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Subject: Re: [f2fs-dev] [PATCH] f2fs: add bug_on when f2fs_gc even fails to
 get one victim
To:     Chao Yu <chao@kernel.org>, <jaegeuk@kernel.org>,
        <yuchao0@huawei.com>, <yunlong.song@icloud.com>
CC:     <linux-fsdevel@vger.kernel.org>, <miaoxie@huawei.com>,
        <linux-kernel@vger.kernel.org>,
        <linux-f2fs-devel@lists.sourceforge.net>
References: <1507729864-118702-1-git-send-email-yunlong.song@huawei.com>
 <7a3f0052-86e0-4e46-c89b-048d6137b820@kernel.org>
From:   Yunlong Song <yunlong.song@huawei.com>
Message-ID: <ec42530e-ec96-65dd-64c3-9cc1e42d0ef7@huawei.com>
Date:   Fri, 13 Oct 2017 19:20:22 +0800
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Yep, both are OK, since I do not care it is foreground or background. 
Here it just needs to do gc.

On 2017/10/13 19:09, Chao Yu wrote:
> On 2017/10/11 21:51, Yunlong Song wrote:
>> This can help us to debug on some corner case.
>>
>> Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
>> ---
>>   fs/f2fs/gc.c | 6 +++++-
>>   1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
>> index 197ebf4..960503e 100644
>> --- a/fs/f2fs/gc.c
>> +++ b/fs/f2fs/gc.c
>> @@ -986,6 +986,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
>>   		.ilist = LIST_HEAD_INIT(gc_list.ilist),
>>   		.iroot = RADIX_TREE_INIT(GFP_NOFS),
>>   	};
>> +	bool need_gc = false;
> How about changing variable name to need_fggc for better readability?
>
> Thanks,
>
>>   
>>   	trace_f2fs_gc_begin(sbi->sb, sync, background,
>>   				get_pages(sbi, F2FS_DIRTY_NODES),
>> @@ -1018,8 +1019,10 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
>>   			if (ret)
>>   				goto stop;
>>   		}
>> -		if (has_not_enough_free_secs(sbi, 0, 0))
>> +		if (has_not_enough_free_secs(sbi, 0, 0)) {
>>   			gc_type = FG_GC;
>> +			need_gc = true;
>> +		}
>>   	}
>>   
>>   	/* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
>> @@ -1028,6 +1031,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
>>   		goto stop;
>>   	}
>>   	if (!__get_victim(sbi, &segno, gc_type)) {
>> +		f2fs_bug_on(sbi, !total_freed && need_gc);
>>   		ret = -ENODATA;
>>   		goto stop;
>>   	}
>>
> .
>

-- 
Thanks,
Yunlong Song


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