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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 F0300C433F5 for ; Thu, 30 Aug 2018 02:20:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9DF9620644 for ; Thu, 30 Aug 2018 02:20:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9DF9620644 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727339AbeH3GUF (ORCPT ); Thu, 30 Aug 2018 02:20:05 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:11206 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727178AbeH3GUE (ORCPT ); Thu, 30 Aug 2018 02:20:04 -0400 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id C949956943FFB; Thu, 30 Aug 2018 10:20:14 +0800 (CST) Received: from [127.0.0.1] (10.134.22.195) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.399.0; Thu, 30 Aug 2018 10:20:12 +0800 Subject: Re: [PATCH v2] f2fs: avoid wrong decrypted data from disk To: Jaegeuk Kim , , References: <20180827225226.14272-1-jaegeuk@kernel.org> <20180830014858.GA91444@jaegeuk-macbookpro.roam.corp.google.com> From: Chao Yu Message-ID: Date: Thu, 30 Aug 2018 10:20:12 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180830014858.GA91444@jaegeuk-macbookpro.roam.corp.google.com> Content-Type: text/plain; charset="windows-1252" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.134.22.195] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018/8/30 9:48, Jaegeuk Kim wrote: > 1. Create a file in an encrypted directory > 2. Do GC & drop caches > 3. Read stale data before its bio for metapage was not issued yet > > Signed-off-by: Jaegeuk Kim > --- > Change log from v1: > - move to bio != NULL > > fs/f2fs/data.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index 382c1ef9a9e4..159e411785e9 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -1556,6 +1556,12 @@ static int f2fs_mpage_readpages(struct address_space *mapping, > bio = NULL; > goto set_error_page; > } > + } else if (unlikely(f2fs_encrypted_file(inode))) { For android scenario, encryption becomes a common case now, so I think we can remove unlikely here. > + /* > + * If the page is under writeback, we need to wait for > + * its completion to see the correct decrypted data. > + */ > + f2fs_wait_on_block_writeback(F2FS_I_SB(inode), block_nr); > } Look at this again, it seems f2fs_wait_on_block_writeback() is not related to f2fs_grab_read_bio(), so we can move it here to make code logic more clear: if (f2fs_encrypted_file(inode)) { /* */ f2fs_wait_on_block_writeback(F2FS_I_SB(inode), block_nr); } Also, in f2fs_submit_page_read(), we need to adjust to: - f2fs_grab_read_bio() - f2fs_wait_on_block_writeback() - bio_add_page() How do you think? Thanks, > > if (bio_add_page(bio, page, blocksize, 0) < blocksize) >