From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753113Ab2IHJkq (ORCPT ); Sat, 8 Sep 2012 05:40:46 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:57906 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752754Ab2IHJkn (ORCPT ); Sat, 8 Sep 2012 05:40:43 -0400 Date: Sat, 8 Sep 2012 17:41:05 +0800 From: "Jianpeng Ma" To: gregkh Cc: linux-kernel Subject: About function __create_file in debugfs X-Priority: 3 X-Has-Attach: no X-Mailer: Foxmail 7.0.1.91[en] Mime-Version: 1.0 Message-ID: <201209081741013286843@gmail.com> Content-Type: text/plain; charset="gb2312" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id q889fdEo010958 Hi: At present,i used blktrace to trace block io.But i always met error, the message like: >BLKTRACESETUP(2) /dev/sdc failed: 2/No such file or directory >Thread 0 failed open /sys/kernel/debug/block/(null)/trace0: 2/No such file or directory >Thread 2 failed open /sys/kernel/debug/block/(null)/trace2: 2/No such file or directory >Thread 3 failed open /sys/kernel/debug/block/(null)/trace3: 2/No such file or directory >Thread 1 failed open /sys/kernel/debug/block/(null)/trace1: 2/No such file or directory >FAILED to start thread on CPU 0: 1/Operation not permitted >FAILED to start thread on CPU 1: 1/Operation not permitted >FAILED to start thread on CPU 2: 1/Operation not permitted >FAILED to start thread on CPU 3: 1/Operation not permitted But those isn't important. I add some message in kernel and found the reason is inode already existed. But the function __create_file dosen't return correctly errno.So blktrace tool can't print correctly message. I think func __create_file should return correctly message(ERR_PTR(error)) not NULL. {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I