xfs_open_by_handle(
	struct file		*parfilp,
	xfs_fsop_handlereq_t	*hreq)
{
	const struct cred	*cred = current_cred();
	int			error;
	int			fd;
	int			permflag;
	struct file		*filp;
	struct inode		*inode;
	struct dentry		*dentry;
	fmode_t			fmode;
	struct path		path;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	dentry = xfs_handlereq_to_dentry(parfilp, hreq);
	if (IS_ERR(dentry))
		return PTR_ERR(dentry);
	inode = d_inode(dentry);

	/* Restrict xfs_open_by_handle to directories & regular files. */
	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))) {
		error = -EPERM;
		goto out_dput;
	}

#if BITS_PER_LONG != 32
	hreq->oflags |= O_LARGEFILE;
#endif

	permflag = hreq->oflags;
	fmode = OPEN_FMODE(permflag);
	if ((!(permflag & O_APPEND) || (permflag & O_TRUNC)) &&
	    (fmode & FMODE_WRITE) && IS_APPEND(inode)) {
		error = -EPERM;
		goto out_dput;
	}

	if ((fmode & FMODE_WRITE) && IS_IMMUTABLE(inode)) {
		error = -EPERM;
		goto out_dput;
	}

	/* Can't write directories. */
	if (S_ISDIR(inode->i_mode) && (fmode & FMODE_WRITE)) {
		error = -EISDIR;
		goto out_dput;
	}

	fd = get_unused_fd_flags(0);
	if (fd < 0) {
		error = fd;
		goto out_dput;
	}

	path.mnt = parfilp->f_path.mnt;
	path.dentry = dentry;
	filp = dentry_open(&path, hreq->oflags, cred);
	dput(dentry);
	if (IS_ERR(filp)) {
		put_unused_fd(fd);
		return PTR_ERR(filp);
	}

	if (S_ISREG(inode->i_mode)) {
		filp->f_flags |= O_NOATIME;
		filp->f_mode |= FMODE_NOCMTIME;
	}

	fd_install(fd, filp);
	return fd;

 out_dput:
	dput(dentry);
	return error;
}
Unknown