[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <201209081741013286843@gmail.com>
Date: Sat, 8 Sep 2012 17:41:05 +0800
From: "Jianpeng Ma" <majianpeng@...il.com>
To: gregkh <gregkh@...uxfoundation.org>
Cc: linux-kernel <linux-kernel@...r.kernel.org>
Subject: About function __create_file in debugfs
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.
Powered by blists - more mailing lists