From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757346AbdJMBKO (ORCPT ); Thu, 12 Oct 2017 21:10:14 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:7993 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754178AbdJMBKM (ORCPT ); Thu, 12 Oct 2017 21:10:12 -0400 Subject: Re: [PATCH] f2fs: add bug_on when f2fs_gc even fails to get one victim To: Jaegeuk Kim CC: , , , , , , , References: <1507729864-118702-1-git-send-email-yunlong.song@huawei.com> <20171012232308.GA19689@jaegeuk-macbookpro.roam.corp.google.com> From: Yunlong Song Message-ID: <702a755a-1af2-5ddb-9d2f-da5bf67c7705@huawei.com> Date: Fri, 13 Oct 2017 09:09:17 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20171012232308.GA19689@jaegeuk-macbookpro.roam.corp.google.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Originating-IP: [10.111.220.140] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020202.59E0125F.00B9,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2014-11-16 11:51:01, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: b839f88dca1eff5f1c3a460cee831051 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Jay, I think it should not happen when need_gc == true but total_freed ==0, so I add it as bug_on to let it panic at once. And even CHECK_FS is closed, this can also printk WARNING message for notice. On 2017/10/13 7:23, Jaegeuk Kim wrote: > Hi Yunlong, > > On 10/11, Yunlong Song wrote: >> This can help us to debug on some corner case. >> >> Signed-off-by: Yunlong Song >> --- >> 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; >> >> 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); > How about this, if this is for debugging purpose? > > if (!total_freed && need_gc) > f2fs_msg(...); > > It's not a good way to define a value for f2fs_bug_on(), since it is only > activated by CHECK_FS config. > > Thanks, > >> ret = -ENODATA; >> goto stop; >> } >> -- >> 1.8.5.2 > . > -- Thanks, Yunlong Song