[MIPS] Use ARRAY_SIZE macro when appropriate

[sfrench/cifs-2.6.git] / block / cfq-iosched.c

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 533a2938ffd6740f6f41f2c5bd52177e8dde8a0e..07b706243772e46fe2434248bf0e4fba938fca0a 100644 (file)
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -568,6 +568,33 @@ cfq_merged_requests(request_queue_t *q, struct request *rq,
        cfq_remove_request(next);
 }
 
+static int cfq_allow_merge(request_queue_t *q, struct request *rq,
+                          struct bio *bio)
+{
+       struct cfq_data *cfqd = q->elevator->elevator_data;
+       const int rw = bio_data_dir(bio);
+       struct cfq_queue *cfqq;
+       pid_t key;
+
+       /*
+        * Disallow merge of a sync bio into an async request.
+        */
+       if ((bio_data_dir(bio) == READ || bio_sync(bio)) && !rq_is_sync(rq))
+               return 0;
+
+       /*
+        * Lookup the cfqq that this bio will be queued with. Allow
+        * merge only if rq is queued there.
+        */
+       key = cfq_queue_pid(current, rw, bio_sync(bio));
+       cfqq = cfq_find_cfq_hash(cfqd, key, current->ioprio);
+
+       if (cfqq == RQ_CFQQ(rq))
+               return 1;
+
+       return 0;
+}
+
 static inline void
 __cfq_set_active_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 {
@@ -2125,6 +2152,7 @@ static struct elevator_type iosched_cfq = {
                .elevator_merge_fn =            cfq_merge,
                .elevator_merged_fn =           cfq_merged_request,
                .elevator_merge_req_fn =        cfq_merged_requests,
+               .elevator_allow_merge_fn =      cfq_allow_merge,
                .elevator_dispatch_fn =         cfq_dispatch_requests,
                .elevator_add_req_fn =          cfq_insert_request,
                .elevator_activate_req_fn =     cfq_activate_request,