Commit b2fab5ac authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe
Browse files

elevator: make elevator_init_fn() return 0/-errno 



elevator_ops->elevator_init_fn() has a weird return value.  It returns
a void * which the caller should assign to q->elevator->elevator_data
and %NULL return denotes init failure.

Update such that it returns integer 0/-errno and sets elevator_data
directly as necessary.

This makes the interface more conventional and eases further cleanup.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 5a5bafdc

block/cfq-iosched.c

+5 −4
Original line number Diff line number Diff line
@@ -3656,7 +3656,7 @@ static void cfq_exit_queue(struct elevator_queue *e) 
	kfree(cfqd);

}



static void *cfq_init_queue(struct request_queue *q)

static int cfq_init_queue(struct request_queue *q)

{

	struct cfq_data *cfqd;

	int i, j;
@@ -3665,7 +3665,7 @@ static void *cfq_init_queue(struct request_queue *q) 


	cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node);

	if (!cfqd)

		return NULL;

		return -ENOMEM;



	/* Init root service tree */

	cfqd->grp_service_tree = CFQ_RB_ROOT;
@@ -3692,7 +3692,7 @@ static void *cfq_init_queue(struct request_queue *q) 
	if (blkio_alloc_blkg_stats(&cfqg->blkg)) {

		kfree(cfqg);

		kfree(cfqd);

		return NULL;

		return -ENOMEM;

	}



	rcu_read_lock();
@@ -3723,6 +3723,7 @@ static void *cfq_init_queue(struct request_queue *q) 
	cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, &cfqd->root_group);



	cfqd->queue = q;

	q->elevator->elevator_data = cfqd;



	init_timer(&cfqd->idle_slice_timer);

	cfqd->idle_slice_timer.function = cfq_idle_slice_timer;
@@ -3747,7 +3748,7 @@ static void *cfq_init_queue(struct request_queue *q) 
	 * second, in order to have larger depth for async operations.

	 */

	cfqd->last_delayed_sync = jiffies - HZ;

	return cfqd;

	return 0;

}



/*

block/deadline-iosched.c

+5 −3
Original line number Diff line number Diff line
@@ -337,13 +337,13 @@ static void deadline_exit_queue(struct elevator_queue *e) 
/*

 * initialize elevator private data (deadline_data).

 */

static void *deadline_init_queue(struct request_queue *q)

static int deadline_init_queue(struct request_queue *q)

{

	struct deadline_data *dd;



	dd = kmalloc_node(sizeof(*dd), GFP_KERNEL | __GFP_ZERO, q->node);

	if (!dd)

		return NULL;

		return -ENOMEM;



	INIT_LIST_HEAD(&dd->fifo_list[READ]);

	INIT_LIST_HEAD(&dd->fifo_list[WRITE]);
@@ -354,7 +354,9 @@ static void *deadline_init_queue(struct request_queue *q) 
	dd->writes_starved = writes_starved;

	dd->front_merges = 1;

	dd->fifo_batch = fifo_batch;

	return dd;



	q->elevator->elevator_data = dd;

	return 0;

}



/*

block/elevator.c

+2 −10
Original line number Diff line number Diff line
@@ -121,14 +121,6 @@ static struct elevator_type *elevator_get(const char *name) 
	return e;

}



static int elevator_init_queue(struct request_queue *q)

{

	q->elevator->elevator_data = q->elevator->type->ops.elevator_init_fn(q);

	if (q->elevator->elevator_data)

		return 0;

	return -ENOMEM;

}



static char chosen_elevator[ELV_NAME_MAX];



static int __init elevator_setup(char *str)
@@ -224,7 +216,7 @@ int elevator_init(struct request_queue *q, char *name) 
	if (!q->elevator)

		return -ENOMEM;



	err = elevator_init_queue(q);

	err = e->ops.elevator_init_fn(q);

	if (err) {

		kobject_put(&q->elevator->kobj);

		return err;
@@ -927,7 +919,7 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e) 
	if (!q->elevator)

		goto fail_init;



	err = elevator_init_queue(q);

	err = new_e->ops.elevator_init_fn(q);

	if (err) {

		kobject_put(&q->elevator->kobj);

		goto fail_init;

block/noop-iosched.c

+5 −3
Original line number Diff line number Diff line
@@ -59,15 +59,17 @@ noop_latter_request(struct request_queue *q, struct request *rq) 
	return list_entry(rq->queuelist.next, struct request, queuelist);

}



static void *noop_init_queue(struct request_queue *q)

static int noop_init_queue(struct request_queue *q)

{

	struct noop_data *nd;



	nd = kmalloc_node(sizeof(*nd), GFP_KERNEL, q->node);

	if (!nd)

		return NULL;

		return -ENOMEM;



	INIT_LIST_HEAD(&nd->queue);

	return nd;

	q->elevator->elevator_data = nd;

	return 0;

}



static void noop_exit_queue(struct elevator_queue *e)

include/linux/elevator.h

+1 −1
Original line number Diff line number Diff line
@@ -33,7 +33,7 @@ typedef void (elevator_put_req_fn) (struct request *); 
typedef void (elevator_activate_req_fn) (struct request_queue *, struct request *);

typedef void (elevator_deactivate_req_fn) (struct request_queue *, struct request *);



typedef void *(elevator_init_fn) (struct request_queue *);

typedef int (elevator_init_fn) (struct request_queue *);

typedef void (elevator_exit_fn) (struct elevator_queue *);



struct elevator_ops

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