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>
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index dc5e69d..87ecc98 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -266,6 +266,42 @@
}
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;
diff --git a/block/blk.h b/block/blk.h
index 4943770..3c510a4 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -199,6 +199,7 @@
* 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);
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 9bc5ecc..048fa69 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -468,7 +468,6 @@
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 @@
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];
@@ -2971,45 +2978,6 @@
}
/**
- * 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
* @gfp_mask: allocation mask