Messages in this thread |  | | | Date | Sat, 20 Sep 2008 21:04:44 -0700 | | From | Andrew Morton <> | | Subject | Re: [PATCH] block: Find bio sector offset given idx and offset |
On Sat, 20 Sep 2008 20:13:29 -0400 "Martin K. Petersen" <martin.petersen@oracle.com> wrote:
> @@ -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);
Please avoid sending out kenrel-wide exported-to-modules utility
functions which have no documentation.
Not only is it a bad thing from a maintainability and reliability point
of view - it also makes code review significantly less effective.
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