block: reorganize request fetching functions

Impact: code reorganization

elv_next_request() and elv_dequeue_request() are public block layer
interface than actual elevator implementation.  They mostly deal with
how requests interact with block layer and low level drivers at the
beginning of rqeuest processing whereas __elv_next_request() is the
actual eleveator request fetching interface.

Move the two functions to blk-core.c.  This prepares for further
interface cleanup.

Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 37 insertions, 0 deletions

diff --git a/block/blk.h b/block/blk.h
index 79c85f7c9ff5..9b2c324e4407 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -43,6 +43,43 @@ static inline void blk_clear_rq_complete(struct request *rq)
         clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
 }
 
+/*
+ * Internal elevator interface
+ */
+#define ELV_ON_HASH(rq)         (!hlist_unhashed(&(rq)->hash))
+
+static inline struct request *__elv_next_request(struct request_queue *q)
+{
+        struct request *rq;
+
+        while (1) {
+                while (!list_empty(&q->queue_head)) {
+                        rq = list_entry_rq(q->queue_head.next);
+                        if (blk_do_ordered(q, &rq))
+                                return rq;
+                }
+
+                if (!q->elevator->ops->elevator_dispatch_fn(q, 0))
+                        return NULL;
+        }
+}
+
+static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
+{
+        struct elevator_queue *e = q->elevator;
+
+        if (e->ops->elevator_activate_req_fn)
+                e->ops->elevator_activate_req_fn(q, rq);
+}
+
+static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
+{
+        struct elevator_queue *e = q->elevator;
+
+        if (e->ops->elevator_deactivate_req_fn)
+                e->ops->elevator_deactivate_req_fn(q, rq);
+}
+
 #ifdef CONFIG_FAIL_IO_TIMEOUT
 int blk_should_fake_timeout(struct request_queue *);
 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);