From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751969AbdJaDBC (ORCPT ); Mon, 30 Oct 2017 23:01:02 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:36971 "EHLO huawei.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751399AbdJaDBB (ORCPT ); Mon, 30 Oct 2017 23:01:01 -0400 Subject: Re: [PATCH v2] f2fs: collect prefree segments to avoild write checkpoint fail To: Yunlong Song , , , CC: , , , , References: <1503748019-152845-1-git-send-email-yunlong.song@huawei.com> <1504267219-76575-1-git-send-email-yunlong.song@huawei.com> <6e9b8697-3340-6057-57e2-b98550e310a9@huawei.com> From: Chao Yu Message-ID: <367077e1-c83e-0685-757a-230cdb3ef74e@huawei.com> Date: Tue, 31 Oct 2017 10:56:00 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.134.22.195] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2017/10/31 10:05, Yunlong Song wrote: > So I use CHECK_FS config to control it. When CHECK_FS is off, all the > other f2fs_bug_on also > only printk WARNING info rather than trigger BUG_ON. If this runing out-of-free-segments issue explicitly happens, IMO, its better to face and fix it. BTW, it's better to add bug_on here to detect the issue? Thanks, > > On 2017/10/31 9:59, Chao Yu wrote: >> On 2017/10/31 9:33, Yunlong Song wrote: >>> ping... >>> >>> On 2017/9/1 20:00, Yunlong Song wrote: >>>> In come corner case, the reserved segments are used to do gc, and there are >>>> not enough free segments for write checkpoint to finish its job, then the >>>> gc process will fail to change the prefree segments to free segments. >> I agreed to use this in production for robustness, but for upstream, it's better >> to investigate and fix this issue rather than covering up it. >> >> Thanks, >> >>>> Signed-off-by: Yunlong Song >>>> --- >>>> fs/f2fs/gc.c | 10 ++++++++++ >>>> 1 file changed, 10 insertions(+) >>>> >>>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c >>>> index cd147e7..6552b04 100644 >>>> --- a/fs/f2fs/gc.c >>>> +++ b/fs/f2fs/gc.c >>>> @@ -1056,6 +1056,16 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, >>>> if (!sync) { >>>> if (has_not_enough_free_secs(sbi, sec_freed, 0)) { >>>> segno = NULL_SEGNO; >>>> +#ifndef CONFIG_F2FS_CHECK_FS >>>> + if (prefree_segments(sbi) && >>>> + has_not_enough_free_secs(sbi, >>>> + reserved_sections(sbi), 0)) { >>>> + ret = write_checkpoint(sbi, &cpc); >>>> + if (ret) >>>> + goto stop; >>>> + sec_freed = 0; >>>> + } >>>> +#endif >>>> goto gc_more; >>>> } >>>> >> >> . >> >