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=-8.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 ADC35C3F2CF for ; Fri, 28 Feb 2020 08:39:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 765CD24695 for ; Fri, 28 Feb 2020 08:39:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="bZQ57bhE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726077AbgB1IjD (ORCPT ); Fri, 28 Feb 2020 03:39:03 -0500 Received: from mout.gmx.net ([212.227.15.19]:39979 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725877AbgB1IjD (ORCPT ); Fri, 28 Feb 2020 03:39:03 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1582879128; bh=RH7CSZiXqW0C4T/ypr5krHIp8KFrF58ypQQEtcp5xBk=; h=X-UI-Sender-Class:Subject:To:References:From:Date:In-Reply-To; b=bZQ57bhEqqRNdGacPTNlK9eUihJrR6puHuxkzytUafJL0H8dX/GjoBALL6Cl/D9ii 8ihmWMeEQismjWPwp7wGfC0LwmDmOD99xEgSrw/eEARn8DR0IQaUodeDfqiOLjjyGd BrW9OiFDJIBM8g8eIfAFZJi3qCCLr4uS5vi9lO1k= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([149.28.201.231]) by mail.gmx.com (mrgmx004 [212.227.17.184]) with ESMTPSA (Nemesis) id 1MpUUw-1jjzKN2FMy-00pvjN; Fri, 28 Feb 2020 09:38:48 +0100 Subject: Re: [PATCH 1/4] btrfs: inline checksum name and driver definitions To: David Sterba , linux-btrfs@vger.kernel.org References: <91753cb284a2dbce72e5b5b31b658e1c50ef084e.1582832619.git.dsterba@suse.com> From: Qu Wenruo Autocrypt: addr=quwenruo.btrfs@gmx.com; prefer-encrypt=mutual; keydata= mQENBFnVga8BCACyhFP3ExcTIuB73jDIBA/vSoYcTyysFQzPvez64TUSCv1SgXEByR7fju3o 8RfaWuHCnkkea5luuTZMqfgTXrun2dqNVYDNOV6RIVrc4YuG20yhC1epnV55fJCThqij0MRL 1NxPKXIlEdHvN0Kov3CtWA+R1iNN0RCeVun7rmOrrjBK573aWC5sgP7YsBOLK79H3tmUtz6b 9Imuj0ZyEsa76Xg9PX9Hn2myKj1hfWGS+5og9Va4hrwQC8ipjXik6NKR5GDV+hOZkktU81G5 gkQtGB9jOAYRs86QG/b7PtIlbd3+pppT0gaS+wvwMs8cuNG+Pu6KO1oC4jgdseFLu7NpABEB AAG0IlF1IFdlbnJ1byA8cXV3ZW5ydW8uYnRyZnNAZ214LmNvbT6JAU4EEwEIADgCGwMFCwkI BwIGFQgJCgsCBBYCAwECHgECF4AWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCXZw1oQAKCRDC PZHzoSX+qCY6CACd+mWu3okGwRKXju6bou+7VkqCaHTdyXwWFTsr+/0ly5nUdDtT3yEVggPJ 3VP70wjlrxUjNjFb6iIvGYxiPOrop1NGwGYvQktgRhaIhALG6rPoSSAhGNjwGVRw0km0PlIN D29BTj/lYEk+jVM1YL0QLgAE1AI3krihg/lp/fQT53wLhR8YZIF8ETXbClQG1vJ0cllPuEEv efKxRyiTSjB+PsozSvYWhXsPeJ+KKjFen7ebE5reQTPFzSHctCdPnoR/4jSPlnTlnEvLeqcD ZTuKfQe1gWrPeevQzgCtgBF/WjIOeJs41klnYzC3DymuQlmFubss0jShLOW8eSOOWhLRuQEN BFnVga8BCACqU+th4Esy/c8BnvliFAjAfpzhI1wH76FD1MJPmAhA3DnX5JDORcgaCbPEwhLj 1xlwTgpeT+QfDmGJ5B5BlrrQFZVE1fChEjiJvyiSAO4yQPkrPVYTI7Xj34FnscPj/IrRUUka 68MlHxPtFnAHr25VIuOS41lmYKYNwPNLRz9Ik6DmeTG3WJO2BQRNvXA0pXrJH1fNGSsRb+pK EKHKtL1803x71zQxCwLh+zLP1iXHVM5j8gX9zqupigQR/Cel2XPS44zWcDW8r7B0q1eW4Jrv 0x19p4P923voqn+joIAostyNTUjCeSrUdKth9jcdlam9X2DziA/DHDFfS5eq4fEvABEBAAGJ ATwEGAEIACYCGwwWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCXZw1rgUJCWpOfwAKCRDCPZHz oSX+qFcEB/95cs8cM1OQdE/GgOfCGxwgckMeWyzOR7bkAWW0lDVp2hpgJuxBW/gyfmtBnUai fnggx3EE3ev8HTysZU9q0h+TJwwJKGv6sUc8qcTGFDtavnnl+r6xDUY7A6GvXEsSoCEEynby 72byGeSovfq/4AWGNPBG1L61Exl+gbqfvbECP3ziXnob009+z9I4qXodHSYINfAkZkA523JG ap12LndJeLk3gfWNZfXEWyGnuciRGbqESkhIRav8ootsCIops/SqXm0/k+Kcl4gGUO/iD/T5 oagaDh0QtOd8RWSMwLxwn8uIhpH84Q4X1LadJ5NCgGa6xPP5qqRuiC+9gZqbq4Nj Message-ID: <690a6f32-d219-b3d6-a4b0-795ba6aeeef4@gmx.com> Date: Fri, 28 Feb 2020 16:38:44 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <91753cb284a2dbce72e5b5b31b658e1c50ef084e.1582832619.git.dsterba@suse.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="pyOdW97sL22UylBrPoDLXPqxL3BIc0rrQ" X-Provags-ID: V03:K1:bVs4g4HNUJBkQ4HoE47H5h3+xgE8q8qNmy0nhod59S6BroftJkL +e2M2125nGFXrBWFQE6+dtNg0TYtW1a/BWeUpdlSKRgYe6OM1YQfjvdlu2+k7NLV9KYD5cJ d6VSkD0adUYrPREtkJ/KvuA29qsCz4R4fKLJlpZE5guN5B+cbxc6NFeXocHXH8nBKZe/BLv 9T5+hTgDKgcbGP8Trz9lg== X-UI-Out-Filterresults: notjunk:1;V03:K0:Fms+CdVxz9Y=:NdZAK6N/siLIn8uGVmFxY7 Ex0gB2PIqqZqY9NLIBuHCF1vv1JDZzUsIwmPh+JYJOHzgk2VQ7FteYAGm7XMX1Q+zEKF9jkxF DOq4k1TSEBsS9Hy0lsvuu5/+9LgoVpTP8BdYOFxCDAJOpovOVfGx3joZb5EQ34Z2Dv4CulUSY NdhTX6E1Lgp7K+90DvTVKiG+bASmDUbU4efUN6vegcOAImyADYnaUgHFweqXny/+dnsIagbna Ct3u/rJCVkUuMLqcyasZ6Q6BvTDIb+ItiNxgml7r+e6UgY9eCk0lYM04Qa/P0WWx8Z72wWizM RxmTePCbE91AG2r6JlsXLtppuqVEC62rKFSVEhh2nOPhTB9c1QcmL+znaJyfbqFbuUzD+hOKy y68gi13eUan996MIk5ZU/gcP3lPYh6bq+BwRW4O6InT3Ee9quPPOGdSWMX7qRKfFg6lFNqqLd /oAqMwyuMGVtrWC9k+Q0Je4gb8R/QtDTXzibTkoAXsbn5Ain56vh5YhyxUZg8KYPZQ4pNC+Fk 4FU/CNsT3qREBvvxh39BIr2/hj1urGPQesOxgsnkQdE1B2ezr9cGRbk89m2CUIdcc5eTE49iq LnVjaqZJQyVcb8njF7J3/tK21jLib8/+ankWvAio/k7V9nOPraLUs4IA/f1QayXeVme84B66Y MTDi5l5cuKFY8l2JPfc29ZlIksec9rr7MbESSHWwbFPECtg4VfqqqCs9SqQ60GmG9Dfr/u7FW g+Oo0EIxL+3RrA5YJ9nI9jpmKFdcb64BfwICTLMK897iudD8fRb5On/0zrYz8jjYWUDr9t2z/ P6g4b2mosGSN7xp22lZAyrWsEkmL5FavGJbnxAjfVHDzwBoFIglyd177uFysU95zB48jDAJnQ zqaL8Hx9hSWV8Vi/e0fjG9O0s8EWSchXunXTwYTx+etj+zvCwnOfvRC6UCKrl2EzX9mBALT0/ 9IBwTMCdauLvgSI9SFleOUpyESCozomUEaFEWci3kyalOgmlMESaMR6y+IyXb1J0XUbFL8pJB pZpG1kH2wThbm9FL8wFRHWfgh8BM0+yOghaNC7Xo+NvT0tdtDbwpd/M2Vai14ltkrwqw3rPOY apMR7sffMe+FKSVic8NedzDhA5hoPyApP6MsCHpnx9DqxmWb0Fd1ZNGNi+rZ82kxdLNi7IR1v a5z8H6kOj03AhbBG5XDojmwsO3nXi0vKWSDUPfP5BC+dsevmCYaXedMiHiq/ifPc/SnXpJ07V TeLXQweEQFT0UwXS9 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) --pyOdW97sL22UylBrPoDLXPqxL3BIc0rrQ Content-Type: multipart/mixed; boundary="MraujC4WPO6RiUfs6202t3dWQhpds0DX3" --MraujC4WPO6RiUfs6202t3dWQhpds0DX3 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 2020/2/28 =E4=B8=8A=E5=8D=884:00, David Sterba wrote: > There's an unnecessary indirection in the checksum definition table, > pointer and the string itself. The strings are short and the overall > size of one entry is now 24 bytes. >=20 > Signed-off-by: David Sterba > --- > fs/btrfs/ctree.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) >=20 > diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c > index f948435e87df..bfedbbe2311f 100644 > --- a/fs/btrfs/ctree.c > +++ b/fs/btrfs/ctree.c > @@ -31,8 +31,8 @@ static void del_ptr(struct btrfs_root *root, struct b= trfs_path *path, > =20 > static const struct btrfs_csums { > u16 size; > - const char *name; > - const char *driver; > + const char name[10]; Just a nitpick, the longest name I haven seen is "xxhash64" which is only 8 chars, +1 for '\n'. Thus we can save one extra byte here. Despite that. Reviewed-by: Qu Wenruo Thanks, Qu > + const char driver[12]; > } btrfs_csums[] =3D { > [BTRFS_CSUM_TYPE_CRC32] =3D { .size =3D 4, .name =3D "crc32c" }, > [BTRFS_CSUM_TYPE_XXHASH] =3D { .size =3D 8, .name =3D "xxhash64" }, > @@ -63,7 +63,8 @@ const char *btrfs_super_csum_name(u16 csum_type) > const char *btrfs_super_csum_driver(u16 csum_type) > { > /* csum type is validated at mount time */ > - return btrfs_csums[csum_type].driver ?: > + return btrfs_csums[csum_type].driver[0] ? > + btrfs_csums[csum_type].driver : > btrfs_csums[csum_type].name; > } > =20 >=20 --MraujC4WPO6RiUfs6202t3dWQhpds0DX3-- --pyOdW97sL22UylBrPoDLXPqxL3BIc0rrQ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEELd9y5aWlW6idqkLhwj2R86El/qgFAl5Y0ZQACgkQwj2R86El /qjVqgf+N47IUyvBgh5V6gwekoi8HzQ4wxVSzYobg1+GQiBg6u9iHJnowzYx9G5m wCocYae8U9ev+myU6zolwvDAf0FKWG0gEpQT4PENFqv0hRjzzo5j3Y3AkhAqsFfd 7TW8TsJWbhzuXHS4Jn3o4HoJ3MxIXC+Yo88/gCPgr8yeSZ0l6DrTs9poufEti00Q cbxhI/0WlHp84bX2QFJV/mtbjNeqsEHNcMcwXRKbONYRG0X4mmqoRcKFjEqAMM4a At5VPNrYTUBQdL9rk8+oVwM6CNIZy9jFRKXpSLCxPABjcYcMgubiW8k2vEYXelh9 wQRykZBE9G2Yczo7RWEsoK1MD74dSA== =HOqY -----END PGP SIGNATURE----- --pyOdW97sL22UylBrPoDLXPqxL3BIc0rrQ--