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/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
index ea405f5..ce85715 100644
--- a/arch/alpha/kernel/osf_sys.c
+++ b/arch/alpha/kernel/osf_sys.c
@@ -953,15 +953,25 @@
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 \
diff --git a/arch/i386/kernel/syscall_table.S b/arch/i386/kernel/syscall_table.S
index 2697e92..0772678 100644
--- a/arch/i386/kernel/syscall_table.S
+++ b/arch/i386/kernel/syscall_table.S
@@ -319,3 +319,4 @@
.long sys_move_pages
.long sys_getcpu
.long sys_epoll_pwait
+ .long sys_utimensat /* 320 */
diff --git a/arch/sparc64/kernel/sys_sparc32.c b/arch/sparc64/kernel/sys_sparc32.c
index 7876a02..692e46a 100644
--- a/arch/sparc64/kernel/sys_sparc32.c
+++ b/arch/sparc64/kernel/sys_sparc32.c
@@ -775,15 +775,25 @@
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. */
diff --git a/arch/x86_64/ia32/ia32entry.S b/arch/x86_64/ia32/ia32entry.S
index c48087d..f210683 100644
--- a/arch/x86_64/ia32/ia32entry.S
+++ b/arch/x86_64/ia32/ia32entry.S
@@ -710,9 +710,10 @@
.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:
diff --git a/fs/compat.c b/fs/compat.c
index 9f6248d..9cf75df 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -77,30 +77,57 @@
*/
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)
diff --git a/fs/utimes.c b/fs/utimes.c
index 99cf2cb..480f7c8 100644
--- a/fs/utimes.c
+++ b/fs/utimes.c
@@ -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, ×->actime);
- newattrs.ia_atime.tv_nsec = 0;
- if (!error)
- error = get_user(newattrs.ia_mtime.tv_sec, ×->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, ×->actime) ||
+ get_user(tv[1].tv_sec, ×->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 @@
* 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 @@
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 @@
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(×, utimes, sizeof(times)))
- return -EFAULT;
- return do_utimes(dfd, filename, utimes ? times : NULL);
+ if (utimes) {
+ if (copy_from_user(×, 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)
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);
