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=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 930F9C433EF for ; Fri, 10 Sep 2021 01:00:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7980C611C1 for ; Fri, 10 Sep 2021 01:00:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234194AbhIJBB7 (ORCPT ); Thu, 9 Sep 2021 21:01:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:49216 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234629AbhIJAXw (ORCPT ); Thu, 9 Sep 2021 20:23:52 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 36CC460FC0; Fri, 10 Sep 2021 00:22:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631233362; bh=27KzxcIMQDz5sNuB8NXHcHd7FYuE/tmxcEtRirkwwAk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RuhQEvjElKIrI6xG+OYMNHFZerIGSrpvGCvnYVO/KT5S3Pc0DmEjWv/n+T4xRqgII ruIYFhoJ1J/xZcO/3JQXskcY8lpnEY9arXbiQaq4myoKvRB8Xy5S0aYOPHN6cdJjzo 5DsXTBq5HpqcQRpSJd+d/nE0grwvRypGBXSluxLM/b8EftBTE9UJI7l7cmLIhYP6B9 TTB897U8YUHBIXcxjM4OV63//QuAYhV62lLaerUBQ+L8uyAWJO9dMD7i30MmzKATxX Odkg5aAWm1rvC+uU8Re+kn/z2JHTYFoSz1s7MAecjKI6ia8eRXe8b5S2JhTWTaSvRA tdGuAvhIQoEEg== 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 4.19 06/25] f2fs: fix to force keeping write barrier for strict fsync mode Date: Thu, 9 Sep 2021 20:22:14 -0400 Message-Id: <20210910002234.176125-6-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210910002234.176125-1-sashal@kernel.org> References: <20210910002234.176125-1-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: linux-kernel@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 95330dfdbb1a..3b36ee3d915b 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -253,6 +253,18 @@ 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