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/* Set file access and modification times.
Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Free Software
Foundation, Inc.
This program is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3 of the License, or any
later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* Written by Paul Eggert. */
/* derived from a function in touch.c */
#include <config.h>
#include "utimens.h"
#include <errno.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <unistd.h>
#if HAVE_UTIME_H
# include <utime.h>
#endif
/* Some systems (even some that do have <utime.h>) don't declare this
structure anywhere. */
#ifndef HAVE_STRUCT_UTIMBUF
struct utimbuf
{
long actime;
long modtime;
};
#endif
/* Some systems don't have ENOSYS. */
#ifndef ENOSYS
# ifdef ENOTSUP
# define ENOSYS ENOTSUP
# else
/* Some systems don't have ENOTSUP either. */
# define ENOSYS EINVAL
# endif
#endif
#ifndef __attribute__
# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8)
# define __attribute__(x)
# endif
#endif
#ifndef ATTRIBUTE_UNUSED
# define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
#endif
/* Set the access and modification time stamps of FD (a.k.a. FILE) to be
TIMESPEC[0] and TIMESPEC[1], respectively.
FD must be either negative -- in which case it is ignored --
or a file descriptor that is open on FILE.
If FD is nonnegative, then FILE can be NULL, which means
use just futimes (or equivalent) instead of utimes (or equivalent),
and fail if on an old system without futimes (or equivalent).
If TIMESPEC is null, set the time stamps to the current time.
Return 0 on success, -1 (setting errno) on failure. */
int
gl_futimens (int fd ATTRIBUTE_UNUSED,
char const *file, struct timespec const timespec[2])
{
/* Some Linux-based NFS clients are buggy, and mishandle time stamps
of files in NFS file systems in some cases. We have no
configure-time test for this, but please see
<http://bugs.gentoo.org/show_bug.cgi?id=132673> for references to
some of the problems with Linux 2.6.16. If this affects you,
compile with -DHAVE_BUGGY_NFS_TIME_STAMPS; this is reported to
help in some cases, albeit at a cost in performance. But you
really should upgrade your kernel to a fixed version, since the
problem affects many applications. */
#if HAVE_BUGGY_NFS_TIME_STAMPS
if (fd < 0)
sync ();
else
fsync (fd);
#endif
/* POSIX 200x added two interfaces to set file timestamps with
nanosecond resolution. We provide a fallback for ENOSYS (for
example, compiling against Linux 2.6.25 kernel headers and glibc
2.7, but running on Linux 2.6.18 kernel). */
#if HAVE_UTIMENSAT
if (fd < 0)
{
int result = utimensat (AT_FDCWD, file, timespec, 0);
# ifdef __linux__
/* Work around what might be a kernel bug:
http://bugzilla.redhat.com/442352
http://bugzilla.redhat.com/449910
It appears that utimensat can mistakenly return 280 rather
than -1 upon failure.
FIXME: remove in 2010 or whenever the offending kernels
are no longer in common use. */
if (0 < result)
errno = ENOSYS;
# endif
if (result == 0 || errno != ENOSYS)
return result;
}
#endif
#if HAVE_FUTIMENS
{
int result = futimens (fd, timespec);
# ifdef __linux__
/* Work around the same bug as above. */
if (0 < result)
errno = ENOSYS;
# endif
if (result == 0 || errno != ENOSYS)
return result;
}
#endif
/* The platform lacks an interface to set file timestamps with
nanosecond resolution, so do the best we can, discarding any
fractional part of the timestamp. */
{
#if HAVE_FUTIMESAT || HAVE_WORKING_UTIMES
struct timeval timeval[2];
struct timeval const *t;
if (timespec)
{
timeval[0].tv_sec = timespec[0].tv_sec;
timeval[0].tv_usec = timespec[0].tv_nsec / 1000;
timeval[1].tv_sec = timespec[1].tv_sec;
timeval[1].tv_usec = timespec[1].tv_nsec / 1000;
t = timeval;
}
else
t = NULL;
if (fd < 0)
{
# if HAVE_FUTIMESAT
return futimesat (AT_FDCWD, file, t);
# endif
}
else
{
/* If futimesat or futimes fails here, don't try to speed things
up by returning right away. glibc can incorrectly fail with
errno == ENOENT if /proc isn't mounted. Also, Mandrake 10.0
in high security mode doesn't allow ordinary users to read
/proc/self, so glibc incorrectly fails with errno == EACCES.
If errno == EIO, EPERM, or EROFS, it's probably safe to fail
right away, but these cases are rare enough that they're not
worth optimizing, and who knows what other messed-up systems
are out there? So play it safe and fall back on the code
below. */
# if HAVE_FUTIMESAT
if (futimesat (fd, NULL, t) == 0)
return 0;
# elif HAVE_FUTIMES
if (futimes (fd, t) == 0)
return 0;
# endif
}
#endif /* HAVE_FUTIMESAT || HAVE_WORKING_UTIMES */
if (!file)
{
#if ! (HAVE_FUTIMESAT || (HAVE_WORKING_UTIMES && HAVE_FUTIMES))
errno = ENOSYS;
#endif
/* Prefer EBADF to ENOSYS if both error numbers apply. */
if (errno == ENOSYS)
{
int fd2 = dup (fd);
int dup_errno = errno;
if (0 <= fd2)
close (fd2);
errno = (fd2 < 0 && dup_errno == EBADF ? EBADF : ENOSYS);
}
return -1;
}
#if HAVE_WORKING_UTIMES
return utimes (file, t);
#else
{
struct utimbuf utimbuf;
struct utimbuf const *ut;
if (timespec)
{
utimbuf.actime = timespec[0].tv_sec;
utimbuf.modtime = timespec[1].tv_sec;
ut = &utimbuf;
}
else
ut = NULL;
return utime (file, ut);
}
#endif /* !HAVE_WORKING_UTIMES */
}
}
/* Set the access and modification time stamps of FILE to be
TIMESPEC[0] and TIMESPEC[1], respectively. */
int
utimens (char const *file, struct timespec const timespec[2])
{
return gl_futimens (-1, file, timespec);
}
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