drm/amd: fix init order of sched job

[mirror_ubuntu-artful-kernel.git] / block / elevator.c

diff --git a/block/elevator.c b/block/elevator.c
index 01139f549b5be73047f346153f5b8fedcb23b3d0..dbeecf7be719eaada4457ed3c7ac799fd0bbacec 100644 (file)
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -242,26 +242,21 @@ 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);
 
-void elevator_exit(struct elevator_queue *e)
+void elevator_exit(struct request_queue *q, struct elevator_queue *e)
 {
        mutex_lock(&e->sysfs_lock);
        if (e->uses_mq && e->type->ops.mq.exit_sched)
-               e->type->ops.mq.exit_sched(e);
+               blk_mq_exit_sched(q, e);
        else if (!e->uses_mq && e->type->ops.sq.elevator_exit_fn)
                e->type->ops.sq.elevator_exit_fn(e);
        mutex_unlock(&e->sysfs_lock);
@@ -946,6 +941,45 @@ void elv_unregister(struct elevator_type *e)
 }
 EXPORT_SYMBOL_GPL(elv_unregister);
 
+static int elevator_switch_mq(struct request_queue *q,
+                             struct elevator_type *new_e)
+{
+       int ret;
+
+       blk_mq_freeze_queue(q);
+       blk_mq_quiesce_queue(q);
+
+       if (q->elevator) {
+               if (q->elevator->registered)
+                       elv_unregister_queue(q);
+               ioc_clear_queue(q);
+               elevator_exit(q, q->elevator);
+       }
+
+       ret = blk_mq_init_sched(q, new_e);
+       if (ret)
+               goto out;
+
+       if (new_e) {
+               ret = elv_register_queue(q);
+               if (ret) {
+                       elevator_exit(q, q->elevator);
+                       goto out;
+               }
+       }
+
+       if (new_e)
+               blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name);
+       else
+               blk_add_trace_msg(q, "elv switch: none");
+
+out:
+       blk_mq_unfreeze_queue(q);
+       blk_mq_start_stopped_hw_queues(q, true);
+       return ret;
+
+}
+
 /*
  * switch to new_e io scheduler. be careful not to introduce deadlocks -
  * we don't free the old io scheduler, before we have allocated what we
@@ -958,10 +992,8 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
        bool old_registered = false;
        int err;
 
-       if (q->mq_ops) {
-               blk_mq_freeze_queue(q);
-               blk_mq_quiesce_queue(q);
-       }
+       if (q->mq_ops)
+               return elevator_switch_mq(q, new_e);
 
        /*
         * Turn on BYPASS and drain all requests w/ elevator private data.
@@ -973,11 +1005,7 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
        if (old) {
                old_registered = old->registered;
 
-               if (old->uses_mq)
-                       blk_mq_sched_teardown(q);
-
-               if (!q->mq_ops)
-                       blk_queue_bypass_start(q);
+               blk_queue_bypass_start(q);
 
                /* unregister and clear all auxiliary data of the old elevator */
                if (old_registered)
@@ -987,56 +1015,32 @@ 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;
+       err = new_e->ops.sq.elevator_init_fn(q, new_e);
+       if (err)
+               goto fail_init;
 
-               err = elv_register_queue(q);
-               if (err)
-                       goto fail_register;
-       } else
-               q->elevator = NULL;
+       err = elv_register_queue(q);
+       if (err)
+               goto fail_register;
 
        /* done, kill the old one and finish */
        if (old) {
-               elevator_exit(old);
-               if (!q->mq_ops)
-                       blk_queue_bypass_end(q);
+               elevator_exit(q, old);
+               blk_queue_bypass_end(q);
        }
 
-       if (q->mq_ops) {
-               blk_mq_unfreeze_queue(q);
-               blk_mq_start_stopped_hw_queues(q, true);
-       }
-
-       if (new_e)
-               blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name);
-       else
-               blk_add_trace_msg(q, "elv switch: none");
+       blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name);
 
        return 0;
 
 fail_register:
-       if (q->mq_ops)
-               blk_mq_sched_teardown(q);
-       elevator_exit(q->elevator);
+       elevator_exit(q, q->elevator);
 fail_init:
        /* switch failed, restore and re-register old elevator */
        if (old) {
                q->elevator = old;
                elv_register_queue(q);
-               if (!q->mq_ops)
-                       blk_queue_bypass_end(q);
-       }
-       if (q->mq_ops) {
-               blk_mq_unfreeze_queue(q);
-               blk_mq_start_stopped_hw_queues(q, true);
+               blk_queue_bypass_end(q);
        }
 
        return err;