Fix initdb --sync-only to also sync tablespaces.

630cd14426 added initdb --sync-only, for use by pg_upgrade, by just
exposing the existing fsync code. That's wrong, because initdb so far
had absolutely no reason to deal with tablespaces.

Fix --sync-only by additionally explicitly syncing each of the
tablespaces.

Backpatch to 9.3 where --sync-only was introduced.

Abhijit Menon-Sen and Andres Freund

src/bin/initdb/initdb.c

@@ -60,6 +60,7 @@
 #include "sys/mman.h"
 #endif
 
+#include "catalog/catalog.h"
 #include "common/username.h"
 #include "mb/pg_wchar.h"
 #include "getaddrinfo.h"
@@ -218,6 +219,7 @@ static char **filter_lines_with_token(char **lines, const char *token);
 static char **readfile(const char *path);
 static void writefile(char *path, char **lines);
 static void walkdir(char *path, void (*action) (char *fname, bool isdir));
+static void walktblspc_links(char *path, void (*action) (char *fname, bool isdir));
 static void pre_sync_fname(char *fname, bool isdir);
 static void fsync_fname(char *fname, bool isdir);
 static FILE *popen_check(const char *command, const char *mode);
@@ -587,6 +589,55 @@ walkdir(char *path, void (*action) (char *fname, bool isdir))
 	(*action) (path, true);
 }
 
+/*
+ * walktblspc_links: call walkdir on each entry under the given
+ * pg_tblspc directory, or do nothing if pg_tblspc doesn't exist.
+ */
+static void
+walktblspc_links(char *path, void (*action) (char *fname, bool isdir))
+{
+	DIR		   *dir;
+	struct dirent *direntry;
+	char		subpath[MAXPGPATH];
+
+	dir = opendir(path);
+	if (dir == NULL)
+	{
+		if (errno == ENOENT)
+			return;
+		fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
+				progname, path, strerror(errno));
+		exit_nicely();
+	}
+
+	while (errno = 0, (direntry = readdir(dir)) != NULL)
+	{
+		if (strcmp(direntry->d_name, ".") == 0 ||
+			strcmp(direntry->d_name, "..") == 0)
+			continue;
+
+		/* fsync the version specific tablespace subdirectory */
+		snprintf(subpath, sizeof(subpath), "%s/%s/%s",
+				 path, direntry->d_name, TABLESPACE_VERSION_DIRECTORY);
+
+		walkdir(subpath, action);
+	}
+
+	if (errno)
+	{
+		fprintf(stderr, _("%s: could not read directory \"%s\": %s\n"),
+				progname, path, strerror(errno));
+		exit_nicely();
+	}
+
+	if (closedir(dir))
+	{
+		fprintf(stderr, _("%s: could not close directory \"%s\": %s\n"),
+				progname, path, strerror(errno));
+		exit_nicely();
+	}
+}
+
 /*
  * Hint to the OS that it should get ready to fsync() this file.
  */
@@ -2377,6 +2428,7 @@ static void
 perform_fsync(void)
 {
 	char		pdir[MAXPGPATH];
+	char		pg_tblspc[MAXPGPATH];
 
 	fputs(_("syncing data to disk ... "), stdout);
 	fflush(stdout);
@@ -2395,9 +2447,13 @@ perform_fsync(void)
 	/* first the parent of the PGDATA directory */
 	pre_sync_fname(pdir, true);
 
-	/* then recursively through the directory */
+	/* then recursively through the data directory */
 	walkdir(pg_data, pre_sync_fname);
 
+	/* now do the same thing for everything under pg_tblspc */
+	snprintf(pg_tblspc, MAXPGPATH, "%s/pg_tblspc", pg_data);
+	walktblspc_links(pg_tblspc, pre_sync_fname);
+
 	/*
 	 * Now, do the fsync()s in the same order.
 	 */
@@ -2405,9 +2461,12 @@ perform_fsync(void)
 	/* first the parent of the PGDATA directory */
 	fsync_fname(pdir, true);
 
-	/* then recursively through the directory */
+	/* then recursively through the data directory */
 	walkdir(pg_data, fsync_fname);
 
+	/* and now the same for all tablespaces */
+	walktblspc_links(pg_tblspc, fsync_fname);
+
 	check_ok();
 }