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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 0F15DC433E1 for ; Fri, 19 Jun 2020 02:39:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EAB4420773 for ; Fri, 19 Jun 2020 02:39:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728527AbgFSCjn (ORCPT ); Thu, 18 Jun 2020 22:39:43 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:35730 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726906AbgFSCjn (ORCPT ); Thu, 18 Jun 2020 22:39:43 -0400 Received: from DGGEMS408-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 615274DC5B259B57828C; Fri, 19 Jun 2020 10:39:40 +0800 (CST) Received: from [10.134.22.195] (10.134.22.195) by smtp.huawei.com (10.3.19.208) with Microsoft SMTP Server (TLS) id 14.3.487.0; Fri, 19 Jun 2020 10:39:35 +0800 Subject: Re: [PATCH 3/4] f2fs: add inline encryption support To: Eric Biggers CC: Satya Tangirala , , , , References: <20200617075732.213198-1-satyat@google.com> <20200617075732.213198-4-satyat@google.com> <5e78e1be-f948-d54c-d28e-50f1f0a92ab3@huawei.com> <20200618181357.GC2957@sol.localdomain> From: Chao Yu Message-ID: Date: Fri, 19 Jun 2020 10:39:34 +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: <20200618181357.GC2957@sol.localdomain> 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-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Hi Eric, On 2020/6/19 2:13, Eric Biggers wrote: > Hi Chao, > > On Thu, Jun 18, 2020 at 06:06:02PM +0800, Chao Yu wrote: >>> @@ -936,8 +972,11 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio) >>> >>> inc_page_count(sbi, WB_DATA_TYPE(bio_page)); >>> >>> - if (io->bio && !io_is_mergeable(sbi, io->bio, io, fio, >>> - io->last_block_in_bio, fio->new_blkaddr)) >>> + if (io->bio && >>> + (!io_is_mergeable(sbi, io->bio, io, fio, io->last_block_in_bio, >>> + fio->new_blkaddr) || >>> + !f2fs_crypt_mergeable_bio(io->bio, fio->page->mapping->host, >>> + fio->page->index, fio))) >> >> bio_page->index, fio))) >> >>> __submit_merged_bio(io); >>> alloc_new: >>> if (io->bio == NULL) { >>> @@ -949,6 +988,8 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio) >>> goto skip; >>> } >>> io->bio = __bio_alloc(fio, BIO_MAX_PAGES); >>> + f2fs_set_bio_crypt_ctx(io->bio, fio->page->mapping->host, >>> + fio->page->index, fio, GFP_NOIO); >> >> bio_page->index, fio, GFP_NOIO); >> > > We're using ->mapping->host and ->index. Ordinarily that would mean the page > needs to be a pagecache page. But bio_page can also be a compressed page or a > bounce page containing fs-layer encrypted contents. I'm concerning about compression + inlinecrypt case. > > Is your suggestion to keep using fio->page->mapping->host (since encrypted pages Yup, > don't have a mapping), but start using bio_page->index (since f2fs apparently I meant that we need to use bio_page->index as tweak value in write path to keep consistent as we did in read path, otherwise we may read the wrong decrypted data later to incorrect tweak value. - f2fs_read_multi_pages (only comes from compression inode) - f2fs_alloc_dic - f2fs_set_compressed_page(page, cc->inode, start_idx + i + 1, dic); ^^^^^^^^^^^^^^^^^ - dic->cpages[i] = page; - for () struct page *page = dic->cpages[i]; if (!bio) - f2fs_grab_read_bio(..., page->index,..) - f2fs_set_bio_crypt_ctx(..., first_idx, ..) /* first_idx == cpage->index */ You can see that cpage->index was set to page->index + 1, that's why we need to use one of cpage->index/page->index as tweak value all the time rather than using both index mixed in read/write path. But note that for fs-layer encryption, we have used cpage->index as tweak value, so here I suggest we can keep consistent to use cpage->index in inlinecrypt case. > *does* set ->index for compressed pages, and if the file uses fs-layer > encryption then f2fs_set_bio_crypt_ctx() won't use the index anyway)? > > Does this mean the code is currently broken for compression + inline encryption > because it's using the wrong ->index? I think the answer is no, since I guess it's broken now for compression + inlinecrypt case. > f2fs_write_compressed_pages() will still pass the first 'nr_cpages' pagecache > pages along with the compressed pages. In that case, your suggestion would be a > cleanup rather than a fix? That's a fix. > > It would be helpful if there was an f2fs mount option to auto-enable compression > on all files (similar to how test_dummy_encryption auto-enables encryption on > all files) so that it could be tested more easily. Agreed. Previously I changed mkfs to allow to add compression flag to root inode for compression test. :P Thanks, > > - Eric > . >