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=-7.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_AGENT_MUTT 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 03C79C04AB3 for ; Mon, 27 May 2019 17:19:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CD5D920883 for ; Mon, 27 May 2019 17:19:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726670AbfE0RTB (ORCPT ); Mon, 27 May 2019 13:19:01 -0400 Received: from mx2.suse.de ([195.135.220.15]:38272 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726517AbfE0RTA (ORCPT ); Mon, 27 May 2019 13:19:00 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id CAFD1AED4; Mon, 27 May 2019 17:18:59 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id 0E3B7DA85E; Mon, 27 May 2019 19:19:54 +0200 (CEST) Date: Mon, 27 May 2019 19:19:54 +0200 From: David Sterba To: Johannes Thumshirn Cc: David Sterba , Linux BTRFS Mailinglist , Chris Mason , Richard Weinberger , David Gstir , Nikolay Borisov Subject: Re: [PATCH v3 00/13] Add support for other checksums Message-ID: <20190527171954.GP15290@twin.jikos.cz> Reply-To: dsterba@suse.cz Mail-Followup-To: dsterba@suse.cz, Johannes Thumshirn , David Sterba , Linux BTRFS Mailinglist , Chris Mason , Richard Weinberger , David Gstir , Nikolay Borisov References: <20190522081910.7689-1-jthumshirn@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190522081910.7689-1-jthumshirn@suse.de> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Wed, May 22, 2019 at 10:18:57AM +0200, Johannes Thumshirn wrote: > This patchset add support for adding new checksum types in BTRFS. > > Currently BTRFS only supports CRC32C as data and metadata checksum, which is > good if you only want to detect errors due to data corruption in hardware. > > But CRC32C isn't able cover other use-cases like de-duplication or > cryptographically save data integrity guarantees. > > The following properties made SHA-256 interesting for these use-cases: > - Still considered cryptographically sound > - Reasonably well understood by the security industry > - Result fits into the 32Byte/256Bit we have for the checksum in the on-disk > format > - Small enough collision space to make it feasible for data de-duplication > - Fast enough to calculate and offloadable to crypto hardware via the kernel's > crypto_shash framework. > > The patchset also provides mechanisms for plumbing in different hash > algorithms relatively easy. > > Unfortunately this patchset also partially reverts commit: > 9678c54388b6 ("btrfs: Remove custom crc32c init code") > > This is an intermediate submission, as a) mkfs.btrfs support is still missing > and b) David requested to have three hash algorithms, where 1 is crc32c, one > cryptographically secure and one in between. > > A changelog can be found directly in the patches. The branch is also available > on a gitweb at > https://git.kernel.org/pub/scm/linux/kernel/git/jth/linux.git/log/?h=btrfs-csum-rework.v3 > > Johannes Thumshirn (13): > btrfs: use btrfs_csum_data() instead of directly calling crc32c > btrfs: resurrect btrfs_crc32c() > btrfs: use btrfs_crc32c{,_final}() in for free space cache > btrfs: don't assume ordered sums to be 4 bytes > btrfs: dont assume compressed_bio sums to be 4 bytes > btrfs: format checksums according to type for printing > btrfs: add common checksum type validation > btrfs: check for supported superblock checksum type before checksum > validation > btrfs: Simplify btrfs_check_super_csum() and get rid of size > assumptions > btrfs: add boilerplate code for directly including the crypto > framework > btrfs: directly call into crypto framework for checsumming > btrfs: remove assumption about csum type form > btrfs_print_data_csum_error() > btrfs: add sha256 as another checksum algorithm 1-5 are reviewed and ok, 6 and 13 should be reworked, 7-12 is ok. I can't put the branch to next yet due to the csum formatting "issues" but will do once you resend. Should be ok just 6 and 13 as they're independent.