elevator: use list_{first,prev,next}_entry

To make the intention clearer, use list_{first,prev,next}_entry
instead of list_entry.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/block/noop-iosched.c b/block/noop-iosched.c
index 3de89d4690f3bf3e0d9abec1976a379b5dc171e5..a163c487cf38c8250ccbf0ec7beac913672796f0 100644 (file)
--- a/block/noop-iosched.c
+++ b/block/noop-iosched.c
@@ -21,10 +21,10 @@ static void noop_merged_requests(struct request_queue *q, struct request *rq,
 static int noop_dispatch(struct request_queue *q, int force)
 {
        struct noop_data *nd = q->elevator->elevator_data;
+       struct request *rq;
 
-       if (!list_empty(&nd->queue)) {
-               struct request *rq;
-               rq = list_entry(nd->queue.next, struct request, queuelist);
+       rq = list_first_entry_or_null(&nd->queue, struct request, queuelist);
+       if (rq) {
                list_del_init(&rq->queuelist);
                elv_dispatch_sort(q, rq);
                return 1;
@@ -46,7 +46,7 @@ noop_former_request(struct request_queue *q, struct request *rq)
 
        if (rq->queuelist.prev == &nd->queue)
                return NULL;
-       return list_entry(rq->queuelist.prev, struct request, queuelist);
+       return list_prev_entry(rq, queuelist);
 }
 
 static struct request *
@@ -56,7 +56,7 @@ noop_latter_request(struct request_queue *q, struct request *rq)
 
        if (rq->queuelist.next == &nd->queue)
                return NULL;
-       return list_entry(rq->queuelist.next, struct request, queuelist);
+       return list_next_entry(rq, queuelist);
 }
 
 static int noop_init_queue(struct request_queue *q, struct elevator_type *e)