Fix pg_upgrade file share violation on Windows created by the commit

4741e9af.  This was done by adding an
optional second log file parameter to exec_prog(), and closing and
reopening the log file between system() calls.

Backpatch to 9.2.

contrib/pg_upgrade/check.c

@@ -183,7 +183,7 @@ issue_warnings(char *sequence_script_file_name)
 		if (sequence_script_file_name)
 		{
 			prep_status("Adjusting sequences");
-			exec_prog(true, true, UTILITY_LOG_FILE,
+			exec_prog(true, true, UTILITY_LOG_FILE, NULL,
 					  SYSTEMQUOTE "\"%s/psql\" --echo-queries "
 					  "--set ON_ERROR_STOP=on "
 					  "--no-psqlrc --port %d --username \"%s\" "

contrib/pg_upgrade/dump.c

@@ -23,7 +23,7 @@ generate_old_dump(void)
 	 * --binary-upgrade records the width of dropped columns in pg_class, and
 	 * restores the frozenid's for databases and relations.
 	 */
-	exec_prog(true, true, UTILITY_LOG_FILE,
+	exec_prog(true, true, UTILITY_LOG_FILE, NULL,
 			  SYSTEMQUOTE "\"%s/pg_dumpall\" --port %d --username \"%s\" "
 			  "--schema-only --binary-upgrade %s > \"%s\" 2>> \"%s\""
 			  SYSTEMQUOTE, new_cluster.bindir, old_cluster.port, os_info.user,

contrib/pg_upgrade/exec.c

@@ -33,18 +33,19 @@ static int	win32_check_directory_write_permissions(void);
  *	line to be executed is saved to the specified log file.
  *
  *	If throw_error is TRUE, this function will throw a PG_FATAL error
- *	instead of returning should an error occur.
+ *	instead of returning should an error occur.  The command it appended
+ *	to log_file;  opt_log_file is used in error messages.
  */
 int
-exec_prog(bool throw_error, bool is_priv,
-		  const char *log_file, const char *fmt,...)
+exec_prog(bool throw_error, bool is_priv, const char *log_file,
+		  const char *opt_log_file, const char *fmt,...)
 {
 	va_list		args;
 	int			result;
 	int			retval;
 	char		cmd[MAXPGPATH];
 	mode_t		old_umask = 0;
-	FILE	   *log = fopen(log_file, "a+");
+	FILE	   *log;
 
 	if (is_priv)
 		old_umask = umask(S_IRWXG | S_IRWXO);
@@ -53,9 +54,15 @@ exec_prog(bool throw_error, bool is_priv,
 	vsnprintf(cmd, MAXPGPATH, fmt, args);
 	va_end(args);
 
+	if ((log = fopen_priv(log_file, "a+")) == NULL)
+		pg_log(PG_FATAL, "cannot write to log file %s\n", log_file);
 	pg_log(PG_VERBOSE, "%s\n", cmd);
 	fprintf(log, "command: %s\n", cmd);
-	fflush(log);
+	/*
+	 *	In Windows, we must close then reopen the log file so the file is
+	 *	not open while the command is running, or we get a share violation.
+	 */
+	fclose(log);
 
 	result = system(cmd);
 
@@ -64,18 +71,28 @@ exec_prog(bool throw_error, bool is_priv,
 
 	if (result != 0)
 	{
+		char opt_string[MAXPGPATH];
+
+		/* Create string for optional second log file */
+		if (opt_log_file)
+			snprintf(opt_string, sizeof(opt_string), " or \"%s\"", opt_log_file);
+		else
+			opt_string[0] = '\0';
+
 		report_status(PG_REPORT, "*failure*");
 		fflush(stdout);
 		pg_log(PG_VERBOSE, "There were problems executing \"%s\"\n", cmd);
 		pg_log(throw_error ? PG_FATAL : PG_REPORT,
-			   "Consult the last few lines of \"%s\" for\n"
+			   "Consult the last few lines of \"%s\"%s for\n"
 			   "the probable cause of the failure.\n",
-			   log_file);
+			   log_file, opt_string);
 		retval = 1;
 	}
 	else
 		retval = 0;
 
+	if ((log = fopen_priv(log_file, "a+")) == NULL)
+		pg_log(PG_FATAL, "cannot write to log file %s\n", log_file);
 	fprintf(log, "\n\n");
 	fclose(log);
 

contrib/pg_upgrade/pg_upgrade.c

@@ -140,7 +140,7 @@ main(int argc, char **argv)
 	 * because there is no need to have the schema load use new oids.
 	 */
 	prep_status("Setting next OID for new cluster");
-	exec_prog(true, true, UTILITY_LOG_FILE,
+	exec_prog(true, true, UTILITY_LOG_FILE, NULL,
 			  SYSTEMQUOTE "\"%s/pg_resetxlog\" -o %u \"%s\" >> \"%s\" 2>&1"
 			  SYSTEMQUOTE,
 			  new_cluster.bindir, old_cluster.controldata.chkpnt_nxtoid,
@@ -211,7 +211,7 @@ prepare_new_cluster(void)
 	 * --analyze so autovacuum doesn't update statistics later
 	 */
 	prep_status("Analyzing all rows in the new cluster");
-	exec_prog(true, true, UTILITY_LOG_FILE,
+	exec_prog(true, true, UTILITY_LOG_FILE, NULL,
 			  SYSTEMQUOTE "\"%s/vacuumdb\" --port %d --username \"%s\" "
 			  "--all --analyze %s >> \"%s\" 2>&1" SYSTEMQUOTE,
 			  new_cluster.bindir, new_cluster.port, os_info.user,
@@ -225,7 +225,7 @@ prepare_new_cluster(void)
 	 * later.
 	 */
 	prep_status("Freezing all rows on the new cluster");
-	exec_prog(true, true, UTILITY_LOG_FILE,
+	exec_prog(true, true, UTILITY_LOG_FILE, NULL,
 			  SYSTEMQUOTE "\"%s/vacuumdb\" --port %d --username \"%s\" "
 			  "--all --freeze %s >> \"%s\" 2>&1" SYSTEMQUOTE,
 			  new_cluster.bindir, new_cluster.port, os_info.user,
@@ -263,7 +263,7 @@ prepare_new_databases(void)
 	 * support functions in template1 but pg_dumpall creates database using
 	 * the template0 template.
 	 */
-	exec_prog(true, true, RESTORE_LOG_FILE,
+	exec_prog(true, true, RESTORE_LOG_FILE, NULL,
 			  SYSTEMQUOTE "\"%s/psql\" --echo-queries "
 			  "--set ON_ERROR_STOP=on "
 	/* --no-psqlrc prevents AUTOCOMMIT=off */
@@ -296,7 +296,7 @@ create_new_objects(void)
 	check_ok();
 
 	prep_status("Restoring database schema to new cluster");
-	exec_prog(true, true, RESTORE_LOG_FILE,
+	exec_prog(true, true, RESTORE_LOG_FILE, NULL,
 			  SYSTEMQUOTE "\"%s/psql\" --echo-queries "
 			  "--set ON_ERROR_STOP=on "
 			  "--no-psqlrc --port %d --username \"%s\" "
@@ -331,7 +331,7 @@ copy_subdir_files(char *subdir)
 
 	prep_status("Copying old %s to new server", subdir);
 
-	exec_prog(true, false, UTILITY_LOG_FILE,
+	exec_prog(true, false, UTILITY_LOG_FILE, NULL,
 #ifndef WIN32
 			  SYSTEMQUOTE "%s \"%s\" \"%s\" >> \"%s\" 2>&1" SYSTEMQUOTE,
 			  "cp -Rf",
@@ -353,7 +353,7 @@ copy_clog_xlog_xid(void)
 
 	/* set the next transaction id of the new cluster */
 	prep_status("Setting next transaction ID for new cluster");
-	exec_prog(true, true, UTILITY_LOG_FILE,
+	exec_prog(true, true, UTILITY_LOG_FILE, NULL,
 			  SYSTEMQUOTE
 			  "\"%s/pg_resetxlog\" -f -x %u \"%s\" >> \"%s\" 2>&1"
 			  SYSTEMQUOTE, new_cluster.bindir,
@@ -363,7 +363,7 @@ copy_clog_xlog_xid(void)
 
 	/* now reset the wal archives in the new cluster */
 	prep_status("Resetting WAL archives");
-	exec_prog(true, true, UTILITY_LOG_FILE,
+	exec_prog(true, true, UTILITY_LOG_FILE, NULL,
 			  SYSTEMQUOTE
 			  "\"%s/pg_resetxlog\" -l %s \"%s\" >> \"%s\" 2>&1"
 			  SYSTEMQUOTE, new_cluster.bindir,

contrib/pg_upgrade/pg_upgrade.h

@@ -317,9 +317,9 @@ void		split_old_dump(void);
 /* exec.c */
 
 int
-exec_prog(bool throw_error, bool is_priv,
-		  const char *log_file, const char *cmd,...)
-__attribute__((format(PG_PRINTF_ATTRIBUTE, 4, 5)));
+exec_prog(bool throw_error, bool is_priv, const char *log_file,
+		  const char *opt_log_file, const char *cmd,...)
+__attribute__((format(PG_PRINTF_ATTRIBUTE, 5, 6)));
 void		verify_directories(void);
 bool		is_server_running(const char *datadir);
 

contrib/pg_upgrade/server.c

@@ -171,11 +171,10 @@ start_postmaster(ClusterInfo *cluster)
 	 * Don't throw an error right away, let connecting throw the error because
 	 * it might supply a reason for the failure.
 	 */
-	pg_ctl_return = exec_prog(false, true,
+	pg_ctl_return = exec_prog(false, true, SERVER_START_LOG_FILE,
 	/* pass both file names if the differ */
-					  (strcmp(SERVER_LOG_FILE, SERVER_START_LOG_FILE) == 0) ?
-							  SERVER_LOG_FILE :
-							  SERVER_LOG_FILE " or " SERVER_START_LOG_FILE,
+					  (strcmp(SERVER_LOG_FILE, SERVER_START_LOG_FILE) != 0) ?
+							  SERVER_LOG_FILE : NULL,
 							  "%s", cmd);
 
 	/* Check to see if we can connect to the server; if not, report it. */
@@ -220,7 +219,7 @@ stop_postmaster(bool fast)
 			 cluster->pgopts ? cluster->pgopts : "",
 			 fast ? "-m fast" : "", SERVER_STOP_LOG_FILE);
 
-	exec_prog(fast ? false : true, true, SERVER_STOP_LOG_FILE, "%s", cmd);
+	exec_prog(fast ? false : true, true, SERVER_STOP_LOG_FILE, NULL, "%s", cmd);
 
 	os_info.running_cluster = NULL;
 }