1/*++
2/* NAME
3/*	sane_rename 3
4/* SUMMARY
5/*	sanitize rename() error returns
6/* SYNOPSIS
7/*	#include <sane_fsops.h>
8/*
9/*	int	sane_rename(old, new)
10/*	const char *from;
11/*	const char *to;
12/* DESCRIPTION
13/*	sane_rename() implements the rename(2) system call, and works
14/*	around some errors that are possible with NFS file systems.
15/* LICENSE
16/* .ad
17/* .fi
18/*	The Secure Mailer license must be distributed with this software.
19/* AUTHOR(S)
20/*	Wietse Venema
21/*	IBM T.J. Watson Research
22/*	P.O. Box 704
23/*	Yorktown Heights, NY 10598, USA
24/*--*/
25
26/* System library. */
27
28#include "sys_defs.h"
29#include <sys/stat.h>
30#include <errno.h>
31#include <stdio.h>			/* rename(2) syscall in stdio.h? */
32
33/* Utility library. */
34
35#include "msg.h"
36#include "sane_fsops.h"
37#include "warn_stat.h"
38
39/* sane_rename - sanitize rename() error returns */
40
41int     sane_rename(const char *from, const char *to)
42{
43    const char *myname = "sane_rename";
44    int     saved_errno;
45    struct stat st;
46
47    /*
48     * Normal case: rename() succeeds.
49     */
50    if (rename(from, to) >= 0)
51	return (0);
52
53    /*
54     * Woops. Save errno, and see if the error is an NFS artefact. If it is,
55     * pretend the error never happened.
56     */
57    saved_errno = errno;
58    if (stat(from, &st) < 0 && stat(to, &st) >= 0) {
59	msg_info("%s(%s,%s): worked around spurious NFS error",
60		 myname, from, to);
61	return (0);
62    }
63
64    /*
65     * Nope, it didn't. Restore errno and report the error.
66     */
67    errno = saved_errno;
68    return (-1);
69}
70