Messages in this thread Patch in this message | | | Subject | [PATCH] block: Find bio sector offset given idx and offset | From | "Martin K. Petersen" <> | Date | Sat, 20 Sep 2008 20:13:29 -0400 |
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Helper function to find the sector offset in a bio given bvec index and page offset.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> --- 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
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