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>
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 388fe01..72680a6 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -3656,7 +3656,7 @@
kfree(cfqd);
}
-static void *cfq_init_queue(struct request_queue *q)
+static int cfq_init_queue(struct request_queue *q)
{
struct cfq_data *cfqd;
int i, j;
@@ -3665,7 +3665,7 @@
cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node);
if (!cfqd)
- return NULL;
+ return -ENOMEM;
/* Init root service tree */
cfqd->grp_service_tree = CFQ_RB_ROOT;
@@ -3692,7 +3692,7 @@
if (blkio_alloc_blkg_stats(&cfqg->blkg)) {
kfree(cfqg);
kfree(cfqd);
- return NULL;
+ return -ENOMEM;
}
rcu_read_lock();
@@ -3723,6 +3723,7 @@
cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, &cfqd->root_group);
cfqd->queue = q;
+ q->elevator->elevator_data = cfqd;
init_timer(&cfqd->idle_slice_timer);
cfqd->idle_slice_timer.function = cfq_idle_slice_timer;
@@ -3747,7 +3748,7 @@
* second, in order to have larger depth for async operations.
*/
cfqd->last_delayed_sync = jiffies - HZ;
- return cfqd;
+ return 0;
}
/*