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Message-ID: <ff35b3fa-5af8-ac9b-3fae-d60c422c4393@gmail.com>
Date:   Thu, 18 May 2023 23:02:04 +0800
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Subject: Re: [f2fs-dev] [PATCH 1/1] f2fs: pass I_NEW flag to trace event
To:     Jaegeuk Kim <jaegeuk@kernel.org>
Cc:     Chao Yu <chao@kernel.org>, Wu Bo <bo.wu@vivo.com>,
        linux-f2fs-devel@lists.sourceforge.net,
        linux-kernel@vger.kernel.org
References: <45eb63c6-a147-776a-99b5-7ac06848ede8@kernel.org>
 <20230517035953.47810-1-bo.wu@vivo.com>
 <94958409-f726-9da6-3b9f-76efa022ee9d@kernel.org>
 <4a512db8-cfca-80a5-ba62-780f56d014f6@gmail.com>
 <ZGVyOTqQy5ZhNvAr@google.com>
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From:   Wu Bo <wubo.oduw@gmail.com>
In-Reply-To: <ZGVyOTqQy5ZhNvAr@google.com>
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On 2023/5/18 08:32, Jaegeuk Kim wrote:
> On 05/17, Wu Bo wrote:
>> On 2023/5/17 16:36, Chao Yu wrote:
>>> On 2023/5/17 11:59, Wu Bo wrote:
>>>> On 2023/5/17 10:44, Chao Yu wrote:
>>>>> On 2023/5/16 20:07, Wu Bo wrote:
>>>>>> Modify the order between 'trace_f2fs_iget' &
>>>>>> 'unlock_new_inode', so the
>>>>>> I_NEW can pass to the trace event when the inode initialised.
>>>>> Why is it needed? And trace_f2fs_iget() won't print inode->i_state?
>>>> When connect a trace_probe to f2fs_iget, it will be able to
>>>> determine whether
>>>> the inode is new initialised in order to do different process.
>>> I didn't get it, you want to hook __tracepoint_f2fs_iget() w/ your own
>>> callback?
>> Yes,  to use 'tracepoint_probe_register ' to register a probe at
>> trace_f2fs_iget
> Why?

Sorry, I don't understand what is your real question.

In my understanding, a trace_event is also a  non-volatile point in 
kernel for probing.

And for my case, I want to develop a tool by trace_probe to collect some 
information.

Thanks

>
>>> Thanks,
>>>
>>>>> Thanks,
>>>>>
>>>>>> Signed-off-by: Wu Bo <bo.wu@vivo.com>
>>>>>> ---
>>>>>>     fs/f2fs/inode.c | 2 +-
>>>>>>     1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>>
>>>>>> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
>>>>>> index cf4327ad106c..caf959289fe7 100644
>>>>>> --- a/fs/f2fs/inode.c
>>>>>> +++ b/fs/f2fs/inode.c
>>>>>> @@ -577,8 +577,8 @@ struct inode *f2fs_iget(struct super_block *sb,
>>>>>> unsigned long ino)
>>>>>>             file_dont_truncate(inode);
>>>>>>         }
>>>>>>     -    unlock_new_inode(inode);
>>>>>>         trace_f2fs_iget(inode);
>>>>>> +    unlock_new_inode(inode);
>>>>>>         return inode;
>>>>>>       bad_inode:
>>>>>
>>>>> _______________________________________________
>>>>> Linux-f2fs-devel mailing list
>>>>> Linux-f2fs-devel@lists.sourceforge.net
>>>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
>>>>>