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=-0.7 required=3.0 tests=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,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 E44AFC43441 for ; Wed, 28 Nov 2018 13:50:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD1AF20832 for ; Wed, 28 Nov 2018 13:50:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AD1AF20832 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=gmx.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-btrfs-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728215AbeK2AwD (ORCPT ); Wed, 28 Nov 2018 19:52:03 -0500 Received: from mout.gmx.net ([212.227.17.20]:35607 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727982AbeK2AwD (ORCPT ); Wed, 28 Nov 2018 19:52:03 -0500 Received: from [0.0.0.0] ([210.140.77.29]) by mail.gmx.com (mrgmx102 [212.227.17.174]) with ESMTPSA (Nemesis) id 0MPZuP-1gNrMK2WZd-004mdp; Wed, 28 Nov 2018 14:50:15 +0100 Subject: Re: [PATCH 0/9] Switch defines to enums To: dsterba@suse.cz, David Sterba , linux-btrfs@vger.kernel.org References: <45dcab9e-fb88-8980-90d9-1875ea1ee992@gmx.com> <20181128132549.GM2842@twin.jikos.cz> From: Qu Wenruo Openpgp: preference=signencrypt Autocrypt: addr=quwenruo.btrfs@gmx.com; prefer-encrypt=mutual; keydata= xsBNBFnVga8BCACyhFP3ExcTIuB73jDIBA/vSoYcTyysFQzPvez64TUSCv1SgXEByR7fju3o 8RfaWuHCnkkea5luuTZMqfgTXrun2dqNVYDNOV6RIVrc4YuG20yhC1epnV55fJCThqij0MRL 1NxPKXIlEdHvN0Kov3CtWA+R1iNN0RCeVun7rmOrrjBK573aWC5sgP7YsBOLK79H3tmUtz6b 9Imuj0ZyEsa76Xg9PX9Hn2myKj1hfWGS+5og9Va4hrwQC8ipjXik6NKR5GDV+hOZkktU81G5 gkQtGB9jOAYRs86QG/b7PtIlbd3+pppT0gaS+wvwMs8cuNG+Pu6KO1oC4jgdseFLu7NpABEB AAHNIlF1IFdlbnJ1byA8cXV3ZW5ydW8uYnRyZnNAZ214LmNvbT7CwJQEEwEIAD4CGwMFCwkI BwIGFQgJCgsCBBYCAwECHgECF4AWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCWdWCnQUJCWYC bgAKCRDCPZHzoSX+qAR8B/94VAsSNygx1C6dhb1u1Wp1Jr/lfO7QIOK/nf1PF0VpYjTQ2au8 ihf/RApTna31sVjBx3jzlmpy+lDoPdXwbI3Czx1PwDbdhAAjdRbvBmwM6cUWyqD+zjVm4RTG rFTPi3E7828YJ71Vpda2qghOYdnC45xCcjmHh8FwReLzsV2A6FtXsvd87bq6Iw2axOHVUax2 FGSbardMsHrya1dC2jF2R6n0uxaIc1bWGweYsq0LXvLcvjWH+zDgzYCUB0cfb+6Ib/ipSCYp 3i8BevMsTs62MOBmKz7til6Zdz0kkqDdSNOq8LgWGLOwUTqBh71+lqN2XBpTDu1eLZaNbxSI ilaVzsBNBFnVga8BCACqU+th4Esy/c8BnvliFAjAfpzhI1wH76FD1MJPmAhA3DnX5JDORcga CbPEwhLj1xlwTgpeT+QfDmGJ5B5BlrrQFZVE1fChEjiJvyiSAO4yQPkrPVYTI7Xj34FnscPj /IrRUUka68MlHxPtFnAHr25VIuOS41lmYKYNwPNLRz9Ik6DmeTG3WJO2BQRNvXA0pXrJH1fN GSsRb+pKEKHKtL1803x71zQxCwLh+zLP1iXHVM5j8gX9zqupigQR/Cel2XPS44zWcDW8r7B0 q1eW4Jrv0x19p4P923voqn+joIAostyNTUjCeSrUdKth9jcdlam9X2DziA/DHDFfS5eq4fEv ABEBAAHCwHwEGAEIACYWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCWdWBrwIbDAUJA8JnAAAK CRDCPZHzoSX+qA3xB/4zS8zYh3Cbm3FllKz7+RKBw/ETBibFSKedQkbJzRlZhBc+XRwF61mi f0SXSdqKMbM1a98fEg8H5kV6GTo62BzvynVrf/FyT+zWbIVEuuZttMk2gWLIvbmWNyrQnzPl mnjK4AEvZGIt1pk+3+N/CMEfAZH5Aqnp0PaoytRZ/1vtMXNgMxlfNnb96giC3KMR6U0E+siA 4V7biIoyNoaN33t8m5FwEwd2FQDG9dAXWhG13zcm9gnk63BN3wyCQR+X5+jsfBaS4dvNzvQv h8Uq/YGjCoV1ofKYh3WKMY8avjq25nlrhzD/Nto9jHp8niwr21K//pXVA81R2qaXqGbql+zo Message-ID: <03fc4e39-205c-9bac-33f0-cc3fb19ede6e@gmx.com> Date: Wed, 28 Nov 2018 21:50:06 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.1 MIME-Version: 1.0 In-Reply-To: <20181128132549.GM2842@twin.jikos.cz> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="wonZRvP8wpInTlmhV9dRZYmV7P5tvBC0V" X-Provags-ID: V03:K1:pbYjGsJKLfG8xpGur7N5+W9V0WEoz3vaJY0u0r+pTENgAPhlJVr DatvCr7nRbhgrA6yf9pS0QRSWcGH/mqX11jopaU1BlS8wmUIWmO5xG+mXTN86lQh+qhq/Gx 9cYI2iuhZHudgjzjYJsxPXoIP5vTJVXtCS9WZy8fUSo7lXICPaDfZbs770dcSZTqJR5y0F/ Wgt19VWTa/lZtcF6CIc4A== X-UI-Out-Filterresults: notjunk:1;V03:K0:LAEGcFQqpKA=:vJkEK0mjMD0rdPhF0cYPKE oQg6Tu8Illn4kImEBQ2NDus/QrHSxUPAM+PfxNNG5B+gYGqW0LwlajaTHVL3pbAEyLtjxtq+f b/d+AjKevV4zTd2xFIVMfoAd04X2lOLw86DIj5ql5HFu/FTYH5ORXYOabw2zk0PZbBNPcnMB0 gRVI/fkipR+sgbF42rGPGfrmP0L2udyqdHsfpbCip/UfgxiROrMcjIrxuYR1ZkqmjhUdD0Pfr pGRbWjUmw9/aN7OEVEzSs0ZNrOcu5a1ulFjjjIfaeRmSXYwr4JwVZ4uxYWhz3PvcM2evZc9BU Px5u+cthbi9Ri37Su1VR1w20TEqPOU4V/hQQVRxcVu4xKfv9ewj3z/GV68Q+9nQRzfVb6qQHZ Y58hmZZCQF6Tn3/3C/CvW1Q8HuxZIv3qzBYHiex5zltgBfBrnnXYvWhOOBMZYZ75CCA83tLD5 3iZ3Q0P0tTVTd+dU11d9s1KeuulPorDd19f79FK1F+8LhSOvTP50MxR29aZcYpQJowZZ371xu nIY1hts+TBC7jYbX4Ldl715bDCtSMHv5K4bzuSKHhujG6jL1ESdzs/6rOEO2lVitTgpSKAyy+ 5m5+mGHGt4fRwNtTtseFBSdmKmYVPxehMezJa+/nM5CwpFFHI3jUQ8GjCwTqubtcNYsR4uOAa VCXhYrlw2oGONmVj/BRgg8ojPMV8X6rM5jrNfBK8joisBFCFh1Jlkbu7plrv1BDy6ESH1kmnY PIxFrkB7n6i+WsNfm9/kQQaTLyjc2s4xNJt9BHty3ZGjshg/YnaS3XfUcGxzOfDM3F609l9ZO GBLWiHIHkYjBy06IiVlLM+iZiNwCp6+fnVBmKgOsnmH9nRlPOdYYq821ZVGwbKxVjQjRCuMJk s0Tm8s1DkpW1nb2R/cJsXfd3CoV3bBKpDvErSWYnsQ9Aiojak9yHjeFh56v8Pc Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --wonZRvP8wpInTlmhV9dRZYmV7P5tvBC0V Content-Type: multipart/mixed; boundary="iwWAiKL4VyBN51eJtPTNswMdKzk6L6tWc"; protected-headers="v1" From: Qu Wenruo To: dsterba@suse.cz, David Sterba , linux-btrfs@vger.kernel.org Message-ID: <03fc4e39-205c-9bac-33f0-cc3fb19ede6e@gmx.com> Subject: Re: [PATCH 0/9] Switch defines to enums References: <45dcab9e-fb88-8980-90d9-1875ea1ee992@gmx.com> <20181128132549.GM2842@twin.jikos.cz> In-Reply-To: <20181128132549.GM2842@twin.jikos.cz> --iwWAiKL4VyBN51eJtPTNswMdKzk6L6tWc Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 2018/11/28 =E4=B8=8B=E5=8D=889:25, David Sterba wrote: > On Wed, Nov 28, 2018 at 09:33:50AM +0800, Qu Wenruo wrote: >> On 2018/11/28 =E4=B8=8A=E5=8D=883:53, David Sterba wrote: >>> This is motivated by a merging mistake that happened a few releases a= go. >>> Two patches updated BTRFS_FS_* flags independently to the same value,= >>> git did not see any direct merge conflict. The two values got mixed a= t >>> runtime and caused crash. >>> >>> Update all #define sequential values, the above merging problem would= >>> not happen as there would be a conflict and the enum value >>> auto-increment would prevent duplicated values anyway. >> >> Just one small question for the bitmap usage. >> >> For enum we won't directly know the last number is, my concern is if >> we're using u16 as bitmap and there is some enum over 15, will we get = a >> warning at compile time or some bug would just sneak into kernel? >=20 > Do you have a concrete example where this would happen? Most bits are > used in 'long' that should be at least 32. I'm not aware of 16bit bits > flags. >=20 OK, I'm too paranoid here. The set_bit() definition needs unsigned long *, and passing a u16 * will cause compile time warning, so it shouldn't be a problem. And for enum over 63, reviewers will definitely complain anyway. Thanks, Qu --iwWAiKL4VyBN51eJtPTNswMdKzk6L6tWc-- --wonZRvP8wpInTlmhV9dRZYmV7P5tvBC0V Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEELd9y5aWlW6idqkLhwj2R86El/qgFAlv+nQ4ACgkQwj2R86El /qj0FQf+JdVAIsJsdqJT8Ul/jVuxBMomy1JxnfNI4F8ViiLioRBpiKouU22Dv28m ET303+qhluRsyZxjpcMiiiVOkI8IMReOlA27A/9sAVkmP///GNj+j6bDNfMj0vn9 53yhR5Bq4H9P6uQdPb8lFxrPDTMtSSJBFKUCEPkMtuSOmJ8uxor0MZBK4QAahSfK ZOabbweEz3g0Yft4ESoD/Xj72/lKDweUiQwJKFkwM+zQWQCijK7LfjezBorFMYqv L1e9ZQDEt217YyDJzop0L+IkNXZlUyI/hHAc2bSF8h8JS3YiM7bUJc/YGPRdKCqd 9TKi2BXyH/uZsFog9KvNuhA2SdPFMw== =USxY -----END PGP SIGNATURE----- --wonZRvP8wpInTlmhV9dRZYmV7P5tvBC0V--