From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaegeuk Kim Subject: Re: [PATCH v3] f2fs: fix a missing discard prefree segments Date: Wed, 21 Dec 2016 18:21:22 -0800 Message-ID: <20161222022122.GA33509@jaegeuk.local> References: <20161221092716.18049-1-heyunlei@huawei.com> <20161221180431.GB1361@jaegeuk.local> <69ab3186-0d74-624b-0d4c-2b10a187c230@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1cJt0g-0007Xq-OY for linux-f2fs-devel@lists.sourceforge.net; Thu, 22 Dec 2016 02:21:34 +0000 Received: from mail.kernel.org ([198.145.29.136]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1cJt0c-00055K-VE for linux-f2fs-devel@lists.sourceforge.net; Thu, 22 Dec 2016 02:21:34 +0000 Content-Disposition: inline In-Reply-To: <69ab3186-0d74-624b-0d4c-2b10a187c230@huawei.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: heyunlei Cc: heyunlei@huwei.com, linux-f2fs-devel@lists.sourceforge.net On 12/22, heyunlei wrote: > Hi Jaegeuk, > > On 2016/12/22 2:04, Jaegeuk Kim wrote: > > On 12/21, Yunlei He wrote: > > > If userspace issue a fstrim with a range not involve prefree segments, > > > it will reuse these segments without discard. This patch fix it. > > > > > > Signed-off-by: Yunlei He > > > --- > > > fs/f2fs/segment.c | 9 +++++++-- > > > 1 file changed, 7 insertions(+), 2 deletions(-) > > > > > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > > > index 0738f48..e0fff28 100644 > > > --- a/fs/f2fs/segment.c > > > +++ b/fs/f2fs/segment.c > > > @@ -916,9 +916,13 @@ void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc) > > > > > > dirty_i->nr_dirty[PRE] -= end - start; > > > > > > - if (force || !test_opt(sbi, DISCARD)) > > > + if (!test_opt(sbi, DISCARD)) > > > continue; > > > > > > + if (force && start >= cpc->trim_start && > > > + (end -1) <= cpc->trim_end) > > > + continue; > > > + > > > if (!test_opt(sbi, LFS) || sbi->segs_per_sec == 1) { > > > f2fs_issue_discard(sbi, START_BLOCK(sbi, start), > > > (end - start) << sbi->log_blocks_per_seg); > > > @@ -2263,7 +2267,8 @@ void flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc) > > > f2fs_bug_on(sbi, sit_i->dirty_sentries); > > > out: > > > if (cpc->reason == CP_DISCARD) { > > > - for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++) > > > + __u64 trim_start = cpc->trim_start; > > > + for (; trim_start <= cpc->trim_end; trim_start++) > > > > BTW, why do we need this? > > The below add_discard_addrs() will use cpc->trim_start. > > Here, we need to reserve the original value of cpc->trim_start, because > we will use it as a boundary judgement for skipping prefree segments > discard. How about this: Looks good to me. :) Could you send v4? Thanks, > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index 0738f48..30cd445 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -916,9 +916,13 @@ void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc) > > dirty_i->nr_dirty[PRE] -= end - start; > > - if (force || !test_opt(sbi, DISCARD)) > + if (!test_opt(sbi, DISCARD)) > continue; > > + if (force && start >= cpc->trim_start && > + (end -1) <= cpc->trim_end) > + continue; > + > if (!test_opt(sbi, LFS) || sbi->segs_per_sec == 1) { > f2fs_issue_discard(sbi, START_BLOCK(sbi, start), > (end - start) << sbi->log_blocks_per_seg); > @@ -2263,8 +2267,11 @@ void flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc) > f2fs_bug_on(sbi, sit_i->dirty_sentries); > out: > if (cpc->reason == CP_DISCARD) { > + __u64 trim_start = cpc->trim_start; > for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++) > add_discard_addrs(sbi, cpc); > + > + cpc->trim_start = trim_start; > } > mutex_unlock(&sit_i->sentry_lock); > > Thanks, > > > > > Thanks, > > > > > add_discard_addrs(sbi, cpc); > > > } > > > mutex_unlock(&sit_i->sentry_lock); > > > -- > > > 2.10.1 > > > > > > > > > ------------------------------------------------------------------------------ > > > Developer Access Program for Intel Xeon Phi Processors > > > Access to Intel Xeon Phi processor-based developer platforms. > > > With one year of Intel Parallel Studio XE. > > > Training and support from Colfax. > > > Order your platform today.http://sdm.link/intel > > > _______________________________________________ > > > Linux-f2fs-devel mailing list > > > Linux-f2fs-devel@lists.sourceforge.net > > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel > > > > . > > ------------------------------------------------------------------------------ Developer Access Program for Intel Xeon Phi Processors Access to Intel Xeon Phi processor-based developer platforms. With one year of Intel Parallel Studio XE. Training and support from Colfax. Order your platform today.http://sdm.link/intel