[PATCH 8/8] block: use bio_has_data to check if a bio has bvecs

[Christoph Hellwig]

Now that Write Same is gone and discard bios never have a payload we
can simply use bio_has_data as an indicator that the bio has bvecs
that need to be handled.

Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 block/bio.c         |  8 +-------
 block/blk-merge.c   |  9 +--------
 include/linux/bio.h | 21 +++++----------------
 3 files changed, 7 insertions(+), 31 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index b310e7ef3fbf..1c9f04c30ba9 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -679,15 +679,9 @@ static struct bio *__bio_clone_bioset(struct bio *bio_src, 
gfp_t gfp_mask,
        bio->bi_iter.bi_sector  = bio_src->bi_iter.bi_sector;
        bio->bi_iter.bi_size    = bio_src->bi_iter.bi_size;
 
-       switch (bio_op(bio)) {
-       case REQ_OP_DISCARD:
-       case REQ_OP_SECURE_ERASE:
-       case REQ_OP_WRITE_ZEROES:
-               break;
-       default:
+       if (bio_has_data(bio)) {
                __bio_for_each_segment(bv, bio_src, iter, iter_src)
                        bio->bi_io_vec[bio->bi_vcnt++] = bv;
-               break;
        }
 
        if (bio_integrity(bio_src)) {
diff --git a/block/blk-merge.c b/block/blk-merge.c
index d6c86bfc5722..549d060097f1 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -232,16 +232,9 @@ static unsigned int __blk_recalc_rq_segments(struct 
request_queue *q,
        struct bio *fbio, *bbio;
        struct bvec_iter iter;
 
-       if (!bio)
+       if (!bio || !bio_has_data(bio))
                return 0;
 
-       switch (bio_op(bio)) {
-       case REQ_OP_DISCARD:
-       case REQ_OP_SECURE_ERASE:
-       case REQ_OP_WRITE_ZEROES:
-               return 0;
-       }
-
        fbio = bio;
        cluster = blk_queue_cluster(q);
        seg_size = 0;
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 7a24a1a24967..86bf531f97aa 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -178,26 +178,15 @@ static inline void bio_advance_iter(struct bio *bio, 
struct bvec_iter *iter,
 static inline unsigned __bio_segments(struct bio *bio, struct bvec_iter *bvec)
 {
        unsigned segs = 0;
-       struct bio_vec bv;
-       struct bvec_iter iter;
 
-       /*
-        * We special case discard/write same/write zeroes, because they
-        * interpret bi_size differently:
-        */
+       if (bio_has_data(bio)) {
+               struct bio_vec bv;
+               struct bvec_iter iter;
 
-       switch (bio_op(bio)) {
-       case REQ_OP_DISCARD:
-       case REQ_OP_SECURE_ERASE:
-       case REQ_OP_WRITE_ZEROES:
-               return 0;
-       default:
-               break;
+               __bio_for_each_segment(bv, bio, iter, *bvec)
+                       segs++;
        }
 
-       __bio_for_each_segment(bv, bio, iter, *bvec)
-               segs++;
-
        return segs;
 }
 
-- 
2.11.0