Commit 47fdd4ca authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe
Browse files

block, cfq: move io_cq lookup to blk-ioc.c 



Now that all io_cq related data structures are in block core layer,
io_cq lookup can be moved from cfq-iosched.c to blk-ioc.c.

Lookup logic from cfq_cic_lookup() is moved to ioc_lookup_icq() with
parameter return type changes (cfqd -> request_queue, cfq_io_cq ->
io_cq) and cfq_cic_lookup() becomes thin wrapper around
cfq_cic_lookup().

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a612fddf

block/blk-ioc.c

+36 −0
Original line number Diff line number Diff line
@@ -266,6 +266,42 @@ struct io_context *get_task_io_context(struct task_struct *task, 
}

EXPORT_SYMBOL(get_task_io_context);



/**

 * ioc_lookup_icq - lookup io_cq from ioc

 * @ioc: the associated io_context

 * @q: the associated request_queue

 *

 * Look up io_cq associated with @ioc - @q pair from @ioc.  Must be called

 * with @q->queue_lock held.

 */

struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q)

{

	struct io_cq *icq;



	lockdep_assert_held(q->queue_lock);



	/*

	 * icq's are indexed from @ioc using radix tree and hint pointer,

	 * both of which are protected with RCU.  All removals are done

	 * holding both q and ioc locks, and we're holding q lock - if we

	 * find a icq which points to us, it's guaranteed to be valid.

	 */

	rcu_read_lock();

	icq = rcu_dereference(ioc->icq_hint);

	if (icq && icq->q == q)

		goto out;



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

	if (icq && icq->q == q)

		rcu_assign_pointer(ioc->icq_hint, icq);	/* allowed to race */

	else

		icq = NULL;

out:

	rcu_read_unlock();

	return icq;

}

EXPORT_SYMBOL(ioc_lookup_icq);



void ioc_set_changed(struct io_context *ioc, int which)

{

	struct io_cq *icq;

block/blk.h

+1 −0
Original line number Diff line number Diff line
@@ -199,6 +199,7 @@ static inline int blk_do_io_stat(struct request *rq) 
 * Internal io_context interface

 */

void get_io_context(struct io_context *ioc);

struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);



void create_io_context_slowpath(struct task_struct *task, gfp_t gfp_mask,

				int node);

block/cfq-iosched.c

+8 −40
Original line number Diff line number Diff line
@@ -468,7 +468,6 @@ static inline int cfqg_busy_async_queues(struct cfq_data *cfqd, 
static void cfq_dispatch_insert(struct request_queue *, struct request *);

static struct cfq_queue *cfq_get_queue(struct cfq_data *, bool,

				       struct io_context *, gfp_t);

static struct cfq_io_cq *cfq_cic_lookup(struct cfq_data *, struct io_context *);



static inline struct cfq_io_cq *icq_to_cic(struct io_cq *icq)

{
@@ -476,6 +475,14 @@ static inline struct cfq_io_cq *icq_to_cic(struct io_cq *icq) 
	return container_of(icq, struct cfq_io_cq, icq);

}



static inline struct cfq_io_cq *cfq_cic_lookup(struct cfq_data *cfqd,

					       struct io_context *ioc)

{

	if (ioc)

		return icq_to_cic(ioc_lookup_icq(ioc, cfqd->queue));

	return NULL;

}



static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_cq *cic, bool is_sync)

{

	return cic->cfqq[is_sync];
@@ -2970,45 +2977,6 @@ cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct io_context *ioc, 
	return cfqq;

}



/**

 * cfq_cic_lookup - lookup cfq_io_cq

 * @cfqd: the associated cfq_data

 * @ioc: the associated io_context

 *

 * Look up cfq_io_cq associated with @cfqd - @ioc pair.  Must be called

 * with queue_lock held.

 */

static struct cfq_io_cq *

cfq_cic_lookup(struct cfq_data *cfqd, struct io_context *ioc)

{

	struct request_queue *q = cfqd->queue;

	struct io_cq *icq;



	lockdep_assert_held(cfqd->queue->queue_lock);

	if (unlikely(!ioc))

		return NULL;



	/*

	 * icq's are indexed from @ioc using radix tree and hint pointer,

	 * both of which are protected with RCU.  All removals are done

	 * holding both q and ioc locks, and we're holding q lock - if we

	 * find a icq which points to us, it's guaranteed to be valid.

	 */

	rcu_read_lock();

	icq = rcu_dereference(ioc->icq_hint);

	if (icq && icq->q == q)

		goto out;



	icq = radix_tree_lookup(&ioc->icq_tree, cfqd->queue->id);

	if (icq && icq->q == q)

		rcu_assign_pointer(ioc->icq_hint, icq);	/* allowed to race */

	else

		icq = NULL;

out:

	rcu_read_unlock();

	return icq_to_cic(icq);

}



/**

 * cfq_create_cic - create and link a cfq_io_cq

 * @cfqd: cfqd of interest

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