/storage/fd.h b/src/include/storage/fd.h
index 6791a406fc..aea30c0622 100644
--- a/src/include/storage/fd.h
+++ b/src/include/storage/fd.h
@@ -195,8 +195,4 @@ extern int	durable_unlink(const char *fname, int elevel);
 extern void SyncDataDirectory(void);
 extern int	data_sync_elevel(int elevel);
 
-/* Filename components */
-#define PG_TEMP_FILES_DIR "pgsql_tmp"
-#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
-
 #endif							/* FD_H */
-- 
2.25.1

From ae51ea0182e88398a5c8ebd644fea9e98229e1d0 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Thu, 31 Aug 2023 07:38:42 -0700
Subject: [PATCH v9 2/4] make common enum for sync methods

---
 src/backend/storage/file/fd.c       | 4 ++--
 src/backend/utils/misc/guc_tables.c | 7 ++++---
 src/include/common/file_utils.h     | 6 ++++++
 src/include/storage/fd.h            | 6 ------
 src/tools/pgindent/typedefs.list    | 1 +
 5 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index b490a76ba7..3fed475c38 100644
--- a/src/backend/storage/file/fd.c
+++ b/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;
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index e565a3092f..5abebe9a9c 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/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}
 };
@@ -4964,7 +4965,7 @@ 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
 	},
 
diff --git a/src/include/common/file_utils.h b/src/include/common/file_utils.h
index dd1532bcb0..7da21f15e6 100644
--- a/src/include/common/file_utils.h
+++ b/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
diff --git a/src/include/storage/fd.h b/src/include/storage/fd.h
index aea30c0622..d9d5d9da5f 100644
--- a/src/include/storage/fd.h
+++ b/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;
 
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 49a33c0387..fe571c6265 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -545,6 +545,7 @@ DR_printtup
 DR_sqlfunction
 DR_transientrel
 DWORD
+DataDirSyncMethod
 DataDumperPtr
 DataPageDeleteStack
 DatabaseInfo
-- 
2.25.1

From 0176762890bc8ddc02e26696ba4414c6c8bac2e5 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Thu, 31 Aug 2023 07:59:52 -0700
Subject: [PATCH v9 3/4] add support for syncfs in frontend support functions

---
 src/bin/initdb/initdb.c               |   5 +-
 src/bin/pg_basebackup/pg_basebackup.c |   5 +-
 src/bin/pg_checksums/pg_checksums.c   |   3 +-
 src/bin/pg_dump/pg_backup.h           |   4 +-
 src/bin/pg_dump/pg_backup_archiver.c  |  14 ++-
 src/bin/pg_dump/pg_backup_archiver.h  |   1 +
 src/bin/pg_dump/pg_backup_directory.c |   2 +-
 src/bin/pg_dump/pg_dump.c             |   3 +-
 src/bin/pg_rewind/file_ops.c          |   2 +-
 src/bin/pg_rewind/pg_rewind.c         |   1 +
 src/bin/pg_rewind/pg_rewind.h         |   2 +
 src/common/file_utils.c               | 170 +++++++++++++++++++++-----
 src/include/common/file_utils.h       |   5 +-
 13 files changed, 172 insertions(+), 45 deletions(-)

diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index 905b979947..bbea1e412b 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -165,6 +165,7 @@ static bool show_setting = false;
 static bool data_checksums = false;
 static char *xlog_dir = NULL;
 static int	wal_segment_size_mb = (DEFAULT_XLOG_SEG_SIZE) / (1024 * 1024);
+static DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 
 /* internal vars */
@@ -3333,7 +3334,7 @@ main(int argc, char *argv[])
 
 		fputs(_("syncing data to disk ... "), stdout);
 		fflush(stdout);
-		fsync_pgdata(pg_data, PG_VERSION_NUM);
+		fsync_pgdata(pg_data, PG_VERSION_NUM, sync_method);
 		check_ok();
 		return 0;
 	}
@@ -3396,7 +3397,7 @@ main(int argc, char *argv[])
 	{
 		fputs(_("syncing data to disk ... "), stdout);
 		fflush(stdout);
-		fsync_pgdata(pg_data, PG_VERSION_NUM);
+		fsync_pgdata(pg_data, PG_VERSION_NUM, sync_method);
 		check_ok();
 	}
 	else
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 1dc8efe0cb..1a6eacf6d5 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -148,6 +148,7 @@ static bool verify_checksums = true;
 static bool manifest = true;
 static bool manifest_force_encode = false;
 static char *manifest_checksums = NULL;
+static DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 static bool success = false;
 static bool made_new_pgdata = false;
@@ -2199,11 +2200,11 @@ BaseBackup(char *compression_algorithm, char *compression_detail,
 		if (format == 't')
 		{
 			if (strcmp(basedir, "-") != 0)
-				(void) fsync_dir_recurse(basedir);
+				(void) fsync_dir_recurse(basedir, sync_method);
 		}
 		else
 		{
-			(void) fsync_pgdata(basedir, serverVersion);
+			(void) fsync_pgdata(basedir, serverVersion, sync_method);
 		}
 	}
 
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 9011a19b4e..123450f483 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -44,6 +44,7 @@ static char *only_filenode = NULL;
 static bool do_sync = true;
 static bool verbose = false;
 static bool showprogress = false;
+static DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 typedef enum
 {
@@ -623,7 +624,7 @@ main(int argc, char *argv[])
 		if (do_sync)
 		{
 			pg_log_info("syncing data directory");
-			fsync_pgdata(DataDir, PG_VERSION_NUM);
+			fsync_pgdata(DataDir, PG_VERSION_NUM, sync_method);
 		}
 
 		pg_log_info("updating control file");
diff --git a/src/bin/pg_dump/pg_backup.h b/src/bin/pg_dump/pg_backup.h
index aba780ef4b..3a57cdd97d 100644
--- a/src/bin/pg_dump/pg_backup.h
+++ b/src/bin/pg_dump/pg_backup.h
@@ -24,6 +24,7 @@
 #define PG_BACKUP_H
 
 #include "common/compression.h"
+#include "common/file_utils.h"
 #include "fe_utils/simple_list.h"
 #include "libpq-fe.h"
 
@@ -307,7 +308,8 @@ extern Archive *OpenArchive(const char *FileSpec, const ArchiveFormat fmt);
 extern Archive *CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 							  const pg_compress_specification compression_spec,
 							  bool dosync, ArchiveMode mode,
-							  SetupWorkerPtrType setupDumpWorker);
+							  SetupWorkerPtrType setupDumpWorker,
+							  DataDirSyncMethod sync_method);
 
 /* The --list option */
 extern void PrintTOCSummary(Archive *AHX);
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index 39ebcfec32..4d83381d84 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -66,7 +66,8 @@ typedef struct _parallelReadyList
 static ArchiveHandle *_allocAH(const char *FileSpec, const ArchiveFormat fmt,
 							   const pg_compress_specification compression_spec,
 							   bool dosync, ArchiveMode mode,
-							   SetupWorkerPtrType setupWorkerPtr);
+							   SetupWorkerPtrType setupWorkerPtr,
+							   DataDirSyncMethod sync_method);
 static void _getObjectDescription(PQExpBuffer buf, const TocEntry *te);
 static void _printTocEntry(ArchiveHandle *AH, TocEntry *te, bool isData);
 static char *sanitize_line(const char *str, bool want_hyphen);
@@ -238,11 +239,12 @@ Archive *
 CreateArchive(const char *FileSpec, const ArchiveFormat fmt,
 			  const pg_compress_specification compression_spec,
 			  bool dosync, ArchiveMode mode,
-			  SetupWorkerPtrType setupDumpWorker)
+			  SetupWorkerPtrType setupDumpWorker,
+			  DataDirSyncMethod sync_method)
 
 {
 	ArchiveHandle *AH = _allocAH(FileSpec, fmt, compression_spec,
-								 dosync, mode, setupDumpWorker);
+								 dosync, mode, setupDumpWorker, sync_method);
 
 	return (Archive *) AH;
 }
@@ -257,7 +259,8 @@ OpenArchive(const char *FileSpec, const ArchiveFormat fmt)
 
 	compression_spec.algorithm = PG_COMPRESSION_NONE;
 	AH = _allocAH(FileSpec, fmt, compression_spec, true,
-				  archModeRead, setupRestoreWorker);
+				  archModeRead, setupRestoreWorker,
+				  DATA_DIR_SYNC_METHOD_FSYNC);
 
 	return (Archive *) AH;
 }
@@ -2233,7 +2236,7 @@ static ArchiveHandle *
 _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 		 const pg_compress_specification compression_spec,
 		 bool dosync, ArchiveMode mode,
-		 SetupWorkerPtrType setupWorkerPtr)
+		 SetupWorkerPtrType setupWorkerPtr, DataDirSyncMethod sync_method)
 {
 	ArchiveHandle *AH;
 	CompressFileHandle *CFH;
@@ -2287,6 +2290,7 @@ _allocAH(const char *FileSpec, const ArchiveFormat fmt,
 	AH->mode = mode;
 	AH->compression_spec = compression_spec;
 	AH->dosync = dosync;
+	AH->sync_method = sync_method;
 
 	memset(&(AH->sqlparse), 0, sizeof(AH->sqlparse));
 
diff --git a/src/bin/pg_dump/pg_backup_archiver.h b/src/bin/pg_dump/pg_backup_archiver.h
index 18b38c17ab..b07673933d 100644
--- a/src/bin/pg_dump/pg_backup_archiver.h
+++ b/src/bin/pg_dump/pg_backup_archiver.h
@@ -312,6 +312,7 @@ struct _archiveHandle
 	pg_compress_specification compression_spec; /* Requested specification for
 												 * compression */
 	bool		dosync;			/* data requested to be synced on sight */
+	DataDirSyncMethod sync_method;
 	ArchiveMode mode;			/* File mode - r or w */
 	void	   *formatData;		/* Header data specific to file format */
 
diff --git a/src/bin/pg_dump/pg_backup_directory.c b/src/bin/pg_dump/pg_backup_directory.c
index 7f2ac7c7fd..6faa3a511f 100644
--- a/src/bin/pg_dump/pg_backup_directory.c
+++ b/src/bin/pg_dump/pg_backup_directory.c
@@ -613,7 +613,7 @@ _CloseArchive(ArchiveHandle *AH)
 		 * individually. Just recurse once through all the files generated.
 		 */
 		if (AH->dosync)
-			fsync_dir_recurse(ctx->directory);
+			fsync_dir_recurse(ctx->directory, AH->sync_method);
 	}
 	AH->FH = NULL;
 }
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 65f64c282d..39a468b131 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -357,6 +357,7 @@ main(int argc, char **argv)
 	char	   *compression_algorithm_str = "none";
 	char	   *error_detail = NULL;
 	bool		user_compression_defined = false;
+	DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 	static DumpOptions dopt;
 
@@ -777,7 +778,7 @@ main(int argc, char **argv)
 
 	/* Open the output file */
 	fout = CreateArchive(filename, archiveFormat, compression_spec,
-						 dosync, archiveMode, setupDumpWorker);
+						 dosync, archiveMode, setupDumpWorker, sync_method);
 
 	/* Make dump options accessible right away */
 	SetArchiveOptions(fout, &dopt, NULL);
diff --git a/src/bin/pg_rewind/file_ops.c b/src/bin/pg_rewind/file_ops.c
index 25996b4da4..451fb1856e 100644
--- a/src/bin/pg_rewind/file_ops.c
+++ b/src/bin/pg_rewind/file_ops.c
@@ -296,7 +296,7 @@ sync_target_dir(void)
 	if (!do_sync || dry_run)
 		return;
 
-	fsync_pgdata(datadir_target, PG_VERSION_NUM);
+	fsync_pgdata(datadir_target, PG_VERSION_NUM, sync_method);
 }
 
 
diff --git a/src/bin/pg_rewind/pg_rewind.c b/src/bin/pg_rewind/pg_rewind.c
index 7f69f02441..bdfacf3263 100644
--- a/src/bin/pg_rewind/pg_rewind.c
+++ b/src/bin/pg_rewind/pg_rewind.c
@@ -74,6 +74,7 @@ bool		showprogress = false;
 bool		dry_run = false;
 bool		do_sync = true;
 bool		restore_wal = false;
+DataDirSyncMethod sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
 
 /* Target history */
 TimeLineHistoryEntry *targetHistory;
diff --git a/src/bin/pg_rewind/pg_rewind.h b/src/bin/pg_rewind/pg_rewind.h
index ef8bdc1fbb..05729adfef 100644
--- a/src/bin/pg_rewind/pg_rewind.h
+++ b/src/bin/pg_rewind/pg_rewind.h
@@ -13,6 +13,7 @@
 
 #include "access/timeline.h"
 #include "common/logging.h"
+#include "common/file_utils.h"
 #include "datapagemap.h"
 #include "libpq-fe.h"
 #include "storage/block.h"
@@ -24,6 +25,7 @@ extern bool showprogress;
 extern bool dry_run;
 extern bool do_sync;
 extern int	WalSegSz;
+extern DataDirSyncMethod sync_method;
 
 /* Target history */
 extern TimeLineHistoryEntry *targetHistory;
diff --git a/src/common/file_utils.c b/src/common/file_utils.c
index 74833c4acb..05c73c0bb7 100644
--- a/src/common/file_utils.c
+++ b/src/common/file_utils.c
@@ -51,6 +51,31 @@ static void walkdir(const char *path,
 					int (*action) (const char *fname, bool isdir),
 					bool process_symlinks);
 
+#ifdef HAVE_SYNCFS
+static void
+do_syncfs(const char *path)
+{
+	int			fd;
+
+	fd = open(path, O_RDONLY, 0);
+
+	if (fd < 0)
+	{
+		pg_log_error("could not open file \"%s\": %m", path);
+		return;
+	}
+
+	if (syncfs(fd) < 0)
+	{
+		pg_log_error("could not synchronize file system for file \"%s\": %m", path);
+		(void) close(fd);
+		exit(EXIT_FAILURE);
+	}
+
+	(void) close(fd);
+}
+#endif
+
 /*
  * Issue fsync recursively on PGDATA and all its contents.
  *
@@ -63,7 +88,8 @@ static void walkdir(const char *path,
  */
 void
 fsync_pgdata(const char *pg_data,
-			 int serverVersion)
+			 int serverVersion,
+			 DataDirSyncMethod sync_method)
 {
 	bool		xlog_is_symlink;
 	char		pg_wal[MAXPGPATH];
@@ -89,30 +115,93 @@ fsync_pgdata(const char *pg_data,
 			xlog_is_symlink = true;
 	}
 
-	/*
-	 * If possible, hint to the kernel that we're soon going to fsync the data
-	 * directory and its contents.
-	 */
+	switch (sync_method)
+	{
+		case DATA_DIR_SYNC_METHOD_SYNCFS:
+			{
+#ifndef HAVE_SYNCFS
+				pg_log_error("this build does not support sync method \"%s\"",
+							 "syncfs");
+				exit(EXIT_FAILURE);
+#else
+				DIR		   *dir;
+				struct dirent *de;
+
+				/*
+				 * On Linux, we don't have to open every single file one by
+				 * one.  We can use syncfs() to sync whole filesystems.  We
+				 * only expect filesystem boundaries to exist where we
+				 * tolerate symlinks, namely pg_wal and the tablespaces, so we
+				 * call syncfs() for each of those directories.
+				 */
+
+				/* Sync the top level pgdata directory. */
+				do_syncfs(pg_data);
+
+				/* If any tablespaces are configured, sync each of those. */
+				dir = opendir(pg_tblspc);
+				if (dir == NULL)
+					pg_log_error("could not open directory \"%s\": %m",
+								 pg_tblspc);
+				else
+				{
+					while (errno = 0, (de = readdir(dir)) != NULL)
+					{
+						char		subpath[MAXPGPATH * 2];
+
+						if (strcmp(de->d_name, ".") == 0 ||
+							strcmp(de->d_name, "..") == 0)
+							continue;
+
+						snprintf(subpath, sizeof(subpath), "%s/%s",
+								 pg_tblspc, de->d_name);
+						do_syncfs(subpath);
+					}
+
+					if (errno)
+						pg_log_error("could not read directory \"%s\": %m",
+									 pg_tblspc);
+
+					(void) closedir(dir);
+				}
+
+				/* If pg_wal is a symlink, process that too. */
+				if (xlog_is_symlink)
+					do_syncfs(pg_wal);
+#endif							/* HAVE_SYNCFS */
+			}
+			break;
+
+		case DATA_DIR_SYNC_METHOD_FSYNC:
+			{
+				/*
+				 * If possible, hint to the kernel that we're soon going to
+				 * fsync the data directory and its contents.
+				 */
 #ifdef PG_FLUSH_DATA_WORKS
-	walkdir(pg_data, pre_sync_fname, false);
-	if (xlog_is_symlink)
-		walkdir(pg_wal, pre_sync_fname, false);
-	walkdir(pg_tblspc, pre_sync_fname, true);
+				walkdir(pg_data, pre_sync_fname, false);
+				if (xlog_is_symlink)
+					walkdir(pg_wal, pre_sync_fname, false);
+				walkdir(pg_tblspc, pre_sync_fname, true);
 #endif
 
-	/*
-	 * Now we do the fsync()s in the same order.
-	 *
-	 * The main call ignores symlinks, so in addition to specially processing
-	 * pg_wal if it's a symlink, pg_tblspc has to be visited separately with
-	 * process_symlinks = true.  Note that if there are any plain directories
-	 * in pg_tblspc, they'll get fsync'd twice.  That's not an expected case
-	 * so we don't worry about optimizing it.
-	 */
-	walkdir(pg_data, fsync_fname, false);
-	if (xlog_is_symlink)
-		walkdir(pg_wal, fsync_fname, false);
-	walkdir(pg_tblspc, fsync_fname, true);
+				/*
+				 * Now we do the fsync()s in the same order.
+				 *
+				 * The main call ignores symlinks, so in addition to specially
+				 * processing pg_wal if it's a symlink, pg_tblspc has to be
+				 * visited separately with process_symlinks = true.  Note that
+				 * if there are any plain directories in pg_tblspc, they'll
+				 * get fsync'd twice. That's not an expected case so we don't
+				 * worry about optimizing it.
+				 */
+				walkdir(pg_data, fsync_fname, false);
+				if (xlog_is_symlink)
+					walkdir(pg_wal, fsync_fname, false);
+				walkdir(pg_tblspc, fsync_fname, true);
+			}
+			break;
+	}
 }
 
 /*
@@ -121,17 +210,40 @@ fsync_pgdata(const char *pg_data,
  * This is a convenient wrapper on top of walkdir().
  */
 void
-fsync_dir_recurse(const char *dir)
+fsync_dir_recurse(const char *dir, DataDirSyncMethod sync_method)
 {
-	/*
-	 * If possible, hint to the kernel that we're soon going to fsync the data
-	 * directory and its contents.
-	 */
+	switch (sync_method)
+	{
+		case DATA_DIR_SYNC_METHOD_SYNCFS:
+			{
+#ifndef HAVE_SYNCFS
+				pg_log_error("this build does not support sync method \"%s\"",
+							 "syncfs");
+				exit(EXIT_FAILURE);
+#else
+				/*
+				 * On Linux, we don't have to open every single file one by
+				 * one.  We can use syncfs() to sync the whole filesystem.
+				 */
+				do_syncfs(dir);
+#endif							/* HAVE_SYNCFS */
+			}
+			break;
+
+		case DATA_DIR_SYNC_METHOD_FSYNC:
+			{
+				/*
+				 * If possible, hint to the kernel that we're soon going to
+				 * fsync the data directory and its contents.
+				 */
 #ifdef PG_FLUSH_DATA_WORKS
-	walkdir(dir, pre_sync_fname, false);
+				walkdir(dir, pre_sync_fname, false);
 #endif
 
-	walkdir(dir, fsync_fname, false);
+				walkdir(dir, fsync_fname, false);
+			}
+			break;
+	}
 }
 
 /*
diff --git a/src/include/common/file_utils.h b/src/include/common/file_utils.h
index 7da21f15e6..cae6159bf6 100644
--- a/src/include/common/file_utils.h
+++ b/src/include/common/file_utils.h
@@ -34,8 +34,9 @@ struct iovec;					/* avoid including port/pg_iovec.h here */
 
 #ifdef FRONTEND
 extern int	fsync_fname(const char *fname, bool isdir);
-extern void fsync_pgdata(const char *pg_data, int serverVersion);
-extern void fsync_dir_recurse(const char *dir);
+extern void fsync_pgdata(const char *pg_data, int serverVersion,
+						 DataDirSyncMethod sync_method);
+extern void fsync_dir_recurse(const char *dir, DataDirSyncMethod sync_method);
 extern int	durable_rename(const char *oldfile, const char *newfile);
 extern int	fsync_parent_path(const char *fname);
 #endif
-- 
2.25.1

From 215eb53c8f28a8c54dd14fb8877b377fb72d7fba Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Fri, 28 Jul 2023 15:56:24 -0700
Subject: [PATCH v9 4/4] allow syncfs in frontend utilities

---
 doc/src/sgml/config.sgml              | 12 +++------
 doc/src/sgml/filelist.sgml            |  1 +
 doc/src/sgml/postgres.sgml            |  1 +
 doc/src/sgml/ref/initdb.sgml          | 22 ++++++++++++++++
 doc/src/sgml/ref/pg_basebackup.sgml   | 25 +++++++++++++++++++
 doc/src/sgml/ref/pg_checksums.sgml    | 22 ++++++++++++++++
 doc/src/sgml/ref/pg_dump.sgml         | 21 ++++++++++++++++
 doc/src/sgml/ref/pg_rewind.sgml       | 22 ++++++++++++++++
 doc/src/sgml/ref/pgupgrade.sgml       | 23 +++++++++++++++++
 doc/src/sgml/syncfs.sgml              | 36 +++++++++++++++++++++++++++
 src/bin/initdb/initdb.c               |  6 +++++
 src/bin/initdb/t/001_initdb.pl        | 12 +++++++++
 src/bin/pg_basebackup/pg_basebackup.c |  7 ++++++
 src/bin/pg_checksums/pg_checksums.c   |  6 +++++
 src/bin/pg_dump/pg_dump.c             |  7 ++++++
 src/bin/pg_rewind/pg_rewind.c         |  8 ++++++
 src/bin/pg_upgrade/option.c           | 13 ++++++++++
 src/bin/pg_upgrade/pg_upgrade.c       |  6 +++--
 src/bin/pg_upgrade/pg_upgrade.h       |  1 +
 src/fe_utils/option_utils.c           | 24 ++++++++++++++++++
 src/include/fe_utils/option_utils.h   |  4 +++
 21 files changed, 268 insertions(+), 11 deletions(-)
 create mode 100644 doc/src/sgml/syncfs.sgml

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 694d667bf9..2c7d9f1262 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -10580,15 +10580,9 @@ dynamic_library_path = 'C:\tools\postgresql;H:\my_project\lib;$libdir'
         On Linux, <literal>syncfs</literal> may be used instead, to ask the
         operating system to synchronize the whole file systems that contain the
         data directory, the WAL files and each tablespace (but not any other
-        file systems that may be reachable through symbolic links).  This may
-        be a lot faster than the <literal>fsync</literal> setting, because it
-        doesn't need to open each file one by one.  On the other hand, it may
-        be slower if a file system is shared by other applications that
-        modify a lot of files, since those files will also be written to disk.
-        Furthermore, on versions of Linux before 5.8, I/O errors encountered
-        while writing data to disk may not be reported to
-        <productname>PostgreSQL</productname>, and relevant error messages may
-        appear only in kernel logs.
+        file systems that may be reachable through symbolic links).  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
        </para>
        <para>
         This parameter can only be set in the
diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
index 63b0fc2a46..df5d7c3025 100644
--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -184,6 +184,7 @@
 <!ENTITY acronyms   SYSTEM "acronyms.sgml">
 <!ENTITY glossary   SYSTEM "glossary.sgml">
 <!ENTITY color      SYSTEM "color.sgml">
+<!ENTITY syncfs     SYSTEM "syncfs.sgml">
 
 <!ENTITY features-supported   SYSTEM "features-supported.sgml">
 <!ENTITY features-unsupported SYSTEM "features-unsupported.sgml">
diff --git a/doc/src/sgml/postgres.sgml b/doc/src/sgml/postgres.sgml
index 2e271862fc..f629524be0 100644
--- a/doc/src/sgml/postgres.sgml
+++ b/doc/src/sgml/postgres.sgml
@@ -294,6 +294,7 @@ break is not needed in a wider output rendering.
   &acronyms;
   &glossary;
   &color;
+  &syncfs;
   &obsolete;
 
  </part>
diff --git a/doc/src/sgml/ref/initdb.sgml b/doc/src/sgml/ref/initdb.sgml
index 22f1011781..8a09c5c438 100644
--- a/doc/src/sgml/ref/initdb.sgml
+++ b/doc/src/sgml/ref/initdb.sgml
@@ -365,6 +365,28 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry id="app-initdb-option-sync-method">
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>initdb</command> will recursively open and synchronize all
+        files in the data directory.  The search for files will follow symbolic
+        links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="app-initdb-option-sync-only">
       <term><option>-S</option></term>
       <term><option>--sync-only</option></term>
diff --git a/doc/src/sgml/ref/pg_basebackup.sgml b/doc/src/sgml/ref/pg_basebackup.sgml
index 79d3e657c3..d2b8ddd200 100644
--- a/doc/src/sgml/ref/pg_basebackup.sgml
+++ b/doc/src/sgml/ref/pg_basebackup.sgml
@@ -594,6 +594,31 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_basebackup</command> will recursively open and synchronize
+        all files in the backup directory.  When the plain format is used, the
+        search for files will follow symbolic links for the WAL directory and
+        each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file system that contains the
+        backup directory.  When the plain format is used,
+        <command>pg_basebackup</command> will also synchronize the file systems
+        that contain the WAL files and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-v</option></term>
       <term><option>--verbose</option></term>
diff --git a/doc/src/sgml/ref/pg_checksums.sgml b/doc/src/sgml/ref/pg_checksums.sgml
index a3d0b0f0a3..7b44ba71cf 100644
--- a/doc/src/sgml/ref/pg_checksums.sgml
+++ b/doc/src/sgml/ref/pg_checksums.sgml
@@ -139,6 +139,28 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_checksums</command> will recursively open and synchronize
+        all files in the data directory.  The search for files will follow
+        symbolic links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-v</option></term>
       <term><option>--verbose</option></term>
diff --git a/doc/src/sgml/ref/pg_dump.sgml b/doc/src/sgml/ref/pg_dump.sgml
index a3cf0608f5..c1e2220b3c 100644
--- a/doc/src/sgml/ref/pg_dump.sgml
+++ b/doc/src/sgml/ref/pg_dump.sgml
@@ -1179,6 +1179,27 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_dump --format=directory</command> will recursively open and
+        synchronize all files in the archive directory.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file system that contains the
+        archive directory.  See <xref linkend="syncfs"/> for more information
+        about using <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used or
+        <option>--format</option> is not set to <literal>directory</literal>.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>--table-and-children=<replaceable class="parameter">pattern</replaceable></option></term>
       <listitem>
diff --git a/doc/src/sgml/ref/pg_rewind.sgml b/doc/src/sgml/ref/pg_rewind.sgml
index 15cddd086b..80dff16168 100644
--- a/doc/src/sgml/ref/pg_rewind.sgml
+++ b/doc/src/sgml/ref/pg_rewind.sgml
@@ -284,6 +284,28 @@ PostgreSQL documentation
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_rewind</command> will recursively open and synchronize all
+        files in the data directory.  The search for files will follow symbolic
+        links for the WAL directory and each configured tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        data directory, the WAL files, and each tablespace.  See
+        <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-V</option></term>
       <term><option>--version</option></term>
diff --git a/doc/src/sgml/ref/pgupgrade.sgml b/doc/src/sgml/ref/pgupgrade.sgml
index 7816b4c685..6c033485ea 100644
--- a/doc/src/sgml/ref/pgupgrade.sgml
+++ b/doc/src/sgml/ref/pgupgrade.sgml
@@ -190,6 +190,29 @@ PostgreSQL documentation
       variable <envar>PGSOCKETDIR</envar></para></listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><option>--sync-method</option></term>
+      <listitem>
+       <para>
+        When set to <literal>fsync</literal>, which is the default,
+        <command>pg_upgrade</command> will recursively open and synchronize all
+        files in the upgraded cluster's data directory.  The search for files
+        will follow symbolic links for the WAL directory and each configured
+        tablespace.
+       </para>
+       <para>
+        On Linux, <literal>syncfs</literal> may be used instead to ask the
+        operating system to synchronize the whole file systems that contain the
+        upgrade cluster's data directory, its WAL files, and each tablespace.
+        See <xref linkend="syncfs"/> for more information about using
+        <function>syncfs()</function>.
+       </para>
+       <para>
+        This option has no effect when <option>--no-sync</option> is used.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry>
       <term><option>-U</option> <replaceable>username</replaceable></term>
       <term><option>--username=</option><replaceable>username</replaceable></term>
diff --git a/doc/src/sgml/syncfs.sgml b/doc/src/sgml/syncfs.sgml
new file mode 100644
index 0000000000..00457d2457
--- /dev/null
+++ b/doc/src/sgml/syncfs.sgml
@@ -0,0 +1,36 @@
+<!-- doc/src/sgml/syncfs.sgml -->
+
+<appendix id="syncfs">
+ <title><function>syncfs()</function> Caveats</title>
+
+ <indexterm zone="syncfs">
+  <primary>syncfs</primary>
+ </indexterm>
+
+ <para>
+  On Linux <function>syncfs()</function> may be specified for some
+  configuration parameters (e.g.,
+  <xref linkend="guc-recovery-init-sync-method"/>), server applications (e.g.,
+  <application>pg_upgrade</application>), and client applications (e.g.,
+  <application>pg_basebackup</application>) that involve synchronizing many
+  files to disk.  <function>syncfs()</function> is advantageous in many cases,
+  but there are some trade-offs to keep in mind.
+ </para>
+
+ <para>
+  Since <function>syncfs()</function> instructs the operating system to
+  synchronize a whole file system, it typically requires many fewer system
+  calls than using <function>fsync()</function> to synchronize each file one by
+  one.  Therefore, using <function>syncfs()</function> may be a lot faster than
+  using <function>fsync()</function>.  However, it may be slower if a file
+  system is shared by other applications that modify a lot of files, since
+  those files will also be written to disk.
+ </para>
+
+ <para>
+  Furthermore, on versions of Linux before 5.8, I/O errors encountered while
+  writing data to disk may not be reported to the calling program, and relevant
+  error messages may appear only in kernel logs.
+ </para>
+
+</appendix>
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index bbea1e412b..543927b8b4 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -2467,6 +2467,7 @@ usage(const char *progname)
 	printf(_("  -N, --no-sync             do not wait for changes to be written safely to disk\n"));
 	printf(_("      --no-instructions     do not print instructions for next steps\n"));
 	printf(_("  -s, --show                show internal settings\n"));
+	printf(_("      --sync-method=METHOD  set method for syncing files to disk\n"));
 	printf(_("  -S, --sync-only           only sync database files to disk, then exit\n"));
 	printf(_("\nOther options:\n"));
 	printf(_("  -V, --version             output version information, then exit\n"));
@@ -3107,6 +3108,7 @@ main(int argc, char *argv[])
 		{"locale-provider", required_argument, NULL, 15},
 		{"icu-locale", required_argument, NULL, 16},
 		{"icu-rules", required_argument, NULL, 17},
+		{"sync-method", required_argument, NULL, 18},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -3287,6 +3289,10 @@ main(int argc, char *argv[])
 			case 17:
 				icu_rules = pg_strdup(optarg);
 				break;
+			case 18:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/initdb/t/001_initdb.pl b/src/bin/initdb/t/001_initdb.pl
index 2d7469d2fc..45f96cd8bb 100644
--- a/src/bin/initdb/t/001_initdb.pl
+++ b/src/bin/initdb/t/001_initdb.pl
@@ -16,6 +16,7 @@ use Test::More;
 my $tempdir = PostgreSQL::Test::Utils::tempdir;
 my $xlogdir = "$tempdir/pgxlog";
 my $datadir = "$tempdir/data";
+my $supports_syncfs = check_pg_config("#define HAVE_SYNCFS 1");
 
 program_help_ok('initdb');
 program_version_ok('initdb');
@@ -82,6 +83,17 @@ command_fails([ 'pg_checksums', '-D', $datadir ],
 command_ok([ 'initdb', '-S', $datadir ], 'sync only');
 command_fails([ 'initdb', $datadir ], 'existing data directory');
 
+if ($supports_syncfs)
+{
+	command_ok([ 'initdb', '-S', $datadir, '--sync-method', 'syncfs' ],
+		'sync method syncfs');
+}
+else
+{
+	command_fails([ 'initdb', '-S', $datadir, '--sync-method', 'syncfs' ],
+		'sync method syncfs');
+}
+
 # Check group access on PGDATA
 SKIP:
 {
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 1a6eacf6d5..977c793a67 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -425,6 +425,8 @@ usage(void)
 	printf(_("      --no-slot          prevent creation of temporary replication slot\n"));
 	printf(_("      --no-verify-checksums\n"
 			 "                         do not verify checksums\n"));
+	printf(_("      --sync-method=METHOD\n"
+			 "                         set method for syncing files to disk\n"));
 	printf(_("  -?, --help             show this help, then exit\n"));
 	printf(_("\nConnection options:\n"));
 	printf(_("  -d, --dbname=CONNSTR   connection string\n"));
@@ -2282,6 +2284,7 @@ main(int argc, char **argv)
 		{"no-manifest", no_argument, NULL, 5},
 		{"manifest-force-encode", no_argument, NULL, 6},
 		{"manifest-checksums", required_argument, NULL, 7},
+		{"sync-method", required_argument, NULL, 8},
 		{NULL, 0, NULL, 0}
 	};
 	int			c;
@@ -2453,6 +2456,10 @@ main(int argc, char **argv)
 			case 7:
 				manifest_checksums = pg_strdup(optarg);
 				break;
+			case 8:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_checksums/pg_checksums.c b/src/bin/pg_checksums/pg_checksums.c
index 123450f483..9fb2c5b3c7 100644
--- a/src/bin/pg_checksums/pg_checksums.c
+++ b/src/bin/pg_checksums/pg_checksums.c
@@ -78,6 +78,7 @@ usage(void)
 	printf(_("  -f, --filenode=FILENODE  check only relation with specified filenode\n"));
 	printf(_("  -N, --no-sync            do not wait for changes to be written safely to disk\n"));
 	printf(_("  -P, --progress           show progress information\n"));
+	printf(_("      --sync-method=METHOD set method for syncing files to disk\n"));
 	printf(_("  -v, --verbose            output verbose messages\n"));
 	printf(_("  -V, --version            output version information, then exit\n"));
 	printf(_("  -?, --help               show this help, then exit\n"));
@@ -436,6 +437,7 @@ main(int argc, char *argv[])
 		{"no-sync", no_argument, NULL, 'N'},
 		{"progress", no_argument, NULL, 'P'},
 		{"verbose", no_argument, NULL, 'v'},
+		{"sync-method", required_argument, NULL, 1},
 		{NULL, 0, NULL, 0}
 	};
 
@@ -494,6 +496,10 @@ main(int argc, char *argv[])
 			case 'v':
 				verbose = true;
 				break;
+			case 1:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 39a468b131..dc4a28e81e 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -432,6 +432,7 @@ main(int argc, char **argv)
 		{"table-and-children", required_argument, NULL, 12},
 		{"exclude-table-and-children", required_argument, NULL, 13},
 		{"exclude-table-data-and-children", required_argument, NULL, 14},
+		{"sync-method", required_argument, NULL, 15},
 
 		{NULL, 0, NULL, 0}
 	};
@@ -658,6 +659,11 @@ main(int argc, char **argv)
 										  optarg);
 				break;
 
+			case 15:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit_nicely(1);
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
@@ -1069,6 +1075,7 @@ help(const char *progname)
 			 "                               compress as specified\n"));
 	printf(_("  --lock-wait-timeout=TIMEOUT  fail after waiting TIMEOUT for a table lock\n"));
 	printf(_("  --no-sync                    do not wait for changes to be written safely to disk\n"));
+	printf(_("  --sync-method=METHOD         set method for syncing files to disk\n"));
 	printf(_("  -?, --help                   show this help, then exit\n"));
 
 	printf(_("\nOptions controlling the output content:\n"));
diff --git a/src/bin/pg_rewind/pg_rewind.c b/src/bin/pg_rewind/pg_rewind.c
index bdfacf3263..bfd44a284e 100644
--- a/src/bin/pg_rewind/pg_rewind.c
+++ b/src/bin/pg_rewind/pg_rewind.c
@@ -22,6 +22,7 @@
 #include "common/file_perm.h"
 #include "common/restricted_token.h"
 #include "common/string.h"
+#include "fe_utils/option_utils.h"
 #include "fe_utils/recovery_gen.h"
 #include "fe_utils/string_utils.h"
 #include "file_ops.h"
@@ -108,6 +109,7 @@ usage(const char *progname)
 			 "                                 file when running target cluster\n"));
 	printf(_("      --debug                    write a lot of debug messages\n"));
 	printf(_("      --no-ensure-shutdown       do not automatically fix unclean shutdown\n"));
+	printf(_("      --sync-method=METHOD       set method for syncing files to disk\n"));
 	printf(_("  -V, --version                  output version information, then exit\n"));
 	printf(_("  -?, --help                     show this help, then exit\n"));
 	printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
@@ -132,6 +134,7 @@ main(int argc, char **argv)
 		{"no-sync", no_argument, NULL, 'N'},
 		{"progress", no_argument, NULL, 'P'},
 		{"debug", no_argument, NULL, 3},
+		{"sync-method", required_argument, NULL, 6},
 		{NULL, 0, NULL, 0}
 	};
 	int			option_index;
@@ -219,6 +222,11 @@ main(int argc, char **argv)
 				config_file = pg_strdup(optarg);
 				break;
 
+			case 6:
+				if (!parse_sync_method(optarg, &sync_method))
+					exit(1);
+				break;
+
 			default:
 				/* getopt_long already emitted a complaint */
 				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
diff --git a/src/bin/pg_upgrade/option.c b/src/bin/pg_upgrade/option.c
index 640361009e..b9d900d0db 100644
--- a/src/bin/pg_upgrade/option.c
+++ b/src/bin/pg_upgrade/option.c
@@ -14,6 +14,7 @@
 #endif
 
 #include "common/string.h"
+#include "fe_utils/option_utils.h"
 #include "getopt_long.h"
 #include "pg_upgrade.h"
 #include "utils/pidfile.h"
@@ -57,12 +58,14 @@ parseCommandLine(int argc, char *argv[])
 		{"verbose", no_argument, NULL, 'v'},
 		{"clone", no_argument, NULL, 1},
 		{"copy", no_argument, NULL, 2},
+		{"sync-method", required_argument, NULL, 3},
 
 		{NULL, 0, NULL, 0}
 	};
 	int			option;			/* Command line option */
 	int			optindex = 0;	/* used by getopt_long */
 	int			os_user_effective_id;
+	DataDirSyncMethod unused;
 
 	user_opts.do_sync = true;
 	user_opts.transfer_mode = TRANSFER_MODE_COPY;
@@ -199,6 +202,12 @@ parseCommandLine(int argc, char *argv[])
 				user_opts.transfer_mode = TRANSFER_MODE_COPY;
 				break;
 
+			case 3:
+				if (!parse_sync_method(optarg, &unused))
+					exit(1);
+				user_opts.sync_method = pg_strdup(optarg);
+				break;
+
 			default:
 				fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
 						os_info.progname);
@@ -209,6 +218,9 @@ parseCommandLine(int argc, char *argv[])
 	if (optind < argc)
 		pg_fatal("too many command-line arguments (first is \"%s\")", argv[optind]);
 
+	if (!user_opts.sync_method)
+		user_opts.sync_method = pg_strdup("fsync");
+
 	if (log_opts.verbose)
 		pg_log(PG_REPORT, "Running in verbose mode");
 
@@ -289,6 +301,7 @@ usage(void)
 	printf(_("  -V, --version                 display version information, then exit\n"));
 	printf(_("  --clone                       clone instead of copying files to new cluster\n"));
 	printf(_("  --copy                        copy files to new cluster (default)\n"));
+	printf(_("  --sync-method=METHOD          set method for syncing files to disk\n"));
 	printf(_("  -?, --help                    show this help, then exit\n"));
 	printf(_("\n"
 			 "Before running pg_upgrade you must:\n"
diff --git a/src/bin/pg_upgrade/pg_upgrade.c b/src/bin/pg_upgrade/pg_upgrade.c
index 4562dafcff..96bfb67167 100644
--- a/src/bin/pg_upgrade/pg_upgrade.c
+++ b/src/bin/pg_upgrade/pg_upgrade.c
@@ -192,8 +192,10 @@ main(int argc, char **argv)
 	{
 		prep_status("Sync data directory to disk");
 		exec_prog(UTILITY_LOG_FILE, NULL, true, true,
-				  "\"%s/initdb\" --sync-only \"%s\"", new_cluster.bindir,
-				  new_cluster.pgdata);
+				  "\"%s/initdb\" --sync-only \"%s\" --sync-method %s",
+				  new_cluster.bindir,
+				  new_cluster.pgdata,
+				  user_opts.sync_method);
 		check_ok();
 	}
 
diff --git a/src/bin/pg_upgrade/pg_upgrade.h b/src/bin/pg_upgrade/pg_upgrade.h
index 7afa96716e..842f3b6cd3 100644
--- a/src/bin/pg_upgrade/pg_upgrade.h
+++ b/src/bin/pg_upgrade/pg_upgrade.h
@@ -304,6 +304,7 @@ typedef struct
 	transferMode transfer_mode; /* copy files or link them? */
 	int			jobs;			/* number of processes/threads to use */
 	char	   *socketdir;		/* directory to use for Unix sockets */
+	char	   *sync_method;
 } UserOpts;
 
 typedef struct
diff --git a/src/fe_utils/option_utils.c b/src/fe_utils/option_utils.c
index 763c991015..36ac689964 100644
--- a/src/fe_utils/option_utils.c
+++ b/src/fe_utils/option_utils.c
@@ -82,3 +82,27 @@ option_parse_int(const char *optarg, const char *optname,
 		*result = val;
 	return true;
 }
+
+bool
+parse_sync_method(const char *optarg, DataDirSyncMethod *sync_method)
+{
+	if (strcmp(optarg, "fsync") == 0)
+		*sync_method = DATA_DIR_SYNC_METHOD_FSYNC;
+	else if (strcmp(optarg, "syncfs") == 0)
+	{
+#ifdef HAVE_SYNCFS
+		*sync_method = DATA_DIR_SYNC_METHOD_SYNCFS;
+#else
+		pg_log_error("this build does not support sync method \"%s\"",
+					 "syncfs");
+		return false;
+#endif
+	}
+	else
+	{
+		pg_log_error("unrecognized sync method: %s", optarg);
+		return false;
+	}
+
+	return true;
+}
diff --git a/src/include/fe_utils/option_utils.h b/src/include/fe_utils/option_utils.h
index b7b0654cee..6f3a965916 100644
--- a/src/include/fe_utils/option_utils.h
+++ b/src/include/fe_utils/option_utils.h
@@ -14,6 +14,8 @@
 
 #include "postgres_fe.h"
 
+#include "common/file_utils.h"
+
 typedef void (*help_handler) (const char *progname);
 
 extern void handle_help_version_opts(int argc, char *argv[],
@@ -22,5 +24,7 @@ extern void handle_help_version_opts(int argc, char *argv[],
 extern bool option_parse_int(const char *optarg, const char *optname,
 							 int min_range, int max_range,
 							 int *result);
+extern bool parse_sync_method(const char *optarg,
+							  DataDirSyncMethod *sync_method);
 
 #endif							/* OPTION_UTILS_H */
-- 
2.25.1

diff --git a/src/include/storage/bufpage.h b/src/include/storage/bufpage.h
index 424ecba028f..3aa1fc60cb4 100644
--- a/src/include/storage/bufpage.h
+++ b/src/include/storage/bufpage.h
@@ -18,6 +18,8 @@
 #include "storage/block.h"
 #include "storage/item.h"
 #include "storage/off.h"
+#include "postgres.h"
+#include "utils/rel.h"
 
 /*
  * A postgres disk page is an abstraction layered on top of a postgres

From bcf744b93d31ae42ffb4122b8d16fddb3e5391d2 Mon Sep 17 00:00:00 2001
From: Maxim Orlov <orlovmg@gmail.com>
Date: Wed, 20 Sep 2023 14:57:46 +0300
Subject: [PATCH v10] Fix conflicting types for sync_method.

Rename xlog's sync_method in order to:
- avoid conflicting types error for sync_method if include order is changed;
- be consistent with GUC name.

See also:
3ed19567198ddb34ab32be6ebdf132148287abdf
cccc6cdeb32f010f1cf777a9e9a85344a4317ab8
8c16ad3b43299695f203f9157a2b27c22b9ed634
---
 src/backend/access/transam/xlog.c   | 31 ++++++++++++++++-------------
 src/backend/storage/file/fd.c       |  2 +-
 src/backend/utils/misc/guc_tables.c |  6 +++---
 src/include/access/xlog.h           |  2 +-
 4 files changed, 22 insertions(+), 19 deletions(-)

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index fcbde10529b..4ccb62e4c2a 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -130,7 +130,7 @@ bool	   *wal_consistency_checking = NULL;
 bool		wal_init_zero = true;
 bool		wal_recycle = true;
 bool		log_checkpoints = true;
-int			sync_method = DEFAULT_SYNC_METHOD;
+int			wal_sync_method = DEFAULT_SYNC_METHOD;
 int			wal_level = WAL_LEVEL_REPLICA;
 int			CommitDelay = 0;	/* precommit delay in microseconds */
 int			CommitSiblings = 5; /* # concurrent xacts needed to sleep */
@@ -171,7 +171,7 @@ static bool check_wal_consistency_checking_deferred = false;
 /*
  * GUC support
  */
-const struct config_enum_entry sync_method_options[] = {
+const struct config_enum_entry wal_sync_method_options[] = {
 	{"fsync", SYNC_METHOD_FSYNC, false},
 #ifdef HAVE_FSYNC_WRITETHROUGH
 	{"fsync_writethrough", SYNC_METHOD_FSYNC_WRITETHROUGH, false},
@@ -2328,8 +2328,8 @@ XLogWrite(XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible)
 		 * have no open file or the wrong one.  However, we do not need to
 		 * fsync more than one file.
 		 */
-		if (sync_method != SYNC_METHOD_OPEN &&
-			sync_method != SYNC_METHOD_OPEN_DSYNC)
+		if (wal_sync_method != SYNC_METHOD_OPEN &&
+			wal_sync_method != SYNC_METHOD_OPEN_DSYNC)
 		{
 			if (openLogFile >= 0 &&
 				!XLByteInPrevSeg(LogwrtResult.Write, openLogSegNo,
@@ -2959,7 +2959,7 @@ XLogFileInitInternal(XLogSegNo logsegno, TimeLineID logtli,
 	 */
 	*added = false;
 	fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
-					   get_sync_bit(sync_method));
+					   get_sync_bit(wal_sync_method));
 	if (fd < 0)
 	{
 		if (errno != ENOENT)
@@ -3124,7 +3124,7 @@ XLogFileInit(XLogSegNo logsegno, TimeLineID logtli)
 
 	/* Now open original target segment (might not be file I just made) */
 	fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
-					   get_sync_bit(sync_method));
+					   get_sync_bit(wal_sync_method));
 	if (fd < 0)
 		ereport(ERROR,
 				(errcode_for_file_access(),
@@ -3356,7 +3356,7 @@ XLogFileOpen(XLogSegNo segno, TimeLineID tli)
 	XLogFilePath(path, tli, segno, wal_segment_size);
 
 	fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
-					   get_sync_bit(sync_method));
+					   get_sync_bit(wal_sync_method));
 	if (fd < 0)
 		ereport(PANIC,
 				(errcode_for_file_access(),
@@ -8141,9 +8141,9 @@ get_sync_bit(int method)
  * GUC support
  */
 void
-assign_xlog_sync_method(int new_sync_method, void *extra)
+assign_xlog_sync_method(int new_wal_sync_method, void *extra)
 {
-	if (sync_method != new_sync_method)
+	if (wal_sync_method != new_wal_sync_method)
 	{
 		/*
 		 * To ensure that no blocks escape unsynced, force an fsync on the
@@ -8169,8 +8169,11 @@ assign_xlog_sync_method(int new_sync_method, void *extra)
 			}
 
 			pgstat_report_wait_end();
-			if (get_sync_bit(sync_method) != get_sync_bit(new_sync_method))
+			if (get_sync_bit(wal_sync_method) !=
+				get_sync_bit(new_wal_sync_method))
+			{
 				XLogFileClose();
+			}
 		}
 	}
 }
@@ -8195,8 +8198,8 @@ issue_xlog_fsync(int fd, XLogSegNo segno, TimeLineID tli)
 	 * file.
 	 */
 	if (!enableFsync ||
-		sync_method == SYNC_METHOD_OPEN ||
-		sync_method == SYNC_METHOD_OPEN_DSYNC)
+		wal_sync_method == SYNC_METHOD_OPEN ||
+		wal_sync_method == SYNC_METHOD_OPEN_DSYNC)
 		return;
 
 	/* Measure I/O timing to sync the WAL file */
@@ -8206,7 +8209,7 @@ issue_xlog_fsync(int fd, XLogSegNo segno, TimeLineID tli)
 		INSTR_TIME_SET_ZERO(start);
 
 	pgstat_report_wait_start(WAIT_EVENT_WAL_SYNC);
-	switch (sync_method)
+	switch (wal_sync_method)
 	{
 		case SYNC_METHOD_FSYNC:
 			if (pg_fsync_no_writethrough(fd) != 0)
@@ -8228,7 +8231,7 @@ issue_xlog_fsync(int fd, XLogSegNo segno, TimeLineID tli)
 			Assert(false);
 			break;
 		default:
-			elog(PANIC, "unrecognized wal_sync_method: %d", sync_method);
+			elog(PANIC, "unrecognized wal_sync_method: %d", wal_sync_method);
 			break;
 	}
 
diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index 3fed475c381..2f8737fa426 100644
--- a/src/backend/storage/file/fd.c
+++ b/src/backend/storage/file/fd.c
@@ -400,7 +400,7 @@ pg_fsync(int fd)
 
 	/* #if is to skip the sync_method test if there's no need for it */
 #if defined(HAVE_FSYNC_WRITETHROUGH)
-	if (sync_method == SYNC_METHOD_FSYNC_WRITETHROUGH)
+	if (wal_sync_method == SYNC_METHOD_FSYNC_WRITETHROUGH)
 		return pg_fsync_writethrough(fd);
 	else
 #endif
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index bdb26e2b77d..12639a6cf6d 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -484,7 +484,7 @@ static const struct config_enum_entry wal_compression_options[] = {
 extern const struct config_enum_entry wal_level_options[];
 extern const struct config_enum_entry archive_mode_options[];
 extern const struct config_enum_entry recovery_target_action_options[];
-extern const struct config_enum_entry sync_method_options[];
+extern const struct config_enum_entry wal_sync_method_options[];
 extern const struct config_enum_entry dynamic_shared_memory_options[];
 
 /*
@@ -4832,8 +4832,8 @@ struct config_enum ConfigureNamesEnum[] =
 			gettext_noop("Selects the method used for forcing WAL updates to disk."),
 			NULL
 		},
-		&sync_method,
-		DEFAULT_SYNC_METHOD, sync_method_options,
+		&wal_sync_method,
+		DEFAULT_SYNC_METHOD, wal_sync_method_options,
 		NULL, assign_xlog_sync_method, NULL
 	},
 
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index 48ca8523810..4c3beea36c4 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -24,7 +24,7 @@
 #define SYNC_METHOD_OPEN		2	/* for O_SYNC */
 #define SYNC_METHOD_FSYNC_WRITETHROUGH	3
 #define SYNC_METHOD_OPEN_DSYNC	4	/* for O_DSYNC */
-extern PGDLLIMPORT int sync_method;
+extern PGDLLIMPORT int wal_sync_method;
 
 extern PGDLLIMPORT XLogRecPtr ProcLastRecPtr;
 extern PGDLLIMPORT XLogRecPtr XactLastRecEnd;
-- 
2.41.0

From b51f1e306a7f724082ee014e35f09709dd288a35 Mon Sep 17 00:00:00 2001
From: Maxim Orlov <orlovmg@gmail.com>
Date: Wed, 20 Sep 2023 14:57:46 +0300
Subject: [PATCH v11] Fix conflicting types for sync_method.

Rename xlog's sync_method in order to:
- avoid conflicting types error for sync_method if include order is changed;
- be consistent with GUC name.

Also:
- use enum for WAL sync methods;
- rename WAL sync methods (add WAL_ prefix).

See also:
3ed19567198ddb34ab32be6ebdf132148287abdf
cccc6cdeb32f010f1cf777a9e9a85344a4317ab8
8c16ad3b43299695f203f9157a2b27c22b9ed634
---
 src/backend/access/transam/xlog.c   | 61 +++++++++++++++--------------
 src/backend/storage/file/fd.c       |  2 +-
 src/backend/utils/misc/guc_tables.c |  6 +--
 src/include/access/xlog.h           | 17 ++++----
 src/include/access/xlogdefs.h       |  8 ++--
 src/include/port/freebsd.h          |  2 +-
 src/include/port/linux.h            |  2 +-
 7 files changed, 52 insertions(+), 46 deletions(-)

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index fcbde10529b..f31819434a4 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -130,7 +130,7 @@ bool	   *wal_consistency_checking = NULL;
 bool		wal_init_zero = true;
 bool		wal_recycle = true;
 bool		log_checkpoints = true;
-int			sync_method = DEFAULT_SYNC_METHOD;
+int			wal_sync_method = DEFAULT_WAL_SYNC_METHOD;
 int			wal_level = WAL_LEVEL_REPLICA;
 int			CommitDelay = 0;	/* precommit delay in microseconds */
 int			CommitSiblings = 5; /* # concurrent xacts needed to sleep */
@@ -171,17 +171,17 @@ static bool check_wal_consistency_checking_deferred = false;
 /*
  * GUC support
  */
-const struct config_enum_entry sync_method_options[] = {
-	{"fsync", SYNC_METHOD_FSYNC, false},
+const struct config_enum_entry wal_sync_method_options[] = {
+	{"fsync", WAL_SYNC_METHOD_FSYNC, false},
 #ifdef HAVE_FSYNC_WRITETHROUGH
-	{"fsync_writethrough", SYNC_METHOD_FSYNC_WRITETHROUGH, false},
+	{"fsync_writethrough", WAL_SYNC_METHOD_FSYNC_WRITETHROUGH, false},
 #endif
-	{"fdatasync", SYNC_METHOD_FDATASYNC, false},
+	{"fdatasync", WAL_SYNC_METHOD_FDATASYNC, false},
 #ifdef O_SYNC
-	{"open_sync", SYNC_METHOD_OPEN, false},
+	{"open_sync", WAL_SYNC_METHOD_OPEN, false},
 #endif
 #ifdef O_DSYNC
-	{"open_datasync", SYNC_METHOD_OPEN_DSYNC, false},
+	{"open_datasync", WAL_SYNC_METHOD_OPEN_DSYNC, false},
 #endif
 	{NULL, 0, false}
 };
@@ -2328,8 +2328,8 @@ XLogWrite(XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible)
 		 * have no open file or the wrong one.  However, we do not need to
 		 * fsync more than one file.
 		 */
-		if (sync_method != SYNC_METHOD_OPEN &&
-			sync_method != SYNC_METHOD_OPEN_DSYNC)
+		if (wal_sync_method != WAL_SYNC_METHOD_OPEN &&
+			wal_sync_method != WAL_SYNC_METHOD_OPEN_DSYNC)
 		{
 			if (openLogFile >= 0 &&
 				!XLByteInPrevSeg(LogwrtResult.Write, openLogSegNo,
@@ -2959,7 +2959,7 @@ XLogFileInitInternal(XLogSegNo logsegno, TimeLineID logtli,
 	 */
 	*added = false;
 	fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
-					   get_sync_bit(sync_method));
+					   get_sync_bit(wal_sync_method));
 	if (fd < 0)
 	{
 		if (errno != ENOENT)
@@ -3124,7 +3124,7 @@ XLogFileInit(XLogSegNo logsegno, TimeLineID logtli)
 
 	/* Now open original target segment (might not be file I just made) */
 	fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
-					   get_sync_bit(sync_method));
+					   get_sync_bit(wal_sync_method));
 	if (fd < 0)
 		ereport(ERROR,
 				(errcode_for_file_access(),
@@ -3356,7 +3356,7 @@ XLogFileOpen(XLogSegNo segno, TimeLineID tli)
 	XLogFilePath(path, tli, segno, wal_segment_size);
 
 	fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
-					   get_sync_bit(sync_method));
+					   get_sync_bit(wal_sync_method));
 	if (fd < 0)
 		ereport(PANIC,
 				(errcode_for_file_access(),
@@ -8118,16 +8118,16 @@ get_sync_bit(int method)
 			 * not included in the enum option array, and therefore will never
 			 * be seen here.
 			 */
-		case SYNC_METHOD_FSYNC:
-		case SYNC_METHOD_FSYNC_WRITETHROUGH:
-		case SYNC_METHOD_FDATASYNC:
+		case WAL_SYNC_METHOD_FSYNC:
+		case WAL_SYNC_METHOD_FSYNC_WRITETHROUGH:
+		case WAL_SYNC_METHOD_FDATASYNC:
 			return o_direct_flag;
 #ifdef O_SYNC
-		case SYNC_METHOD_OPEN:
+		case WAL_SYNC_METHOD_OPEN:
 			return O_SYNC | o_direct_flag;
 #endif
 #ifdef O_DSYNC
-		case SYNC_METHOD_OPEN_DSYNC:
+		case WAL_SYNC_METHOD_OPEN_DSYNC:
 			return O_DSYNC | o_direct_flag;
 #endif
 		default:
@@ -8141,9 +8141,9 @@ get_sync_bit(int method)
  * GUC support
  */
 void
-assign_xlog_sync_method(int new_sync_method, void *extra)
+assign_xlog_sync_method(int new_wal_sync_method, void *extra)
 {
-	if (sync_method != new_sync_method)
+	if (wal_sync_method != new_wal_sync_method)
 	{
 		/*
 		 * To ensure that no blocks escape unsynced, force an fsync on the
@@ -8169,8 +8169,11 @@ assign_xlog_sync_method(int new_sync_method, void *extra)
 			}
 
 			pgstat_report_wait_end();
-			if (get_sync_bit(sync_method) != get_sync_bit(new_sync_method))
+			if (get_sync_bit(wal_sync_method) !=
+				get_sync_bit(new_wal_sync_method))
+			{
 				XLogFileClose();
+			}
 		}
 	}
 }
@@ -8195,8 +8198,8 @@ issue_xlog_fsync(int fd, XLogSegNo segno, TimeLineID tli)
 	 * file.
 	 */
 	if (!enableFsync ||
-		sync_method == SYNC_METHOD_OPEN ||
-		sync_method == SYNC_METHOD_OPEN_DSYNC)
+		wal_sync_method == WAL_SYNC_METHOD_OPEN ||
+		wal_sync_method == WAL_SYNC_METHOD_OPEN_DSYNC)
 		return;
 
 	/* Measure I/O timing to sync the WAL file */
@@ -8206,29 +8209,29 @@ issue_xlog_fsync(int fd, XLogSegNo segno, TimeLineID tli)
 		INSTR_TIME_SET_ZERO(start);
 
 	pgstat_report_wait_start(WAIT_EVENT_WAL_SYNC);
-	switch (sync_method)
+	switch (wal_sync_method)
 	{
-		case SYNC_METHOD_FSYNC:
+		case WAL_SYNC_METHOD_FSYNC:
 			if (pg_fsync_no_writethrough(fd) != 0)
 				msg = _("could not fsync file \"%s\": %m");
 			break;
 #ifdef HAVE_FSYNC_WRITETHROUGH
-		case SYNC_METHOD_FSYNC_WRITETHROUGH:
+		case WAL_SYNC_METHOD_FSYNC_WRITETHROUGH:
 			if (pg_fsync_writethrough(fd) != 0)
 				msg = _("could not fsync write-through file \"%s\": %m");
 			break;
 #endif
-		case SYNC_METHOD_FDATASYNC:
+		case WAL_SYNC_METHOD_FDATASYNC:
 			if (pg_fdatasync(fd) != 0)
 				msg = _("could not fdatasync file \"%s\": %m");
 			break;
-		case SYNC_METHOD_OPEN:
-		case SYNC_METHOD_OPEN_DSYNC:
+		case WAL_SYNC_METHOD_OPEN:
+		case WAL_SYNC_METHOD_OPEN_DSYNC:
 			/* not reachable */
 			Assert(false);
 			break;
 		default:
-			elog(PANIC, "unrecognized wal_sync_method: %d", sync_method);
+			elog(PANIC, "unrecognized wal_sync_method: %d", wal_sync_method);
 			break;
 	}
 
diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index 3fed475c381..f5412214b69 100644
--- a/src/backend/storage/file/fd.c
+++ b/src/backend/storage/file/fd.c
@@ -400,7 +400,7 @@ pg_fsync(int fd)
 
 	/* #if is to skip the sync_method test if there's no need for it */
 #if defined(HAVE_FSYNC_WRITETHROUGH)
-	if (sync_method == SYNC_METHOD_FSYNC_WRITETHROUGH)
+	if (wal_sync_method == WAL_SYNC_METHOD_FSYNC_WRITETHROUGH)
 		return pg_fsync_writethrough(fd);
 	else
 #endif
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index bdb26e2b77d..3df821a958e 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -484,7 +484,7 @@ static const struct config_enum_entry wal_compression_options[] = {
 extern const struct config_enum_entry wal_level_options[];
 extern const struct config_enum_entry archive_mode_options[];
 extern const struct config_enum_entry recovery_target_action_options[];
-extern const struct config_enum_entry sync_method_options[];
+extern const struct config_enum_entry wal_sync_method_options[];
 extern const struct config_enum_entry dynamic_shared_memory_options[];
 
 /*
@@ -4832,8 +4832,8 @@ struct config_enum ConfigureNamesEnum[] =
 			gettext_noop("Selects the method used for forcing WAL updates to disk."),
 			NULL
 		},
-		&sync_method,
-		DEFAULT_SYNC_METHOD, sync_method_options,
+		&wal_sync_method,
+		DEFAULT_WAL_SYNC_METHOD, wal_sync_method_options,
 		NULL, assign_xlog_sync_method, NULL
 	},
 
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index 48ca8523810..d82c7f7c040 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -18,13 +18,16 @@
 #include "nodes/pg_list.h"
 
 
-/* Sync methods */
-#define SYNC_METHOD_FSYNC		0
-#define SYNC_METHOD_FDATASYNC	1
-#define SYNC_METHOD_OPEN		2	/* for O_SYNC */
-#define SYNC_METHOD_FSYNC_WRITETHROUGH	3
-#define SYNC_METHOD_OPEN_DSYNC	4	/* for O_DSYNC */
-extern PGDLLIMPORT int sync_method;
+/* WAL sync methods */
+typedef enum WalSyncMethod
+{
+	WAL_SYNC_METHOD_FSYNC = 0,
+	WAL_SYNC_METHOD_FDATASYNC,
+	WAL_SYNC_METHOD_OPEN,		/* for O_SYNC */
+	WAL_SYNC_METHOD_FSYNC_WRITETHROUGH,
+	WAL_SYNC_METHOD_OPEN_DSYNC,	/* for O_DSYNC */
+} WalSyncMethod;
+extern PGDLLIMPORT int wal_sync_method;
 
 extern PGDLLIMPORT XLogRecPtr ProcLastRecPtr;
 extern PGDLLIMPORT XLogRecPtr XactLastRecEnd;
diff --git a/src/include/access/xlogdefs.h b/src/include/access/xlogdefs.h
index fe794c77405..5f54c2816bc 100644
--- a/src/include/access/xlogdefs.h
+++ b/src/include/access/xlogdefs.h
@@ -71,12 +71,12 @@ typedef uint16 RepOriginId;
  *
  * Note that we define our own O_DSYNC on Windows, but not O_SYNC.
  */
-#if defined(PLATFORM_DEFAULT_SYNC_METHOD)
-#define DEFAULT_SYNC_METHOD		PLATFORM_DEFAULT_SYNC_METHOD
+#if defined(PLATFORM_DEFAULT_WAL_SYNC_METHOD)
+#define DEFAULT_WAL_SYNC_METHOD		PLATFORM_DEFAULT_WAL_SYNC_METHOD
 #elif defined(O_DSYNC) && (!defined(O_SYNC) || O_DSYNC != O_SYNC)
-#define DEFAULT_SYNC_METHOD		SYNC_METHOD_OPEN_DSYNC
+#define DEFAULT_WAL_SYNC_METHOD		WAL_SYNC_METHOD_OPEN_DSYNC
 #else
-#define DEFAULT_SYNC_METHOD		SYNC_METHOD_FDATASYNC
+#define DEFAULT_WAL_SYNC_METHOD		WAL_SYNC_METHOD_FDATASYNC
 #endif
 
 #endif							/* XLOG_DEFS_H */
diff --git a/src/include/port/freebsd.h b/src/include/port/freebsd.h
index 0e3fde55d6d..c604187acdd 100644
--- a/src/include/port/freebsd.h
+++ b/src/include/port/freebsd.h
@@ -5,4 +5,4 @@
  * would prefer open_datasync on FreeBSD 13+, but that is not a good choice on
  * many systems.
  */
-#define PLATFORM_DEFAULT_SYNC_METHOD	SYNC_METHOD_FDATASYNC
+#define PLATFORM_DEFAULT_WAL_SYNC_METHOD	WAL_SYNC_METHOD_FDATASYNC
diff --git a/src/include/port/linux.h b/src/include/port/linux.h
index 7a6e46cdbb7..8101af2b93f 100644
--- a/src/include/port/linux.h
+++ b/src/include/port/linux.h
@@ -19,4 +19,4 @@
  * perform better and (b) causes outright failures on ext4 data=journal
  * filesystems, because those don't support O_DIRECT.
  */
-#define PLATFORM_DEFAULT_SYNC_METHOD	SYNC_METHOD_FDATASYNC
+#define PLATFORM_DEFAULT_WAL_SYNC_METHOD	WAL_SYNC_METHOD_FDATASYNC
-- 
2.41.0

From 481efed2b47ab1cf37308a789698069d1a84561b Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Mon, 9 Oct 2023 11:07:29 -0500
Subject: [PATCH v12 1/1] Align names of variables, etc. in
 wal_sync_method-related code.

Author: Maxim Orlov
Discussion: https://postgr.es/m/CACG%3DezbL1gwE7_K7sr9uqaCGkWhmvRTcTEnm3%2BX1xsRNwbXULQ%40mail.gmail.com
---
 src/backend/access/transam/xlog.c   | 58 ++++++++++++++---------------
 src/backend/storage/file/fd.c       |  4 +-
 src/backend/utils/misc/guc_tables.c |  8 ++--
 src/include/access/xlog.h           | 15 +++++---
 src/include/access/xlogdefs.h       |  8 ++--
 src/include/port/freebsd.h          |  2 +-
 src/include/port/linux.h            |  2 +-
 src/include/utils/guc_hooks.h       |  2 +-
 src/tools/pgindent/typedefs.list    |  1 +
 9 files changed, 52 insertions(+), 48 deletions(-)

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index fcbde10529..a0acd67772 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -130,7 +130,7 @@ bool	   *wal_consistency_checking = NULL;
 bool		wal_init_zero = true;
 bool		wal_recycle = true;
 bool		log_checkpoints = true;
-int			sync_method = DEFAULT_SYNC_METHOD;
+int			wal_sync_method = DEFAULT_WAL_SYNC_METHOD;
 int			wal_level = WAL_LEVEL_REPLICA;
 int			CommitDelay = 0;	/* precommit delay in microseconds */
 int			CommitSiblings = 5; /* # concurrent xacts needed to sleep */
@@ -171,17 +171,17 @@ static bool check_wal_consistency_checking_deferred = false;
 /*
  * GUC support
  */
-const struct config_enum_entry sync_method_options[] = {
-	{"fsync", SYNC_METHOD_FSYNC, false},
+const struct config_enum_entry wal_sync_method_options[] = {
+	{"fsync", WAL_SYNC_METHOD_FSYNC, false},
 #ifdef HAVE_FSYNC_WRITETHROUGH
-	{"fsync_writethrough", SYNC_METHOD_FSYNC_WRITETHROUGH, false},
+	{"fsync_writethrough", WAL_SYNC_METHOD_FSYNC_WRITETHROUGH, false},
 #endif
-	{"fdatasync", SYNC_METHOD_FDATASYNC, false},
+	{"fdatasync", WAL_SYNC_METHOD_FDATASYNC, false},
 #ifdef O_SYNC
-	{"open_sync", SYNC_METHOD_OPEN, false},
+	{"open_sync", WAL_SYNC_METHOD_OPEN, false},
 #endif
 #ifdef O_DSYNC
-	{"open_datasync", SYNC_METHOD_OPEN_DSYNC, false},
+	{"open_datasync", WAL_SYNC_METHOD_OPEN_DSYNC, false},
 #endif
 	{NULL, 0, false}
 };
@@ -2328,8 +2328,8 @@ XLogWrite(XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible)
 		 * have no open file or the wrong one.  However, we do not need to
 		 * fsync more than one file.
 		 */
-		if (sync_method != SYNC_METHOD_OPEN &&
-			sync_method != SYNC_METHOD_OPEN_DSYNC)
+		if (wal_sync_method != WAL_SYNC_METHOD_OPEN &&
+			wal_sync_method != WAL_SYNC_METHOD_OPEN_DSYNC)
 		{
 			if (openLogFile >= 0 &&
 				!XLByteInPrevSeg(LogwrtResult.Write, openLogSegNo,
@@ -2959,7 +2959,7 @@ XLogFileInitInternal(XLogSegNo logsegno, TimeLineID logtli,
 	 */
 	*added = false;
 	fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
-					   get_sync_bit(sync_method));
+					   get_sync_bit(wal_sync_method));
 	if (fd < 0)
 	{
 		if (errno != ENOENT)
@@ -3124,7 +3124,7 @@ XLogFileInit(XLogSegNo logsegno, TimeLineID logtli)
 
 	/* Now open original target segment (might not be file I just made) */
 	fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
-					   get_sync_bit(sync_method));
+					   get_sync_bit(wal_sync_method));
 	if (fd < 0)
 		ereport(ERROR,
 				(errcode_for_file_access(),
@@ -3356,7 +3356,7 @@ XLogFileOpen(XLogSegNo segno, TimeLineID tli)
 	XLogFilePath(path, tli, segno, wal_segment_size);
 
 	fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
-					   get_sync_bit(sync_method));
+					   get_sync_bit(wal_sync_method));
 	if (fd < 0)
 		ereport(PANIC,
 				(errcode_for_file_access(),
@@ -8118,16 +8118,16 @@ get_sync_bit(int method)
 			 * not included in the enum option array, and therefore will never
 			 * be seen here.
 			 */
-		case SYNC_METHOD_FSYNC:
-		case SYNC_METHOD_FSYNC_WRITETHROUGH:
-		case SYNC_METHOD_FDATASYNC:
+		case WAL_SYNC_METHOD_FSYNC:
+		case WAL_SYNC_METHOD_FSYNC_WRITETHROUGH:
+		case WAL_SYNC_METHOD_FDATASYNC:
 			return o_direct_flag;
 #ifdef O_SYNC
-		case SYNC_METHOD_OPEN:
+		case WAL_SYNC_METHOD_OPEN:
 			return O_SYNC | o_direct_flag;
 #endif
 #ifdef O_DSYNC
-		case SYNC_METHOD_OPEN_DSYNC:
+		case WAL_SYNC_METHOD_OPEN_DSYNC:
 			return O_DSYNC | o_direct_flag;
 #endif
 		default:
@@ -8141,9 +8141,9 @@ get_sync_bit(int method)
  * GUC support
  */
 void
-assign_xlog_sync_method(int new_sync_method, void *extra)
+assign_wal_sync_method(int new_wal_sync_method, void *extra)
 {
-	if (sync_method != new_sync_method)
+	if (wal_sync_method != new_wal_sync_method)
 	{
 		/*
 		 * To ensure that no blocks escape unsynced, force an fsync on the
@@ -8169,7 +8169,7 @@ assign_xlog_sync_method(int new_sync_method, void *extra)
 			}
 
 			pgstat_report_wait_end();
-			if (get_sync_bit(sync_method) != get_sync_bit(new_sync_method))
+			if (get_sync_bit(wal_sync_method) != get_sync_bit(new_wal_sync_method))
 				XLogFileClose();
 		}
 	}
@@ -8195,8 +8195,8 @@ issue_xlog_fsync(int fd, XLogSegNo segno, TimeLineID tli)
 	 * file.
 	 */
 	if (!enableFsync ||
-		sync_method == SYNC_METHOD_OPEN ||
-		sync_method == SYNC_METHOD_OPEN_DSYNC)
+		wal_sync_method == WAL_SYNC_METHOD_OPEN ||
+		wal_sync_method == WAL_SYNC_METHOD_OPEN_DSYNC)
 		return;
 
 	/* Measure I/O timing to sync the WAL file */
@@ -8206,29 +8206,29 @@ issue_xlog_fsync(int fd, XLogSegNo segno, TimeLineID tli)
 		INSTR_TIME_SET_ZERO(start);
 
 	pgstat_report_wait_start(WAIT_EVENT_WAL_SYNC);
-	switch (sync_method)
+	switch (wal_sync_method)
 	{
-		case SYNC_METHOD_FSYNC:
+		case WAL_SYNC_METHOD_FSYNC:
 			if (pg_fsync_no_writethrough(fd) != 0)
 				msg = _("could not fsync file \"%s\": %m");
 			break;
 #ifdef HAVE_FSYNC_WRITETHROUGH
-		case SYNC_METHOD_FSYNC_WRITETHROUGH:
+		case WAL_SYNC_METHOD_FSYNC_WRITETHROUGH:
 			if (pg_fsync_writethrough(fd) != 0)
 				msg = _("could not fsync write-through file \"%s\": %m");
 			break;
 #endif
-		case SYNC_METHOD_FDATASYNC:
+		case WAL_SYNC_METHOD_FDATASYNC:
 			if (pg_fdatasync(fd) != 0)
 				msg = _("could not fdatasync file \"%s\": %m");
 			break;
-		case SYNC_METHOD_OPEN:
-		case SYNC_METHOD_OPEN_DSYNC:
+		case WAL_SYNC_METHOD_OPEN:
+		case WAL_SYNC_METHOD_OPEN_DSYNC:
 			/* not reachable */
 			Assert(false);
 			break;
 		default:
-			elog(PANIC, "unrecognized wal_sync_method: %d", sync_method);
+			elog(PANIC, "unrecognized wal_sync_method: %d", wal_sync_method);
 			break;
 	}
 
diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index 3fed475c38..f0ae034207 100644
--- a/src/backend/storage/file/fd.c
+++ b/src/backend/storage/file/fd.c
@@ -398,9 +398,9 @@ pg_fsync(int fd)
 	errno = 0;
 #endif
 
-	/* #if is to skip the sync_method test if there's no need for it */
+	/* #if is to skip the wal_sync_method test if there's no need for it */
 #if defined(HAVE_FSYNC_WRITETHROUGH)
-	if (sync_method == SYNC_METHOD_FSYNC_WRITETHROUGH)
+	if (wal_sync_method == SYNC_METHOD_FSYNC_WRITETHROUGH)
 		return pg_fsync_writethrough(fd);
 	else
 #endif
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 16ec6c5ef0..4c58574166 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -485,7 +485,7 @@ static const struct config_enum_entry wal_compression_options[] = {
 extern const struct config_enum_entry wal_level_options[];
 extern const struct config_enum_entry archive_mode_options[];
 extern const struct config_enum_entry recovery_target_action_options[];
-extern const struct config_enum_entry sync_method_options[];
+extern const struct config_enum_entry wal_sync_method_options[];
 extern const struct config_enum_entry dynamic_shared_memory_options[];
 
 /*
@@ -4843,9 +4843,9 @@ struct config_enum ConfigureNamesEnum[] =
 			gettext_noop("Selects the method used for forcing WAL updates to disk."),
 			NULL
 		},
-		&sync_method,
-		DEFAULT_SYNC_METHOD, sync_method_options,
-		NULL, assign_xlog_sync_method, NULL
+		&wal_sync_method,
+		DEFAULT_WAL_SYNC_METHOD, wal_sync_method_options,
+		NULL, assign_wal_sync_method, NULL
 	},
 
 	{
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index 48ca852381..4ad572cb87 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -19,12 +19,15 @@
 
 
 /* Sync methods */
-#define SYNC_METHOD_FSYNC		0
-#define SYNC_METHOD_FDATASYNC	1
-#define SYNC_METHOD_OPEN		2	/* for O_SYNC */
-#define SYNC_METHOD_FSYNC_WRITETHROUGH	3
-#define SYNC_METHOD_OPEN_DSYNC	4	/* for O_DSYNC */
-extern PGDLLIMPORT int sync_method;
+typedef enum WalSyncMethod
+{
+	WAL_SYNC_METHOD_FSYNC = 0,
+	WAL_SYNC_METHOD_FDATASYNC,
+	WAL_SYNC_METHOD_OPEN,		/* for O_SYNC */
+	WAL_SYNC_METHOD_FSYNC_WRITETHROUGH,
+	WAL_SYNC_METHOD_OPEN_DSYNC	/* for O_DSYNC */
+} WalSyncMethod;
+extern PGDLLIMPORT int wal_sync_method;
 
 extern PGDLLIMPORT XLogRecPtr ProcLastRecPtr;
 extern PGDLLIMPORT XLogRecPtr XactLastRecEnd;
diff --git a/src/include/access/xlogdefs.h b/src/include/access/xlogdefs.h
index fe794c7740..5f54c2816b 100644
--- a/src/include/access/xlogdefs.h
+++ b/src/include/access/xlogdefs.h
@@ -71,12 +71,12 @@ typedef uint16 RepOriginId;
  *
  * Note that we define our own O_DSYNC on Windows, but not O_SYNC.
  */
-#if defined(PLATFORM_DEFAULT_SYNC_METHOD)
-#define DEFAULT_SYNC_METHOD		PLATFORM_DEFAULT_SYNC_METHOD
+#if defined(PLATFORM_DEFAULT_WAL_SYNC_METHOD)
+#define DEFAULT_WAL_SYNC_METHOD		PLATFORM_DEFAULT_WAL_SYNC_METHOD
 #elif defined(O_DSYNC) && (!defined(O_SYNC) || O_DSYNC != O_SYNC)
-#define DEFAULT_SYNC_METHOD		SYNC_METHOD_OPEN_DSYNC
+#define DEFAULT_WAL_SYNC_METHOD		WAL_SYNC_METHOD_OPEN_DSYNC
 #else
-#define DEFAULT_SYNC_METHOD		SYNC_METHOD_FDATASYNC
+#define DEFAULT_WAL_SYNC_METHOD		WAL_SYNC_METHOD_FDATASYNC
 #endif
 
 #endif							/* XLOG_DEFS_H */
diff --git a/src/include/port/freebsd.h b/src/include/port/freebsd.h
index 0e3fde55d6..c604187acd 100644
--- a/src/include/port/freebsd.h
+++ b/src/include/port/freebsd.h
@@ -5,4 +5,4 @@
  * would prefer open_datasync on FreeBSD 13+, but that is not a good choice on
  * many systems.
  */
-#define PLATFORM_DEFAULT_SYNC_METHOD	SYNC_METHOD_FDATASYNC
+#define PLATFORM_DEFAULT_WAL_SYNC_METHOD	WAL_SYNC_METHOD_FDATASYNC
diff --git a/src/include/port/linux.h b/src/include/port/linux.h
index 7a6e46cdbb..8101af2b93 100644
--- a/src/include/port/linux.h
+++ b/src/include/port/linux.h
@@ -19,4 +19,4 @@
  * perform better and (b) causes outright failures on ext4 data=journal
  * filesystems, because those don't support O_DIRECT.
  */
-#define PLATFORM_DEFAULT_SYNC_METHOD	SYNC_METHOD_FDATASYNC
+#define PLATFORM_DEFAULT_WAL_SYNC_METHOD	WAL_SYNC_METHOD_FDATASYNC
diff --git a/src/include/utils/guc_hooks.h b/src/include/utils/guc_hooks.h
index f04b99e3b9..2a191830a8 100644
--- a/src/include/utils/guc_hooks.h
+++ b/src/include/utils/guc_hooks.h
@@ -159,6 +159,6 @@ extern bool check_wal_consistency_checking(char **newval, void **extra,
 										   GucSource source);
 extern void assign_wal_consistency_checking(const char *newval, void *extra);
 extern bool check_wal_segment_size(int *newval, void **extra, GucSource source);
-extern void assign_xlog_sync_method(int new_sync_method, void *extra);
+extern void assign_wal_sync_method(int new_wal_sync_method, void *extra);
 
 #endif							/* GUC_HOOKS_H */
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 8de90c4958..e69bb671bf 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3016,6 +3016,7 @@ WalSnd
 WalSndCtlData
 WalSndSendDataCallback
 WalSndState
+WalSyncMethod
 WalTimeSample
 WalUsage
 WalWriteMethod
-- 
2.25.1

From b1829fea8f81cceceabd37585ab74a290505d0d5 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Mon, 9 Oct 2023 11:07:29 -0500
Subject: [PATCH v13 1/1] Align names of variables, etc. in
 wal_sync_method-related code.

Author: Maxim Orlov
Discussion: https://postgr.es/m/CACG%3DezbL1gwE7_K7sr9uqaCGkWhmvRTcTEnm3%2BX1xsRNwbXULQ%40mail.gmail.com
---
 src/backend/access/transam/xlog.c   | 58 ++++++++++++++---------------
 src/backend/storage/file/fd.c       |  4 +-
 src/backend/utils/misc/guc_tables.c |  8 ++--
 src/include/access/xlog.h           | 15 +++++---
 src/include/access/xlogdefs.h       |  8 ++--
 src/include/port/freebsd.h          |  2 +-
 src/include/port/linux.h            |  2 +-
 src/include/utils/guc_hooks.h       |  2 +-
 src/tools/pgindent/typedefs.list    |  1 +
 9 files changed, 52 insertions(+), 48 deletions(-)

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index fcbde10529..a0acd67772 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -130,7 +130,7 @@ bool	   *wal_consistency_checking = NULL;
 bool		wal_init_zero = true;
 bool		wal_recycle = true;
 bool		log_checkpoints = true;
-int			sync_method = DEFAULT_SYNC_METHOD;
+int			wal_sync_method = DEFAULT_WAL_SYNC_METHOD;
 int			wal_level = WAL_LEVEL_REPLICA;
 int			CommitDelay = 0;	/* precommit delay in microseconds */
 int			CommitSiblings = 5; /* # concurrent xacts needed to sleep */
@@ -171,17 +171,17 @@ static bool check_wal_consistency_checking_deferred = false;
 /*
  * GUC support
  */
-const struct config_enum_entry sync_method_options[] = {
-	{"fsync", SYNC_METHOD_FSYNC, false},
+const struct config_enum_entry wal_sync_method_options[] = {
+	{"fsync", WAL_SYNC_METHOD_FSYNC, false},
 #ifdef HAVE_FSYNC_WRITETHROUGH
-	{"fsync_writethrough", SYNC_METHOD_FSYNC_WRITETHROUGH, false},
+	{"fsync_writethrough", WAL_SYNC_METHOD_FSYNC_WRITETHROUGH, false},
 #endif
-	{"fdatasync", SYNC_METHOD_FDATASYNC, false},
+	{"fdatasync", WAL_SYNC_METHOD_FDATASYNC, false},
 #ifdef O_SYNC
-	{"open_sync", SYNC_METHOD_OPEN, false},
+	{"open_sync", WAL_SYNC_METHOD_OPEN, false},
 #endif
 #ifdef O_DSYNC
-	{"open_datasync", SYNC_METHOD_OPEN_DSYNC, false},
+	{"open_datasync", WAL_SYNC_METHOD_OPEN_DSYNC, false},
 #endif
 	{NULL, 0, false}
 };
@@ -2328,8 +2328,8 @@ XLogWrite(XLogwrtRqst WriteRqst, TimeLineID tli, bool flexible)
 		 * have no open file or the wrong one.  However, we do not need to
 		 * fsync more than one file.
 		 */
-		if (sync_method != SYNC_METHOD_OPEN &&
-			sync_method != SYNC_METHOD_OPEN_DSYNC)
+		if (wal_sync_method != WAL_SYNC_METHOD_OPEN &&
+			wal_sync_method != WAL_SYNC_METHOD_OPEN_DSYNC)
 		{
 			if (openLogFile >= 0 &&
 				!XLByteInPrevSeg(LogwrtResult.Write, openLogSegNo,
@@ -2959,7 +2959,7 @@ XLogFileInitInternal(XLogSegNo logsegno, TimeLineID logtli,
 	 */
 	*added = false;
 	fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
-					   get_sync_bit(sync_method));
+					   get_sync_bit(wal_sync_method));
 	if (fd < 0)
 	{
 		if (errno != ENOENT)
@@ -3124,7 +3124,7 @@ XLogFileInit(XLogSegNo logsegno, TimeLineID logtli)
 
 	/* Now open original target segment (might not be file I just made) */
 	fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
-					   get_sync_bit(sync_method));
+					   get_sync_bit(wal_sync_method));
 	if (fd < 0)
 		ereport(ERROR,
 				(errcode_for_file_access(),
@@ -3356,7 +3356,7 @@ XLogFileOpen(XLogSegNo segno, TimeLineID tli)
 	XLogFilePath(path, tli, segno, wal_segment_size);
 
 	fd = BasicOpenFile(path, O_RDWR | PG_BINARY | O_CLOEXEC |
-					   get_sync_bit(sync_method));
+					   get_sync_bit(wal_sync_method));
 	if (fd < 0)
 		ereport(PANIC,
 				(errcode_for_file_access(),
@@ -8118,16 +8118,16 @@ get_sync_bit(int method)
 			 * not included in the enum option array, and therefore will never
 			 * be seen here.
 			 */
-		case SYNC_METHOD_FSYNC:
-		case SYNC_METHOD_FSYNC_WRITETHROUGH:
-		case SYNC_METHOD_FDATASYNC:
+		case WAL_SYNC_METHOD_FSYNC:
+		case WAL_SYNC_METHOD_FSYNC_WRITETHROUGH:
+		case WAL_SYNC_METHOD_FDATASYNC:
 			return o_direct_flag;
 #ifdef O_SYNC
-		case SYNC_METHOD_OPEN:
+		case WAL_SYNC_METHOD_OPEN:
 			return O_SYNC | o_direct_flag;
 #endif
 #ifdef O_DSYNC
-		case SYNC_METHOD_OPEN_DSYNC:
+		case WAL_SYNC_METHOD_OPEN_DSYNC:
 			return O_DSYNC | o_direct_flag;
 #endif
 		default:
@@ -8141,9 +8141,9 @@ get_sync_bit(int method)
  * GUC support
  */
 void
-assign_xlog_sync_method(int new_sync_method, void *extra)
+assign_wal_sync_method(int new_wal_sync_method, void *extra)
 {
-	if (sync_method != new_sync_method)
+	if (wal_sync_method != new_wal_sync_method)
 	{
 		/*
 		 * To ensure that no blocks escape unsynced, force an fsync on the
@@ -8169,7 +8169,7 @@ assign_xlog_sync_method(int new_sync_method, void *extra)
 			}
 
 			pgstat_report_wait_end();
-			if (get_sync_bit(sync_method) != get_sync_bit(new_sync_method))
+			if (get_sync_bit(wal_sync_method) != get_sync_bit(new_wal_sync_method))
 				XLogFileClose();
 		}
 	}
@@ -8195,8 +8195,8 @@ issue_xlog_fsync(int fd, XLogSegNo segno, TimeLineID tli)
 	 * file.
 	 */
 	if (!enableFsync ||
-		sync_method == SYNC_METHOD_OPEN ||
-		sync_method == SYNC_METHOD_OPEN_DSYNC)
+		wal_sync_method == WAL_SYNC_METHOD_OPEN ||
+		wal_sync_method == WAL_SYNC_METHOD_OPEN_DSYNC)
 		return;
 
 	/* Measure I/O timing to sync the WAL file */
@@ -8206,29 +8206,29 @@ issue_xlog_fsync(int fd, XLogSegNo segno, TimeLineID tli)
 		INSTR_TIME_SET_ZERO(start);
 
 	pgstat_report_wait_start(WAIT_EVENT_WAL_SYNC);
-	switch (sync_method)
+	switch (wal_sync_method)
 	{
-		case SYNC_METHOD_FSYNC:
+		case WAL_SYNC_METHOD_FSYNC:
 			if (pg_fsync_no_writethrough(fd) != 0)
 				msg = _("could not fsync file \"%s\": %m");
 			break;
 #ifdef HAVE_FSYNC_WRITETHROUGH
-		case SYNC_METHOD_FSYNC_WRITETHROUGH:
+		case WAL_SYNC_METHOD_FSYNC_WRITETHROUGH:
 			if (pg_fsync_writethrough(fd) != 0)
 				msg = _("could not fsync write-through file \"%s\": %m");
 			break;
 #endif
-		case SYNC_METHOD_FDATASYNC:
+		case WAL_SYNC_METHOD_FDATASYNC:
 			if (pg_fdatasync(fd) != 0)
 				msg = _("could not fdatasync file \"%s\": %m");
 			break;
-		case SYNC_METHOD_OPEN:
-		case SYNC_METHOD_OPEN_DSYNC:
+		case WAL_SYNC_METHOD_OPEN:
+		case WAL_SYNC_METHOD_OPEN_DSYNC:
 			/* not reachable */
 			Assert(false);
 			break;
 		default:
-			elog(PANIC, "unrecognized wal_sync_method: %d", sync_method);
+			elog(PANIC, "unrecognized wal_sync_method: %d", wal_sync_method);
 			break;
 	}
 
diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index 3fed475c38..b7607aa1be 100644
--- a/src/backend/storage/file/fd.c
+++ b/src/backend/storage/file/fd.c
@@ -398,9 +398,9 @@ pg_fsync(int fd)
 	errno = 0;
 #endif
 
-	/* #if is to skip the sync_method test if there's no need for it */
+	/* #if is to skip the wal_sync_method test if there's no need for it */
 #if defined(HAVE_FSYNC_WRITETHROUGH)
-	if (sync_method == SYNC_METHOD_FSYNC_WRITETHROUGH)
+	if (wal_sync_method == WAL_SYNC_METHOD_FSYNC_WRITETHROUGH)
 		return pg_fsync_writethrough(fd);
 	else
 #endif
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 16ec6c5ef0..4c58574166 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -485,7 +485,7 @@ static const struct config_enum_entry wal_compression_options[] = {
 extern const struct config_enum_entry wal_level_options[];
 extern const struct config_enum_entry archive_mode_options[];
 extern const struct config_enum_entry recovery_target_action_options[];
-extern const struct config_enum_entry sync_method_options[];
+extern const struct config_enum_entry wal_sync_method_options[];
 extern const struct config_enum_entry dynamic_shared_memory_options[];
 
 /*
@@ -4843,9 +4843,9 @@ struct config_enum ConfigureNamesEnum[] =
 			gettext_noop("Selects the method used for forcing WAL updates to disk."),
 			NULL
 		},
-		&sync_method,
-		DEFAULT_SYNC_METHOD, sync_method_options,
-		NULL, assign_xlog_sync_method, NULL
+		&wal_sync_method,
+		DEFAULT_WAL_SYNC_METHOD, wal_sync_method_options,
+		NULL, assign_wal_sync_method, NULL
 	},
 
 	{
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index 48ca852381..4ad572cb87 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -19,12 +19,15 @@
 
 
 /* Sync methods */
-#define SYNC_METHOD_FSYNC		0
-#define SYNC_METHOD_FDATASYNC	1
-#define SYNC_METHOD_OPEN		2	/* for O_SYNC */
-#define SYNC_METHOD_FSYNC_WRITETHROUGH	3
-#define SYNC_METHOD_OPEN_DSYNC	4	/* for O_DSYNC */
-extern PGDLLIMPORT int sync_method;
+typedef enum WalSyncMethod
+{
+	WAL_SYNC_METHOD_FSYNC = 0,
+	WAL_SYNC_METHOD_FDATASYNC,
+	WAL_SYNC_METHOD_OPEN,		/* for O_SYNC */
+	WAL_SYNC_METHOD_FSYNC_WRITETHROUGH,
+	WAL_SYNC_METHOD_OPEN_DSYNC	/* for O_DSYNC */
+} WalSyncMethod;
+extern PGDLLIMPORT int wal_sync_method;
 
 extern PGDLLIMPORT XLogRecPtr ProcLastRecPtr;
 extern PGDLLIMPORT XLogRecPtr XactLastRecEnd;
diff --git a/src/include/access/xlogdefs.h b/src/include/access/xlogdefs.h
index fe794c7740..5f54c2816b 100644
--- a/src/include/access/xlogdefs.h
+++ b/src/include/access/xlogdefs.h
@@ -71,12 +71,12 @@ typedef uint16 RepOriginId;
  *
  * Note that we define our own O_DSYNC on Windows, but not O_SYNC.
  */
-#if defined(PLATFORM_DEFAULT_SYNC_METHOD)
-#define DEFAULT_SYNC_METHOD		PLATFORM_DEFAULT_SYNC_METHOD
+#if defined(PLATFORM_DEFAULT_WAL_SYNC_METHOD)
+#define DEFAULT_WAL_SYNC_METHOD		PLATFORM_DEFAULT_WAL_SYNC_METHOD
 #elif defined(O_DSYNC) && (!defined(O_SYNC) || O_DSYNC != O_SYNC)
-#define DEFAULT_SYNC_METHOD		SYNC_METHOD_OPEN_DSYNC
+#define DEFAULT_WAL_SYNC_METHOD		WAL_SYNC_METHOD_OPEN_DSYNC
 #else
-#define DEFAULT_SYNC_METHOD		SYNC_METHOD_FDATASYNC
+#define DEFAULT_WAL_SYNC_METHOD		WAL_SYNC_METHOD_FDATASYNC
 #endif
 
 #endif							/* XLOG_DEFS_H */
diff --git a/src/include/port/freebsd.h b/src/include/port/freebsd.h
index 0e3fde55d6..c604187acd 100644
--- a/src/include/port/freebsd.h
+++ b/src/include/port/freebsd.h
@@ -5,4 +5,4 @@
  * would prefer open_datasync on FreeBSD 13+, but that is not a good choice on
  * many systems.
  */
-#define PLATFORM_DEFAULT_SYNC_METHOD	SYNC_METHOD_FDATASYNC
+#define PLATFORM_DEFAULT_WAL_SYNC_METHOD	WAL_SYNC_METHOD_FDATASYNC
diff --git a/src/include/port/linux.h b/src/include/port/linux.h
index 7a6e46cdbb..8101af2b93 100644
--- a/src/include/port/linux.h
+++ b/src/include/port/linux.h
@@ -19,4 +19,4 @@
  * perform better and (b) causes outright failures on ext4 data=journal
  * filesystems, because those don't support O_DIRECT.
  */
-#define PLATFORM_DEFAULT_SYNC_METHOD	SYNC_METHOD_FDATASYNC
+#define PLATFORM_DEFAULT_WAL_SYNC_METHOD	WAL_SYNC_METHOD_FDATASYNC
diff --git a/src/include/utils/guc_hooks.h b/src/include/utils/guc_hooks.h
index f04b99e3b9..2a191830a8 100644
--- a/src/include/utils/guc_hooks.h
+++ b/src/include/utils/guc_hooks.h
@@ -159,6 +159,6 @@ extern bool check_wal_consistency_checking(char **newval, void **extra,
 										   GucSource source);
 extern void assign_wal_consistency_checking(const char *newval, void *extra);
 extern bool check_wal_segment_size(int *newval, void **extra, GucSource source);
-extern void assign_xlog_sync_method(int new_sync_method, void *extra);
+extern void assign_wal_sync_method(int new_wal_sync_method, void *extra);
 
 #endif							/* GUC_HOOKS_H */
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 8de90c4958..e69bb671bf 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -3016,6 +3016,7 @@ WalSnd
 WalSndCtlData
 WalSndSendDataCallback
 WalSndState
+WalSyncMethod
 WalTimeSample
 WalUsage
 WalWriteMethod
-- 
2.25.1