#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>
  
  #ifdef __ARCH_WANT_SYS_UTIME
  
  /*
   * sys_utime() can be implemented in user-level using sys_utimes().
   * Is this for backwards compatibility?  If so, why not move it
   * into the appropriate arch directory (for those architectures that
   * need it).
   */
  
  /* 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.
   */

  asmlinkage long sys_utime(char __user *filename, struct utimbuf __user *times)

  {

  	struct timespec tv[2];

  	if (times) {

  		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;

  	}

  	return do_utimes(AT_FDCWD, filename, times ? tv : NULL, 0);

  }
  
  #endif
  
  /* 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 (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;
  }

  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) {
  		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)
  {
  	return sys_futimesat(AT_FDCWD, filename, utimes);
  }