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 1B934C433FE for ; Wed, 19 Oct 2022 06:19:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230053AbiJSGTA (ORCPT ); Wed, 19 Oct 2022 02:19:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38540 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230094AbiJSGS7 (ORCPT ); Wed, 19 Oct 2022 02:18:59 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 52F68604B1 for ; Tue, 18 Oct 2022 23:18:59 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B02BD61775 for ; Wed, 19 Oct 2022 06:18:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AE66CC433C1; Wed, 19 Oct 2022 06:18:56 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="eEj3ILsA" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1666160335; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=5lgNruFtZc4EKeZifv/B1Sh7sE++KTxKWx6axbdbs9c=; b=eEj3ILsAwSrt6IrLPjuIVL/NWdn4sGrSHjvuJKsnEk9/EhTdzvdYKRlrKzPCwLHIA4BXrK wuiZZn5VxOzZ6+q2dsdZ8OKhy0jEA3k3RaN/MMhPoS8wsuPt07Rly4AmMV2wS30GZeRptB cowUjDOvEeFgtMTmB0VGl9vvQetfLBU= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id f995c9c5 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Wed, 19 Oct 2022 06:18:54 +0000 (UTC) Date: Wed, 19 Oct 2022 00:18:52 -0600 From: "Jason A. Donenfeld" To: Linus Torvalds Cc: Christoph Hellwig , Mike Snitzer , dm-devel@redhat.com, linux-block@vger.kernel.org, Alasdair G Kergon , Genjian Zhang , Jiangshan Yi , Jilin Yuan , Mikulas Patocka , Milan Broz , Nathan Huckleberry , Nikos Tsironis , Shaomin Deng Subject: Re: [git pull] device mapper changes for 6.1 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Tue, Oct 18, 2022 at 11:54:49AM -0700, Linus Torvalds wrote: > I think we have one major interface that is string-based (apart from > the obvious pathname ones and the strings passed to 'execve()'). > > It's 'mount()' (and now fsconfig() etc), and it's string-based mainly > because it has that nasty "arbitrary things that different filesystem > may need for configuration"). And it has some nasty logging model > associated with it too for output. > > But no, we absolutely do *not* want to emulate that particular horror > anywhere else. This might ruin your day, but FYI, Netlink [...did you already run off screaming at the mention of Netlink?...] Netlink has the whole "extack" extended acknowledgement mechanism, in which netlink replies can and do contain error strings. Grep the kernel for NL_SET_ERR_MSG and you'll see a bunch of these. (And as you suggested, I wouldn't be surprised if some bad userspaces parse them.) Jason 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 us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2D2F9C433FE for ; Thu, 20 Oct 2022 06:45:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1666248346; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:list-id:list-help: list-unsubscribe:list-subscribe:list-post; bh=AlqnRY6lBu5Wqh9BwJqfM+c4zP6zOOl1dvAVL+kCP0w=; b=DMjQcv4oFEwH3JAwQTWSM5F3RHUBp6D+1SUUTj5eh7SrSASp/bYYHRMcm19TYzxhcPYDGy ZxN7Ww2BlwW6BK3cYniM5BNJBt4BqjMuMX9o4n5/+GkA9bmHsR1lrHui/P/HELmiTz8IBV RNRBPPT+7haG654kFwoHvl9TNGXd0vA= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-505-7b7nAt0cOUK6oZiDGaczRg-1; Thu, 20 Oct 2022 02:45:42 -0400 X-MC-Unique: 7b7nAt0cOUK6oZiDGaczRg-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id CC589864763; Thu, 20 Oct 2022 06:45:40 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com [10.30.29.100]) by smtp.corp.redhat.com (Postfix) with ESMTP id 421C14021CA; Thu, 20 Oct 2022 06:45:39 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (localhost [IPv6:::1]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id 1C6961946595; Thu, 20 Oct 2022 06:45:39 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id C36571946595 for ; Wed, 19 Oct 2022 06:27:40 +0000 (UTC) Received: by smtp.corp.redhat.com (Postfix) id 23046202323C; Wed, 19 Oct 2022 06:27:40 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast10.extmail.prod.ext.rdu2.redhat.com [10.11.55.26]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1B2BD200C0EA for ; Wed, 19 Oct 2022 06:27:39 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-1.mimecast.com [205.139.110.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 3C83E1C0A59F for ; Wed, 19 Oct 2022 06:27:38 +0000 (UTC) Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-532-zJPfKCIMMvma0Nm_V2vPzA-1; Wed, 19 Oct 2022 02:27:36 -0400 X-MC-Unique: zJPfKCIMMvma0Nm_V2vPzA-1 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A7F95615FD; Wed, 19 Oct 2022 06:18:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AE66CC433C1; Wed, 19 Oct 2022 06:18:56 +0000 (UTC) Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id f995c9c5 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Wed, 19 Oct 2022 06:18:54 +0000 (UTC) Date: Wed, 19 Oct 2022 00:18:52 -0600 From: "Jason A. Donenfeld" To: Linus Torvalds Message-ID: References: MIME-Version: 1.0 In-Reply-To: X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 X-Mailman-Approved-At: Thu, 20 Oct 2022 06:45:37 +0000 Subject: Re: [dm-devel] [git pull] device mapper changes for 6.1 X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-block@vger.kernel.org, Jilin Yuan , Nikos Tsironis , Shaomin Deng , Mike Snitzer , Nathan Huckleberry , Christoph Hellwig , dm-devel@redhat.com, Mikulas Patocka , Genjian Zhang , Milan Broz , Alasdair G Kergon , Jiangshan Yi Errors-To: dm-devel-bounces@redhat.com Sender: "dm-devel" X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Tue, Oct 18, 2022 at 11:54:49AM -0700, Linus Torvalds wrote: > I think we have one major interface that is string-based (apart from > the obvious pathname ones and the strings passed to 'execve()'). > > It's 'mount()' (and now fsconfig() etc), and it's string-based mainly > because it has that nasty "arbitrary things that different filesystem > may need for configuration"). And it has some nasty logging model > associated with it too for output. > > But no, we absolutely do *not* want to emulate that particular horror > anywhere else. This might ruin your day, but FYI, Netlink [...did you already run off screaming at the mention of Netlink?...] Netlink has the whole "extack" extended acknowledgement mechanism, in which netlink replies can and do contain error strings. Grep the kernel for NL_SET_ERR_MSG and you'll see a bunch of these. (And as you suggested, I wouldn't be surprised if some bad userspaces parse them.) Jason -- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel