/*
* do_utimes - change times on filename or file descriptor
* @dfd: open file descriptor, -1 or AT_FDCWD
* @filename: path name or NULL
* @times: new times or NULL
* @flags: zero or more flags (only AT_SYMLINK_NOFOLLOW for the moment)
*
* If filename is NULL and dfd refers to an open file, then operate on
* the file. Otherwise look up filename, possibly using dfd as a
* starting point.
*
* If times==NULL, set access and modification to current time,
* must be owner or have write permission.
* Else, update from *times, must be owner or super user.
*/
long do_utimes(int dfd, const char __user *filename, struct timespec *times,
int flags)
{
int error = -EINVAL;
if (times && (!nsec_valid(times[0].tv_nsec) ||
!nsec_valid(times[1].tv_nsec))) {
goto out;
}
if (flags & ~AT_SYMLINK_NOFOLLOW)
goto out;
if (filename == NULL && dfd != AT_FDCWD) {
struct fd f;
if (flags & AT_SYMLINK_NOFOLLOW)
goto out;
f = fdget(dfd);
error = -EBADF;
if (!f.file)
goto out;
error = utimes_common(&f.file->f_path, times);
fdput(f);
} else {
struct path path;
int lookup_flags = 0;
if (!(flags & AT_SYMLINK_NOFOLLOW))
lookup_flags |= LOOKUP_FOLLOW;
retry:
error = user_path_at(dfd, filename, lookup_flags, &path);
if (error)
goto out;
error = utimes_common(&path, times);
path_put(&path);
if (retry_estale(error, lookup_flags)) {
lookup_flags |= LOOKUP_REVAL;
goto retry;
}
}
out:
return error;
}
/* If times==NULL, set access and modification to current time,
* 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 timespec *times, int flags)
{
int error;
struct nameidata nd;
struct dentry *dentry;
struct inode *inode;
struct iattr newattrs;
struct file *f = NULL;
error = -EINVAL;
if (times && (!nsec_valid(times[0].tv_nsec) ||
!nsec_valid(times[1].tv_nsec))) {
goto out;
}
if (flags & ~AT_SYMLINK_NOFOLLOW)
goto out;
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))
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;
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))
goto dput_and_out;
if (!is_owner_or_cap(inode)) {
if (f) {
if (!(f->f_mode & FMODE_WRITE))
goto dput_and_out;
} else {
error = vfs_permission(&nd, MAY_WRITE);
if (error)
goto dput_and_out;
}
}
}
mutex_lock(&inode->i_mutex);
error = notify_change(dentry, &newattrs);
mutex_unlock(&inode->i_mutex);
dput_and_out:
if (f)
fput(f);
else
path_release(&nd);
out:
return error;
}