From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161021AbcFGMSM (ORCPT ); Tue, 7 Jun 2016 08:18:12 -0400 Received: from mail-pa0-f53.google.com ([209.85.220.53]:35120 "EHLO mail-pa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932382AbcFGMSI (ORCPT ); Tue, 7 Jun 2016 08:18:08 -0400 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 v4 1/4] block: Introduce blk_bio_map_sg() to map one bio Date: Tue, 7 Jun 2016 20:17:04 +0800 Message-Id: <311c342ac55d36ab03e44c31dc65ebfa24cbc8aa.1465301616.git.baolin.wang@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 | 19 +++++++++++++++++++ include/linux/blkdev.h | 2 ++ 2 files changed, 21 insertions(+) diff --git a/block/blk-merge.c b/block/blk-merge.c index 2613531..bca0609 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -417,6 +417,25 @@ single_segment: } /* + * Map a bio to scatterlist, return number of sg entries setup. Caller must + * make sure sg can hold bio segments entries and detach the bio from list. + */ +int blk_bio_map_sg(struct request_queue *q, struct bio *bio, + struct scatterlist *sglist) +{ + struct scatterlist *sg = NULL; + int nsegs; + + nsegs = __blk_bios_map_sg(q, bio, sglist, &sg); + + if (sg) + sg_mark_end(sg); + + 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 3d9cf32..cbe31f9 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1024,6 +1024,8 @@ 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); extern void blk_dump_rq_flags(struct request *, char *); extern long nr_blockdev_pages(void); -- 1.7.9.5