From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754413AbYIUANn (ORCPT ); Sat, 20 Sep 2008 20:13:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751808AbYIUANf (ORCPT ); Sat, 20 Sep 2008 20:13:35 -0400 Received: from agminet01.oracle.com ([141.146.126.228]:26206 "EHLO agminet01.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751714AbYIUANe (ORCPT ); Sat, 20 Sep 2008 20:13:34 -0400 To: jens.axboe@oracle.com Cc: linux-kernel@vger.kernel.org Subject: [PATCH] block: Find bio sector offset given idx and offset From: "Martin K. Petersen" Organization: Oracle Date: Sat, 20 Sep 2008 20:13:29 -0400 Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Brightmail-Tracker: AAAAAQAAAAI= X-Brightmail-Tracker: AAAAAQAAAAI= X-Whitelist: TRUE X-Whitelist: TRUE Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Helper function to find the sector offset in a bio given bvec index and page offset. Signed-off-by: Martin K. Petersen --- fs/bio.c | 24 ++++++++++++++++++++++++ include/linux/bio.h | 2 ++ 2 files changed, 26 insertions(+), 0 deletions(-) diff --git a/fs/bio.c b/fs/bio.c index e56e768..6fd3a86 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -1300,6 +1300,30 @@ struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors) return bp; } +sector_t bio_sector_offset(struct bio *bio, unsigned short index, unsigned int offset) +{ + struct bio_vec *bv; + unsigned int sector_sz = bio->bi_bdev->bd_disk->queue->hardsect_size; + sector_t sectors; + int i; + + sectors = 0; + + BUG_ON(index >= bio->bi_vcnt); + + bio_for_each_segment(bv, bio, i) { + if (i == index) { + if (offset > bv->bv_offset) + sectors += (offset - bv->bv_offset) / sector_sz; + return sectors; + } + + sectors += bv->bv_len / sector_sz; + } + + BUG(); +} +EXPORT_SYMBOL(bio_sector_offset); /* * create memory pools for biovec's in a bio_set. diff --git a/include/linux/bio.h b/include/linux/bio.h index 6aba97d..895a960 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -327,6 +327,8 @@ extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int); extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *, unsigned int, unsigned int); extern int bio_get_nr_vecs(struct block_device *); +extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int); + extern struct bio *bio_map_user(struct request_queue *, struct block_device *, unsigned long, unsigned int, int, gfp_t); struct sg_iovec; -- 1.5.5.1