Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933195AbcL0QIc (ORCPT ); Tue, 27 Dec 2016 11:08:32 -0500 Received: from mail-pg0-f68.google.com ([74.125.83.68]:35399 "EHLO mail-pg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933171AbcL0QIP (ORCPT ); Tue, 27 Dec 2016 11:08:15 -0500 From: Ming Lei To: Jens Axboe , linux-kernel@vger.kernel.org Cc: linux-block@vger.kernel.org, Christoph Hellwig , Ming Lei , Johannes Berg Subject: [PATCH v1 15/54] block: implement sp version of bvec iterator helpers Date: Tue, 27 Dec 2016 23:56:04 +0800 Message-Id: <1482854250-13481-16-git-send-email-tom.leiming@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1482854250-13481-1-git-send-email-tom.leiming@gmail.com> References: <1482854250-13481-1-git-send-email-tom.leiming@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1839 Lines: 57 This patch implements singlepage version of the following 3 helpers: - bvec_iter_offset_sp() - bvec_iter_len_sp() - bvec_iter_page_sp() So that one multipage bvec can be splited to singlepage bvec, and make users of current bvec iterator happy. Signed-off-by: Ming Lei --- include/linux/bvec.h | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/include/linux/bvec.h b/include/linux/bvec.h index 307a387eb29c..d77c3cabce8c 100644 --- a/include/linux/bvec.h +++ b/include/linux/bvec.h @@ -22,6 +22,7 @@ #include #include +#include /* * What is multipage bvecs(segment)? @@ -95,14 +96,25 @@ struct bvec_iter { #define bvec_iter_offset_mp(bvec, iter) \ (__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done) +#define bvec_iter_page_idx_mp(bvec, iter) \ + (bvec_iter_offset_mp((bvec), (iter)) / PAGE_SIZE) + + /* * of singlepage(sp) segment. * * This helpers will be implemented for building sp bvec in flight. */ -#define bvec_iter_offset_sp(bvec, iter) bvec_iter_offset_mp((bvec), (iter)) -#define bvec_iter_len_sp(bvec, iter) bvec_iter_len_mp((bvec), (iter)) -#define bvec_iter_page_sp(bvec, iter) bvec_iter_page_mp((bvec), (iter)) +#define bvec_iter_offset_sp(bvec, iter) \ + (bvec_iter_offset_mp((bvec), (iter)) % PAGE_SIZE) + +#define bvec_iter_len_sp(bvec, iter) \ + min_t(unsigned, bvec_iter_len_mp((bvec), (iter)), \ + (PAGE_SIZE - (bvec_iter_offset_sp((bvec), (iter))))) + +#define bvec_iter_page_sp(bvec, iter) \ + nth_page(bvec_iter_page_mp((bvec), (iter)), \ + bvec_iter_page_idx_mp((bvec), (iter))) /* current interfaces support sp style at default */ #define bvec_iter_page(bvec, iter) bvec_iter_page_sp((bvec), (iter)) -- 2.7.4