From patchwork Thu Jul 15 03:36:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12378775 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 4B20AC07E96 for ; Thu, 15 Jul 2021 04:49:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2D6AC6127C for ; Thu, 15 Jul 2021 04:49:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238186AbhGOEw1 (ORCPT ); Thu, 15 Jul 2021 00:52:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33352 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230260AbhGOEwY (ORCPT ); Thu, 15 Jul 2021 00:52:24 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64076C06175F; Wed, 14 Jul 2021 21:49:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=bVPSf8Zkk6csbsziZBtmmFnz26QKcpfneTyu4NcWG00=; b=MP98r+uaUTbvmm2JId8fjdzTC4 2qNmDz1mcEOLAJIB2JrVexA7t8KC5MtIDjVBlZyqiciFtMfr6W1st2wxwfe9B7K/iDlxvmMULBvoa e5gBNEkSEBZclNRiXhhDRtreYGZ09wu5GJnrNDOOuoOszIsDOUttihW47+OZjLj5beA2cEO4IR6Bx g7IpKRFsTajYH9NMbmoQMkRJw2jWSwTOm7u5qBQOLS61D1J9yk6RnlL36tcNLT7KitqvKVYhXfKs1 VtRQYcN59+iqjnD/gV6IXnmYSLlfhQlnlbhKSw0HqLV4lb+zjq0ln8D2VthPyGLeUrZ71YVYOoqso iK+zp5Aw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m3tIO-002yla-TH; Thu, 15 Jul 2021 04:48:30 +0000 From: "Matthew Wilcox (Oracle)" To: linux-kernel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v14 090/138] block: Add bio_add_folio() Date: Thu, 15 Jul 2021 04:36:16 +0100 Message-Id: <20210715033704.692967-91-willy@infradead.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210715033704.692967-1-willy@infradead.org> References: <20210715033704.692967-1-willy@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org This is a thin wrapper around bio_add_page(). The main advantage here is the documentation that the submitter can expect to see folios in the completion handler, and that stupidly large folios are not supported. It's not currently possible to allocate stupidly large folios, but if it ever becomes possible, this function will fail gracefully instead of doing I/O to the wrong bytes. Signed-off-by: Matthew Wilcox (Oracle) --- block/bio.c | 21 +++++++++++++++++++++ include/linux/bio.h | 3 ++- 2 files changed, 23 insertions(+), 1 deletion(-) diff --git a/block/bio.c b/block/bio.c index 1fab762e079b..1b500611d25c 100644 --- a/block/bio.c +++ b/block/bio.c @@ -933,6 +933,27 @@ int bio_add_page(struct bio *bio, struct page *page, } EXPORT_SYMBOL(bio_add_page); +/** + * 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 larger than 2GiB. + * + * 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); +} + void bio_release_pages(struct bio *bio, bool mark_dirty) { struct bvec_iter_all iter_all; diff --git a/include/linux/bio.h b/include/linux/bio.h index 2203b686e1f0..ade93e2de6a1 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -462,7 +462,8 @@ extern void bio_uninit(struct bio *); extern void bio_reset(struct bio *); void bio_chain(struct bio *, struct bio *); -extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int); +int bio_add_page(struct bio *, struct page *, unsigned len, unsigned off); +size_t bio_add_folio(struct bio *, struct folio *, size_t len, size_t off); extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *, unsigned int, unsigned int); int bio_add_zone_append_page(struct bio *bio, struct page *page,