lkml.org 
[lkml]   [2007]   [May]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4/10] block: convert to using sg helpers
    Date
    Convert the main rq mapper (blk_rq_map_sg()) to the sg helper setup.

    Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
    ---
    block/ll_rw_blk.c | 19 ++++++++++++-------
    1 files changed, 12 insertions(+), 7 deletions(-)
    diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
    index d99d402..0ad4c34 100644
    --- a/block/ll_rw_blk.c
    +++ b/block/ll_rw_blk.c
    @@ -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
    @@ -1307,9 +1308,11 @@ static int blk_hw_contig_segment(request_queue_t *q, struct bio *bio,
    * map a request to scatterlist, return number of sg entries setup. Caller
    * must make sure sg can hold rq->nr_phys_segments entries
    */
    -int blk_rq_map_sg(request_queue_t *q, struct request *rq, struct scatterlist *sg)
    +int blk_rq_map_sg(request_queue_t *q, struct request *rq,
    + struct scatterlist *sglist)
    {
    struct bio_vec *bvec, *bvprv;
    + struct scatterlist *next_sg, *sg;
    struct bio *bio;
    int nsegs, i, cluster;

    @@ -1320,6 +1323,7 @@ int blk_rq_map_sg(request_queue_t *q, struct request *rq, struct scatterlist *sg
    * for each bio in rq
    */
    bvprv = NULL;
    + sg = next_sg = &sglist[0];
    rq_for_each_bio(bio, rq) {
    /*
    * for each segment in bio
    @@ -1328,7 +1332,7 @@ int blk_rq_map_sg(request_queue_t *q, struct request *rq, struct scatterlist *sg
    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))
    @@ -1336,14 +1340,15 @@ int blk_rq_map_sg(request_queue_t *q, struct request *rq, struct scatterlist *sg
    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;
    --
    1.5.2.rc1
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2007-05-09 10:03    [from the cache]
    ©2003-2014 Jasper Spaans. Advertise on this site