blk-mq-sched: refactor scheduler initialization

Preparation cleanup for the next couple of fixes, push
blk_mq_sched_setup() and e->ops.mq.init_sched() into a helper.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 12 insertions, 20 deletions

diff --git a/block/elevator.c b/block/elevator.c
index 01139f549b5b..f236ef1d2be9 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -242,17 +242,12 @@ int elevator_init(struct request_queue *q, char *name)
                 }
         }
 
-        if (e->uses_mq) {
-                err = blk_mq_sched_setup(q);
-                if (!err)
-                        err = e->ops.mq.init_sched(q, e);
-        } else
+        if (e->uses_mq)
+                err = blk_mq_init_sched(q, e);
+        else
                 err = e->ops.sq.elevator_init_fn(q, e);
-        if (err) {
-                if (e->uses_mq)
-                        blk_mq_sched_teardown(q);
+        if (err)
                 elevator_put(e);
-        }
         return err;
 }
 EXPORT_SYMBOL(elevator_init);
@@ -987,21 +982,18 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
         }
 
         /* allocate, init and register new elevator */
-        if (new_e) {
-                if (new_e->uses_mq) {
-                        err = blk_mq_sched_setup(q);
-                        if (!err)
-                                err = new_e->ops.mq.init_sched(q, new_e);
-                } else
-                        err = new_e->ops.sq.elevator_init_fn(q, new_e);
-                if (err)
-                        goto fail_init;
+        if (q->mq_ops)
+                err = blk_mq_init_sched(q, new_e);
+        else
+                err = new_e->ops.sq.elevator_init_fn(q, new_e);
+        if (err)
+                goto fail_init;
 
+        if (new_e) {
                 err = elv_register_queue(q);
                 if (err)
                         goto fail_register;
-        } else
-                q->elevator = NULL;
+        }
 
         /* done, kill the old one and finish */
         if (old) {