Remove flush_dry_bio_endio

The entire function of flush_dry_bio_endio is to undo the effects
of bio_endio (when called on a barrier request).  So remove the
function and the call to bio_endio.

This allows us to remove "bi_size" from "struct request_queue".

Signed-off-by: Neil Brown <neilb@suse.de>

### Diffstat output
 ./block/ll_rw_blk.c      |   39 ++-------------------------------------
 ./include/linux/blkdev.h |    1 -
 2 files changed, 2 insertions(+), 38 deletions(-)

diff .prev/block/ll_rw_blk.c ./block/ll_rw_blk.c
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 2 insertions, 37 deletions

diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 3b2eff4e83a6..dfe0948ec8b2 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -431,7 +431,6 @@ static void queue_flush(struct request_queue *q, unsigned which)
 static inline struct request *start_ordered(struct request_queue *q,
                                             struct request *rq)
 {
-        q->bi_size = 0;
         q->orderr = 0;
         q->ordered = q->next_ordered;
         q->ordseq |= QUEUE_ORDSEQ_STARTED;
@@ -528,55 +527,21 @@ int blk_do_ordered(struct request_queue *q, struct request **rqp)
         return 1;
 }
 
-static int flush_dry_bio_endio(struct bio *bio, unsigned int bytes, int error)
-{
-        struct request_queue *q = bio->bi_private;
-
-        /*
-         * This is dry run, restore bio_sector and size.  We'll finish
-         * this request again with the original bi_end_io after an
-         * error occurs or post flush is complete.
-         */
-        q->bi_size += bytes;
-
-        if (bio->bi_size)
-                return 1;
-
-        /* Reset bio */
-        set_bit(BIO_UPTODATE, &bio->bi_flags);
-        bio->bi_size = q->bi_size;
-        bio->bi_sector -= (q->bi_size >> 9);
-        q->bi_size = 0;
-
-        return 0;
-}
-
 static int ordered_bio_endio(struct request *rq, struct bio *bio,
                              unsigned int nbytes, int error)
 {
         struct request_queue *q = rq->q;
-        bio_end_io_t *endio;
-        void *private;
 
         if (&q->bar_rq != rq)
                 return 0;
 
         /*
-         * Okay, this is the barrier request in progress, dry finish it.
+         * Okay, this is the barrier request in progress, just
+         * record the error;
          */
         if (error && !q->orderr)
                 q->orderr = error;
 
-        endio = bio->bi_end_io;
-        private = bio->bi_private;
-        bio->bi_end_io = flush_dry_bio_endio;
-        bio->bi_private = q;
-
-        bio_endio(bio, nbytes, error);
-
-        bio->bi_end_io = endio;
-        bio->bi_private = private;
-
         return 1;
 }