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=-5.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 D0A91C433E3 for ; Fri, 14 Aug 2020 00:48:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AD34C20838 for ; Fri, 14 Aug 2020 00:48:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="k1OXUbZL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726622AbgHNAr0 (ORCPT ); Thu, 13 Aug 2020 20:47:26 -0400 Received: from mout.gmx.net ([212.227.15.18]:58629 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726567AbgHNArZ (ORCPT ); Thu, 13 Aug 2020 20:47:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1597366042; bh=2NH264VYkdDdXmVRkw+viNhPuFsfJNlBRLd1nj+tgTc=; h=X-UI-Sender-Class:Subject:To:References:From:Date:In-Reply-To; b=k1OXUbZL4ypXAjPCwIVvkHjmN61SJA0hV0tWhsjdx2TTe4vJMrW/t/u1FKlhxRxj6 DSFxvZmSR/bpyWpHXfDVdb5NL3P39klNwfN/6gbVUpYt9BQYeyDICHuKCTl8LLPLjT fxkjGxfN2QdWe5BpN9KnIn6Eq+eCeHD3qeQTU3Ro= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([149.28.201.231]) by mail.gmx.com (mrgmx005 [212.227.17.184]) with ESMTPSA (Nemesis) id 1N4QwW-1knebn1BNm-011Tht; Fri, 14 Aug 2020 02:47:21 +0200 Subject: Re: [PATCH v4 1/4] btrfs: extent_io: Do extra check for extent buffer read write functions To: dsterba@suse.cz, Qu Wenruo , linux-btrfs@vger.kernel.org, Josef Bacik References: <20200812060509.71590-1-wqu@suse.com> <20200812060509.71590-2-wqu@suse.com> <20200813140503.GH2026@twin.jikos.cz> 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: <6f6a76e7-57b5-5e73-af6c-855cc5256a34@gmx.com> Date: Fri, 14 Aug 2020 08:47:17 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20200813140503.GH2026@twin.jikos.cz> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="GIn1RzZiBQi7UBfs1TV4UwJS4Fyk8fxKX" X-Provags-ID: V03:K1:0OasViSDXjTMmF19RrRrrHKeRkN/8SWesyIYjgtaIz8o0D74BN1 nMpBt2SYs17XYKj02gT+fhgnuvgeK4nsdE/Ot6FM5GqfUZO2sk2g6RMzn2wn/6dZF80PHxV rAeBHOl6n6TKKU/UVGcBMURbrghd4SPE2p3wlWLhxcQtMxvHz9/QfrwpkzRbEU/Ru6KGbqy p0o3hcbE7NpIJOh9G4BoQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:hdVmmy81cWk=:qSHmwCSq5BbvXGnReHyRAa xi609ZH+I98dL1sFDFTkrWRrFxdJ6gd/DsoLA1GMpYx51QkL4lKrdvKEJSkz3Uch2t27mtHw4 NRi0JEJFoMsqFl96p3AEXbj7HdkxyuJ7JXK8YUhCN0+ftZgUVnJel1mFK85u+rPGT2Ik8fmiZ vFHj21+Qk3tOkwWPQlHEDPPvQrVIwe+lY2FbRUvbFrayM7YWKOD0EnZAWCDLfkaWTeXv+ymPK F2xjONu8w1SnSjf9DF1SbvTSJEomtT7aWgIGFyxI1qebsuEsWdQ5ig7s9FD/ax4a410xWfeYe kNgO3f55ngpJIKrOYaqBBzeAHCABT/VADxEHgHm7CbjhbCbIxlA5zP6tNzvyMEHWHBzcaemRX qwxS0WFjkJf2ON/jh7pIwhzpTshuJsEjSl/kV/EHoXBgjCKfadZP4nF43jo4mTPxEqfTmZVMc uh044dOyOAr2LDoLN8K/uzwhG8/KZRxjmkLQYtv9mYWUYa2WxdXTbrBvkdZk91sqdigtedJUQ TdQNN5F6h7nv3gt4YLyfXK11dSQ4VXHTYew/hMnMt7Xta9zirCWX5VpVj/R/jMFN9CzWMNxhH 1h8AyIc4S+Z9gvMrJmAYxbnqeacaAcFv7UBl9Zx+g70Yc4Sy567SRCxB6Nuh95jsbplst8IuV v8gG87BUR3XA0HEzyvfVi3Wcu+y+Do2bceSSnCALGWTDb9DmRP9w9Ncy+uCWcnPZTlllEjAUW rosKfPViHMeJRY7g6+g27Ldb6EeHxLJ1Yk+YTZWR48zIpJ2arn6BEKnbfD1u7liPZ0mQrPpk+ MyYm4nBKif0Mruj7uKb5l1B6IcFo/Xk+mdBHdKO4R9xb37Jje0uDOiMcAuRxxwJLPBwhnoVV6 ptk1xAvDP/C4PxKSuPV8lB9n7mTPoy/LAVQ54CW5JUou7N9lvnoscwgUV8Szk++fqKzjkZZwW /Px+C3rBj6fOzC/7wF2S3eMApiHPXS7bL/qoQAMmCNcqLqas4d8NpctSG9eOVmMGQp3dm1Utz dAhHFTfJjhC6goKb/FXgB07IHFEtkjnjV5Frr8eHahq5blCCrJEUMXo7UjPI38LfBaEhQiSmP BlvN9eLsBvBlOm2eu+8PUzjeJkNd5quv5xILiVzVWBLl1Eib3GnKiMjG8OA5pv+y3T/yI1Ir8 Yvq8Ts5JUgEEd6IcYnKtk8FbznvfD3UVE1jxfqtqDxenAQfMQYsG/ewzHaP8L75wdyc7eUFOz jJ1RQ4+R1vJQuNXFKgCi+r9lMh3F17q/kTyYQSQ== 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) --GIn1RzZiBQi7UBfs1TV4UwJS4Fyk8fxKX Content-Type: multipart/mixed; boundary="oaPP7hcZXtyPqg3VVsEwk8iYFbR2xVwJ7" --oaPP7hcZXtyPqg3VVsEwk8iYFbR2xVwJ7 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 2020/8/13 =E4=B8=8B=E5=8D=8810:05, David Sterba wrote: > On Wed, Aug 12, 2020 at 02:05:06PM +0800, Qu Wenruo wrote: >> +/* >> + * Check if the [start, start + len) range is valid before reading/wr= iting >> + * the eb. >> + * NOTE: @start and @len are offset *INSIDE* the eb, *NOT* logical ad= dress. >> + * >> + * Caller should not touch the dst/src memory if this function return= s error. >> + */ >> +static int check_eb_range(const struct extent_buffer *eb, unsigned lo= ng start, >> + unsigned long len) >> +{ >> + /* start, start + len should not go beyond eb->len nor overflow */ >> + if (unlikely(start > eb->len || start + len > eb->len || >> + len > eb->len)) { >> + btrfs_warn(eb->fs_info, >> +"btrfs: bad eb rw request, eb bytenr=3D%llu len=3D%lu rw start=3D%lu = len=3D%lu\n", >> + eb->start, eb->len, start, len); >> + WARN_ON(IS_ENABLED(CONFIG_BTRFS_DEBUG)); >> + return -EINVAL; >> + } >> + return 0; >> +} >=20 > This helper is similar to the check_setget_bounds that have some > performance impact, > https://lore.kernel.org/linux-btrfs/20200730110943.GE3703@twin.jikos.cz= / > . >=20 > The extent buffer helpers are not called that often as the setget > helpers but still it could be improved to avoid the function call > penalty on the hot path. >=20 > static inline in check_eb_range(...) { > if (unlikely(out of range)) > return report_eb_range(...) > return 0; > } I thought we should avoid manual inline, but let the compiler to determine if it's needed. Or in this particular case, we're better than the compiler? Thanks, Qu >=20 > In the original code the range check was open coded and the above will > lead to the same asm output, while keeping the C code readable. >=20 --oaPP7hcZXtyPqg3VVsEwk8iYFbR2xVwJ7-- --GIn1RzZiBQi7UBfs1TV4UwJS4Fyk8fxKX Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEELd9y5aWlW6idqkLhwj2R86El/qgFAl813xYACgkQwj2R86El /qhUMAf/ftNLzeOSif1EMH2gwBgjf2HuXOTKtFKolEEdAN+SSN92DMZ4FW19xQ2s d1WqHK43oR9HEeP7xmcBJ/1WiBtuXBG6f8+SI0oEJFgh4R+J0AbeUkkS4zK07qPr uOYPM8eXjisAyBnauTAKxX7UOwyW7oFeo//2xGp0XnqGhCN4p5SU7xNC6EJrwvzH mPUGynvbbHnuv6FySC18KIQupOD6OBdx/J7wdSw7ntu4gazJ8VhXv1n66cRJtB+R 6syxTDOVaZzOgTxHOTbEWfIvddT/wt2hcSYAaw2EXdhWPPwiman+p1ksjQBnAkmu wbfb1FuAW/x8nAqY0mJvTmZygqUg0A== =XeOL -----END PGP SIGNATURE----- --GIn1RzZiBQi7UBfs1TV4UwJS4Fyk8fxKX--