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[2620:137:e000::1:20]) by mx.google.com with ESMTP id 11-20020a62170b000000b00589c467f33fsi8434355pfx.55.2023.01.12.07.06.44; Thu, 12 Jan 2023 07:06:51 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=bombadil.20210309 header.b=iqxJLhoR; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235956AbjALORR (ORCPT + 51 others); Thu, 12 Jan 2023 09:17:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41412 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235773AbjALOQN (ORCPT ); Thu, 12 Jan 2023 09:16:13 -0500 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9757455878; Thu, 12 Jan 2023 06:08:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=FkB/gFOcG5Pqv2OovO6QG5NeQJyO7VnpkEiyzK71KNM=; b=iqxJLhoRUS9SDfYu7zkgVeqiF1 hSsTY22/joMJuqE0JVxXU5Hq0Eeuv44KqhPBfr899GUMd3IwzWAWer4d+SOYOBtwH1vCLINFXEEh2 EpVw+CeUuM2sEjDTu103Vj2yvnPMR7kwMx/sVkGpltaK1c6YC4yM10t5ALcQSpPNcq0bs+8ye8z8+ 637afNlqlviQdCDNTkSpP1BavBor520z0W6Ke27MWKFowgMECSK+dRstSqLunliazRUGeDbBU7kTV JP0XJSmwxNcb30J1+pRH+eZkTq9+SH8TN2IqjWvEG/7F1sEL2oKsNxY14hhTc4rRm+0BiUVqsJd+e ONrDHtCQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1pFyFa-00FJWp-6u; Thu, 12 Jan 2023 14:08:14 +0000 Date: Thu, 12 Jan 2023 06:08:14 -0800 From: Christoph Hellwig To: David Howells Cc: Christoph Hellwig , Al Viro , Matthew Wilcox , Jens Axboe , Jan Kara , Jeff Layton , Logan Gunthorpe , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 3/9] iov_iter: Use IOCB/IOMAP_WRITE if available rather than iterator direction Message-ID: References: <167344725490.2425628.13771289553670112965.stgit@warthog.procyon.org.uk> <167344727810.2425628.4715663653893036683.stgit@warthog.procyon.org.uk> <15330.1673519461@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <15330.1673519461@warthog.procyon.org.uk> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 12, 2023 at 10:31:01AM +0000, David Howells wrote: > > And use the information in the request for this one (see patch below), > > and then move this patch first in the series, add an explicit direction > > parameter in the gup_flags to the get/pin helper and drop iov_iter_rw > > and the whole confusing source/dest information in the iov_iter entirely, > > which is a really nice big tree wide cleanup that remove redundant > > information. > > Fine by me, but Al might object as I think he wanted the internal checks. Al? I'm happy to have another discussion, but the fact the information in the iov_iter is 98% redundant and various callers got it wrong and away is a pretty good sign that we should drop this information. It also nicely simplified the API.