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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 7A381C4167D for ; Fri, 10 Sep 2021 00:45:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 62BB961108 for ; Fri, 10 Sep 2021 00:45:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242439AbhIJAq6 (ORCPT ); Thu, 9 Sep 2021 20:46:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:48636 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229990AbhIJAXF (ORCPT ); Thu, 9 Sep 2021 20:23:05 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2DB2060F24; Fri, 10 Sep 2021 00:21:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631233315; bh=HUjSc51v8Q/VSajJJxCN9AZhLPCBhX+xYJx2+V+j7iY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TdD1sa2zsKvLwLZoVw7ODh+WTY6NT0yD+DmTeCYGGviwJQ8kcvWlaRuSCcGuHJFNt gzSwk3TqH3zNkuLAnk4Uq6RrtyGzmNT7gmRmi8QtBFZq01c1QRRytbG8wNWDkDiCgV 6fi1AwQVMlykRcT354s0KOp482jZNdZSQ8EyY8pn865284fnr1Cd77YWcE92OwfriU NxP+t7AX7hThizwQ10Ags0vnqBUGi1KdCMVx1BXNnOK88bdq7X5/g84RjkZMiD5ERh Zyl6NPRRzSJtEjWy+LUOPhSrsJw1pAFM//nzE37T1JGW1ourXowq9gYZf3duuiaCFt V083GuYvRw4Ew== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Chao Yu , Jaegeuk Kim , Sasha Levin , linux-f2fs-devel@lists.sourceforge.net Subject: [PATCH AUTOSEL 5.4 09/37] f2fs: fix to force keeping write barrier for strict fsync mode Date: Thu, 9 Sep 2021 20:21:14 -0400 Message-Id: <20210910002143.175731-9-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210910002143.175731-1-sashal@kernel.org> References: <20210910002143.175731-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Chao Yu [ Upstream commit 2787991516468bfafafb9bf2b45a848e6b202e7c ] [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 use atomic write sematics to keep write order in between data/node and last node, so that it avoids potential data corruption during fsync(). Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin --- fs/f2fs/file.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 6e58b2e62b18..4fc0e62a5ef3 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -259,6 +259,18 @@ 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 use atomic write sematics + * to keep write order in between data/node and last node to + * avoid potential data corruption. + */ + if (F2FS_OPTION(sbi).fsync_mode == + FSYNC_MODE_STRICT && !atomic) + atomic = true; } go_write: /* -- 2.30.2