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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 0C78FC07E95 for ; Tue, 20 Jul 2021 11:17:41 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A029E6023D for ; Tue, 20 Jul 2021 11:17:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A029E6023D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 369326B00A1; Tue, 20 Jul 2021 07:17:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2F29E6B00A3; Tue, 20 Jul 2021 07:17:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 16CB26B00A8; Tue, 20 Jul 2021 07:17:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0184.hostedemail.com [216.40.44.184]) by kanga.kvack.org (Postfix) with ESMTP id DCBD26B00A1 for ; Tue, 20 Jul 2021 07:17:40 -0400 (EDT) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 7020218500A16 for ; Tue, 20 Jul 2021 11:17:39 +0000 (UTC) X-FDA: 78382715838.06.16B745E Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf03.hostedemail.com (Postfix) with ESMTP id 2E7CB30001A3 for ; Tue, 20 Jul 2021 11:17:38 +0000 (UTC) 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=4FkZvqXeAIk4BuCEW9n8PvCXADxw3t7wT89TribEmJ4=; b=dGlxFd7VdA60iqtsgKTmLNv6gL zuMCMdEGLQhXpslEtymGFCdaZSQ+RefhzQqO+vUjOMjCU+EhnKhnxiQdm8sCEMIK9YfIe80VY89eQ mk4wGqYpWRryKk9cIT46Jld57JGhixwB1Q4yeSzwgzt7eQdChsS80zxItJTM4LCtJBHtMQIJxbC6g GwNR7KGWmNytX6w85Gokb7aq1KbwHrcDdxkX1JZljXMuLomALqJZtOkyPy1+o4hVCnpgdL+MwbTyb DiOZzif46Sd1RS2ObzKCdaBp9XEIN4eS+DqLdrs81vTXrZJ4y5MxyObgnL1XuVmqfVfP8F6RLPs7H egrYC1zw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m5nk5-0082bU-1k; Tue, 20 Jul 2021 11:17:03 +0000 Date: Tue, 20 Jul 2021 12:16:53 +0100 From: Matthew Wilcox To: Christoph Hellwig Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-block@vger.kernel.org Subject: Re: [PATCH v15 01/17] block: Add bio_add_folio() Message-ID: References: <20210719184001.1750630-1-willy@infradead.org> <20210719184001.1750630-2-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=dGlxFd7V; spf=none (imf03.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none X-Rspamd-Server: rspam05 X-Stat-Signature: qt1h316xw4ccznhgiubz4bndiu5ypzjb X-Rspamd-Queue-Id: 2E7CB30001A3 X-HE-Tag: 1626779858-307561 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 Tue, Jul 20, 2021 at 07:42:00AM +0100, Christoph Hellwig wrote: > On Mon, Jul 19, 2021 at 07:39:45PM +0100, Matthew Wilcox (Oracle) wrote: > > +/** > > + * bio_add_folio - Attempt to add part of a folio to a bio. > > + * @bio: Bio to add to. > > + * @folio: Folio to add. > > + * @len: How many bytes from the folio to add. > > + * @off: First byte in this folio to add. > > + * > > + * Always uses the head page of the folio in the bio. If a submitter only > > + * uses bio_add_folio(), it can count on never seeing tail pages in the > > + * completion routine. BIOs do not support folios that are 4GiB or larger. > > + * > > + * Return: The number of bytes from this folio added to the bio. > > + */ > > +size_t bio_add_folio(struct bio *bio, struct folio *folio, size_t len, > > + size_t off) > > +{ > > + if (len > UINT_MAX || off > UINT_MAX) > > + return 0; > > + return bio_add_page(bio, &folio->page, len, off); > > +} > > I'd use the opportunity to switch to a true/false return instead of > the length. This has been on my todo list for bio_add_page for a while, > so it might make sense to start out the new API the right way. ok.