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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: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Tejun Heo 2011-12-14 00:33:42 +01:00 committed by Jens Axboe
parent a612fddf0d
commit 47fdd4ca96
3 changed files with 45 additions and 40 deletions
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36
block/blk-ioc.c
View File

@ -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;

1
block/blk.h
View File

@ -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);

48
block/cfq-iosched.c
View File

@ -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