block: untangle the end of blk_bio_segment_split [Linux 5.3]

This Linux kernel change "block: untangle the end of blk_bio_segment_split" is included in the Linux 5.3 release. This change is authored by Christoph Hellwig <hch [at] lst.de> on Thu Jun 6 12:29:03 2019 +0200. The commit for this change in Linux stable tree is d627065 (patch).

block: untangle the end of blk_bio_segment_split

Now that we don't need to assign the front/back segment sizes, we can
duplicating the segs assignment for the split vs no-split case and
remove a whole chunk of boilerplate code.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

There are 14 lines of Linux source code added/deleted in this change. Code changes to Linux kernel are as follows.

 block/blk-merge.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 2ea21ff..ca45eb5 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -202,8 +202,6 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
    struct bio_vec bv, bvprv, *bvprvp = NULL;
    struct bvec_iter iter;
    unsigned nsegs = 0, sectors = 0;
-   bool do_split = true;
-   struct bio *new = NULL;
    const unsigned max_sectors = get_max_io_size(q, bio);
    const unsigned max_segs = queue_max_segments(q);

@@ -245,17 +243,11 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
        }
    }

-   do_split = false;
+   *segs = nsegs;
+   return NULL;
 split:
    *segs = nsegs;
-
-   if (do_split) {
-       new = bio_split(bio, sectors, GFP_NOIO, bs);
-       if (new)
-           bio = new;
-   }
-
-   return do_split ? new : NULL;
+   return bio_split(bio, sectors, GFP_NOIO, bs);
 }

 void __blk_queue_split(struct request_queue *q, struct bio **bio,

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