Commit 8406a4d5 authored Apr 23, 2015 by Chao Yu Committed by Jens Axboe Apr 23, 2015

elevator: fix double release of elevator module



Our issue is descripted in below call path:
->elevator_init
 ->elevator_init_fn
  ->{cfq,deadline,noop}_init_queue
   ->elevator_alloc
    ->kzalloc_node
   fail to call kzalloc_node and then put module in elevator_alloc;
fail to call elevator_init_fn and then put module again in elevator_init.

Remove elevator_put invoking in error path of elevator_alloc to avoid
double release issue.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

parent 464d1387

block/elevator.c

+1 −5

Original line number	Diff line number	Diff line
		@@ -157,7 +157,7 @@ struct elevator_queue elevator_alloc(struct request_queue q,

		eq = kzalloc_node(sizeof(*eq), GFP_KERNEL, q->node);
		if (unlikely(!eq))
		goto err;
		return NULL;

		eq->type = e;
		kobject_init(&eq->kobj, &elv_ktype);
		@@ -165,10 +165,6 @@ struct elevator_queue elevator_alloc(struct request_queue q,
		hash_init(eq->hash);

		return eq;
		err:
		kfree(eq);
		elevator_put(e);
		return NULL;
		}
		EXPORT_SYMBOL(elevator_alloc);

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