From 47fdd4ca96bf4b28ac4d05d7a6e382df31d3d758 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 14 Dec 2011 00:33:42 +0100 Subject: 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 Signed-off-by: Jens Axboe --- block/blk-ioc.c | 36 ++++++++++++++++++++++++++++++++++++ block/blk.h | 1 + block/cfq-iosched.c | 48 ++++++++---------------------------------------- 3 files changed, 45 insertions(+), 40 deletions(-) (limited to 'block') diff --git a/block/blk-ioc.c b/block/blk-ioc.c index dc5e69d335a..87ecc98b8ad 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 4943770e079..3c510a4b505 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 9bc5ecc1b33..048fa699adf 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]; @@ -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 -- cgit v1.2.3