Comment 5 for bug 530047

The specific part of the kernel code is

1452 static void cic_free_func(struct io_context *ioc, struct cfq_io_context *cic)
1453 {
1454 unsigned long flags;
1455
1456 BUG_ON(!cic->dead_key);
1457
1458 spin_lock_irqsave(&ioc->lock, flags);
1459 radix_tree_delete(&ioc->radix_root, cic->dead_key);
1460 hlist_del_rcu(&cic->cic_list);
1461 spin_unlock_irqrestore(&ioc->lock, flags);
1462
1463 cfq_cic_free(cic);
1464 }
1465