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block: convert to using sg helpers

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Convert the main rq mapper (blk_rq_map_sg()) to the sg helper setup.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Jens Axboe 2007-09-21 10:44:19 +02:00
parent 96b418c960
commit f565913ef8
1 changed files with 11 additions and 7 deletions
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18
block/ll_rw_blk.c
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@ -30,6 +30,7 @@
#include <linux/cpu.h>
#include <linux/blktrace_api.h>
#include <linux/fault-inject.h>
#include <linux/scatterlist.h>
/*
* for max sense size
@ -1318,9 +1319,10 @@ static int blk_hw_contig_segment(struct request_queue *q, struct bio *bio,
* must make sure sg can hold rq->nr_phys_segments entries
*/
int blk_rq_map_sg(struct request_queue *q, struct request *rq,
struct scatterlist *sg)
struct scatterlist *sglist)
{
struct bio_vec *bvec, *bvprv;
struct scatterlist *next_sg, *sg;
struct req_iterator iter;
int nsegs, cluster;
@ -1331,11 +1333,12 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq,
* for each bio in rq
*/
bvprv = NULL;
sg = next_sg = &sglist[0];
rq_for_each_segment(bvec, rq, iter) {
int nbytes = bvec->bv_len;
if (bvprv && cluster) {
if (sg[nsegs - 1].length + nbytes > q->max_segment_size)
if (sg->length + nbytes > q->max_segment_size)
goto new_segment;
if (!BIOVEC_PHYS_MERGEABLE(bvprv, bvec))
@ -1343,14 +1346,15 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq,
if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bvec))
goto new_segment;
sg[nsegs - 1].length += nbytes;
sg->length += nbytes;
} else {
new_segment:
memset(&sg[nsegs],0,sizeof(struct scatterlist));
sg[nsegs].page = bvec->bv_page;
sg[nsegs].length = nbytes;
sg[nsegs].offset = bvec->bv_offset;
sg = next_sg;
next_sg = sg_next(sg);
sg->page = bvec->bv_page;
sg->length = nbytes;
sg->offset = bvec->bv_offset;
nsegs++;
}
bvprv = bvec;