elevator: make elevator_init_fn() return 0/-errno

elevator_ops->elevator_init_fn() has a weird return value.  It returns
a void * which the caller should assign to q->elevator->elevator_data
and %NULL return denotes init failure.

Update such that it returns integer 0/-errno and sets elevator_data
directly as necessary.

This makes the interface more conventional and eases further cleanup.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 2 insertions, 10 deletions

diff --git a/block/elevator.c b/block/elevator.c
index f8c08e1bff2..f81c061dad1 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -121,14 +121,6 @@ static struct elevator_type *elevator_get(const char *name)
         return e;
 }
 
-static int elevator_init_queue(struct request_queue *q)
-{
-        q->elevator->elevator_data = q->elevator->type->ops.elevator_init_fn(q);
-        if (q->elevator->elevator_data)
-                return 0;
-        return -ENOMEM;
-}
-
 static char chosen_elevator[ELV_NAME_MAX];
 
 static int __init elevator_setup(char *str)
@@ -224,7 +216,7 @@ int elevator_init(struct request_queue *q, char *name)
         if (!q->elevator)
                 return -ENOMEM;
 
-        err = elevator_init_queue(q);
+        err = e->ops.elevator_init_fn(q);
         if (err) {
                 kobject_put(&q->elevator->kobj);
                 return err;
@@ -927,7 +919,7 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
         if (!q->elevator)
                 goto fail_init;
 
-        err = elevator_init_queue(q);
+        err = new_e->ops.elevator_init_fn(q);
         if (err) {
                 kobject_put(&q->elevator->kobj);
                 goto fail_init;