/**
* blk_release_queue: - release a &struct request_queue when it is no longer needed
* @kobj: the kobj belonging to the request queue to be released
*
* Description:
* blk_release_queue is the pair to blk_init_queue() or
* blk_queue_make_request(). It should be called when a request queue is
* being released; typically when a block device is being de-registered.
* Currently, its primary task it to free all the &struct request
* structures that were allocated to the queue and the queue itself.
*
* Caveat:
* Hopefully the low level driver will have finished any
* outstanding requests first...
**/
static void blk_release_queue(struct kobject *kobj)
{
struct request_queue *q =
container_of(kobj, struct request_queue, kobj);
blk_sync_queue(q);
blkcg_exit_queue(q);
if (q->elevator) {
spin_lock_irq(q->queue_lock);
ioc_clear_queue(q);
spin_unlock_irq(q->queue_lock);
elevator_exit(q->elevator);
}
blk_exit_rl(&q->root_rl);
if (q->queue_tags)
__blk_queue_free_tags(q);
if (q->mq_ops)
blk_mq_free_queue(q);
kfree(q->flush_rq);
blk_trace_shutdown(q);
bdi_destroy(&q->backing_dev_info);
ida_simple_remove(&blk_queue_ida, q->id);
call_rcu(&q->rcu_head, blk_free_queue_rcu);
}
static void null_del_dev(struct nullb *nullb)
{
list_del_init(&nullb->list);
del_gendisk(nullb->disk);
if (queue_mode == NULL_Q_MQ)
blk_mq_free_queue(nullb->q);
else
blk_cleanup_queue(nullb->q);
put_disk(nullb->disk);
kfree(nullb);
}
static int null_add_dev(void)
{
struct gendisk *disk;
struct nullb *nullb;
sector_t size;
nullb = kzalloc_node(sizeof(*nullb), GFP_KERNEL, home_node);
if (!nullb)
return -ENOMEM;
spin_lock_init(&nullb->lock);
if (setup_queues(nullb))
goto err;
if (queue_mode == NULL_Q_MQ) {
null_mq_reg.numa_node = home_node;
null_mq_reg.queue_depth = hw_queue_depth;
if (use_per_node_hctx) {
null_mq_reg.ops->alloc_hctx = null_alloc_hctx;
null_mq_reg.ops->free_hctx = null_free_hctx;
null_mq_reg.nr_hw_queues = nr_online_nodes;
} else {
null_mq_reg.ops->alloc_hctx = blk_mq_alloc_single_hw_queue;
null_mq_reg.ops->free_hctx = blk_mq_free_single_hw_queue;
null_mq_reg.nr_hw_queues = submit_queues;
}
nullb->q = blk_mq_init_queue(&null_mq_reg, nullb);
} else if (queue_mode == NULL_Q_BIO) {
nullb->q = blk_alloc_queue_node(GFP_KERNEL, home_node);
blk_queue_make_request(nullb->q, null_queue_bio);
} else {
nullb->q = blk_init_queue_node(null_request_fn, &nullb->lock, home_node);
blk_queue_prep_rq(nullb->q, null_rq_prep_fn);
if (nullb->q)
blk_queue_softirq_done(nullb->q, null_softirq_done_fn);
}
if (!nullb->q)
goto queue_fail;
nullb->q->queuedata = nullb;
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, nullb->q);
disk = nullb->disk = alloc_disk_node(1, home_node);
if (!disk) {
queue_fail:
if (queue_mode == NULL_Q_MQ)
blk_mq_free_queue(nullb->q);
else
blk_cleanup_queue(nullb->q);
cleanup_queues(nullb);
err:
kfree(nullb);
return -ENOMEM;
}
mutex_lock(&lock);
list_add_tail(&nullb->list, &nullb_list);
nullb->index = nullb_indexes++;
mutex_unlock(&lock);
blk_queue_logical_block_size(nullb->q, bs);
blk_queue_physical_block_size(nullb->q, bs);
size = gb * 1024 * 1024 * 1024ULL;
sector_div(size, bs);
set_capacity(disk, size);
disk->flags |= GENHD_FL_EXT_DEVT;
disk->major = null_major;
disk->first_minor = nullb->index;
disk->fops = &null_fops;
disk->private_data = nullb;
disk->queue = nullb->q;
sprintf(disk->disk_name, "nullb%d", nullb->index);
add_disk(disk);
return 0;
}
