From patchwork Wed May 25 06:12:29 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "(Exiting) Baolin Wang" X-Patchwork-Id: 9134809 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id ACA5D607D3 for ; Wed, 25 May 2016 06:13:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9EAF0280D2 for ; Wed, 25 May 2016 06:13:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 919D2282B0; Wed, 25 May 2016 06:13:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 12F9F280D2 for ; Wed, 25 May 2016 06:13:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755498AbcEYGM5 (ORCPT ); Wed, 25 May 2016 02:12:57 -0400 Received: from mail-pf0-f175.google.com ([209.85.192.175]:34761 "EHLO mail-pf0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755489AbcEYGMz (ORCPT ); Wed, 25 May 2016 02:12:55 -0400 Received: by mail-pf0-f175.google.com with SMTP id y69so14982006pfb.1 for ; Tue, 24 May 2016 23:12:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :in-reply-to:references; bh=hjLd/m7uOUrw6EfBiJhyV1i8B/YXwVtwYQq5Gd+Cu6o=; b=U3Cfr5wrMgTs1YuQp7ka05yYjic61yeFVqHEc9QqkQfQGFmDCGAdnd3lc0JF1/8Cfm rogtilh9/u18yVQh3UUV7zMVFFQ1eu2nuFhWMvZuxYIp0/d5kUx5fYqIkTG+B3Q6wUVR NnC/RNVPCwGSd7CloWsan2HvEd0voR08BzZ1A= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:in-reply-to:references; bh=hjLd/m7uOUrw6EfBiJhyV1i8B/YXwVtwYQq5Gd+Cu6o=; b=PnCels2+SIgz3e53hVpYwCKvaSgGvWmwTtooo6+g4FAFK3wlmXSjU+HZ31TsJgsbbc asfQRXenWlQSuKuk8RD19UgdXijv7qamKmksv47p8hIZNOTCw4NKzDXQwMkP4obzoXl4 1+VCqthlx4309myaF3EXXV7sTOvBxwqHl2ZSbxJ+f6NyHoyshSiS+MASunvApZf+0zIn qU89Eka1+2QS0DKDpcZa2vRgacaMVIp2auSqSPXAF0NWxavkUEZTVDcqQNeiVVRQH3tA m5u7bDrQvGVM6FJHN6Uw56tRmEpKbGhV+OqDlk8DRUWGnBeCYb0PfMphw0lbLh7vWA2f 4g4Q== X-Gm-Message-State: ALyK8tJDdW8N47o3bujxyNwUu3447fJH7rNr63FB8R6Nkx52n/klZqKQo77yjoFad+TJBKoe X-Received: by 10.98.55.129 with SMTP id e123mr3247936pfa.4.1464156774591; Tue, 24 May 2016 23:12:54 -0700 (PDT) Received: from baolinwangubtpc.spreadtrum.com ([175.111.195.49]) by smtp.gmail.com with ESMTPSA id l129sm17484335pfc.5.2016.05.24.23.12.47 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 24 May 2016 23:12:53 -0700 (PDT) From: Baolin Wang To: axboe@kernel.dk, agk@redhat.com, snitzer@redhat.com, dm-devel@redhat.com, herbert@gondor.apana.org.au, davem@davemloft.net Cc: ebiggers3@gmail.com, js1304@gmail.com, tadeusz.struk@intel.com, smueller@chronox.de, standby24x7@gmail.com, shli@kernel.org, dan.j.williams@intel.com, martin.petersen@oracle.com, sagig@mellanox.com, kent.overstreet@gmail.com, keith.busch@intel.com, tj@kernel.org, ming.lei@canonical.com, broonie@kernel.org, arnd@arndb.de, linux-crypto@vger.kernel.org, linux-block@vger.kernel.org, linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, baolin.wang@linaro.org Subject: [RFC 1/3] block: Introduce blk_bio_map_sg() to map one bio Date: Wed, 25 May 2016 14:12:29 +0800 Message-Id: X-Mailer: git-send-email 1.7.9.5 In-Reply-To: References: In-Reply-To: References: Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In dm-crypt, it need to map one bio to scatterlist for improving the hardware engine encryption efficiency. Thus this patch introduces the blk_bio_map_sg() function to map one bio with scatterlists. Signed-off-by: Baolin Wang --- block/blk-merge.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/blkdev.h | 3 +++ 2 files changed, 48 insertions(+) diff --git a/block/blk-merge.c b/block/blk-merge.c index 2613531..9b92af4 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -417,6 +417,51 @@ single_segment: } /* + * map a bio to scatterlist, return number of sg entries setup. + */ +int blk_bio_map_sg(struct request_queue *q, struct bio *bio, + struct scatterlist *sglist, + struct scatterlist **sg) +{ + struct bio_vec bvec, bvprv = { NULL }; + struct bvec_iter iter; + int nsegs, cluster; + + nsegs = 0; + cluster = blk_queue_cluster(q); + + if (bio->bi_rw & REQ_DISCARD) { + /* + * This is a hack - drivers should be neither modifying the + * biovec, nor relying on bi_vcnt - but because of + * blk_add_request_payload(), a discard bio may or may not have + * a payload we need to set up here (thank you Christoph) and + * bi_vcnt is really the only way of telling if we need to. + */ + + if (bio->bi_vcnt) + goto single_segment; + + return 0; + } + + if (bio->bi_rw & REQ_WRITE_SAME) { +single_segment: + *sg = sglist; + bvec = bio_iovec(bio); + sg_set_page(*sg, bvec.bv_page, bvec.bv_len, bvec.bv_offset); + return 1; + } + + bio_for_each_segment(bvec, bio, iter) + __blk_segment_map_sg(q, &bvec, sglist, &bvprv, sg, + &nsegs, &cluster); + + return nsegs; +} +EXPORT_SYMBOL(blk_bio_map_sg); + +/* * map a request to scatterlist, return number of sg entries setup. Caller * must make sure sg can hold rq->nr_phys_segments entries */ diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 1fd8fdf..e5de4f8 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1013,6 +1013,9 @@ extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fu extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *); +extern int blk_bio_map_sg(struct request_queue *q, struct bio *bio, + struct scatterlist *sglist, + struct scatterlist **sg); extern void blk_dump_rq_flags(struct request *, char *); extern long nr_blockdev_pages(void);