cfq: pass around cfq_io_cq instead of io_context

Now that io_cq is managed by block core and guaranteed to exist for
any in-flight request, it is easier and carries more information to
pass around cfq_io_cq than io_context.

This patch updates cfq_init_prio_data(), cfq_find_alloc_queue() and
cfq_get_queue() to take @cic instead of @ioc.  This change removes a
duplicate cfq_cic_lookup() from cfq_find_alloc_queue().

This change enables the use of cic-cached ioprio in the next patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index f2387b5..9e8624e 100644 (file)
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -468,7 +468,7 @@ 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 *cfqd, bool is_sync,
-                                      struct io_context *ioc, struct bio *bio,
+                                      struct cfq_io_cq *cic, struct bio *bio,
                                       gfp_t gfp_mask);
 
 static inline struct cfq_io_cq *icq_to_cic(struct io_cq *icq)
@@ -2560,7 +2560,7 @@ static void cfq_exit_icq(struct io_cq *icq)
        }
 }
 
-static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc)
+static void cfq_init_prio_data(struct cfq_queue *cfqq, struct cfq_io_cq *cic)
 {
        struct task_struct *tsk = current;
        int ioprio_class;
@@ -2568,7 +2568,7 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc)
        if (!cfq_cfqq_prio_changed(cfqq))
                return;
 
-       ioprio_class = IOPRIO_PRIO_CLASS(ioc->ioprio);
+       ioprio_class = IOPRIO_PRIO_CLASS(cic->icq.ioc->ioprio);
        switch (ioprio_class) {
        default:
                printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class);
@@ -2580,11 +2580,11 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc)
                cfqq->ioprio_class = task_nice_ioclass(tsk);
                break;
        case IOPRIO_CLASS_RT:
-               cfqq->ioprio = task_ioprio(ioc);
+               cfqq->ioprio = task_ioprio(cic->icq.ioc);
                cfqq->ioprio_class = IOPRIO_CLASS_RT;
                break;
        case IOPRIO_CLASS_BE:
-               cfqq->ioprio = task_ioprio(ioc);
+               cfqq->ioprio = task_ioprio(cic->icq.ioc);
                cfqq->ioprio_class = IOPRIO_CLASS_BE;
                break;
        case IOPRIO_CLASS_IDLE:
@@ -2613,8 +2613,8 @@ static void changed_ioprio(struct cfq_io_cq *cic, struct bio *bio)
        cfqq = cic->cfqq[BLK_RW_ASYNC];
        if (cfqq) {
                struct cfq_queue *new_cfqq;
-               new_cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic->icq.ioc,
-                                        bio, GFP_ATOMIC);
+               new_cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic, bio,
+                                        GFP_ATOMIC);
                if (new_cfqq) {
                        cic->cfqq[BLK_RW_ASYNC] = new_cfqq;
                        cfq_put_queue(cfqq);
@@ -2671,23 +2671,18 @@ static void changed_cgroup(struct cfq_io_cq *cic)
 #endif  /* CONFIG_CFQ_GROUP_IOSCHED */
 
 static struct cfq_queue *
-cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync,
-                    struct io_context *ioc, struct bio *bio, gfp_t gfp_mask)
+cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic,
+                    struct bio *bio, gfp_t gfp_mask)
 {
        struct blkio_cgroup *blkcg;
        struct cfq_queue *cfqq, *new_cfqq = NULL;
-       struct cfq_io_cq *cic;
        struct cfq_group *cfqg;
 
 retry:
        rcu_read_lock();
 
        blkcg = bio_blkio_cgroup(bio);
-
        cfqg = cfq_lookup_create_cfqg(cfqd, blkcg);
-
-       cic = cfq_cic_lookup(cfqd, ioc);
-       /* cic always exists here */
        cfqq = cic_to_cfqq(cic, is_sync);
 
        /*
@@ -2716,7 +2711,7 @@ retry:
 
                if (cfqq) {
                        cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync);
-                       cfq_init_prio_data(cfqq, ioc);
+                       cfq_init_prio_data(cfqq, cic);
                        cfq_link_cfqq_cfqg(cfqq, cfqg);
                        cfq_log_cfqq(cfqd, cfqq, "alloced");
                } else
@@ -2746,11 +2741,11 @@ cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio)
 }
 
 static struct cfq_queue *
-cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct io_context *ioc,
+cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic,
              struct bio *bio, gfp_t gfp_mask)
 {
-       const int ioprio = task_ioprio(ioc);
-       const int ioprio_class = task_ioprio_class(ioc);
+       const int ioprio = task_ioprio(cic->icq.ioc);
+       const int ioprio_class = task_ioprio_class(cic->icq.ioc);
        struct cfq_queue **async_cfqq = NULL;
        struct cfq_queue *cfqq = NULL;
 
@@ -2760,7 +2755,7 @@ cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct io_context *ioc,
        }
 
        if (!cfqq)
-               cfqq = cfq_find_alloc_queue(cfqd, is_sync, ioc, bio, gfp_mask);
+               cfqq = cfq_find_alloc_queue(cfqd, is_sync, cic, bio, gfp_mask);
 
        /*
         * pin the queue now that it's allocated, scheduler exit will prune it
@@ -3030,7 +3025,7 @@ static void cfq_insert_request(struct request_queue *q, struct request *rq)
        struct cfq_queue *cfqq = RQ_CFQQ(rq);
 
        cfq_log_cfqq(cfqd, cfqq, "insert_request");
-       cfq_init_prio_data(cfqq, RQ_CIC(rq)->icq.ioc);
+       cfq_init_prio_data(cfqq, RQ_CIC(rq));
 
        rq_set_fifo_time(rq, jiffies + cfqd->cfq_fifo_expire[rq_is_sync(rq)]);
        list_add_tail(&rq->queuelist, &cfqq->fifo);
@@ -3234,7 +3229,7 @@ static int cfq_may_queue(struct request_queue *q, int rw)
 
        cfqq = cic_to_cfqq(cic, rw_is_sync(rw));
        if (cfqq) {
-               cfq_init_prio_data(cfqq, cic->icq.ioc);
+               cfq_init_prio_data(cfqq, cic);
 
                return __cfq_may_queue(cfqq);
        }
@@ -3326,7 +3321,7 @@ cfq_set_request(struct request_queue *q, struct request *rq, struct bio *bio,
 new_queue:
        cfqq = cic_to_cfqq(cic, is_sync);
        if (!cfqq || cfqq == &cfqd->oom_cfqq) {
-               cfqq = cfq_get_queue(cfqd, is_sync, cic->icq.ioc, bio, gfp_mask);
+               cfqq = cfq_get_queue(cfqd, is_sync, cic, bio, gfp_mask);
                cic_set_cfqq(cic, cfqq, is_sync);
        } else {
                /*