#define rq_hash_key(rq) ((rq)->sector + (rq)->nr_sectors)
#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash))
+/*
+ * Query io scheduler to see if the current process issuing bio may be
+ * merged with rq.
+ */
+static int elv_iosched_allow_merge(struct request *rq, struct bio *bio)
+{
+ request_queue_t *q = rq->q;
+ elevator_t *e = q->elevator;
+
+ if (e->ops->elevator_allow_merge_fn)
+ return e->ops->elevator_allow_merge_fn(q, rq, bio);
+
+ return 1;
+}
+
/*
* can we safely merge with this request?
*/
return 0;
/*
- * same device and no special stuff set, merge is ok
+ * must be same device and not a special request
*/
- if (rq->rq_disk == bio->bi_bdev->bd_disk && !rq->special)
- return 1;
+ if (rq->rq_disk != bio->bi_bdev->bd_disk || rq->special)
+ return 0;
- return 0;
+ if (!elv_iosched_allow_merge(rq, bio))
+ return 0;
+
+ return 1;
}
EXPORT_SYMBOL(elv_rq_merge_ok);
static struct elevator_type *elevator_find(const char *name)
{
- struct elevator_type *e = NULL;
+ struct elevator_type *e;
struct list_head *entry;
list_for_each(entry, &elv_list) {
- struct elevator_type *__e;
- __e = list_entry(entry, struct elevator_type, list);
+ e = list_entry(entry, struct elevator_type, list);
- if (!strcmp(__e->elevator_name, name)) {
- e = __e;
- break;
- }
+ if (!strcmp(e->elevator_name, name))
+ return e;
}
- return e;
+ return NULL;
}
static void elevator_put(struct elevator_type *e)
static void *elevator_init_queue(request_queue_t *q, struct elevator_queue *eq)
{
- return eq->ops->elevator_init_fn(q, eq);
+ return eq->ops->elevator_init_fn(q);
}
static void elevator_attach(request_queue_t *q, struct elevator_queue *eq,
elevator_t *e = q->elevator;
if (e->ops->elevator_put_req_fn)
- e->ops->elevator_put_req_fn(q, rq);
+ e->ops->elevator_put_req_fn(rq);
}
int elv_may_queue(request_queue_t *q, int rw)
struct list_head *entry;
int len = 0;
- spin_lock_irq(q->queue_lock);
+ spin_lock_irq(&elv_list_lock);
list_for_each(entry, &elv_list) {
struct elevator_type *__e;
else
len += sprintf(name+len, "%s ", __e->elevator_name);
}
- spin_unlock_irq(q->queue_lock);
+ spin_unlock_irq(&elv_list_lock);
len += sprintf(len+name, "\n");
return len;