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utimensat implementation

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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>
This commit is contained in:
Ulrich Drepper 2007-05-08 00:33:25 -07:00 committed by Linus Torvalds
parent ade5fb818f
commit 1c710c896e
10 changed files with 172 additions and 75 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

14
arch/alpha/kernel/osf_sys.c
View file

@ -953,15 +953,25 @@ osf_setitimer(int which, struct itimerval32 __user *in, struct itimerval32 __use
asmlinkage int
osf_utimes(char __user *filename, struct timeval32 __user *tvs)
{
struct timeval ktvs[2];
struct timespec tv[2];
if (tvs) {
struct timeval ktvs[2];
if (get_tv32(&ktvs[0], &tvs[0]) ||
get_tv32(&ktvs[1], &tvs[1]))
return -EFAULT;
if (ktvs[0].tv_usec < 0 || ktvs[0].tv_usec >= 1000000 ||
ktvs[1].tv_usec < 0 || ktvs[1].tv_usec >= 1000000)
return -EINVAL;
tv[0].tv_sec = ktvs[0].tv_sec;
tv[0].tv_nsec = 1000 * ktvs[0].tv_usec;
tv[1].tv_sec = ktvs[1].tv_sec;
tv[1].tv_nsec = 1000 * ktvs[1].tv_usec;
}
return do_utimes(AT_FDCWD, filename, tvs ? ktvs : NULL);
return do_utimes(AT_FDCWD, filename, tvs ? tv : NULL, 0);
}
#define MAX_SELECT_SECONDS \

1
arch/i386/kernel/syscall_table.S
View file

@ -319,3 +319,4 @@ ENTRY(sys_call_table)
.long sys_move_pages
.long sys_getcpu
.long sys_epoll_pwait
.long sys_utimensat /* 320 */

14
arch/sparc64/kernel/sys_sparc32.c
View file

@ -775,15 +775,25 @@ asmlinkage long sys32_settimeofday(struct compat_timeval __user *tv,
asmlinkage long sys32_utimes(char __user *filename,
struct compat_timeval __user *tvs)
{
struct timeval ktvs[2];
struct timespec tv[2];
if (tvs) {
struct timeval ktvs[2];
if (get_tv32(&ktvs[0], tvs) ||
get_tv32(&ktvs[1], 1+tvs))
return -EFAULT;
if (ktvs[0].tv_usec < 0 || ktvs[0].tv_usec >= 1000000 ||
ktvs[1].tv_usec < 0 || ktvs[1].tv_usec >= 1000000)
return -EINVAL;
tv[0].tv_sec = ktvs[0].tv_sec;
tv[0].tv_nsec = 1000 * ktvs[0].tv_usec;
tv[1].tv_sec = ktvs[1].tv_sec;
tv[1].tv_nsec = 1000 * ktvs[1].tv_usec;
}
return do_utimes(AT_FDCWD, filename, (tvs ? &ktvs[0] : NULL));
return do_utimes(AT_FDCWD, filename, tvs ? tv : NULL);
}
/* These are here just in case some old sparc32 binary calls it. */

3
arch/x86_64/ia32/ia32entry.S
View file

@ -710,9 +710,10 @@ ia32_sys_call_table:
.quad compat_sys_get_robust_list
.quad sys_splice
.quad sys_sync_file_range
.quad sys_tee
.quad sys_tee /* 315 */
.quad compat_sys_vmsplice
.quad compat_sys_move_pages
.quad sys_getcpu
.quad sys_epoll_pwait
.quad compat_sys_utimensat /* 320 */
ia32_syscall_end:

43
fs/compat.c
View file

@ -77,30 +77,57 @@ int compat_printk(const char *fmt, ...)
*/
asmlinkage long compat_sys_utime(char __user *filename, struct compat_utimbuf __user *t)
{
struct timeval tv[2];
struct timespec tv[2];
if (t) {
if (get_user(tv[0].tv_sec, &t->actime) ||
get_user(tv[1].tv_sec, &t->modtime))
return -EFAULT;
tv[0].tv_usec = 0;
tv[1].tv_usec = 0;
tv[0].tv_nsec = 0;
tv[1].tv_nsec = 0;
}
return do_utimes(AT_FDCWD, filename, t ? tv : NULL);
return do_utimes(AT_FDCWD, filename, t ? tv : NULL, 0);
}
asmlinkage long compat_sys_utimensat(unsigned int dfd, char __user *filename, struct compat_timespec __user *t, int flags)
{
struct timespec tv[2];
if (t) {
if (get_compat_timespec(&tv[0], &t[0]) ||
get_compat_timespec(&tv[1], &t[1]))
return -EFAULT;
if ((tv[0].tv_nsec == UTIME_OMIT || tv[0].tv_nsec == UTIME_NOW)
&& tv[0].tv_sec != 0)
return -EINVAL;
if ((tv[1].tv_nsec == UTIME_OMIT || tv[1].tv_nsec == UTIME_NOW)
&& tv[1].tv_sec != 0)
return -EINVAL;
if (tv[0].tv_nsec == UTIME_OMIT && tv[1].tv_nsec == UTIME_OMIT)
return 0;
}
return do_utimes(dfd, filename, t ? tv : NULL, flags);
}
asmlinkage long compat_sys_futimesat(unsigned int dfd, char __user *filename, struct compat_timeval __user *t)
{
struct timeval tv[2];
struct timespec tv[2];
if (t) {
if (get_user(tv[0].tv_sec, &t[0].tv_sec) ||
get_user(tv[0].tv_usec, &t[0].tv_usec) ||
get_user(tv[0].tv_nsec, &t[0].tv_usec) ||
get_user(tv[1].tv_sec, &t[1].tv_sec) ||
get_user(tv[1].tv_usec, &t[1].tv_usec))
get_user(tv[1].tv_nsec, &t[1].tv_usec))
return -EFAULT;
if (tv[0].tv_nsec >= 1000000 || tv[0].tv_nsec < 0 ||
tv[1].tv_nsec >= 1000000 || tv[1].tv_nsec < 0)
return -EINVAL;
tv[0].tv_nsec *= 1000;
tv[1].tv_nsec *= 1000;
}
return do_utimes(dfd, filename, t ? tv : NULL);
return do_utimes(dfd, filename, t ? tv : NULL, 0);
}
asmlinkage long compat_sys_utimes(char __user *filename, struct compat_timeval __user *t)

162
fs/utimes.c
View file

@ -1,8 +1,10 @@
#include <linux/compiler.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/linkage.h>
#include <linux/namei.h>
#include <linux/sched.h>
#include <linux/stat.h>
#include <linux/utime.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
@ -20,54 +22,18 @@
* must be owner or have write permission.
* Else, update from *times, must be owner or super user.
*/
asmlinkage long sys_utime(char __user * filename, struct utimbuf __user * times)
asmlinkage long sys_utime(char __user *filename, struct utimbuf __user *times)
{
int error;
struct nameidata nd;
struct inode * inode;
struct iattr newattrs;
struct timespec tv[2];
error = user_path_walk(filename, &nd);
if (error)
goto out;
inode = nd.dentry->d_inode;
error = -EROFS;
if (IS_RDONLY(inode))
goto dput_and_out;
/* Don't worry, the checks are done in inode_change_ok() */
newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
if (times) {
error = -EPERM;
if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
goto dput_and_out;
error = get_user(newattrs.ia_atime.tv_sec, &times->actime);
newattrs.ia_atime.tv_nsec = 0;
if (!error)
error = get_user(newattrs.ia_mtime.tv_sec, &times->modtime);
newattrs.ia_mtime.tv_nsec = 0;
if (error)
goto dput_and_out;
newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET;
} else {
error = -EACCES;
if (IS_IMMUTABLE(inode))
goto dput_and_out;
if (current->fsuid != inode->i_uid &&
(error = vfs_permission(&nd, MAY_WRITE)) != 0)
goto dput_and_out;
if (get_user(tv[0].tv_sec, &times->actime) ||
get_user(tv[1].tv_sec, &times->modtime))
return -EFAULT;
tv[0].tv_nsec = 0;
tv[1].tv_nsec = 0;
}
mutex_lock(&inode->i_mutex);
error = notify_change(nd.dentry, &newattrs);
mutex_unlock(&inode->i_mutex);
dput_and_out:
path_release(&nd);
out:
return error;
return do_utimes(AT_FDCWD, filename, times ? tv : NULL, 0);
}
#endif
@ -76,18 +42,38 @@ out:
* must be owner or have write permission.
* Else, update from *times, must be owner or super user.
*/
long do_utimes(int dfd, char __user *filename, struct timeval *times)
long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags)
{
int error;
struct nameidata nd;
struct inode * inode;
struct dentry *dentry;
struct inode *inode;
struct iattr newattrs;
struct file *f = NULL;
error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd);
if (error)
error = -EINVAL;
if (flags & ~AT_SYMLINK_NOFOLLOW)
goto out;
inode = nd.dentry->d_inode;
if (filename == NULL && dfd != AT_FDCWD) {
error = -EINVAL;
if (flags & AT_SYMLINK_NOFOLLOW)
goto out;
error = -EBADF;
f = fget(dfd);
if (!f)
goto out;
dentry = f->f_path.dentry;
} else {
error = __user_walk_fd(dfd, filename, (flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW, &nd);
if (error)
goto out;
dentry = nd.dentry;
}
inode = dentry->d_inode;
error = -EROFS;
if (IS_RDONLY(inode))
@ -100,11 +86,21 @@ long do_utimes(int dfd, char __user *filename, struct timeval *times)
if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
goto dput_and_out;
newattrs.ia_atime.tv_sec = times[0].tv_sec;
newattrs.ia_atime.tv_nsec = times[0].tv_usec * 1000;
newattrs.ia_mtime.tv_sec = times[1].tv_sec;
newattrs.ia_mtime.tv_nsec = times[1].tv_usec * 1000;
newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET;
if (times[0].tv_nsec == UTIME_OMIT)
newattrs.ia_valid &= ~ATTR_ATIME;
else if (times[0].tv_nsec != UTIME_NOW) {
newattrs.ia_atime.tv_sec = times[0].tv_sec;
newattrs.ia_atime.tv_nsec = times[0].tv_nsec;
newattrs.ia_valid |= ATTR_ATIME_SET;
}
if (times[1].tv_nsec == UTIME_OMIT)
newattrs.ia_valid &= ~ATTR_MTIME;
else if (times[1].tv_nsec != UTIME_NOW) {
newattrs.ia_mtime.tv_sec = times[1].tv_sec;
newattrs.ia_mtime.tv_nsec = times[1].tv_nsec;
newattrs.ia_valid |= ATTR_MTIME_SET;
}
} else {
error = -EACCES;
if (IS_IMMUTABLE(inode))
@ -115,21 +111,67 @@ long do_utimes(int dfd, char __user *filename, struct timeval *times)
goto dput_and_out;
}
mutex_lock(&inode->i_mutex);
error = notify_change(nd.dentry, &newattrs);
error = notify_change(dentry, &newattrs);
mutex_unlock(&inode->i_mutex);
dput_and_out:
path_release(&nd);
if (f)
fput(f);
else
path_release(&nd);
out:
return error;
}
asmlinkage long sys_utimensat(int dfd, char __user *filename, struct timespec __user *utimes, int flags)
{
struct timespec tstimes[2];
if (utimes) {
if (copy_from_user(&tstimes, utimes, sizeof(tstimes)))
return -EFAULT;
if ((tstimes[0].tv_nsec == UTIME_OMIT ||
tstimes[0].tv_nsec == UTIME_NOW) &&
tstimes[0].tv_sec != 0)
return -EINVAL;
if ((tstimes[1].tv_nsec == UTIME_OMIT ||
tstimes[1].tv_nsec == UTIME_NOW) &&
tstimes[1].tv_sec != 0)
return -EINVAL;
/* Nothing to do, we must not even check the path. */
if (tstimes[0].tv_nsec == UTIME_OMIT &&
tstimes[1].tv_nsec == UTIME_OMIT)
return 0;
}
return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags);
}
asmlinkage long sys_futimesat(int dfd, char __user *filename, struct timeval __user *utimes)
{
struct timeval times[2];
struct timespec tstimes[2];
if (utimes && copy_from_user(&times, utimes, sizeof(times)))
return -EFAULT;
return do_utimes(dfd, filename, utimes ? times : NULL);
if (utimes) {
if (copy_from_user(&times, utimes, sizeof(times)))
return -EFAULT;
/* This test is needed to catch all invalid values. If we
would test only in do_utimes we would miss those invalid
values truncated by the multiplication with 1000. Note
that we also catch UTIME_{NOW,OMIT} here which are only
valid for utimensat. */
if (times[0].tv_usec >= 1000000 || times[0].tv_usec < 0 ||
times[1].tv_usec >= 1000000 || times[1].tv_usec < 0)
return -EINVAL;
tstimes[0].tv_sec = times[0].tv_sec;
tstimes[0].tv_nsec = 1000 * times[0].tv_usec;
tstimes[1].tv_sec = times[1].tv_sec;
tstimes[1].tv_nsec = 1000 * times[1].tv_usec;
}
return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0);
}
asmlinkage long sys_utimes(char __user *filename, struct timeval __user *utimes)

3
include/asm-i386/unistd.h
View file

@ -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

2
include/asm-x86_64/unistd.h
View file

@ -619,6 +619,8 @@ __SYSCALL(__NR_sync_file_range, sys_sync_file_range)
__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

3
include/linux/stat.h
View file

@ -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>

2
include/linux/time.h
View file

@ -109,7 +109,7 @@ extern void do_gettimeofday(struct timeval *tv);
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);