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 C16EDC433EF for ; Tue, 5 Apr 2022 05:09:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229477AbiDEFLB (ORCPT ); Tue, 5 Apr 2022 01:11:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42426 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229469AbiDEFLA (ORCPT ); Tue, 5 Apr 2022 01:11:00 -0400 Received: from mout.gmx.net (mout.gmx.net [212.227.15.15]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A36C04B419 for ; Mon, 4 Apr 2022 22:08:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1649135327; bh=NDb03fTWvF3SLaZs4y6l1M4DIRKkBxydLd427/RNc7M=; h=X-UI-Sender-Class:Date:Subject:To:Cc:References:From:In-Reply-To; b=aX8XcI7pQh2bN4yypgMBYL+5tFNBMhjDyBYH/Vu83r7w8FN15572wppu3Toyf709k Oqfj+UewKlUFoWG3850BT61y11L/CbHv0v+LHsFhkE6/VkxqC4Gh+pOKyq1FRLR3Ji D23I/MqttjYn9FTJjPB85klU1nUecm3HgvY/pvIk= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([149.28.201.231]) by mail.gmx.net (mrgmx004 [212.227.17.184]) with ESMTPSA (Nemesis) id 1N1fis-1nzcVK393Y-011yeQ; Tue, 05 Apr 2022 07:08:47 +0200 Message-ID: Date: Tue, 5 Apr 2022 13:08:41 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH] btrfs: replace a wrong memset() with memzero_page() Content-Language: en-US To: Christoph Hellwig , David Sterba Cc: linux-btrfs@vger.kernel.org References: <8d6f911a0282eba76f9e05d6f1e7c6f091d4870b.1648199349.git.wqu@suse.com> From: Qu Wenruo In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:2FmEZxtK4e+pkSfPhgRc2pRpfNEPn1qkxoTLYHtxhHpnsXiSWZZ xqye1Ig6EgS+Dee/I4UV2AULRMiWToh0yntc2pYTh4gSgzAGqXuapb3WaL6KaBhCbo8qeJS a99FYZRWibR0vvTS7xdWqtLx3LIWr0kgDdYxGI0g1NoimDzfN3dOmbuuF+HaBB6h33ABNBe 0Nuv5aFLAv1TZBk+88Uxg== X-UI-Out-Filterresults: notjunk:1;V03:K0:UWkOV6p5UBs=:nekZshCRPFKtueppZ9pTG4 eUpDPctxSjSFeVR3Hy0lGrWWR9zCslCEaecag9yorBNndLECvPq/ZwQm9iyD/dFS9MyMBIHYD ZovCX21QVwdb4ikohUc8y+FA1sz2U3DMU698aPuxNW5VfPc1cC0aPV51hOMC/znK344bOlyT0 1lRPyvgPDUEJcc7TtTJr6eHNBAi7aPHJ6MhNQ5/wj1TW05HT0eVQnZyS66xGpkqwKvckgtJAZ QCWgnWpIXoeb7lzbAKRA1+Wp9aJulnIMGo6zov2c+FQ0yTQm5R++ntJ69QEwbl0LvMzZebIsw sDLuncVYRdLGaX8d85SH8j1reWgyNMR4HbdGGuz/0b7Q03Dc78UQkQlmyZGzlMaOKhAFNYnXo c7UILFeaC2GGju0c2vEmCpOLbFXoZwPgvxoq2USpGfSoQdk4B4lffsY73xZWQpqBCuhJyjN25 5RJ1ox/5EdmF/PpZumiJ8CAzQysOvnEBLp+zdkTMYvv6KvygaRGX/chVuDXQk1lE7QP5csxXl USRN2cZb4HzkKZ7gRE3o3injku1IDcpVB5M3fCVMqwK0W904gzKwczzOa8yBR/XKyYbThCm1V 2qknf2zbPEYeHWF8sIK8vze32d3E6BYtXkipA7T9K7C0pu0TA7GJX6dIRKAARSI6TgM67CwMR wan/XZgv9KK5tG8UgVIvn2USzvdy/+B3EBkjDSfCzyne0dRPquE/ISDTRnb5gDHeUnsKSEjOn /WRFP/YYoyPS9OvMIOoVgoQAXz2ZwAE6MbW20c/FqXdrIYdTTYGNuHhJi4/SYj5moRSeH9w3J 1L/M5FHgiwF5PJbMWJ64tfVCaRAIR+IiGdoMw8fRebMX4xW7PSuTSyWfUlIqf/UHghwY71Zl1 yEfyGi/ZViGI0/QzMNwluLqob0bjSqeyTflMa2Mc6CmTkn+ZwtSrP7cUZIvV+i+Imq0Tm4tzn GxoEhtrCaduWrJSiLQ6WHCZbC+DxKLC0MvMSJEWvV/VcQ5aj/10nUmKBp/MAtujFiv1+dQ8zo q7RLjkYvia5AdcMLZLjVqFSB1zGRKfyxOeaeprsfUJYtAv3POkd/skWeNAlpZ+tRvW5Oeo9VQ vV8P/MBMec4DcI= Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 2022/4/5 12:58, Christoph Hellwig wrote: > On Fri, Mar 25, 2022 at 09:38:16AM -0700, Christoph Hellwig wrote: >>> - memset(kaddr + pgoff, 1, len); >>> + memzero_page(page, pgoff, len); >>> flush_dcache_page(page); >> >> memzero_page already takes care of the flush_dcache_page. > > David, you've picked this up with the stay flush_dcache_page left in > place. Plase try to fix it up instead of spreading the weird cargo cult > flush_dcache_page calls. > Please drop this patch, as discussed with Filipe, the memset() value 0x01 could be a poison value to distinguish from plain 0x00. Furthermore, we are not sure if we even want to zeroing out/poison the content. Thanks, Qu