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Commit 2d263a78 authored by Matias Bjorling's avatar Matias Bjorling Committed by Jens Axboe
Browse files

null_blk: refactor init and init errors code paths 



Simplify the initialization logic of the three block-layers.

- The queue initialization is split into two parts. This allows reuse of
  code when initializing the sq-, bio- and mq-based layers.
- Set submit_queues default value to 0 and always set it at init time.
- Simplify the init error code paths.

Signed-off-by: default avatarMatias Bjorling <m@bjorling.me>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 12f8f4fc

drivers/block/null_blk.c

+38 −25
Original line number Diff line number Diff line
@@ -65,7 +65,7 @@ enum { 
	NULL_Q_MQ		= 2,

};



static int submit_queues = 1;

static int submit_queues;

module_param(submit_queues, int, S_IRUGO);

MODULE_PARM_DESC(submit_queues, "Number of submission queues");
@@ -355,16 +355,24 @@ static void null_free_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_index) 
	kfree(hctx);

}



static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq)

{

	BUG_ON(!nullb);

	BUG_ON(!nq);



	init_waitqueue_head(&nq->wait);

	nq->queue_depth = nullb->queue_depth;

}



static int null_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,

			  unsigned int index)

{

	struct nullb *nullb = data;

	struct nullb_queue *nq = &nullb->queues[index];



	init_waitqueue_head(&nq->wait);

	nq->queue_depth = nullb->queue_depth;

	nullb->nr_queues++;

	hctx->driver_data = nq;

	null_init_queue(nullb, nq);

	nullb->nr_queues++;



	return 0;

}
@@ -417,13 +425,13 @@ static int setup_commands(struct nullb_queue *nq) 


	nq->cmds = kzalloc(nq->queue_depth * sizeof(*cmd), GFP_KERNEL);

	if (!nq->cmds)

		return 1;

		return -ENOMEM;



	tag_size = ALIGN(nq->queue_depth, BITS_PER_LONG) / BITS_PER_LONG;

	nq->tag_map = kzalloc(tag_size * sizeof(unsigned long), GFP_KERNEL);

	if (!nq->tag_map) {

		kfree(nq->cmds);

		return 1;

		return -ENOMEM;

	}



	for (i = 0; i < nq->queue_depth; i++) {
@@ -454,33 +462,37 @@ static void cleanup_queues(struct nullb *nullb) 


static int setup_queues(struct nullb *nullb)

{

	struct nullb_queue *nq;

	int i;



	nullb->queues = kzalloc(submit_queues * sizeof(*nq), GFP_KERNEL);

	nullb->queues = kzalloc(submit_queues * sizeof(struct nullb_queue),

								GFP_KERNEL);

	if (!nullb->queues)

		return 1;

		return -ENOMEM;



	nullb->nr_queues = 0;

	nullb->queue_depth = hw_queue_depth;



	if (queue_mode == NULL_Q_MQ)

	return 0;

}



static int init_driver_queues(struct nullb *nullb)

{

	struct nullb_queue *nq;

	int i, ret = 0;



	for (i = 0; i < submit_queues; i++) {

		nq = &nullb->queues[i];

		init_waitqueue_head(&nq->wait);

		nq->queue_depth = hw_queue_depth;

		if (setup_commands(nq))

			break;



		null_init_queue(nullb, nq);



		ret = setup_commands(nq);

		if (ret)

			goto err_queue;

		nullb->nr_queues++;

	}



	if (i == submit_queues)

	return 0;



err_queue:

	cleanup_queues(nullb);

	return 1;

	return ret;

}



static int null_add_dev(void)
@@ -495,9 +507,6 @@ static int null_add_dev(void) 


	spin_lock_init(&nullb->lock);



	if (queue_mode == NULL_Q_MQ && use_per_node_hctx)

		submit_queues = nr_online_nodes;



	if (setup_queues(nullb))

		goto err;
@@ -518,11 +527,13 @@ static int null_add_dev(void) 
	} 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);

		init_driver_queues(nullb);

	} 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);

		init_driver_queues(nullb);

	}



	if (!nullb->q)
@@ -579,7 +590,9 @@ static int __init null_init(void) 
	}

#endif



	if (submit_queues > nr_cpu_ids)

	if (queue_mode == NULL_Q_MQ && use_per_node_hctx)

		submit_queues = nr_online_nodes;

	else if (submit_queues > nr_cpu_ids)

		submit_queues = nr_cpu_ids;

	else if (!submit_queues)

		submit_queues = 1;