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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 10272C0502F for ; Sat, 27 Aug 2022 22:46:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 72CFE940008; Sat, 27 Aug 2022 18:46:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6DC3E940007; Sat, 27 Aug 2022 18:46:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5C9F9940008; Sat, 27 Aug 2022 18:46:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 4DDB1940007 for ; Sat, 27 Aug 2022 18:46:50 -0400 (EDT) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 2D55B80B0C for ; Sat, 27 Aug 2022 22:46:50 +0000 (UTC) X-FDA: 79846858980.15.4A532BE Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [62.89.141.173]) by imf12.hostedemail.com (Postfix) with ESMTP id A77AF40031 for ; Sat, 27 Aug 2022 22:46:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=0srbmE7se1/webIbEP76hB4Oq2UTvYv6BWdCYbpFU1w=; b=ChDOfgcKFvPYIRhfHui9MjUP9k RKbrn5/23LmkrN9ofk4yMTpEJ7O5fD+5LbBnj5hayWnVAqOKqWGhOiHQtZwCWCVJeWJ9ekR3Odr9H B7mMfOuabOUAvhnUxuQ11Br4WHZIHTUfZ4meQSFtYN578VaGPUjbh3tZd+eY8P5AMeKHYdkDd4taw MorgpTVfleTS5qWole4hAx4v8Thfy0WwnZYXxV1nHOfwYNLzUua+ilCjhJBlofvMABugWOyF7omkh /ahBbStJVf6abaPUDR9k6G0IP+naRoptJNem2u3ep8iMGiRayxIM66YvOg1QENbpi7gaH2oC0AX6V q6juhXXw==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.95 #2 (Red Hat Linux)) id 1oS4ZQ-0097ix-6e; Sat, 27 Aug 2022 22:46:28 +0000 Date: Sat, 27 Aug 2022 23:46:28 +0100 From: Al Viro To: John Hubbard Cc: Andrew Morton , Jens Axboe , Miklos Szeredi , Christoph Hellwig , "Darrick J . Wong" , Trond Myklebust , Anna Schumaker , Jan Kara , Logan Gunthorpe , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-mm@kvack.org, LKML Subject: Re: [PATCH 3/6] iov_iter: new iov_iter_pin_pages*() routines Message-ID: References: <20220827083607.2345453-1-jhubbard@nvidia.com> <20220827083607.2345453-4-jhubbard@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220827083607.2345453-4-jhubbard@nvidia.com> ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1661640409; a=rsa-sha256; cv=none; b=yxKNEaUGIGvrYHhsRufqa2jgEIdQZXhFOV3hYEz14O493a/j+hWNSyqyfYf+Rmr5JdFA/Y cq4/vb9JEKZO2P14gZ4B3S0k29WBBKComJXZSk1RpZfBylOWHEiF0WklVpcKAfuvAl4+NQ NGScqZbsvwIqm3KUXthfiSPvY/sKD4M= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=linux.org.uk header.s=zeniv-20220401 header.b=ChDOfgcK; dmarc=pass (policy=none) header.from=zeniv.linux.org.uk; spf=none (imf12.hostedemail.com: domain of viro@ftp.linux.org.uk has no SPF policy when checking 62.89.141.173) smtp.mailfrom=viro@ftp.linux.org.uk ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1661640409; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=0srbmE7se1/webIbEP76hB4Oq2UTvYv6BWdCYbpFU1w=; b=FFZhLcPPlw/NRLM16bWhBmt2SNdxLCdQWsfkvFgSpMIVwf/orWElaYS3DwF471leldvrAM NfDOT6pul3asAO6xGe/qHEUNbFq1D7TUDQR32W4FvZNRWIvtxRnn9bH2Y/03O6dC/JDtl1 C1eluBiXJY5ljS0SmQYQpYp9989M47o= X-Rspamd-Queue-Id: A77AF40031 Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=linux.org.uk header.s=zeniv-20220401 header.b=ChDOfgcK; dmarc=pass (policy=none) header.from=zeniv.linux.org.uk; spf=none (imf12.hostedemail.com: domain of viro@ftp.linux.org.uk has no SPF policy when checking 62.89.141.173) smtp.mailfrom=viro@ftp.linux.org.uk X-Rspamd-Server: rspam12 X-Rspam-User: X-Stat-Signature: yphk5o1ff7354yuhcaxntag78e8k31yo X-HE-Tag: 1661640409-992269 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sat, Aug 27, 2022 at 01:36:04AM -0700, John Hubbard wrote: > Provide two new wrapper routines that are intended for user space pages > only: > > iov_iter_pin_pages() > iov_iter_pin_pages_alloc() > > Internally, these routines call pin_user_pages_fast(), instead of > get_user_pages_fast(). > > As always, callers must use unpin_user_pages() or a suitable FOLL_PIN > variant, to release the pages, if they actually were acquired via > pin_user_pages_fast(). > > This is a prerequisite to converting bio/block layers over to use > pin_user_pages_fast(). You do realize that O_DIRECT on ITER_BVEC is possible, right?