From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753342AbdKIR7W (ORCPT ); Thu, 9 Nov 2017 12:59:22 -0500 Received: from mail.kernel.org ([198.145.29.99]:50488 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753125AbdKIR7T (ORCPT ); Thu, 9 Nov 2017 12:59:19 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E35BD218EB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=jaegeuk@kernel.org Date: Thu, 9 Nov 2017 09:59:15 -0800 From: Jaegeuk Kim To: Yunlong Song Cc: Chao Yu , chao@kernel.org, yunlong.song@icloud.com, miaoxie@huawei.com, bintian.wang@huawei.com, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] f2fs: add bug_on when f2fs_gc even fails to get one victim Message-ID: <20171109175915.GC55844@jaegeuk-macbookpro.roam.corp.google.com> References: <1507901500-162168-1-git-send-email-yunlong.song@huawei.com> <20171103034402.GC11335@jaegeuk-macbookpro.roam.corp.google.com> <3b26badb-c34e-3c2d-74a2-26ecef1f64ff@huawei.com> <20171107023835.GG88544@jaegeuk-macbookpro.roam.corp.google.com> <20171107024058.GH88544@jaegeuk-macbookpro.roam.corp.google.com> <20171107032636.GB92599@jaegeuk-macbookpro.roam.corp.google.com> <7433d584-b1e0-76e9-a6e4-8da1218dd71d@huawei.com> <19eec8fd-e941-770a-9477-6ad2d266d475@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <19eec8fd-e941-770a-9477-6ad2d266d475@huawei.com> User-Agent: Mutt/1.8.2 (2017-04-18) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/08, Yunlong Song wrote: > So we should use f2fs_bug_on(sbi, !total_freed && !sync && gc_type == > FG_GC); f2fs_bug_on(sbi, !total_freed && has_not_enough_free_secs(sbi, 0, 0)); ? > > On 2017/11/7 14:56, Chao Yu wrote: > > On 2017/11/7 12:01, Yunlong Song wrote: > > > Sorry, misunderstanding, because I think when sync == true, FG_GC does not > > > check has_not_enough_free_secs, so maybe it does not have to do any gc > > > at all. > > > For example, if there are 100 segments for f2fs, and 20 segments are full or > > > valid blocks over fggc_threshold, then it is correct to fail in get victim. > > > > > > > > > On 2017/11/7 11:26, Jaegeuk Kim wrote: > > > > On 11/07, Yunlong Song wrote: > > > > > Because I find that some out-of-free problem is caused by the failure > > > > > of get victim target. For example, chao has pointed out that he has > > > > > found out a bug when adding this bug_on last week. > > > > That's NOT what I asked. Why not checking FG_GC all the time like this? > > > > > > > > f2fs_bug_on(sbi, !total_freed && gc_type == FG_GC); > > ioctl(F2FS_IOC_GARBAGE_COLLECT, &1) will simply trigger this bug_on, so we > > have to check the conditon only when we run out-of-free-space? > > > > Thanks, > > > > > > > On 2017/11/7 10:40, Jaegeuk Kim wrote: > > > > > > On 11/06, Jaegeuk Kim wrote: > > > > > > > On 11/06, Yunlong Song wrote: > > > > > > > > Agree. > > > > > > > > > > > > > > > > On 2017/11/3 11:44, Jaegeuk Kim wrote: > > > > > > > > > On 10/13, Yunlong Song wrote: > > > > > > > > > > This can help us to debug on some corner case. > > > > > > > > > > > > > > > > > > > > Signed-off-by: Yunlong Song > > > > > > > > > > Signed-off-by: Chao Yu > > > > > > > > > > --- > > > > > > > > > > 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); > > > > > > > > > Just like this? > > > > > > > > That's OK. > > > > > > > I'm not quite sure whether this is really a bug_on case. > > > > > > > Let me make it WARN_ON() for debugging purpose first. > > > > > > BTW, why is this the special case where BG_GC detects FG_GC? > > > > > > > > > > > > > Thanks, > > > > > > > > > > > > > > > > f2fs_bug_on(sbi, !total_freed && !sync && gc_type == FG_GC); > > > > > > > > > > > > > > > > > > > ret = -ENODATA; > > > > > > > > > > goto stop; > > > > > > > > > > } > > > > > > > > > > -- > > > > > > > > > > 1.8.5.2 > > > > > > > > > . > > > > > > > > > > > > > > > > > -- > > > > > > > > Thanks, > > > > > > > > Yunlong Song > > > > > > > > > > > > > > . > > > > > > > > > > > -- > > > > > Thanks, > > > > > Yunlong Song > > > > > > > > > . > > > > > > > > . > > > > -- > Thanks, > Yunlong Song > From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaegeuk Kim Subject: Re: [PATCH v2] f2fs: add bug_on when f2fs_gc even fails to get one victim Date: Thu, 9 Nov 2017 09:59:15 -0800 Message-ID: <20171109175915.GC55844@jaegeuk-macbookpro.roam.corp.google.com> References: <1507901500-162168-1-git-send-email-yunlong.song@huawei.com> <20171103034402.GC11335@jaegeuk-macbookpro.roam.corp.google.com> <3b26badb-c34e-3c2d-74a2-26ecef1f64ff@huawei.com> <20171107023835.GG88544@jaegeuk-macbookpro.roam.corp.google.com> <20171107024058.GH88544@jaegeuk-macbookpro.roam.corp.google.com> <20171107032636.GB92599@jaegeuk-macbookpro.roam.corp.google.com> <7433d584-b1e0-76e9-a6e4-8da1218dd71d@huawei.com> <19eec8fd-e941-770a-9477-6ad2d266d475@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sfi-mx-4.v28.ch3.sourceforge.com ([172.29.28.194] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1eCr6q-0003Hd-Qb for linux-f2fs-devel@lists.sourceforge.net; Thu, 09 Nov 2017 17:59:24 +0000 Received: from mail.kernel.org ([198.145.29.99]) by sfi-mx-4.v28.ch3.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) id 1eCr6p-00066I-Lu for linux-f2fs-devel@lists.sourceforge.net; Thu, 09 Nov 2017 17:59:24 +0000 Content-Disposition: inline In-Reply-To: <19eec8fd-e941-770a-9477-6ad2d266d475@huawei.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: Yunlong Song Cc: yunlong.song@icloud.com, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, miaoxie@huawei.com On 11/08, Yunlong Song wrote: > So we should use f2fs_bug_on(sbi, !total_freed && !sync && gc_type == > FG_GC); f2fs_bug_on(sbi, !total_freed && has_not_enough_free_secs(sbi, 0, 0)); ? > > On 2017/11/7 14:56, Chao Yu wrote: > > On 2017/11/7 12:01, Yunlong Song wrote: > > > Sorry, misunderstanding, because I think when sync == true, FG_GC does not > > > check has_not_enough_free_secs, so maybe it does not have to do any gc > > > at all. > > > For example, if there are 100 segments for f2fs, and 20 segments are full or > > > valid blocks over fggc_threshold, then it is correct to fail in get victim. > > > > > > > > > On 2017/11/7 11:26, Jaegeuk Kim wrote: > > > > On 11/07, Yunlong Song wrote: > > > > > Because I find that some out-of-free problem is caused by the failure > > > > > of get victim target. For example, chao has pointed out that he has > > > > > found out a bug when adding this bug_on last week. > > > > That's NOT what I asked. Why not checking FG_GC all the time like this? > > > > > > > > f2fs_bug_on(sbi, !total_freed && gc_type == FG_GC); > > ioctl(F2FS_IOC_GARBAGE_COLLECT, &1) will simply trigger this bug_on, so we > > have to check the conditon only when we run out-of-free-space? > > > > Thanks, > > > > > > > On 2017/11/7 10:40, Jaegeuk Kim wrote: > > > > > > On 11/06, Jaegeuk Kim wrote: > > > > > > > On 11/06, Yunlong Song wrote: > > > > > > > > Agree. > > > > > > > > > > > > > > > > On 2017/11/3 11:44, Jaegeuk Kim wrote: > > > > > > > > > On 10/13, Yunlong Song wrote: > > > > > > > > > > This can help us to debug on some corner case. > > > > > > > > > > > > > > > > > > > > Signed-off-by: Yunlong Song > > > > > > > > > > Signed-off-by: Chao Yu > > > > > > > > > > --- > > > > > > > > > > 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); > > > > > > > > > Just like this? > > > > > > > > That's OK. > > > > > > > I'm not quite sure whether this is really a bug_on case. > > > > > > > Let me make it WARN_ON() for debugging purpose first. > > > > > > BTW, why is this the special case where BG_GC detects FG_GC? > > > > > > > > > > > > > Thanks, > > > > > > > > > > > > > > > > f2fs_bug_on(sbi, !total_freed && !sync && gc_type == FG_GC); > > > > > > > > > > > > > > > > > > > ret = -ENODATA; > > > > > > > > > > goto stop; > > > > > > > > > > } > > > > > > > > > > -- > > > > > > > > > > 1.8.5.2 > > > > > > > > > . > > > > > > > > > > > > > > > > > -- > > > > > > > > Thanks, > > > > > > > > Yunlong Song > > > > > > > > > > > > > > . > > > > > > > > > > > -- > > > > > Thanks, > > > > > Yunlong Song > > > > > > > > > . > > > > > > > > . > > > > -- > Thanks, > Yunlong Song > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot