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author | Martin K. Petersen <martin.petersen@oracle.com> | 2008-10-02 02:42:53 (GMT) |
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committer | Jens Axboe <jens.axboe@oracle.com> | 2008-10-09 06:56:22 (GMT) |
commit | ad3316bf4eeb53c89164f759767f911072b56203 (patch) | |
tree | 12caa0194f385c58e4543ad864a58dff02f33a47 /fs | |
parent | b02739b01c5309d74a59859f2ce92c931d1f1955 (diff) | |
download | linux-fsl-qoriq-ad3316bf4eeb53c89164f759767f911072b56203.tar.xz |
block: Find bio sector offset given idx and offset
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>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/bio.c | 36 |
1 files changed, 36 insertions, 0 deletions
@@ -1300,6 +1300,42 @@ struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors) return bp; } +/** + * bio_sector_offset - Find hardware sector offset in bio + * @bio: bio to inspect + * @index: bio_vec index + * @offset: offset in bv_page + * + * Return the number of hardware sectors between beginning of bio + * and an end point indicated by a bio_vec index and an offset + * within that vector's page. + */ +sector_t bio_sector_offset(struct bio *bio, unsigned short index, + unsigned int offset) +{ + unsigned int sector_sz = queue_hardsect_size(bio->bi_bdev->bd_disk->queue); + struct bio_vec *bv; + sector_t sectors; + int i; + + sectors = 0; + + if (index >= bio->bi_idx) + index = bio->bi_vcnt - 1; + + __bio_for_each_segment(bv, bio, i, 0) { + if (i == index) { + if (offset > bv->bv_offset) + sectors += (offset - bv->bv_offset) / sector_sz; + break; + } + + sectors += bv->bv_len / sector_sz; + } + + return sectors; +} +EXPORT_SYMBOL(bio_sector_offset); /* * create memory pools for biovec's in a bio_set. |