From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.9 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E08F3C47096 for ; Thu, 3 Jun 2021 16:00:56 +0000 (UTC) Received: from lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A8F62610C8; Thu, 3 Jun 2021 16:00:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A8F62610C8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linux-f2fs-devel-bounces@lists.sourceforge.net Received: from [127.0.0.1] (helo=sfs-ml-1.v29.lw.sourceforge.com) by sfs-ml-1.v29.lw.sourceforge.com with esmtp (Exim 4.90_1) (envelope-from ) id 1lopmB-0006lc-B6; Thu, 03 Jun 2021 16:00:55 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-1.v29.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lopmA-0006lT-Qd for linux-f2fs-devel@lists.sourceforge.net; Thu, 03 Jun 2021 16:00:54 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=8wHvGKFx0SJwxuq5qlwRIh/zqvZuAXwAMRdelbTuPUs=; b=Z4Dfc1yvfH1nyg818GKm0Zh7+r n7Ohi8mGBortIuIhMr7qaNZ4/rO1y4wb01F+qkZB0jtju8cH6a2kQdSCHKqJ2j3nTEVh37Eq1DhdZ xaA8hyJDuADVPGPFfoaqu30QQuP+3Mhz1OT6nczwNkul5Oe3F/BqtTNYV5WmnH7q55lQ=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:MIME-Version:Date: Message-ID:From:References:Cc:To:Subject:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=8wHvGKFx0SJwxuq5qlwRIh/zqvZuAXwAMRdelbTuPUs=; b=fK7QjjVsGeWNvb+k+4KJBS8T2T WIO5HcBmr/eUPC9SaJHlHJlqOk3dhykSqbodJaDZhEuBUc6gtTXbjqfn0IZ/zEllEQ2Y4j3VnDR9D soygJZWVVzCdjUE8dhAeBgQ/R02ZSfEHaNOv3F+vTfLiv1hc+ByYOV9amKxzeM6GwjVM=; Received: from mail.kernel.org ([198.145.29.99]) by sfi-mx-2.v28.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.92.3) id 1loplp-00079k-J2 for linux-f2fs-devel@lists.sourceforge.net; Thu, 03 Jun 2021 16:00:54 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 36CCE613E4; Thu, 3 Jun 2021 16:00:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622736029; bh=M9GUJBcQqn8H5w/RTpySxCTtdT8isktpYnd50U1/Vmc=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=myqghbSx06FqpWxgcCThF9ESiJDrnltHdhLkxrkVPLCdKCjxuLDgZRXaiWbHFnoO5 /30vLT4QDqqgFgz3Cp7OfbyMffC4aMAIO+Q/9oBThvdqLDUdFwTVOgFhc6soToQBMZ 6hZdAXOxzLHHdUrLXO7L9bTw01YvNpap9Eqd3Nzxhg8XwcpUVYgd1AIZ78TVItfSm8 0Ptyrq30WuDHtB0caHU9fBXRhIu+IyMtGfNfA8TikMYU9zhc0xSqlIpc8TJ/0j6eJi Z7QQY6DhffX6kEzfl/qFQEfIvh9SJGyWmJ1V/Vxenv7t82q56bTvgYgnYGMo6sxvv9 sQGqQDGn/V01w== To: Chao Yu , jaegeuk@kernel.org References: <20210601101024.119356-1-yuchao0@huawei.com> From: Chao Yu Message-ID: <9b43a461-e348-f16c-31da-fb70e064d6f8@kernel.org> Date: Fri, 4 Jun 2021 00:00:26 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.2 MIME-Version: 1.0 In-Reply-To: <20210601101024.119356-1-yuchao0@huawei.com> Content-Language: en-US X-Headers-End: 1loplp-00079k-J2 Subject: Re: [f2fs-dev] [PATCH v2 RFC] f2fs: fix to force keeping write barrier for strict fsync mode X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net Jaegeuk, Any comments on this patch? On 2021/6/1 18:10, Chao Yu wrote: > [1] https://www.mail-archive.com/linux-f2fs-devel@lists.sourceforge.net/msg15126.html > > As [1] reported, if lower device doesn't support write barrier, in below > case: > > - write page #0; persist > - overwrite page #0 > - fsync > - write data page #0 OPU into device's cache > - write inode page into device's cache > - issue flush > > If SPO is triggered during flush command, inode page can be persisted > before data page #0, so that after recovery, inode page can be recovered > with new physical block address of data page #0, however there may > contains dummy data in new physical block address. > > Then what user will see is: after overwrite & fsync + SPO, old data in > file was corrupted, if any user do care about such case, we can suggest > user to use STRICT fsync mode, in this mode, we will force to trigger > preflush command to persist data in device cache in prior to node > writeback, it avoids potential data corruption during fsync(). > > Signed-off-by: Chao Yu > --- > v2: > - fix this by adding additional preflush command rather than using > atomic write flow. > fs/f2fs/file.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > index 7d5311d54f63..238ca2a733ac 100644 > --- a/fs/f2fs/file.c > +++ b/fs/f2fs/file.c > @@ -301,6 +301,20 @@ static int f2fs_do_sync_file(struct file *file, loff_t start, loff_t end, > f2fs_exist_written_data(sbi, ino, UPDATE_INO)) > goto flush_out; > goto out; > + } else { > + /* > + * for OPU case, during fsync(), node can be persisted before > + * data when lower device doesn't support write barrier, result > + * in data corruption after SPO. > + * So for strict fsync mode, force to trigger preflush to keep > + * data/node write order to avoid potential data corruption. > + */ > + if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_STRICT && > + !atomic) { > + ret = f2fs_issue_flush(sbi, inode->i_ino); > + if (ret) > + goto out; > + } > } > go_write: > /* > _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel