From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757058AbdJMLIy (ORCPT ); Fri, 13 Oct 2017 07:08:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:54730 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751529AbdJMLIw (ORCPT ); Fri, 13 Oct 2017 07:08:52 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ACFDE21877 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=chao@kernel.org Subject: Re: [f2fs-dev] [PATCH] f2fs: update dirty status for CURSEG as well To: Yunlong Song , 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: <1507728318-113117-1-git-send-email-yunlong.song@huawei.com> From: Chao Yu Message-ID: <19ac8324-6743-34bf-a670-d20fec2cfd7f@kernel.org> Date: Fri, 13 Oct 2017 19:08:38 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <1507728318-113117-1-git-send-email-yunlong.song@huawei.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Yunlong, On 2017/10/11 21:25, Yunlong Song wrote: > Without this patch, it will cause all the free segments using up in some > corner case. For example, there are 100 segments, and 20 of them are > reserved for ovp. If 79 segments are full of data, segment 80 becomes > CURSEG segment, write 512 blocks and then delete 511 blocks. Since it is > CURSEG segment, the __locate_dirty_segment will not update its dirty > status. Then the dirty_segments(sbi) is 0, f2fs_gc will fail to > get_victim, and f2fs_balance_fs will fail to trigger gc action. After > f2fs_balance_fs returns, f2fs can continue to write data to segment 81. > Again, segment 81 becomes CURSEG segment, write 512 blocks and delete > 511 blocks, the dirty_segments(sbi) is 0 and f2fs_gc fail again. This > can finally use up all the free segments and cause panic. Should we also remove the check in locate_dirty_segment? Thanks, > > Signed-off-by: Yunlong Song > --- > fs/f2fs/segment.c | 4 ---- > 1 file changed, 4 deletions(-) > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index bfbcff8..0ff52d5 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -686,10 +686,6 @@ static void __locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno, > { > struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); > > - /* need not be added */ > - if (IS_CURSEG(sbi, segno)) > - return; > - > if (!test_and_set_bit(segno, dirty_i->dirty_segmap[dirty_type])) > dirty_i->nr_dirty[dirty_type]++; > >