Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752778AbdFZMRw (ORCPT ); Mon, 26 Jun 2017 08:17:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51049 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751461AbdFZMRm (ORCPT ); Mon, 26 Jun 2017 08:17:42 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com A3CC480472 Authentication-Results: ext-mx04.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx04.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=ming.lei@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com A3CC480472 From: Ming Lei To: Jens Axboe , Christoph Hellwig , Huang Ying , Andrew Morton , Alexander Viro Cc: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Ming Lei Subject: [PATCH v2 28/51] block: introduce bvec_for_each_sp_bvec() Date: Mon, 26 Jun 2017 20:10:11 +0800 Message-Id: <20170626121034.3051-29-ming.lei@redhat.com> In-Reply-To: <20170626121034.3051-1-ming.lei@redhat.com> References: <20170626121034.3051-1-ming.lei@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Mon, 26 Jun 2017 12:17:36 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1088 Lines: 33 This helper can be used to iterate each singlepage bvec from one multipage bvec. Signed-off-by: Ming Lei --- include/linux/bvec.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/include/linux/bvec.h b/include/linux/bvec.h index 5c51c58fe202..7addceea9828 100644 --- a/include/linux/bvec.h +++ b/include/linux/bvec.h @@ -192,4 +192,18 @@ static inline void bvec_iter_advance_mp(const struct bio_vec *bv, .bi_bvec_done = 0, \ } +/* + * This helper iterates over the multipage bvec of @mp_bvec and + * returns each singlepage bvec via @sp_bvl. + */ +#define __bvec_for_each_sp_bvec(sp_bvl, mp_bvec, iter, start) \ + for (iter = start, \ + (iter).bi_size = (mp_bvec)->bv_len - (iter).bi_bvec_done; \ + (iter).bi_size && \ + ((sp_bvl = bvec_iter_bvec((mp_bvec), (iter))), 1); \ + bvec_iter_advance((mp_bvec), &(iter), (sp_bvl).bv_len)) + +#define bvec_for_each_sp_bvec(sp_bvl, mp_bvec, iter) \ + __bvec_for_each_sp_bvec(sp_bvl, mp_bvec, iter, BVEC_ITER_ALL_INIT) + #endif /* __LINUX_BVEC_ITER_H */ -- 2.9.4