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Sat, 26 Mar 2022 01:15:28 +0000 Received: from DB9PR04MB9426.eurprd04.prod.outlook.com ([fe80::39f2:9041:54c:eecc]) by DB9PR04MB9426.eurprd04.prod.outlook.com ([fe80::39f2:9041:54c:eecc%8]) with mapi id 15.20.5102.016; Sat, 26 Mar 2022 01:15:28 +0000 Message-ID: <4ad5f566-8d80-e090-ddae-c409786dcf2d@suse.com> Date: Sat, 26 Mar 2022 09:15:19 +0800 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 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: 7bit X-ClientProxiedBy: PH0PR07CA0010.namprd07.prod.outlook.com (2603:10b6:510:5::15) To DB9PR04MB9426.eurprd04.prod.outlook.com (2603:10a6:10:36a::14) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: c35b9fa7-78be-43f7-8b36-08da0ec61ce0 X-MS-TrafficTypeDiagnostic: VI1PR04MB6304:EE_ X-Microsoft-Antispam-PRVS: X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; 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>> + const u32 len = fs_info->sectorsize; > > Why the spurious and rather pointless const annotation that is unrelated > to the rest of the patch? Because we prefer const for constant variables in btrfs code. As we have experienced some bugs in the past related to reusing some variables. > >> BTRFS_DEV_STAT_CORRUPTION_ERRS); >> - memset(kaddr + pgoff, 1, len); >> + memzero_page(page, pgoff, len); >> flush_dcache_page(page); > > memzero_page already takes care of the flush_dcache_page. > Oh, indeed. Thanks, Qu