From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yunlong Song Subject: [PATCH] f2fs: fix small discards when se->valid_blocks is zero Date: Tue, 3 Jan 2017 17:01:57 +0800 Message-ID: <1483434117-24427-1-git-send-email-yunlong.song@huawei.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Sender: linux-kernel-owner@vger.kernel.org To: jaegeuk@kernel.org, cm224.lee@samsung.com, yuchao0@huawei.com, chao@kernel.org, sylinux@163.com, yunlong.song@huawei.com Cc: bintian.wang@huawei.com, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org List-Id: linux-f2fs-devel.lists.sourceforge.net In the small discard case, when se->valid_blocks is zero, the add_discard_addrs will directly return without __add_discard_entry. This will cause the file delete have no small discard. The case is like this: 1. Allocate free 2M segment 2. Write a file (size n blocks < 512) in that 2M segment, se->valid_blocks = n 3. Delete that file, se->valid_blocks = 0, add_discard_addrs will return without sending any discard of that file, and forever due to cur_map[i] ^ ckpt_map[i] = 0 after that checkpoint Signed-off-by: Yunlong Song --- fs/f2fs/segment.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 0738f48..8610f14 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -838,7 +838,7 @@ static void add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc) return; if (!force) { - if (!test_opt(sbi, DISCARD) || !se->valid_blocks || + if (!test_opt(sbi, DISCARD) || SM_I(sbi)->nr_discards >= SM_I(sbi)->max_discards) return; } -- 1.8.5.2