1 files changed, 79 insertions, 6 deletions

diff --git a/block/noop-iosched.c b/block/noop-iosched.c
index e54f006e7e60..f370e4a7fe6d 100644
--- a/block/noop-iosched.c
+++ b/block/noop-iosched.c
@@ -7,21 +7,94 @@
 #include <linux/module.h>
 #include <linux/init.h>
 
-static void elevator_noop_add_request(request_queue_t *q, struct request *rq)
+struct noop_data {
+        struct list_head queue;
+};
+
+static void noop_merged_requests(request_queue_t *q, struct request *rq,
+                                 struct request *next)
+{
+        list_del_init(&next->queuelist);
+}
+
+static int noop_dispatch(request_queue_t *q, int force)
+{
+        struct noop_data *nd = q->elevator->elevator_data;
+
+        if (!list_empty(&nd->queue)) {
+                struct request *rq;
+                rq = list_entry(nd->queue.next, struct request, queuelist);
+                list_del_init(&rq->queuelist);
+                elv_dispatch_sort(q, rq);
+                return 1;
+        }
+        return 0;
+}
+
+static void noop_add_request(request_queue_t *q, struct request *rq)
+{
+        struct noop_data *nd = q->elevator->elevator_data;
+
+        list_add_tail(&rq->queuelist, &nd->queue);
+}
+
+static int noop_queue_empty(request_queue_t *q)
 {
-        rq->flags |= REQ_NOMERGE;
-        elv_dispatch_add_tail(q, rq);
+        struct noop_data *nd = q->elevator->elevator_data;
+
+        return list_empty(&nd->queue);
+}
+
+static struct request *
+noop_former_request(request_queue_t *q, struct request *rq)
+{
+        struct noop_data *nd = q->elevator->elevator_data;
+
+        if (rq->queuelist.prev == &nd->queue)
+                return NULL;
+        return list_entry(rq->queuelist.prev, struct request, queuelist);
+}
+
+static struct request *
+noop_latter_request(request_queue_t *q, struct request *rq)
+{
+        struct noop_data *nd = q->elevator->elevator_data;
+
+        if (rq->queuelist.next == &nd->queue)
+                return NULL;
+        return list_entry(rq->queuelist.next, struct request, queuelist);
 }
 
-static int elevator_noop_dispatch(request_queue_t *q, int force)
+static int noop_init_queue(request_queue_t *q, elevator_t *e)
 {
+        struct noop_data *nd;
+
+        nd = kmalloc(sizeof(*nd), GFP_KERNEL);
+        if (!nd)
+                return -ENOMEM;
+        INIT_LIST_HEAD(&nd->queue);
+        e->elevator_data = nd;
         return 0;
 }
 
+static void noop_exit_queue(elevator_t *e)
+{
+        struct noop_data *nd = e->elevator_data;
+
+        BUG_ON(!list_empty(&nd->queue));
+        kfree(nd);
+}
+
 static struct elevator_type elevator_noop = {
         .ops = {
-                .elevator_dispatch_fn           = elevator_noop_dispatch,
-                .elevator_add_req_fn            = elevator_noop_add_request,
+                .elevator_merge_req_fn          = noop_merged_requests,
+                .elevator_dispatch_fn           = noop_dispatch,
+                .elevator_add_req_fn            = noop_add_request,
+                .elevator_queue_empty_fn        = noop_queue_empty,
+                .elevator_former_req_fn         = noop_former_request,
+                .elevator_latter_req_fn         = noop_latter_request,
+                .elevator_init_fn               = noop_init_queue,
+                .elevator_exit_fn               = noop_exit_queue,
         },
         .elevator_name = "noop",
         .elevator_owner = THIS_MODULE,