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Message-ID: <b3d2acd5-8289-59fd-c7b4-9befecdc03f5@huaweicloud.com>
Date: Thu, 18 Jan 2024 12:22:31 +0800
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From: yangerkun <yangerkun@huaweicloud.com>
Subject: Re: [PATCH 1/2] ext4: remove unused buddy_loaded in
 ext4_mb_seq_groups_show
To: Jan Kara <jack@suse.cz>, yangerkun <yangerkun@huawei.com>
Cc: tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org
References: <20240117115223.80253-1-yangerkun@huawei.com>
 <20240117125647.4gyqfhngii2dxnlo@quack3>
In-Reply-To: <20240117125647.4gyqfhngii2dxnlo@quack3>
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在 2024/1/17 20:56, Jan Kara 写道:
> On Wed 17-01-24 19:52:22, yangerkun wrote:
>> We can just first call ext4_mb_unload_buddy, then copy information from
>> ext4_group_info. So remove this unused value.
>>
>> Signed-off-by: yangerkun <yangerkun@huawei.com>
> 
> Looks good. Feel free to add:
> 
> Reviewed-by: Jan Kara <jack@suse.cz>
> 
> Although I'd prefer if you add a comment before memcpy() like:
> 
> 	/*
> 	 * We care only about free space counters in the group info and
> 	 * these are safe to access even after the buddy has been unloaded
> 	 */
> 
> 								Honza
> 

Thanks a lot for your review! I will do it next version!

>> ---
>>   fs/ext4/mballoc.c | 9 ++-------
>>   1 file changed, 2 insertions(+), 7 deletions(-)
>>
>> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
>> index f44f668e407f..139f232bdbb5 100644
>> --- a/fs/ext4/mballoc.c
>> +++ b/fs/ext4/mballoc.c
>> @@ -2990,8 +2990,7 @@ static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
>>   {
>>   	struct super_block *sb = pde_data(file_inode(seq->file));
>>   	ext4_group_t group = (ext4_group_t) ((unsigned long) v);
>> -	int i;
>> -	int err, buddy_loaded = 0;
>> +	int i, err;
>>   	struct ext4_buddy e4b;
>>   	struct ext4_group_info *grinfo;
>>   	unsigned char blocksize_bits = min_t(unsigned char,
>> @@ -3021,14 +3020,10 @@ static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
>>   			seq_printf(seq, "#%-5u: I/O error\n", group);
>>   			return 0;
>>   		}
>> -		buddy_loaded = 1;
>> +		ext4_mb_unload_buddy(&e4b);
>>   	}
>>   
>>   	memcpy(&sg, grinfo, i);
>> -
>> -	if (buddy_loaded)
>> -		ext4_mb_unload_buddy(&e4b);
>> -
>>   	seq_printf(seq, "#%-5u: %-5u %-5u %-5u [", group, sg.info.bb_free,
>>   			sg.info.bb_fragments, sg.info.bb_first_free);
>>   	for (i = 0; i <= 13; i++)
>> -- 
>> 2.39.2
>>