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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 DDBA8C43331 for ; Wed, 23 Dec 2020 15:52:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B804D21D79 for ; Wed, 23 Dec 2020 15:52:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728043AbgLWPwb (ORCPT ); Wed, 23 Dec 2020 10:52:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47656 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726390AbgLWPwa (ORCPT ); Wed, 23 Dec 2020 10:52:30 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B2CFC06179C; Wed, 23 Dec 2020 07:51:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=DvH0NyUD3VzfHuiFkeAq1PYtCpt4Xs2NiwNXDYcFb5E=; b=r5Av1aYEpmlsqfXcI87HZwooYp hNoYZTPHlzpf8R3PngDBkeUYyekmPZHjSvP+5Y3t/QDQeOb7PjtU60bOreHBspxZd8YUySWfx6LXs Jc2J9cL/2SNWMnDDg0JGyL1dbeq6bwFLoAYSIkWYQpYYDrcyBWd1k7ay5dhh6Ajknf6vcfWMobB4M d7YDf4C3uW5cb8WAsCp1mdzQnIS5cXmqbZK92BQ+Gkc1Nn7tDAmwqTDjrN+pMSjzMJ8ia/7RQBNPY TuwEJMOQDeNP7zK1fBQ2omM4imubJcd/XoiZyc13i9XFXRjtUoP5Advk/4h1hgU32RFuK0kJecodo rkLAE63g==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1ks6QT-0001ad-OM; Wed, 23 Dec 2020 15:51:45 +0000 Date: Wed, 23 Dec 2020 15:51:45 +0000 From: Christoph Hellwig To: Pavel Begunkov Cc: Christoph Hellwig , Ming Lei , linux-block@vger.kernel.org, Jens Axboe , Matthew Wilcox , Johannes Weiner , Alexander Viro , "Darrick J . Wong" , "Martin K . Petersen" , Jonathan Corbet , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, target-devel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-doc@vger.kernel.org Subject: Re: [PATCH v1 0/6] no-copy bvec Message-ID: <20201223155145.GA5902@infradead.org> References: <20201215014114.GA1777020@T590> <103235c1-e7d0-0b55-65d0-013d1a09304e@gmail.com> <20201215120357.GA1798021@T590> <20201222141112.GE13079@infradead.org> <933030f0-e428-18fd-4668-68db4f14b976@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <933030f0-e428-18fd-4668-68db4f14b976@gmail.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Wed, Dec 23, 2020 at 12:52:59PM +0000, Pavel Begunkov wrote: > Can scatterlist have 0-len entries? Those are directly translated into > bvecs, e.g. in nvme/target/io-cmd-file.c and target/target_core_file.c. > I've audited most of others by this moment, they're fine. For block layer SGLs we should never see them, and for nvme neither. I think the same is true for the SCSI target code, but please double check.