Subject: [PATCH v5 2/2] allow syncfs in frontend utilities

From: Nathan Bossart <[email-masked]>
Date: Fri, 28 Jul 2023 15:56:24 -0700

---
 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

--X1bOJ3K7DJ5YkBrT--