Add pg_upgrade check to make sure the user has full access permission in

the current directory;  if not, throw an error.

contrib/pg_upgrade/exec.c

@@ -93,6 +93,11 @@ is_server_running(const char *datadir)
 void
 verify_directories(void)
 {
+
+	if (access(".", R_OK | W_OK | X_OK) != 0)
+		pg_log(PG_FATAL,
+		"You must have full access permissions in the current directory.\n");
+
 	prep_status("Checking old data directory (%s)", old_cluster.pgdata);
 	check_data_dir(old_cluster.pgdata);
 	check_ok();

contrib/pg_upgrade/pg_upgrade.c

@@ -155,17 +155,13 @@ setup(char *argv0, bool live_check)
 
 	/* no postmasters should be running */
 	if (!live_check && is_server_running(old_cluster.pgdata))
-	{
 		pg_log(PG_FATAL, "There seems to be a postmaster servicing the old cluster.\n"
 			   "Please shutdown that postmaster and try again.\n");
-	}
 
 	/* same goes for the new postmaster */
 	if (is_server_running(new_cluster.pgdata))
-	{
 		pg_log(PG_FATAL, "There seems to be a postmaster servicing the new cluster.\n"
 			   "Please shutdown that postmaster and try again.\n");
-	}
 
 	/* get path to pg_upgrade executable */
 	if (find_my_exec(argv0, exec_path) < 0)