linux-kernel - Re: [PATCH v2] f2fs: ratelimit recovery messages

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Date:   Tue, 28 May 2019 11:17:59 +0800
From:   Chao Yu <yuchao0@...wei.com>
To:     Sahitya Tummala <stummala@...eaurora.org>
CC:     Jaegeuk Kim <jaegeuk@...nel.org>,
        <linux-f2fs-devel@...ts.sourceforge.net>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2] f2fs: ratelimit recovery messages

Hi Sahitya,

On 2019/5/28 11:05, Sahitya Tummala wrote:
> Hi Chao,
> 
> On Tue, May 28, 2019 at 09:23:15AM +0800, Chao Yu wrote:
>> Hi Sahitya,
>>
>> On 2019/5/27 21:10, Sahitya Tummala wrote:
>>> Ratelimit the recovery logs, which are expected in case
>>> of sudden power down and which could result into too
>>> many prints.
>>
>> FYI
>>
>> https://lore.kernel.org/patchwork/patch/973837/
>>
>> IMO, we need those logs to provide evidence during trouble-shooting of file data
>> corruption or file missing problem...
>>
> In one of the logs, I have noticed there were ~400 recovery prints in the

I think its order of magnitudes is not such bad, if there is redundant logs such
as the one in do_recover_data(), we can improve it.

> kernel bootup. I noticed your patch above and with that now we can always get
> the error returned by f2fs_recover_fsync_data(), which should be good enough
> for knowing the status of recovered files I thought. Do you think we need
> individually each file status as well?

Yes, I think so, we need them for the detailed info. :)

Thanks,

> 
> Thanks,
> 
>> So I suggest we can keep log as it is in recover_dentry/recover_inode, and for
>> the log in do_recover_data, we can record recovery info [isize_kept,
>> recovered_count, err ...] into struct fsync_inode_entry, and print them in
>> batch, how do you think?
>>
>> Thanks,
>>
>>>
>>> Signed-off-by: Sahitya Tummala <stummala@...eaurora.org>
>>> ---
>>> v2:
>>>  - fix minor formatting and add new line for printk
>>>
>>>  fs/f2fs/recovery.c | 18 +++++++++---------
>>>  1 file changed, 9 insertions(+), 9 deletions(-)
>>>
>>> diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
>>> index e04f82b..60d7652 100644
>>> --- a/fs/f2fs/recovery.c
>>> +++ b/fs/f2fs/recovery.c
>>> @@ -188,8 +188,8 @@ static int recover_dentry(struct inode *inode, struct page *ipage,
>>>  		name = "<encrypted>";
>>>  	else
>>>  		name = raw_inode->i_name;
>>> -	f2fs_msg(inode->i_sb, KERN_NOTICE,
>>> -			"%s: ino = %x, name = %s, dir = %lx, err = %d",
>>> +	printk_ratelimited(KERN_NOTICE
>>> +			"%s: ino = %x, name = %s, dir = %lx, err = %d\n",
>>>  			__func__, ino_of_node(ipage), name,
>>>  			IS_ERR(dir) ? 0 : dir->i_ino, err);
>>>  	return err;
>>> @@ -292,8 +292,8 @@ static int recover_inode(struct inode *inode, struct page *page)
>>>  	else
>>>  		name = F2FS_INODE(page)->i_name;
>>>  
>>> -	f2fs_msg(inode->i_sb, KERN_NOTICE,
>>> -		"recover_inode: ino = %x, name = %s, inline = %x",
>>> +	printk_ratelimited(KERN_NOTICE
>>> +			"recover_inode: ino = %x, name = %s, inline = %x\n",
>>>  			ino_of_node(page), name, raw->i_inline);
>>>  	return 0;
>>>  }
>>> @@ -642,11 +642,11 @@ static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
>>>  err:
>>>  	f2fs_put_dnode(&dn);
>>>  out:
>>> -	f2fs_msg(sbi->sb, KERN_NOTICE,
>>> -		"recover_data: ino = %lx (i_size: %s) recovered = %d, err = %d",
>>> -		inode->i_ino,
>>> -		file_keep_isize(inode) ? "keep" : "recover",
>>> -		recovered, err);
>>> +	printk_ratelimited(KERN_NOTICE
>>> +			"recover_data: ino = %lx (i_size: %s) recovered = %d, err = %d\n",
>>> +			inode->i_ino,
>>> +			file_keep_isize(inode) ? "keep" : "recover",
>>> +			recovered, err);
>>>  	return err;
>>>  }
>>>  
>>>
>