Adding upstream version 15.5.upstream/15.5

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2797 insertions, 0 deletions

diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
new file mode 100644
index 0000000..73bb8ff
--- /dev/null
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -0,0 +1,2797 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_basebackup.c - receive a base backup using streaming replication protocol
+ *
+ * Author: Magnus Hagander <magnus@hagander.net>
+ *
+ * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *		  src/bin/pg_basebackup/pg_basebackup.c
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres_fe.h"
+
+#include <unistd.h>
+#include <dirent.h>
+#include <limits.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <signal.h>
+#include <time.h>
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+#ifdef HAVE_LIBZ
+#include <zlib.h>
+#endif
+
+#include "access/xlog_internal.h"
+#include "backup/basebackup.h"
+#include "bbstreamer.h"
+#include "common/compression.h"
+#include "common/file_perm.h"
+#include "common/file_utils.h"
+#include "common/logging.h"
+#include "fe_utils/option_utils.h"
+#include "fe_utils/recovery_gen.h"
+#include "getopt_long.h"
+#include "receivelog.h"
+#include "streamutil.h"
+
+#define ERRCODE_DATA_CORRUPTED	"XX001"
+
+typedef struct TablespaceListCell
+{
+	struct TablespaceListCell *next;
+	char		old_dir[MAXPGPATH];
+	char		new_dir[MAXPGPATH];
+} TablespaceListCell;
+
+typedef struct TablespaceList
+{
+	TablespaceListCell *head;
+	TablespaceListCell *tail;
+} TablespaceList;
+
+typedef struct ArchiveStreamState
+{
+	int			tablespacenum;
+	pg_compress_specification *compress;
+	bbstreamer *streamer;
+	bbstreamer *manifest_inject_streamer;
+	PQExpBuffer manifest_buffer;
+	char		manifest_filename[MAXPGPATH];
+	FILE	   *manifest_file;
+} ArchiveStreamState;
+
+typedef struct WriteTarState
+{
+	int			tablespacenum;
+	bbstreamer *streamer;
+} WriteTarState;
+
+typedef struct WriteManifestState
+{
+	char		filename[MAXPGPATH];
+	FILE	   *file;
+} WriteManifestState;
+
+typedef void (*WriteDataCallback) (size_t nbytes, char *buf,
+								   void *callback_data);
+
+/*
+ * pg_xlog has been renamed to pg_wal in version 10.  This version number
+ * should be compared with PQserverVersion().
+ */
+#define MINIMUM_VERSION_FOR_PG_WAL	100000
+
+/*
+ * Temporary replication slots are supported from version 10.
+ */
+#define MINIMUM_VERSION_FOR_TEMP_SLOTS 100000
+
+/*
+ * Backup manifests are supported from version 13.
+ */
+#define MINIMUM_VERSION_FOR_MANIFESTS	130000
+
+/*
+ * Before v15, tar files received from the server will be improperly
+ * terminated.
+ */
+#define MINIMUM_VERSION_FOR_TERMINATED_TARFILE 150000
+
+/*
+ * Different ways to include WAL
+ */
+typedef enum
+{
+	NO_WAL,
+	FETCH_WAL,
+	STREAM_WAL
+} IncludeWal;
+
+/*
+ * Different places to perform compression
+ */
+typedef enum
+{
+	COMPRESS_LOCATION_UNSPECIFIED,
+	COMPRESS_LOCATION_CLIENT,
+	COMPRESS_LOCATION_SERVER
+} CompressionLocation;
+
+/* Global options */
+static char *basedir = NULL;
+static TablespaceList tablespace_dirs = {NULL, NULL};
+static char *xlog_dir = NULL;
+static char format = '\0';		/* p(lain)/t(ar) */
+static char *label = "pg_basebackup base backup";
+static bool noclean = false;
+static bool checksum_failure = false;
+static bool showprogress = false;
+static bool estimatesize = true;
+static int	verbose = 0;
+static IncludeWal includewal = STREAM_WAL;
+static bool fastcheckpoint = false;
+static bool writerecoveryconf = false;
+static bool do_sync = true;
+static int	standby_message_timeout = 10 * 1000;	/* 10 sec = default */
+static pg_time_t last_progress_report = 0;
+static int32 maxrate = 0;		/* no limit by default */
+static char *replication_slot = NULL;
+static bool temp_replication_slot = true;
+static char *backup_target = NULL;
+static bool create_slot = false;
+static bool no_slot = false;
+static bool verify_checksums = true;
+static bool manifest = true;
+static bool manifest_force_encode = false;
+static char *manifest_checksums = NULL;
+
+static bool success = false;
+static bool made_new_pgdata = false;
+static bool found_existing_pgdata = false;
+static bool made_new_xlogdir = false;
+static bool found_existing_xlogdir = false;
+static bool made_tablespace_dirs = false;
+static bool found_tablespace_dirs = false;
+
+/* Progress indicators */
+static uint64 totalsize_kb;
+static uint64 totaldone;
+static int	tablespacecount;
+static char *progress_filename = NULL;
+
+/* Pipe to communicate with background wal receiver process */
+#ifndef WIN32
+static int	bgpipe[2] = {-1, -1};
+#endif
+
+/* Handle to child process */
+static pid_t bgchild = -1;
+static bool in_log_streamer = false;
+
+/* Flag to indicate if child process exited unexpectedly */
+static volatile sig_atomic_t bgchild_exited = false;
+
+/* End position for xlog streaming, empty string if unknown yet */
+static XLogRecPtr xlogendptr;
+
+#ifndef WIN32
+static int	has_xlogendptr = 0;
+#else
+static volatile LONG has_xlogendptr = 0;
+#endif
+
+/* Contents of configuration file to be generated */
+static PQExpBuffer recoveryconfcontents = NULL;
+
+/* Function headers */
+static void usage(void);
+static void verify_dir_is_empty_or_create(char *dirname, bool *created, bool *found);
+static void progress_update_filename(const char *filename);
+static void progress_report(int tablespacenum, bool force, bool finished);
+
+static bbstreamer *CreateBackupStreamer(char *archive_name, char *spclocation,
+										bbstreamer **manifest_inject_streamer_p,
+										bool is_recovery_guc_supported,
+										bool expect_unterminated_tarfile,
+										pg_compress_specification *compress);
+static void ReceiveArchiveStreamChunk(size_t r, char *copybuf,
+									  void *callback_data);
+static char GetCopyDataByte(size_t r, char *copybuf, size_t *cursor);
+static char *GetCopyDataString(size_t r, char *copybuf, size_t *cursor);
+static uint64 GetCopyDataUInt64(size_t r, char *copybuf, size_t *cursor);
+static void GetCopyDataEnd(size_t r, char *copybuf, size_t cursor);
+static void ReportCopyDataParseError(size_t r, char *copybuf);
+static void ReceiveTarFile(PGconn *conn, char *archive_name, char *spclocation,
+						   bool tablespacenum, pg_compress_specification *compress);
+static void ReceiveTarCopyChunk(size_t r, char *copybuf, void *callback_data);
+static void ReceiveBackupManifest(PGconn *conn);
+static void ReceiveBackupManifestChunk(size_t r, char *copybuf,
+									   void *callback_data);
+static void ReceiveBackupManifestInMemory(PGconn *conn, PQExpBuffer buf);
+static void ReceiveBackupManifestInMemoryChunk(size_t r, char *copybuf,
+											   void *callback_data);
+static void BaseBackup(char *compression_algorithm, char *compression_detail,
+					   CompressionLocation compressloc,
+					   pg_compress_specification *client_compress);
+
+static bool reached_end_position(XLogRecPtr segendpos, uint32 timeline,
+								 bool segment_finished);
+
+static const char *get_tablespace_mapping(const char *dir);
+static void tablespace_list_append(const char *arg);
+
+
+static void
+cleanup_directories_atexit(void)
+{
+	if (success || in_log_streamer)
+		return;
+
+	if (!noclean && !checksum_failure)
+	{
+		if (made_new_pgdata)
+		{
+			pg_log_info("removing data directory \"%s\"", basedir);
+			if (!rmtree(basedir, true))
+				pg_log_error("failed to remove data directory");
+		}
+		else if (found_existing_pgdata)
+		{
+			pg_log_info("removing contents of data directory \"%s\"", basedir);
+			if (!rmtree(basedir, false))
+				pg_log_error("failed to remove contents of data directory");
+		}
+
+		if (made_new_xlogdir)
+		{
+			pg_log_info("removing WAL directory \"%s\"", xlog_dir);
+			if (!rmtree(xlog_dir, true))
+				pg_log_error("failed to remove WAL directory");
+		}
+		else if (found_existing_xlogdir)
+		{
+			pg_log_info("removing contents of WAL directory \"%s\"", xlog_dir);
+			if (!rmtree(xlog_dir, false))
+				pg_log_error("failed to remove contents of WAL directory");
+		}
+	}
+	else
+	{
+		if ((made_new_pgdata || found_existing_pgdata) && !checksum_failure)
+			pg_log_info("data directory \"%s\" not removed at user's request", basedir);
+
+		if (made_new_xlogdir || found_existing_xlogdir)
+			pg_log_info("WAL directory \"%s\" not removed at user's request", xlog_dir);
+	}
+
+	if ((made_tablespace_dirs || found_tablespace_dirs) && !checksum_failure)
+		pg_log_info("changes to tablespace directories will not be undone");
+}
+
+static void
+disconnect_atexit(void)
+{
+	if (conn != NULL)
+		PQfinish(conn);
+}
+
+#ifndef WIN32
+/*
+ * If the bgchild exits prematurely and raises a SIGCHLD signal, we can abort
+ * processing rather than wait until the backup has finished and error out at
+ * that time. On Windows, we use a background thread which can communicate
+ * without the need for a signal handler.
+ */
+static void
+sigchld_handler(SIGNAL_ARGS)
+{
+	bgchild_exited = true;
+}
+
+/*
+ * On windows, our background thread dies along with the process. But on
+ * Unix, if we have started a subprocess, we want to kill it off so it
+ * doesn't remain running trying to stream data.
+ */
+static void
+kill_bgchild_atexit(void)
+{
+	if (bgchild > 0 && !bgchild_exited)
+		kill(bgchild, SIGTERM);
+}
+#endif
+
+/*
+ * Split argument into old_dir and new_dir and append to tablespace mapping
+ * list.
+ */
+static void
+tablespace_list_append(const char *arg)
+{
+	TablespaceListCell *cell = (TablespaceListCell *) pg_malloc0(sizeof(TablespaceListCell));
+	char	   *dst;
+	char	   *dst_ptr;
+	const char *arg_ptr;
+
+	dst_ptr = dst = cell->old_dir;
+	for (arg_ptr = arg; *arg_ptr; arg_ptr++)
+	{
+		if (dst_ptr - dst >= MAXPGPATH)
+			pg_fatal("directory name too long");
+
+		if (*arg_ptr == '\\' && *(arg_ptr + 1) == '=')
+			;					/* skip backslash escaping = */
+		else if (*arg_ptr == '=' && (arg_ptr == arg || *(arg_ptr - 1) != '\\'))
+		{
+			if (*cell->new_dir)
+				pg_fatal("multiple \"=\" signs in tablespace mapping");
+			else
+				dst = dst_ptr = cell->new_dir;
+		}
+		else
+			*dst_ptr++ = *arg_ptr;
+	}
+
+	if (!*cell->old_dir || !*cell->new_dir)
+		pg_fatal("invalid tablespace mapping format \"%s\", must be \"OLDDIR=NEWDIR\"", arg);
+
+	/*
+	 * All tablespaces are created with absolute directories, so specifying a
+	 * non-absolute path here would just never match, possibly confusing users.
+	 * Since we don't know whether the remote side is Windows or not, and it
+	 * might be different than the local side, permit any path that could be
+	 * absolute under either set of rules.
+	 *
+	 * (There is little practical risk of confusion here, because someone
+	 * running entirely on Linux isn't likely to have a relative path that
+	 * begins with a backslash or something that looks like a drive
+	 * specification. If they do, and they also incorrectly believe that
+	 * a relative path is acceptable here, we'll silently fail to warn them
+	 * of their mistake, and the -T option will just not get applied, same
+	 * as if they'd specified -T for a nonexistent tablespace.)
+	 */
+	if (!is_nonwindows_absolute_path(cell->old_dir) &&
+		!is_windows_absolute_path(cell->old_dir))
+		pg_fatal("old directory is not an absolute path in tablespace mapping: %s",
+				 cell->old_dir);
+
+	if (!is_absolute_path(cell->new_dir))
+		pg_fatal("new directory is not an absolute path in tablespace mapping: %s",
+				 cell->new_dir);
+
+	/*
+	 * Comparisons done with these values should involve similarly
+	 * canonicalized path values.  This is particularly sensitive on Windows
+	 * where path values may not necessarily use Unix slashes.
+	 */
+	canonicalize_path(cell->old_dir);
+	canonicalize_path(cell->new_dir);
+
+	if (tablespace_dirs.tail)
+		tablespace_dirs.tail->next = cell;
+	else
+		tablespace_dirs.head = cell;
+	tablespace_dirs.tail = cell;
+}
+
+
+static void
+usage(void)
+{
+	printf(_("%s takes a base backup of a running PostgreSQL server.\n\n"),
+		   progname);
+	printf(_("Usage:\n"));
+	printf(_("  %s [OPTION]...\n"), progname);
+	printf(_("\nOptions controlling the output:\n"));
+	printf(_("  -D, --pgdata=DIRECTORY receive base backup into directory\n"));
+	printf(_("  -F, --format=p|t       output format (plain (default), tar)\n"));
+	printf(_("  -r, --max-rate=RATE    maximum transfer rate to transfer data directory\n"
+			 "                         (in kB/s, or use suffix \"k\" or \"M\")\n"));
+	printf(_("  -R, --write-recovery-conf\n"
+			 "                         write configuration for replication\n"));
+	printf(_("  -t, --target=TARGET[:DETAIL]\n"
+			 "                         backup target (if other than client)\n"));
+	printf(_("  -T, --tablespace-mapping=OLDDIR=NEWDIR\n"
+			 "                         relocate tablespace in OLDDIR to NEWDIR\n"));
+	printf(_("      --waldir=WALDIR    location for the write-ahead log directory\n"));
+	printf(_("  -X, --wal-method=none|fetch|stream\n"
+			 "                         include required WAL files with specified method\n"));
+	printf(_("  -z, --gzip             compress tar output\n"));
+	printf(_("  -Z, --compress=[{client|server}-]METHOD[:DETAIL]\n"
+			 "                         compress on client or server as specified\n"));
+	printf(_("  -Z, --compress=none    do not compress tar output\n"));
+	printf(_("\nGeneral options:\n"));
+	printf(_("  -c, --checkpoint=fast|spread\n"
+			 "                         set fast or spread checkpointing\n"));
+	printf(_("  -C, --create-slot      create replication slot\n"));
+	printf(_("  -l, --label=LABEL      set backup label\n"));
+	printf(_("  -n, --no-clean         do not clean up after errors\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(_("  -S, --slot=SLOTNAME    replication slot to use\n"));
+	printf(_("  -v, --verbose          output verbose messages\n"));
+	printf(_("  -V, --version          output version information, then exit\n"));
+	printf(_("      --manifest-checksums=SHA{224,256,384,512}|CRC32C|NONE\n"
+			 "                         use algorithm for manifest checksums\n"));
+	printf(_("      --manifest-force-encode\n"
+			 "                         hex encode all file names in manifest\n"));
+	printf(_("      --no-estimate-size do not estimate backup size in server side\n"));
+	printf(_("      --no-manifest      suppress generation of backup manifest\n"));
+	printf(_("      --no-slot          prevent creation of temporary replication slot\n"));
+	printf(_("      --no-verify-checksums\n"
+			 "                         do not verify checksums\n"));
+	printf(_("  -?, --help             show this help, then exit\n"));
+	printf(_("\nConnection options:\n"));
+	printf(_("  -d, --dbname=CONNSTR   connection string\n"));
+	printf(_("  -h, --host=HOSTNAME    database server host or socket directory\n"));
+	printf(_("  -p, --port=PORT        database server port number\n"));
+	printf(_("  -s, --status-interval=INTERVAL\n"
+			 "                         time between status packets sent to server (in seconds)\n"));
+	printf(_("  -U, --username=NAME    connect as specified database user\n"));
+	printf(_("  -w, --no-password      never prompt for password\n"));
+	printf(_("  -W, --password         force password prompt (should happen automatically)\n"));
+	printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
+	printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
+}
+
+
+/*
+ * Called in the background process every time data is received.
+ * On Unix, we check to see if there is any data on our pipe
+ * (which would mean we have a stop position), and if it is, check if
+ * it is time to stop.
+ * On Windows, we are in a single process, so we can just check if it's
+ * time to stop.
+ */
+static bool
+reached_end_position(XLogRecPtr segendpos, uint32 timeline,
+					 bool segment_finished)
+{
+	if (!has_xlogendptr)
+	{
+#ifndef WIN32
+		fd_set		fds;
+		struct timeval tv;
+		int			r;
+
+		/*
+		 * Don't have the end pointer yet - check our pipe to see if it has
+		 * been sent yet.
+		 */
+		FD_ZERO(&fds);
+		FD_SET(bgpipe[0], &fds);
+
+		MemSet(&tv, 0, sizeof(tv));
+
+		r = select(bgpipe[0] + 1, &fds, NULL, NULL, &tv);
+		if (r == 1)
+		{
+			char		xlogend[64];
+			uint32		hi,
+						lo;
+
+			MemSet(xlogend, 0, sizeof(xlogend));
+			r = read(bgpipe[0], xlogend, sizeof(xlogend) - 1);
+			if (r < 0)
+				pg_fatal("could not read from ready pipe: %m");
+
+			if (sscanf(xlogend, "%X/%X", &hi, &lo) != 2)
+				pg_fatal("could not parse write-ahead log location \"%s\"",
+						 xlogend);
+			xlogendptr = ((uint64) hi) << 32 | lo;
+			has_xlogendptr = 1;
+
+			/*
+			 * Fall through to check if we've reached the point further
+			 * already.
+			 */
+		}
+		else
+		{
+			/*
+			 * No data received on the pipe means we don't know the end
+			 * position yet - so just say it's not time to stop yet.
+			 */
+			return false;
+		}
+#else
+
+		/*
+		 * On win32, has_xlogendptr is set by the main thread, so if it's not
+		 * set here, we just go back and wait until it shows up.
+		 */
+		return false;
+#endif
+	}
+
+	/*
+	 * At this point we have an end pointer, so compare it to the current
+	 * position to figure out if it's time to stop.
+	 */
+	if (segendpos >= xlogendptr)
+		return true;
+
+	/*
+	 * Have end pointer, but haven't reached it yet - so tell the caller to
+	 * keep streaming.
+	 */
+	return false;
+}
+
+typedef struct
+{
+	PGconn	   *bgconn;
+	XLogRecPtr	startptr;
+	char		xlog[MAXPGPATH];	/* directory or tarfile depending on mode */
+	char	   *sysidentifier;
+	int			timeline;
+	pg_compress_algorithm wal_compress_algorithm;
+	int			wal_compress_level;
+} logstreamer_param;
+
+static int
+LogStreamerMain(logstreamer_param *param)
+{
+	StreamCtl	stream;
+
+	in_log_streamer = true;
+
+	MemSet(&stream, 0, sizeof(stream));
+	stream.startpos = param->startptr;
+	stream.timeline = param->timeline;
+	stream.sysidentifier = param->sysidentifier;
+	stream.stream_stop = reached_end_position;
+#ifndef WIN32
+	stream.stop_socket = bgpipe[0];
+#else
+	stream.stop_socket = PGINVALID_SOCKET;
+#endif
+	stream.standby_message_timeout = standby_message_timeout;
+	stream.synchronous = false;
+	/* fsync happens at the end of pg_basebackup for all data */
+	stream.do_sync = false;
+	stream.mark_done = true;
+	stream.partial_suffix = NULL;
+	stream.replication_slot = replication_slot;
+	if (format == 'p')
+		stream.walmethod = CreateWalDirectoryMethod(param->xlog,
+													PG_COMPRESSION_NONE, 0,
+													stream.do_sync);
+	else
+		stream.walmethod = CreateWalTarMethod(param->xlog,
+											  param->wal_compress_algorithm,
+											  param->wal_compress_level,
+											  stream.do_sync);
+
+	if (!ReceiveXlogStream(param->bgconn, &stream))
+	{
+		/*
+		 * Any errors will already have been reported in the function process,
+		 * but we need to tell the parent that we didn't shutdown in a nice
+		 * way.
+		 */
+#ifdef WIN32
+		/*
+		 * In order to signal the main thread of an ungraceful exit we set the
+		 * same flag that we use on Unix to signal SIGCHLD.
+		 */
+		bgchild_exited = true;
+#endif
+		return 1;
+	}
+
+	if (!stream.walmethod->finish())
+	{
+		pg_log_error("could not finish writing WAL files: %m");
+#ifdef WIN32
+		bgchild_exited = true;
+#endif
+		return 1;
+	}
+
+	PQfinish(param->bgconn);
+
+	if (format == 'p')
+		FreeWalDirectoryMethod();
+	else
+		FreeWalTarMethod();
+	pg_free(stream.walmethod);
+
+	return 0;
+}
+
+/*
+ * Initiate background process for receiving xlog during the backup.
+ * The background stream will use its own database connection so we can
+ * stream the logfile in parallel with the backups.
+ */
+static void
+StartLogStreamer(char *startpos, uint32 timeline, char *sysidentifier,
+				 pg_compress_algorithm wal_compress_algorithm,
+				 int wal_compress_level)
+{
+	logstreamer_param *param;
+	uint32		hi,
+				lo;
+	char		statusdir[MAXPGPATH];
+
+	param = pg_malloc0(sizeof(logstreamer_param));
+	param->timeline = timeline;
+	param->sysidentifier = sysidentifier;
+	param->wal_compress_algorithm = wal_compress_algorithm;
+	param->wal_compress_level = wal_compress_level;
+
+	/* Convert the starting position */
+	if (sscanf(startpos, "%X/%X", &hi, &lo) != 2)
+		pg_fatal("could not parse write-ahead log location \"%s\"",
+				 startpos);
+	param->startptr = ((uint64) hi) << 32 | lo;
+	/* Round off to even segment position */
+	param->startptr -= XLogSegmentOffset(param->startptr, WalSegSz);
+
+#ifndef WIN32
+	/* Create our background pipe */
+	if (pipe(bgpipe) < 0)
+		pg_fatal("could not create pipe for background process: %m");
+#endif
+
+	/* Get a second connection */
+	param->bgconn = GetConnection();
+	if (!param->bgconn)
+		/* Error message already written in GetConnection() */
+		exit(1);
+
+	/* In post-10 cluster, pg_xlog has been renamed to pg_wal */
+	snprintf(param->xlog, sizeof(param->xlog), "%s/%s",
+			 basedir,
+			 PQserverVersion(conn) < MINIMUM_VERSION_FOR_PG_WAL ?
+			 "pg_xlog" : "pg_wal");
+
+	/* Temporary replication slots are only supported in 10 and newer */
+	if (PQserverVersion(conn) < MINIMUM_VERSION_FOR_TEMP_SLOTS)
+		temp_replication_slot = false;
+
+	/*
+	 * Create replication slot if requested
+	 */
+	if (temp_replication_slot && !replication_slot)
+		replication_slot = psprintf("pg_basebackup_%u",
+									(unsigned int) PQbackendPID(param->bgconn));
+	if (temp_replication_slot || create_slot)
+	{
+		if (!CreateReplicationSlot(param->bgconn, replication_slot, NULL,
+								   temp_replication_slot, true, true, false, false))
+			exit(1);
+
+		if (verbose)
+		{
+			if (temp_replication_slot)
+				pg_log_info("created temporary replication slot \"%s\"",
+							replication_slot);
+			else
+				pg_log_info("created replication slot \"%s\"",
+							replication_slot);
+		}
+	}
+
+	if (format == 'p')
+	{
+		/*
+		 * Create pg_wal/archive_status or pg_xlog/archive_status (and thus
+		 * pg_wal or pg_xlog) depending on the target server so we can write
+		 * to basedir/pg_wal or basedir/pg_xlog as the directory entry in the
+		 * tar file may arrive later.
+		 */
+		snprintf(statusdir, sizeof(statusdir), "%s/%s/archive_status",
+				 basedir,
+				 PQserverVersion(conn) < MINIMUM_VERSION_FOR_PG_WAL ?
+				 "pg_xlog" : "pg_wal");
+
+		if (pg_mkdir_p(statusdir, pg_dir_create_mode) != 0 && errno != EEXIST)
+			pg_fatal("could not create directory \"%s\": %m", statusdir);
+	}
+
+	/*
+	 * Start a child process and tell it to start streaming. On Unix, this is
+	 * a fork(). On Windows, we create a thread.
+	 */
+#ifndef WIN32
+	bgchild = fork();
+	if (bgchild == 0)
+	{
+		/* in child process */
+		exit(LogStreamerMain(param));
+	}
+	else if (bgchild < 0)
+		pg_fatal("could not create background process: %m");
+
+	/*
+	 * Else we are in the parent process and all is well.
+	 */
+	atexit(kill_bgchild_atexit);
+#else							/* WIN32 */
+	bgchild = _beginthreadex(NULL, 0, (void *) LogStreamerMain, param, 0, NULL);
+	if (bgchild == 0)
+		pg_fatal("could not create background thread: %m");
+#endif
+}
+
+/*
+ * Verify that the given directory exists and is empty. If it does not
+ * exist, it is created. If it exists but is not empty, an error will
+ * be given and the process ended.
+ */
+static void
+verify_dir_is_empty_or_create(char *dirname, bool *created, bool *found)
+{
+	switch (pg_check_dir(dirname))
+	{
+		case 0:
+
+			/*
+			 * Does not exist, so create
+			 */
+			if (pg_mkdir_p(dirname, pg_dir_create_mode) == -1)
+				pg_fatal("could not create directory \"%s\": %m", dirname);
+			if (created)
+				*created = true;
+			return;
+		case 1:
+
+			/*
+			 * Exists, empty
+			 */
+			if (found)
+				*found = true;
+			return;
+		case 2:
+		case 3:
+		case 4:
+
+			/*
+			 * Exists, not empty
+			 */
+			pg_fatal("directory \"%s\" exists but is not empty", dirname);
+		case -1:
+
+			/*
+			 * Access problem
+			 */
+			pg_fatal("could not access directory \"%s\": %m", dirname);
+	}
+}
+
+/*
+ * Callback to update our notion of the current filename.
+ *
+ * No other code should modify progress_filename!
+ */
+static void
+progress_update_filename(const char *filename)
+{
+	/* We needn't maintain this variable if not doing verbose reports. */
+	if (showprogress && verbose)
+	{
+		if (progress_filename)
+			free(progress_filename);
+		if (filename)
+			progress_filename = pg_strdup(filename);
+		else
+			progress_filename = NULL;
+	}
+}
+
+/*
+ * Print a progress report based on the global variables. If verbose output
+ * is enabled, also print the current file name.
+ *
+ * Progress report is written at maximum once per second, unless the force
+ * parameter is set to true.
+ *
+ * If finished is set to true, this is the last progress report. The cursor
+ * is moved to the next line.
+ */
+static void
+progress_report(int tablespacenum, bool force, bool finished)
+{
+	int			percent;
+	char		totaldone_str[32];
+	char		totalsize_str[32];
+	pg_time_t	now;
+
+	if (!showprogress)
+		return;
+
+	now = time(NULL);
+	if (now == last_progress_report && !force && !finished)
+		return;					/* Max once per second */
+
+	last_progress_report = now;
+	percent = totalsize_kb ? (int) ((totaldone / 1024) * 100 / totalsize_kb) : 0;
+
+	/*
+	 * Avoid overflowing past 100% or the full size. This may make the total
+	 * size number change as we approach the end of the backup (the estimate
+	 * will always be wrong if WAL is included), but that's better than having
+	 * the done column be bigger than the total.
+	 */
+	if (percent > 100)
+		percent = 100;
+	if (totaldone / 1024 > totalsize_kb)
+		totalsize_kb = totaldone / 1024;
+
+	snprintf(totaldone_str, sizeof(totaldone_str), UINT64_FORMAT,
+			 totaldone / 1024);
+	snprintf(totalsize_str, sizeof(totalsize_str), UINT64_FORMAT, totalsize_kb);
+
+#define VERBOSE_FILENAME_LENGTH 35
+	if (verbose)
+	{
+		if (!progress_filename)
+
+			/*
+			 * No filename given, so clear the status line (used for last
+			 * call)
+			 */
+			fprintf(stderr,
+					ngettext("%*s/%s kB (100%%), %d/%d tablespace %*s",
+							 "%*s/%s kB (100%%), %d/%d tablespaces %*s",
+							 tablespacecount),
+					(int) strlen(totalsize_str),
+					totaldone_str, totalsize_str,
+					tablespacenum, tablespacecount,
+					VERBOSE_FILENAME_LENGTH + 5, "");
+		else
+		{
+			bool		truncate = (strlen(progress_filename) > VERBOSE_FILENAME_LENGTH);
+
+			fprintf(stderr,
+					ngettext("%*s/%s kB (%d%%), %d/%d tablespace (%s%-*.*s)",
+							 "%*s/%s kB (%d%%), %d/%d tablespaces (%s%-*.*s)",
+							 tablespacecount),
+					(int) strlen(totalsize_str),
+					totaldone_str, totalsize_str, percent,
+					tablespacenum, tablespacecount,
+			/* Prefix with "..." if we do leading truncation */
+					truncate ? "..." : "",
+					truncate ? VERBOSE_FILENAME_LENGTH - 3 : VERBOSE_FILENAME_LENGTH,
+					truncate ? VERBOSE_FILENAME_LENGTH - 3 : VERBOSE_FILENAME_LENGTH,
+			/* Truncate filename at beginning if it's too long */
+					truncate ? progress_filename + strlen(progress_filename) - VERBOSE_FILENAME_LENGTH + 3 : progress_filename);
+		}
+	}
+	else
+		fprintf(stderr,
+				ngettext("%*s/%s kB (%d%%), %d/%d tablespace",
+						 "%*s/%s kB (%d%%), %d/%d tablespaces",
+						 tablespacecount),
+				(int) strlen(totalsize_str),
+				totaldone_str, totalsize_str, percent,
+				tablespacenum, tablespacecount);
+
+	/*
+	 * Stay on the same line if reporting to a terminal and we're not done
+	 * yet.
+	 */
+	fputc((!finished && isatty(fileno(stderr))) ? '\r' : '\n', stderr);
+}
+
+static int32
+parse_max_rate(char *src)
+{
+	double		result;
+	char	   *after_num;
+	char	   *suffix = NULL;
+
+	errno = 0;
+	result = strtod(src, &after_num);
+	if (src == after_num)
+		pg_fatal("transfer rate \"%s\" is not a valid value", src);
+	if (errno != 0)
+		pg_fatal("invalid transfer rate \"%s\": %m", src);
+
+	if (result <= 0)
+	{
+		/*
+		 * Reject obviously wrong values here.
+		 */
+		pg_fatal("transfer rate must be greater than zero");
+	}
+
+	/*
+	 * Evaluate suffix, after skipping over possible whitespace. Lack of
+	 * suffix means kilobytes.
+	 */
+	while (*after_num != '\0' && isspace((unsigned char) *after_num))
+		after_num++;
+
+	if (*after_num != '\0')
+	{
+		suffix = after_num;
+		if (*after_num == 'k')
+		{
+			/* kilobyte is the expected unit. */
+			after_num++;
+		}
+		else if (*after_num == 'M')
+		{
+			after_num++;
+			result *= 1024.0;
+		}
+	}
+
+	/* The rest can only consist of white space. */
+	while (*after_num != '\0' && isspace((unsigned char) *after_num))
+		after_num++;
+
+	if (*after_num != '\0')
+		pg_fatal("invalid --max-rate unit: \"%s\"", suffix);
+
+	/* Valid integer? */
+	if ((uint64) result != (uint64) ((uint32) result))
+		pg_fatal("transfer rate \"%s\" exceeds integer range", src);
+
+	/*
+	 * The range is checked on the server side too, but avoid the server
+	 * connection if a nonsensical value was passed.
+	 */
+	if (result < MAX_RATE_LOWER || result > MAX_RATE_UPPER)
+		pg_fatal("transfer rate \"%s\" is out of range", src);
+
+	return (int32) result;
+}
+
+/*
+ * Basic parsing of a value specified for -Z/--compress.
+ *
+ * We're not concerned here with understanding exactly what behavior the
+ * user wants, but we do need to know whether the user is requesting client
+ * or server side compression or leaving it unspecified, and we need to
+ * separate the name of the compression algorithm from the detail string.
+ *
+ * For instance, if the user writes --compress client-lz4:6, we want to
+ * separate that into (a) client-side compression, (b) algorithm "lz4",
+ * and (c) detail "6". Note, however, that all the client/server prefix is
+ * optional, and so is the detail. The algorithm name is required, unless
+ * the whole string is an integer, in which case we assume "gzip" as the
+ * algorithm and use the integer as the detail.
+ *
+ * We're not concerned with validation at this stage, so if the user writes
+ * --compress client-turkey:sandwich, the requested algorithm is "turkey"
+ * and the detail string is "sandwich". We'll sort out whether that's legal
+ * at a later stage.
+ */
+static void
+parse_compress_options(char *option, char **algorithm, char **detail,
+					   CompressionLocation *locationres)
+{
+	char	   *sep;
+	char	   *endp;
+
+	/*
+	 * Check whether the compression specification consists of a bare integer.
+	 *
+	 * If so, for backward compatibility, assume gzip.
+	 */
+	(void) strtol(option, &endp, 10);
+	if (*endp == '\0')
+	{
+		*locationres = COMPRESS_LOCATION_UNSPECIFIED;
+		*algorithm = pstrdup("gzip");
+		*detail = pstrdup(option);
+		return;
+	}
+
+	/* Strip off any "client-" or "server-" prefix. */
+	if (strncmp(option, "server-", 7) == 0)
+	{
+		*locationres = COMPRESS_LOCATION_SERVER;
+		option += 7;
+	}
+	else if (strncmp(option, "client-", 7) == 0)
+	{
+		*locationres = COMPRESS_LOCATION_CLIENT;
+		option += 7;
+	}
+	else
+		*locationres = COMPRESS_LOCATION_UNSPECIFIED;
+
+	/*
+	 * Check whether there is a compression detail following the algorithm
+	 * name.
+	 */
+	sep = strchr(option, ':');
+	if (sep == NULL)
+	{
+		*algorithm = pstrdup(option);
+		*detail = NULL;
+	}
+	else
+	{
+		char	   *alg;
+
+		alg = palloc((sep - option) + 1);
+		memcpy(alg, option, sep - option);
+		alg[sep - option] = '\0';
+
+		*algorithm = alg;
+		*detail = pstrdup(sep + 1);
+	}
+}
+
+/*
+ * Read a stream of COPY data and invoke the provided callback for each
+ * chunk.
+ */
+static void
+ReceiveCopyData(PGconn *conn, WriteDataCallback callback,
+				void *callback_data)
+{
+	PGresult   *res;
+
+	/* Get the COPY data stream. */
+	res = PQgetResult(conn);
+	if (PQresultStatus(res) != PGRES_COPY_OUT)
+		pg_fatal("could not get COPY data stream: %s",
+				 PQerrorMessage(conn));
+	PQclear(res);
+
+	/* Loop over chunks until done. */
+	while (1)
+	{
+		int			r;
+		char	   *copybuf;
+
+		r = PQgetCopyData(conn, &copybuf, 0);
+		if (r == -1)
+		{
+			/* End of chunk. */
+			break;
+		}
+		else if (r == -2)
+			pg_fatal("could not read COPY data: %s",
+					 PQerrorMessage(conn));
+
+		if (bgchild_exited)
+			pg_fatal("background process terminated unexpectedly");
+
+		(*callback) (r, copybuf, callback_data);
+
+		PQfreemem(copybuf);
+	}
+}
+
+/*
+ * Figure out what to do with an archive received from the server based on
+ * the options selected by the user.  We may just write the results directly
+ * to a file, or we might compress first, or we might extract the tar file
+ * and write each member separately. This function doesn't do any of that
+ * directly, but it works out what kind of bbstreamer we need to create so
+ * that the right stuff happens when, down the road, we actually receive
+ * the data.
+ */
+static bbstreamer *
+CreateBackupStreamer(char *archive_name, char *spclocation,
+					 bbstreamer **manifest_inject_streamer_p,
+					 bool is_recovery_guc_supported,
+					 bool expect_unterminated_tarfile,
+					 pg_compress_specification *compress)
+{
+	bbstreamer *streamer = NULL;
+	bbstreamer *manifest_inject_streamer = NULL;
+	bool		inject_manifest;
+	bool		is_tar,
+				is_tar_gz,
+				is_tar_lz4,
+				is_tar_zstd,
+				is_compressed_tar;
+	bool		must_parse_archive;
+	int			archive_name_len = strlen(archive_name);
+
+	/*
+	 * Normally, we emit the backup manifest as a separate file, but when
+	 * we're writing a tarfile to stdout, we don't have that option, so
+	 * include it in the one tarfile we've got.
+	 */
+	inject_manifest = (format == 't' && strcmp(basedir, "-") == 0 && manifest);
+
+	/* Is this a tar archive? */
+	is_tar = (archive_name_len > 4 &&
+			  strcmp(archive_name + archive_name_len - 4, ".tar") == 0);
+
+	/* Is this a .tar.gz archive? */
+	is_tar_gz = (archive_name_len > 7 &&
+				 strcmp(archive_name + archive_name_len - 7, ".tar.gz") == 0);
+
+	/* Is this a .tar.lz4 archive? */
+	is_tar_lz4 = (archive_name_len > 8 &&
+				  strcmp(archive_name + archive_name_len - 8, ".tar.lz4") == 0);
+
+	/* Is this a .tar.zst archive? */
+	is_tar_zstd = (archive_name_len > 8 &&
+				   strcmp(archive_name + archive_name_len - 8, ".tar.zst") == 0);
+
+	/* Is this any kind of compressed tar? */
+	is_compressed_tar = is_tar_gz || is_tar_lz4 || is_tar_zstd;
+
+	/*
+	 * Injecting the manifest into a compressed tar file would be possible if
+	 * we decompressed it, parsed the tarfile, generated a new tarfile, and
+	 * recompressed it, but compressing and decompressing multiple times just
+	 * to inject the manifest seems inefficient enough that it's probably not
+	 * what the user wants. So, instead, reject the request and tell the user
+	 * to specify something more reasonable.
+	 */
+	if (inject_manifest && is_compressed_tar)
+	{
+		pg_log_error("cannot inject manifest into a compressed tar file");
+		pg_log_error_hint("Use client-side compression, send the output to a directory rather than standard output, or use %s.",
+						  "--no-manifest");
+		exit(1);
+	}
+
+	/*
+	 * We have to parse the archive if (1) we're suppose to extract it, or if
+	 * (2) we need to inject backup_manifest or recovery configuration into
+	 * it. However, we only know how to parse tar archives.
+	 */
+	must_parse_archive = (format == 'p' || inject_manifest ||
+						  (spclocation == NULL && writerecoveryconf));
+
+	/* At present, we only know how to parse tar archives. */
+	if (must_parse_archive && !is_tar && !is_compressed_tar)
+	{
+		pg_log_error("cannot parse archive \"%s\"", archive_name);
+		pg_log_error_detail("Only tar archives can be parsed.");
+		if (format == 'p')
+			pg_log_error_detail("Plain format requires pg_basebackup to parse the archive.");
+		if (inject_manifest)
+			pg_log_error_detail("Using - as the output directory requires pg_basebackup to parse the archive.");
+		if (writerecoveryconf)
+			pg_log_error_detail("The -R option requires pg_basebackup to parse the archive.");
+		exit(1);
+	}
+
+	if (format == 'p')
+	{
+		const char *directory;
+
+		/*
+		 * In plain format, we must extract the archive. The data for the main
+		 * tablespace will be written to the base directory, and the data for
+		 * other tablespaces will be written to the directory where they're
+		 * located on the server, after applying any user-specified tablespace
+		 * mappings.
+		 */
+		directory = spclocation == NULL ? basedir
+			: get_tablespace_mapping(spclocation);
+		streamer = bbstreamer_extractor_new(directory,
+											get_tablespace_mapping,
+											progress_update_filename);
+	}
+	else
+	{
+		FILE	   *archive_file;
+		char		archive_filename[MAXPGPATH];
+
+		/*
+		 * In tar format, we just write the archive without extracting it.
+		 * Normally, we write it to the archive name provided by the caller,
+		 * but when the base directory is "-" that means we need to write to
+		 * standard output.
+		 */
+		if (strcmp(basedir, "-") == 0)
+		{
+			snprintf(archive_filename, sizeof(archive_filename), "-");
+			archive_file = stdout;
+		}
+		else
+		{
+			snprintf(archive_filename, sizeof(archive_filename),
+					 "%s/%s", basedir, archive_name);
+			archive_file = NULL;
+		}
+
+		if (compress->algorithm == PG_COMPRESSION_NONE)
+			streamer = bbstreamer_plain_writer_new(archive_filename,
+												   archive_file);
+		else if (compress->algorithm == PG_COMPRESSION_GZIP)
+		{
+			strlcat(archive_filename, ".gz", sizeof(archive_filename));
+			streamer = bbstreamer_gzip_writer_new(archive_filename,
+												  archive_file, compress);
+		}
+		else if (compress->algorithm == PG_COMPRESSION_LZ4)
+		{
+			strlcat(archive_filename, ".lz4", sizeof(archive_filename));
+			streamer = bbstreamer_plain_writer_new(archive_filename,
+												   archive_file);
+			streamer = bbstreamer_lz4_compressor_new(streamer, compress);
+		}
+		else if (compress->algorithm == PG_COMPRESSION_ZSTD)
+		{
+			strlcat(archive_filename, ".zst", sizeof(archive_filename));
+			streamer = bbstreamer_plain_writer_new(archive_filename,
+												   archive_file);
+			streamer = bbstreamer_zstd_compressor_new(streamer, compress);
+		}
+		else
+		{
+			Assert(false);		/* not reachable */
+		}
+
+		/*
+		 * If we need to parse the archive for whatever reason, then we'll
+		 * also need to re-archive, because, if the output format is tar, the
+		 * only point of parsing the archive is to be able to inject stuff
+		 * into it.
+		 */
+		if (must_parse_archive)
+			streamer = bbstreamer_tar_archiver_new(streamer);
+		progress_update_filename(archive_filename);
+	}
+
+	/*
+	 * If we're supposed to inject the backup manifest into the results, it
+	 * should be done here, so that the file content can be injected directly,
+	 * without worrying about the details of the tar format.
+	 */
+	if (inject_manifest)
+		manifest_inject_streamer = streamer;
+
+	/*
+	 * If this is the main tablespace and we're supposed to write recovery
+	 * information, arrange to do that.
+	 */
+	if (spclocation == NULL && writerecoveryconf)
+	{
+		Assert(must_parse_archive);
+		streamer = bbstreamer_recovery_injector_new(streamer,
+													is_recovery_guc_supported,
+													recoveryconfcontents);
+	}
+
+	/*
+	 * If we're doing anything that involves understanding the contents of the
+	 * archive, we'll need to parse it. If not, we can skip parsing it, but
+	 * old versions of the server send improperly terminated tarfiles, so if
+	 * we're talking to such a server we'll need to add the terminator here.
+	 */
+	if (must_parse_archive)
+		streamer = bbstreamer_tar_parser_new(streamer);
+	else if (expect_unterminated_tarfile)
+		streamer = bbstreamer_tar_terminator_new(streamer);
+
+	/*
+	 * If the user has requested a server compressed archive along with
+	 * archive extraction at client then we need to decompress it.
+	 */
+	if (format == 'p')
+	{
+		if (is_tar_gz)
+			streamer = bbstreamer_gzip_decompressor_new(streamer);
+		else if (is_tar_lz4)
+			streamer = bbstreamer_lz4_decompressor_new(streamer);
+		else if (is_tar_zstd)
+			streamer = bbstreamer_zstd_decompressor_new(streamer);
+	}
+
+	/* Return the results. */
+	*manifest_inject_streamer_p = manifest_inject_streamer;
+	return streamer;
+}
+
+/*
+ * Receive all of the archives the server wants to send - and the backup
+ * manifest if present - as a single COPY stream.
+ */
+static void
+ReceiveArchiveStream(PGconn *conn, pg_compress_specification *compress)
+{
+	ArchiveStreamState state;
+
+	/* Set up initial state. */
+	memset(&state, 0, sizeof(state));
+	state.tablespacenum = -1;
+	state.compress = compress;
+
+	/* All the real work happens in ReceiveArchiveStreamChunk. */
+	ReceiveCopyData(conn, ReceiveArchiveStreamChunk, &state);
+
+	/* If we wrote the backup manifest to a file, close the file. */
+	if (state.manifest_file !=NULL)
+	{
+		fclose(state.manifest_file);
+		state.manifest_file = NULL;
+	}
+
+	/*
+	 * If we buffered the backup manifest in order to inject it into the
+	 * output tarfile, do that now.
+	 */
+	if (state.manifest_inject_streamer != NULL &&
+		state.manifest_buffer != NULL)
+	{
+		bbstreamer_inject_file(state.manifest_inject_streamer,
+							   "backup_manifest",
+							   state.manifest_buffer->data,
+							   state.manifest_buffer->len);
+		destroyPQExpBuffer(state.manifest_buffer);
+		state.manifest_buffer = NULL;
+	}
+
+	/* If there's still an archive in progress, end processing. */
+	if (state.streamer != NULL)
+	{
+		bbstreamer_finalize(state.streamer);
+		bbstreamer_free(state.streamer);
+		state.streamer = NULL;
+	}
+}
+
+/*
+ * Receive one chunk of data sent by the server as part of a single COPY
+ * stream that includes all archives and the manifest.
+ */
+static void
+ReceiveArchiveStreamChunk(size_t r, char *copybuf, void *callback_data)
+{
+	ArchiveStreamState *state = callback_data;
+	size_t		cursor = 0;
+
+	/* Each CopyData message begins with a type byte. */
+	switch (GetCopyDataByte(r, copybuf, &cursor))
+	{
+		case 'n':
+			{
+				/* New archive. */
+				char	   *archive_name;
+				char	   *spclocation;
+
+				/*
+				 * We force a progress report at the end of each tablespace. A
+				 * new tablespace starts when the previous one ends, except in
+				 * the case of the very first one.
+				 */
+				if (++state->tablespacenum > 0)
+					progress_report(state->tablespacenum, true, false);
+
+				/* Sanity check. */
+				if (state->manifest_buffer != NULL ||
+					state->manifest_file !=NULL)
+					pg_fatal("archives must precede manifest");
+
+				/* Parse the rest of the CopyData message. */
+				archive_name = GetCopyDataString(r, copybuf, &cursor);
+				spclocation = GetCopyDataString(r, copybuf, &cursor);
+				GetCopyDataEnd(r, copybuf, cursor);
+
+				/*
+				 * Basic sanity checks on the archive name: it shouldn't be
+				 * empty, it shouldn't start with a dot, and it shouldn't
+				 * contain a path separator.
+				 */
+				if (archive_name[0] == '\0' || archive_name[0] == '.' ||
+					strchr(archive_name, '/') != NULL ||
+					strchr(archive_name, '\\') != NULL)
+					pg_fatal("invalid archive name: \"%s\"",
+							 archive_name);
+
+				/*
+				 * An empty spclocation is treated as NULL. We expect this
+				 * case to occur for the data directory itself, but not for
+				 * any archives that correspond to tablespaces.
+				 */
+				if (spclocation[0] == '\0')
+					spclocation = NULL;
+
+				/* End processing of any prior archive. */
+				if (state->streamer != NULL)
+				{
+					bbstreamer_finalize(state->streamer);
+					bbstreamer_free(state->streamer);
+					state->streamer = NULL;
+				}
+
+				/*
+				 * Create an appropriate backup streamer, unless a backup
+				 * target was specified. In that case, it's up to the server
+				 * to put the backup wherever it needs to go.
+				 */
+				if (backup_target == NULL)
+				{
+					/*
+					 * We know that recovery GUCs are supported, because this
+					 * protocol can only be used on v15+.
+					 */
+					state->streamer =
+						CreateBackupStreamer(archive_name,
+											 spclocation,
+											 &state->manifest_inject_streamer,
+											 true, false,
+											 state->compress);
+				}
+				break;
+			}
+
+		case 'd':
+			{
+				/* Archive or manifest data. */
+				if (state->manifest_buffer != NULL)
+				{
+					/* Manifest data, buffer in memory. */
+					appendPQExpBuffer(state->manifest_buffer, copybuf + 1,
+									  r - 1);
+				}
+				else if (state->manifest_file !=NULL)
+				{
+					/* Manifest data, write to disk. */
+					if (fwrite(copybuf + 1, r - 1, 1,
+							   state->manifest_file) != 1)
+					{
+						/*
+						 * If fwrite() didn't set errno, assume that the
+						 * problem is that we're out of disk space.
+						 */
+						if (errno == 0)
+							errno = ENOSPC;
+						pg_fatal("could not write to file \"%s\": %m",
+								 state->manifest_filename);
+					}
+				}
+				else if (state->streamer != NULL)
+				{
+					/* Archive data. */
+					bbstreamer_content(state->streamer, NULL, copybuf + 1,
+									   r - 1, BBSTREAMER_UNKNOWN);
+				}
+				else
+					pg_fatal("unexpected payload data");
+				break;
+			}
+
+		case 'p':
+			{
+				/*
+				 * Progress report.
+				 *
+				 * The remainder of the message is expected to be an 8-byte
+				 * count of bytes completed.
+				 */
+				totaldone = GetCopyDataUInt64(r, copybuf, &cursor);
+				GetCopyDataEnd(r, copybuf, cursor);
+
+				/*
+				 * The server shouldn't send progress report messages too
+				 * often, so we force an update each time we receive one.
+				 */
+				progress_report(state->tablespacenum, true, false);
+				break;
+			}
+
+		case 'm':
+			{
+				/*
+				 * Manifest data will be sent next. This message is not
+				 * expected to have any further payload data.
+				 */
+				GetCopyDataEnd(r, copybuf, cursor);
+
+				/*
+				 * If a backup target was specified, figuring out where to put
+				 * the manifest is the server's problem. Otherwise, we need to
+				 * deal with it.
+				 */
+				if (backup_target == NULL)
+				{
+					/*
+					 * If we're supposed inject the manifest into the archive,
+					 * we prepare to buffer it in memory; otherwise, we
+					 * prepare to write it to a temporary file.
+					 */
+					if (state->manifest_inject_streamer != NULL)
+						state->manifest_buffer = createPQExpBuffer();
+					else
+					{
+						snprintf(state->manifest_filename,
+								 sizeof(state->manifest_filename),
+								 "%s/backup_manifest.tmp", basedir);
+						state->manifest_file =
+							fopen(state->manifest_filename, "wb");
+						if (state->manifest_file == NULL)
+							pg_fatal("could not create file \"%s\": %m",
+									 state->manifest_filename);
+					}
+				}
+				break;
+			}
+
+		default:
+			ReportCopyDataParseError(r, copybuf);
+			break;
+	}
+}
+
+/*
+ * Get a single byte from a CopyData message.
+ *
+ * Bail out if none remain.
+ */
+static char
+GetCopyDataByte(size_t r, char *copybuf, size_t *cursor)
+{
+	if (*cursor >= r)
+		ReportCopyDataParseError(r, copybuf);
+
+	return copybuf[(*cursor)++];
+}
+
+/*
+ * Get a NUL-terminated string from a CopyData message.
+ *
+ * Bail out if the terminating NUL cannot be found.
+ */
+static char *
+GetCopyDataString(size_t r, char *copybuf, size_t *cursor)
+{
+	size_t		startpos = *cursor;
+	size_t		endpos = startpos;
+
+	while (1)
+	{
+		if (endpos >= r)
+			ReportCopyDataParseError(r, copybuf);
+		if (copybuf[endpos] == '\0')
+			break;
+		++endpos;
+	}
+
+	*cursor = endpos + 1;
+	return &copybuf[startpos];
+}
+
+/*
+ * Get an unsigned 64-bit integer from a CopyData message.
+ *
+ * Bail out if there are not at least 8 bytes remaining.
+ */
+static uint64
+GetCopyDataUInt64(size_t r, char *copybuf, size_t *cursor)
+{
+	uint64		result;
+
+	if (*cursor + sizeof(uint64) > r)
+		ReportCopyDataParseError(r, copybuf);
+	memcpy(&result, &copybuf[*cursor], sizeof(uint64));
+	*cursor += sizeof(uint64);
+	return pg_ntoh64(result);
+}
+
+/*
+ * Bail out if we didn't parse the whole message.
+ */
+static void
+GetCopyDataEnd(size_t r, char *copybuf, size_t cursor)
+{
+	if (r != cursor)
+		ReportCopyDataParseError(r, copybuf);
+}
+
+/*
+ * Report failure to parse a CopyData message from the server. Then exit.
+ *
+ * As a debugging aid, we try to give some hint about what kind of message
+ * provoked the failure. Perhaps this is not detailed enough, but it's not
+ * clear that it's worth expending any more code on what should be a
+ * can't-happen case.
+ */
+static void
+ReportCopyDataParseError(size_t r, char *copybuf)
+{
+	if (r == 0)
+		pg_fatal("empty COPY message");
+	else
+		pg_fatal("malformed COPY message of type %d, length %zu",
+				 copybuf[0], r);
+}
+
+/*
+ * Receive raw tar data from the server, and stream it to the appropriate
+ * location. If we're writing a single tarfile to standard output, also
+ * receive the backup manifest and inject it into that tarfile.
+ */
+static void
+ReceiveTarFile(PGconn *conn, char *archive_name, char *spclocation,
+			   bool tablespacenum, pg_compress_specification *compress)
+{
+	WriteTarState state;
+	bbstreamer *manifest_inject_streamer;
+	bool		is_recovery_guc_supported;
+	bool		expect_unterminated_tarfile;
+
+	/* Pass all COPY data through to the backup streamer. */
+	memset(&state, 0, sizeof(state));
+	is_recovery_guc_supported =
+		PQserverVersion(conn) >= MINIMUM_VERSION_FOR_RECOVERY_GUC;
+	expect_unterminated_tarfile =
+		PQserverVersion(conn) < MINIMUM_VERSION_FOR_TERMINATED_TARFILE;
+	state.streamer = CreateBackupStreamer(archive_name, spclocation,
+										  &manifest_inject_streamer,
+										  is_recovery_guc_supported,
+										  expect_unterminated_tarfile,
+										  compress);
+	state.tablespacenum = tablespacenum;
+	ReceiveCopyData(conn, ReceiveTarCopyChunk, &state);
+	progress_update_filename(NULL);
+
+	/*
+	 * The decision as to whether we need to inject the backup manifest into
+	 * the output at this stage is made by CreateBackupStreamer; if that is
+	 * needed, manifest_inject_streamer will be non-NULL; otherwise, it will
+	 * be NULL.
+	 */
+	if (manifest_inject_streamer != NULL)
+	{
+		PQExpBufferData buf;
+
+		/* Slurp the entire backup manifest into a buffer. */
+		initPQExpBuffer(&buf);
+		ReceiveBackupManifestInMemory(conn, &buf);
+		if (PQExpBufferDataBroken(buf))
+			pg_fatal("out of memory");
+
+		/* Inject it into the output tarfile. */
+		bbstreamer_inject_file(manifest_inject_streamer, "backup_manifest",
+							   buf.data, buf.len);
+
+		/* Free memory. */
+		termPQExpBuffer(&buf);
+	}
+
+	/* Cleanup. */
+	bbstreamer_finalize(state.streamer);
+	bbstreamer_free(state.streamer);
+
+	progress_report(tablespacenum, true, false);
+
+	/*
+	 * Do not sync the resulting tar file yet, all files are synced once at
+	 * the end.
+	 */
+}
+
+/*
+ * Receive one chunk of tar-format data from the server.
+ */
+static void
+ReceiveTarCopyChunk(size_t r, char *copybuf, void *callback_data)
+{
+	WriteTarState *state = callback_data;
+
+	bbstreamer_content(state->streamer, NULL, copybuf, r, BBSTREAMER_UNKNOWN);
+
+	totaldone += r;
+	progress_report(state->tablespacenum, false, false);
+}
+
+
+/*
+ * Retrieve tablespace path, either relocated or original depending on whether
+ * -T was passed or not.
+ */
+static const char *
+get_tablespace_mapping(const char *dir)
+{
+	TablespaceListCell *cell;
+	char		canon_dir[MAXPGPATH];
+
+	/* Canonicalize path for comparison consistency */
+	strlcpy(canon_dir, dir, sizeof(canon_dir));
+	canonicalize_path(canon_dir);
+
+	for (cell = tablespace_dirs.head; cell; cell = cell->next)
+		if (strcmp(canon_dir, cell->old_dir) == 0)
+			return cell->new_dir;
+
+	return dir;
+}
+
+/*
+ * Receive the backup manifest file and write it out to a file.
+ */
+static void
+ReceiveBackupManifest(PGconn *conn)
+{
+	WriteManifestState state;
+
+	snprintf(state.filename, sizeof(state.filename),
+			 "%s/backup_manifest.tmp", basedir);
+	state.file = fopen(state.filename, "wb");
+	if (state.file == NULL)
+		pg_fatal("could not create file \"%s\": %m", state.filename);
+
+	ReceiveCopyData(conn, ReceiveBackupManifestChunk, &state);
+
+	fclose(state.file);
+}
+
+/*
+ * Receive one chunk of the backup manifest file and write it out to a file.
+ */
+static void
+ReceiveBackupManifestChunk(size_t r, char *copybuf, void *callback_data)
+{
+	WriteManifestState *state = callback_data;
+
+	errno = 0;
+	if (fwrite(copybuf, r, 1, state->file) != 1)
+	{
+		/* if write didn't set errno, assume problem is no disk space */
+		if (errno == 0)
+			errno = ENOSPC;
+		pg_fatal("could not write to file \"%s\": %m", state->filename);
+	}
+}
+
+/*
+ * Receive the backup manifest file and write it out to a file.
+ */
+static void
+ReceiveBackupManifestInMemory(PGconn *conn, PQExpBuffer buf)
+{
+	ReceiveCopyData(conn, ReceiveBackupManifestInMemoryChunk, buf);
+}
+
+/*
+ * Receive one chunk of the backup manifest file and write it out to a file.
+ */
+static void
+ReceiveBackupManifestInMemoryChunk(size_t r, char *copybuf,
+								   void *callback_data)
+{
+	PQExpBuffer buf = callback_data;
+
+	appendPQExpBuffer(buf, copybuf, r);
+}
+
+static void
+BaseBackup(char *compression_algorithm, char *compression_detail,
+		   CompressionLocation compressloc, pg_compress_specification *client_compress)
+{
+	PGresult   *res;
+	char	   *sysidentifier;
+	TimeLineID	latesttli;
+	TimeLineID	starttli;
+	char	   *basebkp;
+	int			i;
+	char		xlogstart[64];
+	char		xlogend[64];
+	int			minServerMajor,
+				maxServerMajor;
+	int			serverVersion,
+				serverMajor;
+	int			writing_to_stdout;
+	bool		use_new_option_syntax = false;
+	PQExpBufferData buf;
+
+	Assert(conn != NULL);
+	initPQExpBuffer(&buf);
+
+	/*
+	 * Check server version. BASE_BACKUP command was introduced in 9.1, so we
+	 * can't work with servers older than 9.1.
+	 */
+	minServerMajor = 901;
+	maxServerMajor = PG_VERSION_NUM / 100;
+	serverVersion = PQserverVersion(conn);
+	serverMajor = serverVersion / 100;
+	if (serverMajor < minServerMajor || serverMajor > maxServerMajor)
+	{
+		const char *serverver = PQparameterStatus(conn, "server_version");
+
+		pg_fatal("incompatible server version %s",
+				 serverver ? serverver : "'unknown'");
+	}
+	if (serverMajor >= 1500)
+		use_new_option_syntax = true;
+
+	/*
+	 * If WAL streaming was requested, also check that the server is new
+	 * enough for that.
+	 */
+	if (includewal == STREAM_WAL && !CheckServerVersionForStreaming(conn))
+	{
+		/*
+		 * Error message already written in CheckServerVersionForStreaming(),
+		 * but add a hint about using -X none.
+		 */
+		pg_log_error_hint("Use -X none or -X fetch to disable log streaming.");
+		exit(1);
+	}
+
+	/*
+	 * Build contents of configuration file if requested
+	 */
+	if (writerecoveryconf)
+		recoveryconfcontents = GenerateRecoveryConfig(conn, replication_slot);
+
+	/*
+	 * Run IDENTIFY_SYSTEM so we can get the timeline
+	 */
+	if (!RunIdentifySystem(conn, &sysidentifier, &latesttli, NULL, NULL))
+		exit(1);
+
+	/*
+	 * Start the actual backup
+	 */
+	AppendStringCommandOption(&buf, use_new_option_syntax, "LABEL", label);
+	if (estimatesize)
+		AppendPlainCommandOption(&buf, use_new_option_syntax, "PROGRESS");
+	if (includewal == FETCH_WAL)
+		AppendPlainCommandOption(&buf, use_new_option_syntax, "WAL");
+	if (fastcheckpoint)
+	{
+		if (use_new_option_syntax)
+			AppendStringCommandOption(&buf, use_new_option_syntax,
+									  "CHECKPOINT", "fast");
+		else
+			AppendPlainCommandOption(&buf, use_new_option_syntax, "FAST");
+	}
+	if (includewal != NO_WAL)
+	{
+		if (use_new_option_syntax)
+			AppendIntegerCommandOption(&buf, use_new_option_syntax, "WAIT", 0);
+		else
+			AppendPlainCommandOption(&buf, use_new_option_syntax, "NOWAIT");
+	}
+	if (maxrate > 0)
+		AppendIntegerCommandOption(&buf, use_new_option_syntax, "MAX_RATE",
+								   maxrate);
+	if (format == 't')
+		AppendPlainCommandOption(&buf, use_new_option_syntax, "TABLESPACE_MAP");
+	if (!verify_checksums)
+	{
+		if (use_new_option_syntax)
+			AppendIntegerCommandOption(&buf, use_new_option_syntax,
+									   "VERIFY_CHECKSUMS", 0);
+		else
+			AppendPlainCommandOption(&buf, use_new_option_syntax,
+									 "NOVERIFY_CHECKSUMS");
+	}
+
+	if (manifest)
+	{
+		AppendStringCommandOption(&buf, use_new_option_syntax, "MANIFEST",
+								  manifest_force_encode ? "force-encode" : "yes");
+		if (manifest_checksums != NULL)
+			AppendStringCommandOption(&buf, use_new_option_syntax,
+									  "MANIFEST_CHECKSUMS", manifest_checksums);
+	}
+
+	if (backup_target != NULL)
+	{
+		char	   *colon;
+
+		if (serverMajor < 1500)
+			pg_fatal("backup targets are not supported by this server version");
+
+		if (writerecoveryconf)
+			pg_fatal("recovery configuration cannot be written when a backup target is used");
+
+		AppendPlainCommandOption(&buf, use_new_option_syntax, "TABLESPACE_MAP");
+
+		if ((colon = strchr(backup_target, ':')) == NULL)
+		{
+			AppendStringCommandOption(&buf, use_new_option_syntax,
+									  "TARGET", backup_target);
+		}
+		else
+		{
+			char	   *target;
+
+			target = pnstrdup(backup_target, colon - backup_target);
+			AppendStringCommandOption(&buf, use_new_option_syntax,
+									  "TARGET", target);
+			AppendStringCommandOption(&buf, use_new_option_syntax,
+									  "TARGET_DETAIL", colon + 1);
+		}
+	}
+	else if (serverMajor >= 1500)
+		AppendStringCommandOption(&buf, use_new_option_syntax,
+								  "TARGET", "client");
+
+	if (compressloc == COMPRESS_LOCATION_SERVER)
+	{
+		if (!use_new_option_syntax)
+			pg_fatal("server does not support server-side compression");
+		AppendStringCommandOption(&buf, use_new_option_syntax,
+								  "COMPRESSION", compression_algorithm);
+		if (compression_detail != NULL)
+			AppendStringCommandOption(&buf, use_new_option_syntax,
+									  "COMPRESSION_DETAIL",
+									  compression_detail);
+	}
+
+	if (verbose)
+		pg_log_info("initiating base backup, waiting for checkpoint to complete");
+
+	if (showprogress && !verbose)
+	{
+		fprintf(stderr, _("waiting for checkpoint"));
+		if (isatty(fileno(stderr)))
+			fprintf(stderr, "\r");
+		else
+			fprintf(stderr, "\n");
+	}
+
+	if (use_new_option_syntax && buf.len > 0)
+		basebkp = psprintf("BASE_BACKUP (%s)", buf.data);
+	else
+		basebkp = psprintf("BASE_BACKUP %s", buf.data);
+
+	if (PQsendQuery(conn, basebkp) == 0)
+		pg_fatal("could not send replication command \"%s\": %s",
+				 "BASE_BACKUP", PQerrorMessage(conn));
+
+	/*
+	 * Get the starting WAL location
+	 */
+	res = PQgetResult(conn);
+	if (PQresultStatus(res) != PGRES_TUPLES_OK)
+		pg_fatal("could not initiate base backup: %s",
+				 PQerrorMessage(conn));
+	if (PQntuples(res) != 1)
+		pg_fatal("server returned unexpected response to BASE_BACKUP command; got %d rows and %d fields, expected %d rows and %d fields",
+				 PQntuples(res), PQnfields(res), 1, 2);
+
+	strlcpy(xlogstart, PQgetvalue(res, 0, 0), sizeof(xlogstart));
+
+	if (verbose)
+		pg_log_info("checkpoint completed");
+
+	/*
+	 * 9.3 and later sends the TLI of the starting point. With older servers,
+	 * assume it's the same as the latest timeline reported by
+	 * IDENTIFY_SYSTEM.
+	 */
+	if (PQnfields(res) >= 2)
+		starttli = atoi(PQgetvalue(res, 0, 1));
+	else
+		starttli = latesttli;
+	PQclear(res);
+	MemSet(xlogend, 0, sizeof(xlogend));
+
+	if (verbose && includewal != NO_WAL)
+		pg_log_info("write-ahead log start point: %s on timeline %u",
+					xlogstart, starttli);
+
+	/*
+	 * Get the header
+	 */
+	res = PQgetResult(conn);
+	if (PQresultStatus(res) != PGRES_TUPLES_OK)
+		pg_fatal("could not get backup header: %s",
+				 PQerrorMessage(conn));
+	if (PQntuples(res) < 1)
+		pg_fatal("no data returned from server");
+
+	/*
+	 * Sum up the total size, for progress reporting
+	 */
+	totalsize_kb = totaldone = 0;
+	tablespacecount = PQntuples(res);
+	for (i = 0; i < PQntuples(res); i++)
+	{
+		totalsize_kb += atol(PQgetvalue(res, i, 2));
+
+		/*
+		 * Verify tablespace directories are empty. Don't bother with the
+		 * first once since it can be relocated, and it will be checked before
+		 * we do anything anyway.
+		 *
+		 * Note that this is skipped for tar format backups and backups that
+		 * the server is storing to a target location, since in that case we
+		 * won't be storing anything into these directories and thus should
+		 * not create them.
+		 */
+		if (backup_target == NULL && format == 'p' && !PQgetisnull(res, i, 1))
+		{
+			char	   *path = unconstify(char *, get_tablespace_mapping(PQgetvalue(res, i, 1)));
+
+			verify_dir_is_empty_or_create(path, &made_tablespace_dirs, &found_tablespace_dirs);
+		}
+	}
+
+	/*
+	 * When writing to stdout, require a single tablespace
+	 */
+	writing_to_stdout = format == 't' && basedir != NULL &&
+		strcmp(basedir, "-") == 0;
+	if (writing_to_stdout && PQntuples(res) > 1)
+		pg_fatal("can only write single tablespace to stdout, database has %d",
+				 PQntuples(res));
+
+	/*
+	 * If we're streaming WAL, start the streaming session before we start
+	 * receiving the actual data chunks.
+	 */
+	if (includewal == STREAM_WAL)
+	{
+		pg_compress_algorithm wal_compress_algorithm;
+		int			wal_compress_level;
+
+		if (verbose)
+			pg_log_info("starting background WAL receiver");
+
+		if (client_compress->algorithm == PG_COMPRESSION_GZIP)
+		{
+			wal_compress_algorithm = PG_COMPRESSION_GZIP;
+			wal_compress_level = client_compress->level;
+		}
+		else
+		{
+			wal_compress_algorithm = PG_COMPRESSION_NONE;
+			wal_compress_level = 0;
+		}
+
+		StartLogStreamer(xlogstart, starttli, sysidentifier,
+						 wal_compress_algorithm,
+						 wal_compress_level);
+	}
+
+	if (serverMajor >= 1500)
+	{
+		/* Receive a single tar stream with everything. */
+		ReceiveArchiveStream(conn, client_compress);
+	}
+	else
+	{
+		/* Receive a tar file for each tablespace in turn */
+		for (i = 0; i < PQntuples(res); i++)
+		{
+			char		archive_name[MAXPGPATH];
+			char	   *spclocation;
+
+			/*
+			 * If we write the data out to a tar file, it will be named
+			 * base.tar if it's the main data directory or <tablespaceoid>.tar
+			 * if it's for another tablespace. CreateBackupStreamer() will
+			 * arrange to add .gz to the archive name if pg_basebackup is
+			 * performing compression.
+			 */
+			if (PQgetisnull(res, i, 0))
+			{
+				strlcpy(archive_name, "base.tar", sizeof(archive_name));
+				spclocation = NULL;
+			}
+			else
+			{
+				snprintf(archive_name, sizeof(archive_name),
+						 "%s.tar", PQgetvalue(res, i, 0));
+				spclocation = PQgetvalue(res, i, 1);
+			}
+
+			ReceiveTarFile(conn, archive_name, spclocation, i,
+						   client_compress);
+		}
+
+		/*
+		 * Now receive backup manifest, if appropriate.
+		 *
+		 * If we're writing a tarfile to stdout, ReceiveTarFile will have
+		 * already processed the backup manifest and included it in the output
+		 * tarfile.  Such a configuration doesn't allow for writing multiple
+		 * files.
+		 *
+		 * If we're talking to an older server, it won't send a backup
+		 * manifest, so don't try to receive one.
+		 */
+		if (!writing_to_stdout && manifest)
+			ReceiveBackupManifest(conn);
+	}
+
+	if (showprogress)
+	{
+		progress_update_filename(NULL);
+		progress_report(PQntuples(res), true, true);
+	}
+
+	PQclear(res);
+
+	/*
+	 * Get the stop position
+	 */
+	res = PQgetResult(conn);
+	if (PQresultStatus(res) != PGRES_TUPLES_OK)
+		pg_fatal("backup failed: %s",
+				 PQerrorMessage(conn));
+	if (PQntuples(res) != 1)
+		pg_fatal("no write-ahead log end position returned from server");
+	strlcpy(xlogend, PQgetvalue(res, 0, 0), sizeof(xlogend));
+	if (verbose && includewal != NO_WAL)
+		pg_log_info("write-ahead log end point: %s", xlogend);
+	PQclear(res);
+
+	res = PQgetResult(conn);
+	if (PQresultStatus(res) != PGRES_COMMAND_OK)
+	{
+		const char *sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE);
+
+		if (sqlstate &&
+			strcmp(sqlstate, ERRCODE_DATA_CORRUPTED) == 0)
+		{
+			pg_log_error("checksum error occurred");
+			checksum_failure = true;
+		}
+		else
+		{
+			pg_log_error("final receive failed: %s",
+						 PQerrorMessage(conn));
+		}
+		exit(1);
+	}
+
+	if (bgchild > 0)
+	{
+#ifndef WIN32
+		int			status;
+		pid_t		r;
+#else
+		DWORD		status;
+
+		/*
+		 * get a pointer sized version of bgchild to avoid warnings about
+		 * casting to a different size on WIN64.
+		 */
+		intptr_t	bgchild_handle = bgchild;
+		uint32		hi,
+					lo;
+#endif
+
+		if (verbose)
+			pg_log_info("waiting for background process to finish streaming ...");
+
+#ifndef WIN32
+		if (write(bgpipe[1], xlogend, strlen(xlogend)) != strlen(xlogend))
+			pg_fatal("could not send command to background pipe: %m");
+
+		/* Just wait for the background process to exit */
+		r = waitpid(bgchild, &status, 0);
+		if (r == (pid_t) -1)
+			pg_fatal("could not wait for child process: %m");
+		if (r != bgchild)
+			pg_fatal("child %d died, expected %d", (int) r, (int) bgchild);
+		if (status != 0)
+			pg_fatal("%s", wait_result_to_str(status));
+		/* Exited normally, we're happy! */
+#else							/* WIN32 */
+
+		/*
+		 * On Windows, since we are in the same process, we can just store the
+		 * value directly in the variable, and then set the flag that says
+		 * it's there.
+		 */
+		if (sscanf(xlogend, "%X/%X", &hi, &lo) != 2)
+			pg_fatal("could not parse write-ahead log location \"%s\"",
+					 xlogend);
+		xlogendptr = ((uint64) hi) << 32 | lo;
+		InterlockedIncrement(&has_xlogendptr);
+
+		/* First wait for the thread to exit */
+		if (WaitForSingleObjectEx((HANDLE) bgchild_handle, INFINITE, FALSE) !=
+			WAIT_OBJECT_0)
+		{
+			_dosmaperr(GetLastError());
+			pg_fatal("could not wait for child thread: %m");
+		}
+		if (GetExitCodeThread((HANDLE) bgchild_handle, &status) == 0)
+		{
+			_dosmaperr(GetLastError());
+			pg_fatal("could not get child thread exit status: %m");
+		}
+		if (status != 0)
+			pg_fatal("child thread exited with error %u",
+					 (unsigned int) status);
+		/* Exited normally, we're happy */
+#endif
+	}
+
+	/* Free the configuration file contents */
+	destroyPQExpBuffer(recoveryconfcontents);
+
+	/*
+	 * End of copy data. Final result is already checked inside the loop.
+	 */
+	PQclear(res);
+	PQfinish(conn);
+	conn = NULL;
+
+	/*
+	 * Make data persistent on disk once backup is completed. For tar format
+	 * sync the parent directory and all its contents as each tar file was not
+	 * synced after being completed.  In plain format, all the data of the
+	 * base directory is synced, taking into account all the tablespaces.
+	 * Errors are not considered fatal.
+	 *
+	 * If, however, there's a backup target, we're not writing anything
+	 * locally, so in that case we skip this step.
+	 */
+	if (do_sync && backup_target == NULL)
+	{
+		if (verbose)
+			pg_log_info("syncing data to disk ...");
+		if (format == 't')
+		{
+			if (strcmp(basedir, "-") != 0)
+				(void) fsync_dir_recurse(basedir);
+		}
+		else
+		{
+			(void) fsync_pgdata(basedir, serverVersion);
+		}
+	}
+
+	/*
+	 * After synchronizing data to disk, perform a durable rename of
+	 * backup_manifest.tmp to backup_manifest, if we wrote such a file. This
+	 * way, a failure or system crash before we reach this point will leave us
+	 * without a backup_manifest file, decreasing the chances that a directory
+	 * we leave behind will be mistaken for a valid backup.
+	 */
+	if (!writing_to_stdout && manifest && backup_target == NULL)
+	{
+		char		tmp_filename[MAXPGPATH];
+		char		filename[MAXPGPATH];
+
+		if (verbose)
+			pg_log_info("renaming backup_manifest.tmp to backup_manifest");
+
+		snprintf(tmp_filename, MAXPGPATH, "%s/backup_manifest.tmp", basedir);
+		snprintf(filename, MAXPGPATH, "%s/backup_manifest", basedir);
+
+		if (do_sync)
+		{
+			/* durable_rename emits its own log message in case of failure */
+			if (durable_rename(tmp_filename, filename) != 0)
+				exit(1);
+		}
+		else
+		{
+			if (rename(tmp_filename, filename) != 0)
+				pg_fatal("could not rename file \"%s\" to \"%s\": %m",
+						 tmp_filename, filename);
+		}
+	}
+
+	if (verbose)
+		pg_log_info("base backup completed");
+}
+
+
+int
+main(int argc, char **argv)
+{
+	static struct option long_options[] = {
+		{"help", no_argument, NULL, '?'},
+		{"version", no_argument, NULL, 'V'},
+		{"pgdata", required_argument, NULL, 'D'},
+		{"format", required_argument, NULL, 'F'},
+		{"checkpoint", required_argument, NULL, 'c'},
+		{"create-slot", no_argument, NULL, 'C'},
+		{"max-rate", required_argument, NULL, 'r'},
+		{"write-recovery-conf", no_argument, NULL, 'R'},
+		{"slot", required_argument, NULL, 'S'},
+		{"target", required_argument, NULL, 't'},
+		{"tablespace-mapping", required_argument, NULL, 'T'},
+		{"wal-method", required_argument, NULL, 'X'},
+		{"gzip", no_argument, NULL, 'z'},
+		{"compress", required_argument, NULL, 'Z'},
+		{"label", required_argument, NULL, 'l'},
+		{"no-clean", no_argument, NULL, 'n'},
+		{"no-sync", no_argument, NULL, 'N'},
+		{"dbname", required_argument, NULL, 'd'},
+		{"host", required_argument, NULL, 'h'},
+		{"port", required_argument, NULL, 'p'},
+		{"username", required_argument, NULL, 'U'},
+		{"no-password", no_argument, NULL, 'w'},
+		{"password", no_argument, NULL, 'W'},
+		{"status-interval", required_argument, NULL, 's'},
+		{"verbose", no_argument, NULL, 'v'},
+		{"progress", no_argument, NULL, 'P'},
+		{"waldir", required_argument, NULL, 1},
+		{"no-slot", no_argument, NULL, 2},
+		{"no-verify-checksums", no_argument, NULL, 3},
+		{"no-estimate-size", no_argument, NULL, 4},
+		{"no-manifest", no_argument, NULL, 5},
+		{"manifest-force-encode", no_argument, NULL, 6},
+		{"manifest-checksums", required_argument, NULL, 7},
+		{NULL, 0, NULL, 0}
+	};
+	int			c;
+
+	int			option_index;
+	char	   *compression_algorithm = "none";
+	char	   *compression_detail = NULL;
+	CompressionLocation compressloc = COMPRESS_LOCATION_UNSPECIFIED;
+	pg_compress_specification client_compress;
+
+	pg_logging_init(argv[0]);
+	progname = get_progname(argv[0]);
+	set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_basebackup"));
+
+	if (argc > 1)
+	{
+		if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
+		{
+			usage();
+			exit(0);
+		}
+		else if (strcmp(argv[1], "-V") == 0
+				 || strcmp(argv[1], "--version") == 0)
+		{
+			puts("pg_basebackup (PostgreSQL) " PG_VERSION);
+			exit(0);
+		}
+	}
+
+	atexit(cleanup_directories_atexit);
+
+	while ((c = getopt_long(argc, argv, "CD:F:r:RS:t:T:X:l:nNzZ:d:c:h:p:U:s:wWkvP",
+							long_options, &option_index)) != -1)
+	{
+		switch (c)
+		{
+			case 'C':
+				create_slot = true;
+				break;
+			case 'D':
+				basedir = pg_strdup(optarg);
+				break;
+			case 'F':
+				if (strcmp(optarg, "p") == 0 || strcmp(optarg, "plain") == 0)
+					format = 'p';
+				else if (strcmp(optarg, "t") == 0 || strcmp(optarg, "tar") == 0)
+					format = 't';
+				else
+					pg_fatal("invalid output format \"%s\", must be \"plain\" or \"tar\"",
+							 optarg);
+				break;
+			case 'r':
+				maxrate = parse_max_rate(optarg);
+				break;
+			case 'R':
+				writerecoveryconf = true;
+				break;
+			case 'S':
+
+				/*
+				 * When specifying replication slot name, use a permanent
+				 * slot.
+				 */
+				replication_slot = pg_strdup(optarg);
+				temp_replication_slot = false;
+				break;
+			case 2:
+				no_slot = true;
+				break;
+			case 't':
+				backup_target = pg_strdup(optarg);
+				break;
+			case 'T':
+				tablespace_list_append(optarg);
+				break;
+			case 'X':
+				if (strcmp(optarg, "n") == 0 ||
+					strcmp(optarg, "none") == 0)
+				{
+					includewal = NO_WAL;
+				}
+				else if (strcmp(optarg, "f") == 0 ||
+						 strcmp(optarg, "fetch") == 0)
+				{
+					includewal = FETCH_WAL;
+				}
+				else if (strcmp(optarg, "s") == 0 ||
+						 strcmp(optarg, "stream") == 0)
+				{
+					includewal = STREAM_WAL;
+				}
+				else
+					pg_fatal("invalid wal-method option \"%s\", must be \"fetch\", \"stream\", or \"none\"",
+							 optarg);
+				break;
+			case 1:
+				xlog_dir = pg_strdup(optarg);
+				break;
+			case 'l':
+				label = pg_strdup(optarg);
+				break;
+			case 'n':
+				noclean = true;
+				break;
+			case 'N':
+				do_sync = false;
+				break;
+			case 'z':
+				compression_algorithm = "gzip";
+				compression_detail = NULL;
+				compressloc = COMPRESS_LOCATION_UNSPECIFIED;
+				break;
+			case 'Z':
+				parse_compress_options(optarg, &compression_algorithm,
+									   &compression_detail, &compressloc);
+				break;
+			case 'c':
+				if (pg_strcasecmp(optarg, "fast") == 0)
+					fastcheckpoint = true;
+				else if (pg_strcasecmp(optarg, "spread") == 0)
+					fastcheckpoint = false;
+				else
+					pg_fatal("invalid checkpoint argument \"%s\", must be \"fast\" or \"spread\"",
+							 optarg);
+				break;
+			case 'd':
+				connection_string = pg_strdup(optarg);
+				break;
+			case 'h':
+				dbhost = pg_strdup(optarg);
+				break;
+			case 'p':
+				dbport = pg_strdup(optarg);
+				break;
+			case 'U':
+				dbuser = pg_strdup(optarg);
+				break;
+			case 'w':
+				dbgetpassword = -1;
+				break;
+			case 'W':
+				dbgetpassword = 1;
+				break;
+			case 's':
+				if (!option_parse_int(optarg, "-s/--status-interval", 0,
+									  INT_MAX / 1000,
+									  &standby_message_timeout))
+					exit(1);
+				standby_message_timeout *= 1000;
+				break;
+			case 'v':
+				verbose++;
+				break;
+			case 'P':
+				showprogress = true;
+				break;
+			case 3:
+				verify_checksums = false;
+				break;
+			case 4:
+				estimatesize = false;
+				break;
+			case 5:
+				manifest = false;
+				break;
+			case 6:
+				manifest_force_encode = true;
+				break;
+			case 7:
+				manifest_checksums = pg_strdup(optarg);
+				break;
+			default:
+				/* getopt_long already emitted a complaint */
+				pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+				exit(1);
+		}
+	}
+
+	/*
+	 * Any non-option arguments?
+	 */
+	if (optind < argc)
+	{
+		pg_log_error("too many command-line arguments (first is \"%s\")",
+					 argv[optind]);
+		pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+		exit(1);
+	}
+
+	/*
+	 * Setting the backup target to 'client' is equivalent to leaving out the
+	 * option. This logic allows us to assume elsewhere that the backup is
+	 * being stored locally if and only if backup_target == NULL.
+	 */
+	if (backup_target != NULL && strcmp(backup_target, "client") == 0)
+	{
+		pg_free(backup_target);
+		backup_target = NULL;
+	}
+
+	/*
+	 * Can't use --format with --target. Without --target, default format is
+	 * tar.
+	 */
+	if (backup_target != NULL && format != '\0')
+	{
+		pg_log_error("cannot specify both format and backup target");
+		pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+		exit(1);
+	}
+	if (format == '\0')
+		format = 'p';
+
+	/*
+	 * Either directory or backup target should be specified, but not both
+	 */
+	if (basedir == NULL && backup_target == NULL)
+	{
+		pg_log_error("must specify output directory or backup target");
+		pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+		exit(1);
+	}
+	if (basedir != NULL && backup_target != NULL)
+	{
+		pg_log_error("cannot specify both output directory and backup target");
+		pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+		exit(1);
+	}
+
+	/*
+	 * If the user has not specified where to perform backup compression,
+	 * default to the client, unless the user specified --target, in which
+	 * case the server is the only choice.
+	 */
+	if (compressloc == COMPRESS_LOCATION_UNSPECIFIED)
+	{
+		if (backup_target == NULL)
+			compressloc = COMPRESS_LOCATION_CLIENT;
+		else
+			compressloc = COMPRESS_LOCATION_SERVER;
+	}
+
+	/*
+	 * If any compression that we're doing is happening on the client side, we
+	 * must try to parse the compression algorithm and detail, but if it's all
+	 * on the server side, then we're just going to pass through whatever was
+	 * requested and let the server decide what to do.
+	 */
+	if (compressloc == COMPRESS_LOCATION_CLIENT)
+	{
+		pg_compress_algorithm alg;
+		char	   *error_detail;
+
+		if (!parse_compress_algorithm(compression_algorithm, &alg))
+			pg_fatal("unrecognized compression algorithm: \"%s\"",
+					 compression_algorithm);
+
+		parse_compress_specification(alg, compression_detail, &client_compress);
+		error_detail = validate_compress_specification(&client_compress);
+		if (error_detail != NULL)
+			pg_fatal("invalid compression specification: %s",
+					 error_detail);
+	}
+	else
+	{
+		Assert(compressloc == COMPRESS_LOCATION_SERVER);
+		client_compress.algorithm = PG_COMPRESSION_NONE;
+		client_compress.options = 0;
+	}
+
+	/*
+	 * Can't perform client-side compression if the backup is not being sent
+	 * to the client.
+	 */
+	if (backup_target != NULL && compressloc == COMPRESS_LOCATION_CLIENT)
+	{
+		pg_log_error("client-side compression is not possible when a backup target is specified");
+		pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+		exit(1);
+	}
+
+	/*
+	 * Client-side compression doesn't make sense unless tar format is in use.
+	 */
+	if (format == 'p' && compressloc == COMPRESS_LOCATION_CLIENT &&
+		client_compress.algorithm != PG_COMPRESSION_NONE)
+	{
+		pg_log_error("only tar mode backups can be compressed");
+		pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+		exit(1);
+	}
+
+	/*
+	 * Sanity checks for WAL method.
+	 */
+	if (backup_target != NULL && includewal == STREAM_WAL)
+	{
+		pg_log_error("WAL cannot be streamed when a backup target is specified");
+		pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+		exit(1);
+	}
+	if (format == 't' && includewal == STREAM_WAL && strcmp(basedir, "-") == 0)
+	{
+		pg_log_error("cannot stream write-ahead logs in tar mode to stdout");
+		pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+		exit(1);
+	}
+
+	if (replication_slot && includewal != STREAM_WAL)
+	{
+		pg_log_error("replication slots can only be used with WAL streaming");
+		pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+		exit(1);
+	}
+
+	/*
+	 * Sanity checks for replication slot options.
+	 */
+	if (no_slot)
+	{
+		if (replication_slot)
+		{
+			pg_log_error("--no-slot cannot be used with slot name");
+			pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+			exit(1);
+		}
+		temp_replication_slot = false;
+	}
+
+	if (create_slot)
+	{
+		if (!replication_slot)
+		{
+			pg_log_error("%s needs a slot to be specified using --slot",
+						 "--create-slot");
+			pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+			exit(1);
+		}
+
+		if (no_slot)
+		{
+			pg_log_error("%s and %s are incompatible options",
+						 "--create-slot", "--no-slot");
+			pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+			exit(1);
+		}
+	}
+
+	/*
+	 * Sanity checks on WAL directory.
+	 */
+	if (xlog_dir)
+	{
+		if (backup_target != NULL)
+		{
+			pg_log_error("WAL directory location cannot be specified along with a backup target");
+			pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+			exit(1);
+		}
+		if (format != 'p')
+		{
+			pg_log_error("WAL directory location can only be specified in plain mode");
+			pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+			exit(1);
+		}
+
+		/* clean up xlog directory name, check it's absolute */
+		canonicalize_path(xlog_dir);
+		if (!is_absolute_path(xlog_dir))
+		{
+			pg_log_error("WAL directory location must be an absolute path");
+			pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+			exit(1);
+		}
+	}
+
+	/*
+	 * Sanity checks for progress reporting options.
+	 */
+	if (showprogress && !estimatesize)
+	{
+		pg_log_error("%s and %s are incompatible options",
+					 "--progress", "--no-estimate-size");
+		pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+		exit(1);
+	}
+
+	/*
+	 * Sanity checks for backup manifest options.
+	 */
+	if (!manifest && manifest_checksums != NULL)
+	{
+		pg_log_error("%s and %s are incompatible options",
+					 "--no-manifest", "--manifest-checksums");
+		pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+		exit(1);
+	}
+
+	if (!manifest && manifest_force_encode)
+	{
+		pg_log_error("%s and %s are incompatible options",
+					 "--no-manifest", "--manifest-force-encode");
+		pg_log_error_hint("Try \"%s --help\" for more information.", progname);
+		exit(1);
+	}
+
+	/* connection in replication mode to server */
+	conn = GetConnection();
+	if (!conn)
+	{
+		/* Error message already written in GetConnection() */
+		exit(1);
+	}
+	atexit(disconnect_atexit);
+
+#ifndef WIN32
+
+	/*
+	 * Trap SIGCHLD to be able to handle the WAL stream process exiting. There
+	 * is no SIGCHLD on Windows, there we rely on the background thread
+	 * setting the signal variable on unexpected but graceful exit. If the WAL
+	 * stream thread crashes on Windows it will bring down the entire process
+	 * as it's a thread, so there is nothing to catch should that happen. A
+	 * crash on UNIX will be caught by the signal handler.
+	 */
+	pqsignal(SIGCHLD, sigchld_handler);
+#endif
+
+	/*
+	 * Set umask so that directories/files are created with the same
+	 * permissions as directories/files in the source data directory.
+	 *
+	 * pg_mode_mask is set to owner-only by default and then updated in
+	 * GetConnection() where we get the mode from the server-side with
+	 * RetrieveDataDirCreatePerm() and then call SetDataDirectoryCreatePerm().
+	 */
+	umask(pg_mode_mask);
+
+	/* Backup manifests are supported in 13 and newer versions */
+	if (PQserverVersion(conn) < MINIMUM_VERSION_FOR_MANIFESTS)
+		manifest = false;
+
+	/*
+	 * If an output directory was specified, verify that it exists, or create
+	 * it. Note that for a tar backup, an output directory of "-" means we are
+	 * writing to stdout, so do nothing in that case.
+	 */
+	if (basedir != NULL && (format == 'p' || strcmp(basedir, "-") != 0))
+		verify_dir_is_empty_or_create(basedir, &made_new_pgdata, &found_existing_pgdata);
+
+	/* determine remote server's xlog segment size */
+	if (!RetrieveWalSegSize(conn))
+		exit(1);
+
+	/* Create pg_wal symlink, if required */
+	if (xlog_dir)
+	{
+		char	   *linkloc;
+
+		verify_dir_is_empty_or_create(xlog_dir, &made_new_xlogdir, &found_existing_xlogdir);
+
+		/*
+		 * Form name of the place where the symlink must go. pg_xlog has been
+		 * renamed to pg_wal in post-10 clusters.
+		 */
+		linkloc = psprintf("%s/%s", basedir,
+						   PQserverVersion(conn) < MINIMUM_VERSION_FOR_PG_WAL ?
+						   "pg_xlog" : "pg_wal");
+
+#ifdef HAVE_SYMLINK
+		if (symlink(xlog_dir, linkloc) != 0)
+			pg_fatal("could not create symbolic link \"%s\": %m", linkloc);
+#else
+		pg_fatal("symlinks are not supported on this platform");
+#endif
+		free(linkloc);
+	}
+
+	BaseBackup(compression_algorithm, compression_detail, compressloc,
+			   &client_compress);
+
+	success = true;
+	return 0;
+}