blk-mq: refactor blk_mq_sched_assign_ioc

blk_mq_sched_assign_ioc now only handles the assigned of the ioc if
the schedule needs it (bfq only at the moment).  The caller to the
per-request initializer is moved out so that it can be merged with
a similar call for the kyber I/O scheduler.

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

3 files changed, 17 insertions, 28 deletions

diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index 22601e5c6f19..254d1c164567 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -31,12 +31,10 @@ void blk_mq_sched_free_hctx_data(struct request_queue *q,
 }
 EXPORT_SYMBOL_GPL(blk_mq_sched_free_hctx_data);
 
-static void __blk_mq_sched_assign_ioc(struct request_queue *q,
-                                      struct request *rq,
-                                      struct bio *bio,
-                                      struct io_context *ioc)
+void blk_mq_sched_assign_ioc(struct request *rq, struct bio *bio)
 {
-        struct elevator_queue *e = q->elevator;
+        struct request_queue *q = rq->q;
+        struct io_context *ioc = rq_ioc(bio);
         struct io_cq *icq;
 
         spin_lock_irq(q->queue_lock);
@@ -48,26 +46,8 @@ static void __blk_mq_sched_assign_ioc(struct request_queue *q,
                 if (!icq)
                         return;
         }
-
-        rq->elv.icq = icq;
-        if (e && e->type->ops.mq.get_rq_priv &&
-            e->type->ops.mq.get_rq_priv(q, rq, bio)) {
-                rq->elv.icq = NULL;
-                return;
-        }
-
-        rq->rq_flags |= RQF_ELVPRIV;
         get_io_context(icq->ioc);
-}
-
-void blk_mq_sched_assign_ioc(struct request_queue *q, struct request *rq,
-                             struct bio *bio)
-{
-        struct io_context *ioc;
-
-        ioc = rq_ioc(bio);
-        if (ioc)
-                __blk_mq_sched_assign_ioc(q, rq, bio, ioc);
+        rq->elv.icq = icq;
 }
 
 void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx)
diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h
index f34e6a522105..e117edd039b1 100644
--- a/block/blk-mq-sched.h
+++ b/block/blk-mq-sched.h
@@ -7,8 +7,7 @@
 void blk_mq_sched_free_hctx_data(struct request_queue *q,
                                  void (*exit)(struct blk_mq_hw_ctx *));
 
-void blk_mq_sched_assign_ioc(struct request_queue *q, struct request *rq,
-                             struct bio *bio);
+void blk_mq_sched_assign_ioc(struct request *rq, struct bio *bio);
 
 void blk_mq_sched_request_inserted(struct request *rq);
 bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio,
diff --git a/block/blk-mq.c b/block/blk-mq.c
index e056725679a8..2f380ab7a603 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -315,8 +315,18 @@ allocated:
 
         if (!op_is_flush(op)) {
                 rq->elv.icq = NULL;
-                if (e && e->type->icq_cache)
-                        blk_mq_sched_assign_ioc(q, rq, bio);
+                if (e && e->type->ops.mq.get_rq_priv) {
+                        if (e->type->icq_cache && rq_ioc(bio))
+                                blk_mq_sched_assign_ioc(rq, bio);
+
+                        if (e->type->ops.mq.get_rq_priv(q, rq, bio)) {
+                                if (rq->elv.icq)
+                                        put_io_context(rq->elv.icq->ioc);
+                                rq->elv.icq = NULL;
+                        } else {
+                                rq->rq_flags |= RQF_ELVPRIV;
+                        }
+                }
         }
         data->hctx->queued++;
         return rq;