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Subject: Re: [PATCH v2] f2fs: add bug_on when f2fs_gc even fails to get one
 victim
To: <jaegeuk@kernel.org>, <chao@kernel.org>, <yuchao0@huawei.com>,
        <yunlong.song@icloud.com>
CC: <miaoxie@huawei.com>, <bintian.wang@huawei.com>,
        <linux-fsdevel@vger.kernel.org>,
        <linux-f2fs-devel@lists.sourceforge.net>,
        <linux-kernel@vger.kernel.org>
References: <1507729864-118702-1-git-send-email-yunlong.song@huawei.com>
 <1507901500-162168-1-git-send-email-yunlong.song@huawei.com>
From: Yunlong Song <yunlong.song@huawei.com>
Message-ID: <661b7977-5588-7917-5fde-edcd98090a07@huawei.com>
Date: Fri, 3 Nov 2017 11:28:11 +0800
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ping...

On 2017/10/13 21:31, Yunlong Song wrote:
> This can help us to debug on some corner case.
>
> Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
> Signed-off-by: Chao Yu <yuchao0@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..2b03202 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_fggc = false;
>   
>   	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_fggc = 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_fggc);
>   		ret = -ENODATA;
>   		goto stop;
>   	}

-- 
Thanks,
Yunlong Song