block: Simplify bvec_split_segs()

Simplify this function by by removing two if-tests. Other than requiring
that the @sectors pointer is not NULL, this patch does not change the
behavior of bvec_split_segs().

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 51ed971..7cea505 100644 (file)
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -167,17 +167,17 @@ static bool bvec_split_segs(const struct request_queue *q,
 {
        unsigned len = bv->bv_len;
        unsigned total_len = 0;
-       unsigned new_nsegs = 0, seg_size = 0;
+       unsigned seg_size = 0;
 
        /*
         * Multi-page bvec may be too big to hold in one segment, so the
         * current bvec has to be splitted as multiple segments.
         */
-       while (len && new_nsegs + *nsegs < max_segs) {
+       while (len && *nsegs < max_segs) {
                seg_size = get_max_segment_size(q, bv->bv_offset + total_len);
                seg_size = min(seg_size, len);
 
-               new_nsegs++;
+               (*nsegs)++;
                total_len += seg_size;
                len -= seg_size;
 
@@ -185,11 +185,7 @@ static bool bvec_split_segs(const struct request_queue *q,
                        break;
        }
 
-       if (new_nsegs) {
-               *nsegs += new_nsegs;
-               if (sectors)
-                       *sectors += total_len >> 9;
-       }
+       *sectors += total_len >> 9;
 
        /* split in the middle of the bvec if len != 0 */
        return !!len;
@@ -349,6 +345,7 @@ EXPORT_SYMBOL(blk_queue_split);
 unsigned int blk_recalc_rq_segments(struct request *rq)
 {
        unsigned int nr_phys_segs = 0;
+       unsigned int nr_sectors = 0;
        struct req_iterator iter;
        struct bio_vec bv;
 
@@ -365,7 +362,8 @@ unsigned int blk_recalc_rq_segments(struct request *rq)
        }
 
        rq_for_each_bvec(bv, rq, iter)
-               bvec_split_segs(rq->q, &bv, &nr_phys_segs, NULL, UINT_MAX);
+               bvec_split_segs(rq->q, &bv, &nr_phys_segs, &nr_sectors,
+                               UINT_MAX);
        return nr_phys_segs;
 }