block: make blk_init_free_list and elevator_init idempotent
blk_init_allocated_queue_node may fail and the caller _could_ retry.
Accommodate the unlikely event that blk_init_allocated_queue_node is
called on an already initialized (possibly partially) request_queue.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/block/elevator.c b/block/elevator.c
index 0abce47..923a913 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -242,9 +242,11 @@
{
struct elevator_type *e = NULL;
struct elevator_queue *eq;
- int ret = 0;
void *data;
+ if (unlikely(q->elevator))
+ return 0;
+
INIT_LIST_HEAD(&q->queue_head);
q->last_merge = NULL;
q->end_sector = 0;
@@ -284,7 +286,7 @@
}
elevator_attach(q, eq, data);
- return ret;
+ return 0;
}
EXPORT_SYMBOL(elevator_init);