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 2C972C28B24 for ; Fri, 10 Sep 2021 00:41:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0FEAC611CC for ; Fri, 10 Sep 2021 00:41:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231444AbhIJAmR (ORCPT ); Thu, 9 Sep 2021 20:42:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:44080 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231132AbhIJARr (ORCPT ); Thu, 9 Sep 2021 20:17:47 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id ED51E611C7; Fri, 10 Sep 2021 00:16:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631232995; bh=NGJRrDCmuWGVT2PPXb6O+gDawF3o8qQtxaYhR2D6vSc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=S7uPaXp8dEo5AKYsX4ODLjhm4Zpb8dAXoolLgFdSv/0OziD+4sKyBGn0mDFKgNHXu i0oKkioh5/F15+HwTkUvHHeGA/09MjJpPcPB5QnXSu1Q3E5zHUx/BFIHWvFhZAhv5O qZTNlBkP2AZixlWZiyCfqkZyPJy2MfdHRwqWswHNNzuYUWEUBGxIua+pXtQAUhe1R0 sGsRAaQv/FNV12OPH6c5RWsPu7M1EIpRza6wmJmQ6pGkYhzlyaD4540hyDSIETn9yz KkE08zGF0lyZVfcI8YUWcWd/d9H53IeGCnQC07TruIfmZ3De/JSzCGSEwYo3O4miii Vmt7iTkXqq4Bw== 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 5.14 27/99] f2fs: fix to force keeping write barrier for strict fsync mode Date: Thu, 9 Sep 2021 20:14:46 -0400 Message-Id: <20210910001558.173296-27-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210910001558.173296-1-sashal@kernel.org> References: <20210910001558.173296-1-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 6afd4562335f..00b45876eaa1 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -301,6 +301,18 @@ 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