block: remove the bi_phys_segments field in struct bio

We only need the number of segments in the blk-mq submission path.
Remove the field from struct bio, and return it from a variant of
blk_queue_split instead of that it can passed as an argument to
those functions that need the value.

This also means we stop recounting segments except for cloning
and partial segments.

To keep the number of arguments in this how path down remove
pointless struct request_queue arguments from any of the functions
that had it and grew a nr_segs argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 3 insertions, 2 deletions

diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index 1876f5712bfd..b8a682b5a1bb 100644
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -469,7 +469,8 @@ static int dd_request_merge(struct request_queue *q, struct request **rq,
         return ELEVATOR_NO_MERGE;
 }
 
-static bool dd_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio)
+static bool dd_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio,
+                unsigned int nr_segs)
 {
         struct request_queue *q = hctx->queue;
         struct deadline_data *dd = q->elevator->elevator_data;
@@ -477,7 +478,7 @@ static bool dd_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio)
         bool ret;
 
         spin_lock(&dd->lock);
-        ret = blk_mq_sched_try_merge(q, bio, &free);
+        ret = blk_mq_sched_try_merge(q, bio, nr_segs, &free);
         spin_unlock(&dd->lock);
 
         if (free)