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Commit 9b84cacd authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe
Browse files

block, cfq: restructure io_cq creation path for io_context interface cleanup 



Add elevator_ops->elevator_init_icq_fn() and restructure
cfq_create_cic() and rename it to ioc_create_icq().

The new function expects its caller to pass in io_context, uses
elevator_type->icq_cache, handles generic init, calls the new elevator
operation for elevator specific initialization, and returns pointer to
created or looked up icq.  This leaves cfq_icq_pool variable without
any user.  Removed.

This prepares for io_context interface cleanup and doesn't introduce
any functional difference.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 7e5a8794

block/cfq-iosched.c

+41 −53
Original line number Diff line number Diff line
@@ -59,7 +59,6 @@ static const int cfq_hist_divisor = 4; 
#define RQ_CFQG(rq)		(struct cfq_group *) ((rq)->elv.priv[1])



static struct kmem_cache *cfq_pool;

static struct kmem_cache *cfq_icq_pool;



#define CFQ_PRIO_LISTS		IOPRIO_BE_NR

#define cfq_class_idle(cfqq)	((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE)
@@ -2707,6 +2706,13 @@ static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) 
	cfq_put_queue(cfqq);

}



static void cfq_init_icq(struct io_cq *icq)

{

	struct cfq_io_cq *cic = icq_to_cic(icq);



	cic->ttime.last_end_request = jiffies;

}



static void cfq_exit_icq(struct io_cq *icq)

{

	struct cfq_io_cq *cic = icq_to_cic(icq);
@@ -2723,21 +2729,6 @@ static void cfq_exit_icq(struct io_cq *icq) 
	}

}



static struct cfq_io_cq *cfq_alloc_cic(struct cfq_data *cfqd, gfp_t gfp_mask)

{

	struct cfq_io_cq *cic;



	cic = kmem_cache_alloc_node(cfq_icq_pool, gfp_mask | __GFP_ZERO,

							cfqd->queue->node);

	if (cic) {

		cic->ttime.last_end_request = jiffies;

		INIT_LIST_HEAD(&cic->icq.q_node);

		INIT_HLIST_NODE(&cic->icq.ioc_node);

	}



	return cic;

}



static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc)

{

	struct task_struct *tsk = current;
@@ -2945,64 +2936,62 @@ cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct io_context *ioc, 
}



/**

 * cfq_create_cic - create and link a cfq_io_cq

 * @cfqd: cfqd of interest

 * ioc_create_icq - create and link io_cq

 * @q: request_queue of interest

 * @gfp_mask: allocation mask

 *

 * Make sure cfq_io_cq linking %current->io_context and @cfqd exists.  If

 * ioc and/or cic doesn't exist, they will be created using @gfp_mask.

 * Make sure io_cq linking %current->io_context and @q exists.  If either

 * io_context and/or icq don't exist, they will be created using @gfp_mask.

 *

 * The caller is responsible for ensuring @ioc won't go away and @q is

 * alive and will stay alive until this function returns.

 */

static int cfq_create_cic(struct cfq_data *cfqd, gfp_t gfp_mask)

static struct io_cq *ioc_create_icq(struct request_queue *q, gfp_t gfp_mask)

{

	struct request_queue *q = cfqd->queue;

	struct io_cq *icq = NULL;

	struct cfq_io_cq *cic;

	struct elevator_type *et = q->elevator->type;

	struct io_context *ioc;

	int ret = -ENOMEM;



	might_sleep_if(gfp_mask & __GFP_WAIT);

	struct io_cq *icq;



	/* allocate stuff */

	ioc = create_io_context(current, gfp_mask, q->node);

	if (!ioc)

		goto out;

		return NULL;



	cic = cfq_alloc_cic(cfqd, gfp_mask);

	if (!cic)

		goto out;

	icq = &cic->icq;

	icq = kmem_cache_alloc_node(et->icq_cache, gfp_mask | __GFP_ZERO,

				    q->node);

	if (!icq)

		return NULL;



	ret = radix_tree_preload(gfp_mask);

	if (ret)

		goto out;

	if (radix_tree_preload(gfp_mask) < 0) {

		kmem_cache_free(et->icq_cache, icq);

		return NULL;

	}



	icq->ioc = ioc;

	icq->q = cfqd->queue;

	icq->q = q;

	INIT_LIST_HEAD(&icq->q_node);

	INIT_HLIST_NODE(&icq->ioc_node);



	/* lock both q and ioc and try to link @icq */

	spin_lock_irq(q->queue_lock);

	spin_lock(&ioc->lock);



	ret = radix_tree_insert(&ioc->icq_tree, q->id, icq);

	if (likely(!ret)) {

	if (likely(!radix_tree_insert(&ioc->icq_tree, q->id, icq))) {

		hlist_add_head(&icq->ioc_node, &ioc->icq_list);

		list_add(&icq->q_node, &q->icq_list);

		icq = NULL;

	} else if (ret == -EEXIST) {

		/* someone else already did it */

		ret = 0;

		if (et->ops.elevator_init_icq_fn)

			et->ops.elevator_init_icq_fn(icq);

	} else {

		kmem_cache_free(et->icq_cache, icq);

		icq = ioc_lookup_icq(ioc, q);

		if (!icq)

			printk(KERN_ERR "cfq: icq link failed!\n");

	}



	spin_unlock(&ioc->lock);

	spin_unlock_irq(q->queue_lock);



	radix_tree_preload_end();

out:

	if (ret)

		printk(KERN_ERR "cfq: icq link failed!\n");

	if (icq)

		kmem_cache_free(cfq_icq_pool, icq);

	return ret;

	return icq;

}



/**
@@ -3022,7 +3011,6 @@ static struct cfq_io_cq *cfq_get_cic(struct cfq_data *cfqd, gfp_t gfp_mask) 
	struct request_queue *q = cfqd->queue;

	struct cfq_io_cq *cic = NULL;

	struct io_context *ioc;

	int err;



	lockdep_assert_held(q->queue_lock);
@@ -3037,9 +3025,9 @@ static struct cfq_io_cq *cfq_get_cic(struct cfq_data *cfqd, gfp_t gfp_mask) 


		/* slow path - unlock, create missing ones and retry */

		spin_unlock_irq(q->queue_lock);

		err = cfq_create_cic(cfqd, gfp_mask);

		cic = icq_to_cic(ioc_create_icq(q, gfp_mask));

		spin_lock_irq(q->queue_lock);

		if (err)

		if (!cic)

			return NULL;

	}
@@ -3975,6 +3963,7 @@ static struct elevator_type iosched_cfq = { 
		.elevator_completed_req_fn =	cfq_completed_request,

		.elevator_former_req_fn =	elv_rb_former_request,

		.elevator_latter_req_fn =	elv_rb_latter_request,

		.elevator_init_icq_fn =		cfq_init_icq,

		.elevator_exit_icq_fn =		cfq_exit_icq,

		.elevator_set_req_fn =		cfq_set_request,

		.elevator_put_req_fn =		cfq_put_request,
@@ -4028,7 +4017,6 @@ static int __init cfq_init(void) 
		kmem_cache_destroy(cfq_pool);

		return ret;

	}

	cfq_icq_pool = iosched_cfq.icq_cache;



	blkio_policy_register(&blkio_policy_cfq);

include/linux/elevator.h

+2 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ typedef struct request *(elevator_request_list_fn) (struct request_queue *, stru 
typedef void (elevator_completed_req_fn) (struct request_queue *, struct request *);

typedef int (elevator_may_queue_fn) (struct request_queue *, int);



typedef void (elevator_init_icq_fn) (struct io_cq *);

typedef void (elevator_exit_icq_fn) (struct io_cq *);

typedef int (elevator_set_req_fn) (struct request_queue *, struct request *, gfp_t);

typedef void (elevator_put_req_fn) (struct request *);
@@ -59,6 +60,7 @@ struct elevator_ops 
	elevator_request_list_fn *elevator_former_req_fn;

	elevator_request_list_fn *elevator_latter_req_fn;



	elevator_init_icq_fn *elevator_init_icq_fn;

	elevator_exit_icq_fn *elevator_exit_icq_fn;



	elevator_set_req_fn *elevator_set_req_fn;