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Wong" , Theodore Ts'o , Miklos Szeredi , Andrew Morton , Chaitanya Kulkarni , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, LKML References: <20220227093434.2889464-1-jhubbard@nvidia.com> <20220227093434.2889464-4-jhubbard@nvidia.com> From: John Hubbard In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: BYAPR05CA0052.namprd05.prod.outlook.com (2603:10b6:a03:74::29) To BY5PR12MB4130.namprd12.prod.outlook.com (2603:10b6:a03:20b::16) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 5f4eba9c-6108-49a8-c08a-08d9fa6a8efd X-MS-TrafficTypeDiagnostic: LV2PR12MB5775:EE_ X-Microsoft-Antispam-PRVS: X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BY5PR12MB4130.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230001)(4636009)(366004)(508600001)(316002)(6506007)(4326008)(86362001)(6486002)(8936002)(36756003)(54906003)(31696002)(53546011)(2616005)(186003)(26005)(6512007)(38100700002)(31686004)(6666004)(66476007)(7416002)(66556008)(2906002)(8676002)(5660300002)(4744005)(66946007)(45980500001)(43740500002);DIR:OUT;SFP:1101; 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And what should happen when O_DIRECT file gets passed to splice()? OK, right, this is not going to work as-is. Any of the remaining iov_iter_get_pages*() callers that do direct IO (vmsplice, ceph, ...) will end up calling bio_release_pages(), which is now unconditionally calling unpin_user_pages(). So this is just completely broken. And so, once again, I'm back to, "must convert the whole pile of iov_iter_get_page*() callers at once". Back to the drawing board. thanks, -- John Hubbard NVIDIA