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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AFCEBEB64DA for ; Fri, 14 Jul 2023 04:29:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234820AbjGNE3o (ORCPT ); Fri, 14 Jul 2023 00:29:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36986 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232372AbjGNE3m (ORCPT ); Fri, 14 Jul 2023 00:29:42 -0400 Received: from out30-101.freemail.mail.aliyun.com (out30-101.freemail.mail.aliyun.com [115.124.30.101]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 67FE62736 for ; Thu, 13 Jul 2023 21:29:40 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R591e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046049;MF=hsiangkao@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0VnKDHcR_1689308975; Received: from 30.97.49.6(mailfrom:hsiangkao@linux.alibaba.com fp:SMTPD_---0VnKDHcR_1689308975) by smtp.aliyun-inc.com; Fri, 14 Jul 2023 12:29:36 +0800 Message-ID: <8a896983-ec76-d705-b4af-b34ffe529a81@linux.alibaba.com> Date: Fri, 14 Jul 2023 12:29:35 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH] erofs: deprecate superblock checksum feature To: Jingbo Xu , chao@kernel.org, huyue2@coolpad.com, linux-erofs@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org, pratikshinde320@gmail.com References: <20230714033832.111740-1-jefflexu@linux.alibaba.com> From: Gao Xiang In-Reply-To: <20230714033832.111740-1-jefflexu@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/7/14 11:38, Jingbo Xu wrote: > Later we're going to introduce fs-verity based verification for the > whole image. Make the superblock checksum feature deprecated. I'd suggest that "Later we're going to try the self-contained image verification. The current superblock checksum feature has quite limited functionality, instead, merkle trees can provide better protection for image integrity. Since the superblock checksum is a compatible feature, just deprecate now. " > > Signed-off-by: Jingbo Xu > --- > fs/erofs/Kconfig | 1 - > fs/erofs/super.c | 44 +++++--------------------------------------- > 2 files changed, 5 insertions(+), 40 deletions(-) > > diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig > index f259d92c9720..ebcb1f6a426a 100644 > --- a/fs/erofs/Kconfig > +++ b/fs/erofs/Kconfig > @@ -4,7 +4,6 @@ config EROFS_FS > tristate "EROFS filesystem support" > depends on BLOCK > select FS_IOMAP > - select LIBCRC32C > help > EROFS (Enhanced Read-Only File System) is a lightweight read-only > file system with modern designs (e.g. no buffer heads, inline > diff --git a/fs/erofs/super.c b/fs/erofs/super.c > index 9d6a3c6158bd..bb6a966ac4d4 100644 > --- a/fs/erofs/super.c > +++ b/fs/erofs/super.c > @@ -8,7 +8,6 @@ > #include > #include > #include > -#include > #include > #include > #include > @@ -51,33 +50,6 @@ void _erofs_info(struct super_block *sb, const char *function, > va_end(args); > } > > -static int erofs_superblock_csum_verify(struct super_block *sb, void *sbdata) > -{ > - size_t len = 1 << EROFS_SB(sb)->blkszbits; > - struct erofs_super_block *dsb; > - u32 expected_crc, crc; > - > - if (len > EROFS_SUPER_OFFSET) > - len -= EROFS_SUPER_OFFSET; > - > - dsb = kmemdup(sbdata + EROFS_SUPER_OFFSET, len, GFP_KERNEL); > - if (!dsb) > - return -ENOMEM; > - > - expected_crc = le32_to_cpu(dsb->checksum); > - dsb->checksum = 0; > - /* to allow for x86 boot sectors and other oddities. */ > - crc = crc32c(~0, dsb, len); > - kfree(dsb); > - > - if (crc != expected_crc) { > - erofs_err(sb, "invalid checksum 0x%08x, 0x%08x expected", > - crc, expected_crc); > - return -EBADMSG; > - } > - return 0; > -} > - > static void erofs_inode_init_once(void *ptr) > { > struct erofs_inode *vi = ptr; > @@ -113,15 +85,16 @@ static void erofs_free_inode(struct inode *inode) > static bool check_layout_compatibility(struct super_block *sb, > struct erofs_super_block *dsb) > { > - const unsigned int feature = le32_to_cpu(dsb->feature_incompat); > + struct erofs_sb_info *sbi = EROFS_SB(sb); > > - EROFS_SB(sb)->feature_incompat = feature; > + sbi->feature_compat = le32_to_cpu(dsb->feature_compat); > + sbi->feature_incompat = le32_to_cpu(dsb->feature_incompat); > > /* check if current kernel meets all mandatory requirements */ > - if (feature & (~EROFS_ALL_FEATURE_INCOMPAT)) { > + if (sbi->feature_incompat & (~EROFS_ALL_FEATURE_INCOMPAT)) { > erofs_err(sb, > "unidentified incompatible feature %x, please upgrade kernel version", > - feature & ~EROFS_ALL_FEATURE_INCOMPAT); > + sbi->feature_incompat & ~EROFS_ALL_FEATURE_INCOMPAT); > return false; > } > return true; > @@ -365,13 +338,6 @@ static int erofs_read_superblock(struct super_block *sb) > goto out; > } > > - sbi->feature_compat = le32_to_cpu(dsb->feature_compat); > - if (erofs_sb_has_sb_chksum(sbi)) { > - ret = erofs_superblock_csum_verify(sb, data); > - if (ret) > - goto out; > - } > - > ret = -EINVAL; > if (!check_layout_compatibility(sb, dsb)) > goto out;