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authorTejun Heo <tj@kernel.org>2011-12-14 00:33:42 +0100
committerJens Axboe <axboe@kernel.dk>2011-12-14 00:33:42 +0100
commit47fdd4ca96bf4b28ac4d05d7a6e382df31d3d758 (patch)
treebcb928575b66511345b00102a7e8cace84526e3e /block
parenta612fddf0d8090f2877305c9168b6c1a34fb5d90 (diff)
downloadlwn-47fdd4ca96bf4b28ac4d05d7a6e382df31d3d758.tar.gz
lwn-47fdd4ca96bf4b28ac4d05d7a6e382df31d3d758.zip
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>
Diffstat (limited to 'block')
-rw-r--r--block/blk-ioc.c36
-rw-r--r--block/blk.h1
-rw-r--r--block/cfq-iosched.c48
3 files changed, 45 insertions, 40 deletions
diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index dc5e69d335a0..87ecc98b8ade 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -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;
diff --git a/block/blk.h b/block/blk.h
index 4943770e0792..3c510a4b5054 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -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);
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 9bc5ecc1b336..048fa699adf9 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -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];
@@ -2971,45 +2978,6 @@ cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct io_context *ioc,
}
/**
- * 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