block, cfq: move cfqd->icq_list to request_queue and add request->elv.icq
Most of icq management is about to be moved out of cfq into blk-ioc.
This patch prepares for it.
* Move cfqd->icq_list to request_queue->icq_list
* Make request explicitly point to icq instead of through elevator
private data. ->elevator_private[3] is replaced with sub struct elv
which contains icq pointer and priv[2]. cfq is updated accordingly.
* Meaningless clearing of ->elevator_private[0] removed from
elv_set_request(). At that point in code, the field was guaranteed
to be %NULL anyway.
This patch doesn't introduce any functional change.
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 d2f16fcd..9bc5ecc 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -54,9 +54,9 @@
#define CFQQ_SECT_THR_NONROT (sector_t)(2 * 32)
#define CFQQ_SEEKY(cfqq) (hweight32(cfqq->seek_history) > 32/8)
-#define RQ_CIC(rq) icq_to_cic((rq)->elevator_private[0])
-#define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elevator_private[1])
-#define RQ_CFQG(rq) (struct cfq_group *) ((rq)->elevator_private[2])
+#define RQ_CIC(rq) icq_to_cic((rq)->elv.icq)
+#define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elv.priv[0])
+#define RQ_CFQG(rq) (struct cfq_group *) ((rq)->elv.priv[1])
static struct kmem_cache *cfq_pool;
static struct kmem_cache *cfq_icq_pool;
@@ -297,8 +297,6 @@
unsigned int cfq_group_idle;
unsigned int cfq_latency;
- struct list_head icq_list;
-
/*
* Fallback dummy cfqq for extreme OOM conditions
*/
@@ -3053,7 +3051,7 @@
ret = radix_tree_insert(&ioc->icq_tree, q->id, icq);
if (likely(!ret)) {
hlist_add_head(&icq->ioc_node, &ioc->icq_list);
- list_add(&icq->q_node, &cfqd->icq_list);
+ list_add(&icq->q_node, &q->icq_list);
icq = NULL;
} else if (ret == -EEXIST) {
/* someone else already did it */
@@ -3605,12 +3603,10 @@
put_io_context(RQ_CIC(rq)->icq.ioc, cfqq->cfqd->queue);
- rq->elevator_private[0] = NULL;
- rq->elevator_private[1] = NULL;
-
/* Put down rq reference on cfqg */
cfq_put_cfqg(RQ_CFQG(rq));
- rq->elevator_private[2] = NULL;
+ rq->elv.priv[0] = NULL;
+ rq->elv.priv[1] = NULL;
cfq_put_queue(cfqq);
}
@@ -3696,9 +3692,9 @@
cfqq->allocated[rw]++;
cfqq->ref++;
- rq->elevator_private[0] = &cic->icq;
- rq->elevator_private[1] = cfqq;
- rq->elevator_private[2] = cfq_ref_get_cfqg(cfqq->cfqg);
+ rq->elv.icq = &cic->icq;
+ rq->elv.priv[0] = cfqq;
+ rq->elv.priv[1] = cfq_ref_get_cfqg(cfqq->cfqg);
spin_unlock_irq(q->queue_lock);
return 0;
@@ -3810,8 +3806,8 @@
if (cfqd->active_queue)
__cfq_slice_expired(cfqd, cfqd->active_queue, 0);
- while (!list_empty(&cfqd->icq_list)) {
- struct io_cq *icq = list_entry(cfqd->icq_list.next,
+ while (!list_empty(&q->icq_list)) {
+ struct io_cq *icq = list_entry(q->icq_list.next,
struct io_cq, q_node);
struct io_context *ioc = icq->ioc;
@@ -3922,8 +3918,6 @@
cfqd->oom_cfqq.ref++;
cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, &cfqd->root_group);
- INIT_LIST_HEAD(&cfqd->icq_list);
-
cfqd->queue = q;
init_timer(&cfqd->idle_slice_timer);