utimensat implementation
Implement utimensat(2) which is an extension to futimesat(2) in that it
a) supports nano-second resolution for the timestamps
b) allows to selectively ignore the atime/mtime value
c) allows to selectively use the current time for either atime or mtime
d) supports changing the atime/mtime of a symlink itself along the lines
of the BSD lutimes(3) functions
For this change the internally used do_utimes() functions was changed to
accept a timespec time value and an additional flags parameter.
Additionally the sys_utime function was changed to match compat_sys_utime
which already use do_utimes instead of duplicating the work.
Also, the completely missing futimensat() functionality is added. We have
such a function in glibc but we have to resort to using /proc/self/fd/* which
not everybody likes (chroot etc).
Test application (the syscall number will need per-arch editing):
#include <errno.h>
#include <fcntl.h>
#include <time.h>
#include <sys/time.h>
#include <stddef.h>
#include <syscall.h>
#define __NR_utimensat 280
#define UTIME_NOW ((1l << 30) - 1l)
#define UTIME_OMIT ((1l << 30) - 2l)
int
main(void)
{
int status = 0;
int fd = open("ttt", O_RDWR|O_CREAT|O_EXCL, 0666);
if (fd == -1)
error (1, errno, "failed to create test file \"ttt\"");
struct stat64 st1;
if (fstat64 (fd, &st1) != 0)
error (1, errno, "fstat failed");
struct timespec t[2];
t[0].tv_sec = 0;
t[0].tv_nsec = 0;
t[1].tv_sec = 0;
t[1].tv_nsec = 0;
if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0)
error (1, errno, "utimensat failed");
struct stat64 st2;
if (fstat64 (fd, &st2) != 0)
error (1, errno, "fstat failed");
if (st2.st_atim.tv_sec != 0 || st2.st_atim.tv_nsec != 0)
{
puts ("atim not reset to zero");
status = 1;
}
if (st2.st_mtim.tv_sec != 0 || st2.st_mtim.tv_nsec != 0)
{
puts ("mtim not reset to zero");
status = 1;
}
if (status != 0)
goto out;
t[0] = st1.st_atim;
t[1].tv_sec = 0;
t[1].tv_nsec = UTIME_OMIT;
if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0)
error (1, errno, "utimensat failed");
if (fstat64 (fd, &st2) != 0)
error (1, errno, "fstat failed");
if (st2.st_atim.tv_sec != st1.st_atim.tv_sec
|| st2.st_atim.tv_nsec != st1.st_atim.tv_nsec)
{
puts ("atim not set");
status = 1;
}
if (st2.st_mtim.tv_sec != 0 || st2.st_mtim.tv_nsec != 0)
{
puts ("mtim changed from zero");
status = 1;
}
if (status != 0)
goto out;
t[0].tv_sec = 0;
t[0].tv_nsec = UTIME_OMIT;
t[1] = st1.st_mtim;
if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0)
error (1, errno, "utimensat failed");
if (fstat64 (fd, &st2) != 0)
error (1, errno, "fstat failed");
if (st2.st_atim.tv_sec != st1.st_atim.tv_sec
|| st2.st_atim.tv_nsec != st1.st_atim.tv_nsec)
{
puts ("mtim changed from original time");
status = 1;
}
if (st2.st_mtim.tv_sec != st1.st_mtim.tv_sec
|| st2.st_mtim.tv_nsec != st1.st_mtim.tv_nsec)
{
puts ("mtim not set");
status = 1;
}
if (status != 0)
goto out;
sleep (2);
t[0].tv_sec = 0;
t[0].tv_nsec = UTIME_NOW;
t[1].tv_sec = 0;
t[1].tv_nsec = UTIME_NOW;
if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0)
error (1, errno, "utimensat failed");
if (fstat64 (fd, &st2) != 0)
error (1, errno, "fstat failed");
struct timeval tv;
gettimeofday(&tv,NULL);
if (st2.st_atim.tv_sec <= st1.st_atim.tv_sec
|| st2.st_atim.tv_sec > tv.tv_sec)
{
puts ("atim not set to NOW");
status = 1;
}
if (st2.st_mtim.tv_sec <= st1.st_mtim.tv_sec
|| st2.st_mtim.tv_sec > tv.tv_sec)
{
puts ("mtim not set to NOW");
status = 1;
}
if (symlink ("ttt", "tttsym") != 0)
error (1, errno, "cannot create symlink");
t[0].tv_sec = 0;
t[0].tv_nsec = 0;
t[1].tv_sec = 0;
t[1].tv_nsec = 0;
if (syscall(__NR_utimensat, AT_FDCWD, "tttsym", t, AT_SYMLINK_NOFOLLOW) != 0)
error (1, errno, "utimensat failed");
if (lstat64 ("tttsym", &st2) != 0)
error (1, errno, "lstat failed");
if (st2.st_atim.tv_sec != 0 || st2.st_atim.tv_nsec != 0)
{
puts ("symlink atim not reset to zero");
status = 1;
}
if (st2.st_mtim.tv_sec != 0 || st2.st_mtim.tv_nsec != 0)
{
puts ("symlink mtim not reset to zero");
status = 1;
}
if (status != 0)
goto out;
t[0].tv_sec = 1;
t[0].tv_nsec = 0;
t[1].tv_sec = 1;
t[1].tv_nsec = 0;
if (syscall(__NR_utimensat, fd, NULL, t, 0) != 0)
error (1, errno, "utimensat failed");
if (fstat64 (fd, &st2) != 0)
error (1, errno, "fstat failed");
if (st2.st_atim.tv_sec != 1 || st2.st_atim.tv_nsec != 0)
{
puts ("atim not reset to one");
status = 1;
}
if (st2.st_mtim.tv_sec != 1 || st2.st_mtim.tv_nsec != 0)
{
puts ("mtim not reset to one");
status = 1;
}
if (status == 0)
puts ("all OK");
out:
close (fd);
unlink ("ttt");
unlink ("tttsym");
return status;
}
[akpm@linux-foundation.org: add missing i386 syscall table entry]
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Cc: Alexey Dobriyan <adobriyan@openvz.org>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/asm-i386/unistd.h b/include/asm-i386/unistd.h
index 833fa17..bd21e79 100644
--- a/include/asm-i386/unistd.h
+++ b/include/asm-i386/unistd.h
@@ -325,10 +325,11 @@
#define __NR_move_pages 317
#define __NR_getcpu 318
#define __NR_epoll_pwait 319
+#define __NR_utimensat 320
#ifdef __KERNEL__
-#define NR_syscalls 320
+#define NR_syscalls 321
#define __ARCH_WANT_IPC_PARSE_VERSION
#define __ARCH_WANT_OLD_READDIR
diff --git a/include/asm-x86_64/unistd.h b/include/asm-x86_64/unistd.h
index 26e23e0..5957039 100644
--- a/include/asm-x86_64/unistd.h
+++ b/include/asm-x86_64/unistd.h
@@ -619,6 +619,8 @@
__SYSCALL(__NR_vmsplice, sys_vmsplice)
#define __NR_move_pages 279
__SYSCALL(__NR_move_pages, sys_move_pages)
+#define __NR_utimensat 280
+__SYSCALL(__NR_utimensat, sys_utimensat)
#ifndef __NO_STUBS
#define __ARCH_WANT_OLD_READDIR
diff --git a/include/linux/stat.h b/include/linux/stat.h
index 679ef0d..611c398 100644
--- a/include/linux/stat.h
+++ b/include/linux/stat.h
@@ -53,6 +53,9 @@
#define S_IWUGO (S_IWUSR|S_IWGRP|S_IWOTH)
#define S_IXUGO (S_IXUSR|S_IXGRP|S_IXOTH)
+#define UTIME_NOW ((1l << 30) - 1l)
+#define UTIME_OMIT ((1l << 30) - 2l)
+
#include <linux/types.h>
#include <linux/time.h>
diff --git a/include/linux/time.h b/include/linux/time.h
index 50e31b1..dda9be6 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -109,7 +109,7 @@
extern int do_settimeofday(struct timespec *tv);
extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
-extern long do_utimes(int dfd, char __user *filename, struct timeval *times);
+extern long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags);
struct itimerval;
extern int do_setitimer(int which, struct itimerval *value,
struct itimerval *ovalue);