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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 33ABFC43331 for ; Mon, 11 Jan 2021 14:56:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 08794225AC for ; Mon, 11 Jan 2021 14:56:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388729AbhAKOzw convert rfc822-to-8bit (ORCPT ); Mon, 11 Jan 2021 09:55:52 -0500 Received: from eu-smtp-delivery-151.mimecast.com ([185.58.86.151]:55728 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731088AbhAKOzv (ORCPT ); Mon, 11 Jan 2021 09:55:51 -0500 Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-259-cwMCCFf6NSqMv-TjxwzQZQ-1; Mon, 11 Jan 2021 14:54:12 +0000 X-MC-Unique: cwMCCFf6NSqMv-TjxwzQZQ-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) by AcuMS.aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Mon, 11 Jan 2021 14:54:11 +0000 Received: from AcuMS.Aculab.com ([fe80::43c:695e:880f:8750]) by AcuMS.aculab.com ([fe80::43c:695e:880f:8750%12]) with mapi id 15.00.1347.000; Mon, 11 Jan 2021 14:54:11 +0000 From: David Laight To: 'Al Viro' CC: 'Mikulas Patocka' , Andrew Morton , Dan Williams , "Vishal Verma" , Dave Jiang , "Ira Weiny" , Matthew Wilcox , Jan Kara , Steven Whitehouse , Eric Sandeen , Dave Chinner , Theodore Ts'o , Wang Jianchao , "Kani, Toshi" , "Norton, Scott J" , "Tadakamadla, Rajesh" , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-nvdimm@lists.01.org" Subject: RE: [RFC v2] nvfs: a filesystem for persistent memory Thread-Topic: [RFC v2] nvfs: a filesystem for persistent memory Thread-Index: AQHW52zcFLyucqAcQUmnqwhwPozPcaoiOfvQgAAVUICAAALF8IAAL2SAgAAB4jA= Date: Mon, 11 Jan 2021 14:54:11 +0000 Message-ID: References: <20210110162008.GV3579531@ZenIV.linux.org.uk> <57dad96341d34822a7943242c9bcad71@AcuMS.aculab.com> <20210111144341.GZ3579531@ZenIV.linux.org.uk> In-Reply-To: <20210111144341.GZ3579531@ZenIV.linux.org.uk> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Al Viro On Behalf Of Al Viro > Sent: 11 January 2021 14:44 > On Mon, Jan 11, 2021 at 11:57:08AM +0000, David Laight wrote: > > > > > size = copy_to_iter(to, ptr, size); > > > > > if (unlikely(!size)) { > > > > > r = -EFAULT; > > > > > goto ret_r; > > > > > } > > > > > > > > > > pos += size; > > > > > total += size; > > > > > } > > > > > > > > David > > > > > > I fixed the arguments to > > > copy_to_iter - other than that, Al's function works. > > > > > Oh - the error return for copy_to_iter() is wrong. > > It should (probably) return 'total' if it is nonzero. > > copy_to_iter() call there has an obvious problem > (arguments in the wrong order), but return value is handled > correctly. It does not do a blind return -EFAULT. RTFS... Ah I was looking at the version I'd cut the tail off... David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)