From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chao Yu Subject: [PATCH 5/5] f2fs: fix to search whole dirty segmap when get_victim Date: Mon, 15 Sep 2014 18:05:44 +0800 Message-ID: <003101cfd0cc$c0335890$409a09b0$@samsung.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 1XTTBM-0005BB-OB for linux-f2fs-devel@lists.sourceforge.net; Mon, 15 Sep 2014 10:06:52 +0000 Received: from mailout2.samsung.com ([203.254.224.25]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-MD5:128) (Exim 4.76) id 1XTTBL-0006Yp-9m for linux-f2fs-devel@lists.sourceforge.net; Mon, 15 Sep 2014 10:06:52 +0000 Received: from epcpsbgm1.samsung.com (epcpsbgm1 [203.254.230.26]) by mailout2.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NBX00F4QTF8WN00@mailout2.samsung.com> for linux-f2fs-devel@lists.sourceforge.net; Mon, 15 Sep 2014 19:06:44 +0900 (KST) Content-language: zh-cn List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: Jaegeuk Kim , Changman Lee Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net In ->get_victim we get max_search value from dirty_i->nr_dirty without protection of seglist_lock, after that, nr_dirty can be increased/decreased before we hold seglist_lock lock. Then in main loop we attempt to traverse all dirty section one time to find victim section, but it's not accurate to use max_search as the total loop count, because we might lose checking several sections or check sections redundantly for the case of nr_dirty are increased or decreased previously. Signed-off-by: Chao Yu --- fs/f2fs/gc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index 075ea1e..4481edc 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -263,14 +263,14 @@ static int get_victim_by_default(struct f2fs_sb_info *sbi, unsigned int secno, max_cost; int nsearched = 0; + mutex_lock(&dirty_i->seglist_lock); + p.alloc_mode = alloc_mode; select_policy(sbi, gc_type, type, &p); p.min_segno = NULL_SEGNO; p.min_cost = max_cost = get_max_cost(sbi, &p); - mutex_lock(&dirty_i->seglist_lock); - if (p.alloc_mode == LFS && gc_type == FG_GC) { p.min_segno = check_bg_victims(sbi); if (p.min_segno != NULL_SEGNO) -- 2.0.1.474.g72c7794 ------------------------------------------------------------------------------ Want excitement? Manually upgrade your production database. When you want reliability, choose Perforce Perforce version control. Predictably reliable. http://pubads.g.doubleclick.net/gampad/clk?id=157508191&iu=/4140/ostg.clktrk