Merge tag 'for-linus-4.18' of git://github.com/cminyard/linux-ipmi

[linux-2.6-block.git] / block / elevator.c

diff --git a/block/elevator.c b/block/elevator.c
index e87e9b43aba09ac2989d4350e225422892ab6944..fa828b5bfd4b14c977b2d3cdea41ff12f1573344 100644 (file)
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -199,76 +199,46 @@ static void elevator_release(struct kobject *kobj)
        kfree(e);
 }
 
-int elevator_init(struct request_queue *q, char *name)
+/*
+ * Use the default elevator specified by config boot param for non-mq devices,
+ * or by config option.  Don't try to load modules as we could be running off
+ * async and request_module() isn't allowed from async.
+ */
+int elevator_init(struct request_queue *q)
 {
        struct elevator_type *e = NULL;
-       int err;
+       int err = 0;
 
        /*
         * q->sysfs_lock must be held to provide mutual exclusion between
         * elevator_switch() and here.
         */
-       lockdep_assert_held(&q->sysfs_lock);
-
+       mutex_lock(&q->sysfs_lock);
        if (unlikely(q->elevator))
-               return 0;
-
-       INIT_LIST_HEAD(&q->queue_head);
-       q->last_merge = NULL;
-       q->end_sector = 0;
-       q->boundary_rq = NULL;
-
-       if (name) {
-               e = elevator_get(q, name, true);
-               if (!e)
-                       return -EINVAL;
-       }
+               goto out_unlock;
 
-       /*
-        * Use the default elevator specified by config boot param for
-        * non-mq devices, or by config option. Don't try to load modules
-        * as we could be running off async and request_module() isn't
-        * allowed from async.
-        */
-       if (!e && !q->mq_ops && *chosen_elevator) {
+       if (*chosen_elevator) {
                e = elevator_get(q, chosen_elevator, false);
                if (!e)
                        printk(KERN_ERR "I/O scheduler %s not found\n",
                                                        chosen_elevator);
        }
 
+       if (!e)
+               e = elevator_get(q, CONFIG_DEFAULT_IOSCHED, false);
        if (!e) {
-               /*
-                * For blk-mq devices, we default to using mq-deadline,
-                * if available, for single queue devices. If deadline
-                * isn't available OR we have multiple queues, default
-                * to "none".
-                */
-               if (q->mq_ops) {
-                       if (q->nr_hw_queues == 1)
-                               e = elevator_get(q, "mq-deadline", false);
-                       if (!e)
-                               return 0;
-               } else
-                       e = elevator_get(q, CONFIG_DEFAULT_IOSCHED, false);
-
-               if (!e) {
-                       printk(KERN_ERR
-                               "Default I/O scheduler not found. " \
-                               "Using noop.\n");
-                       e = elevator_get(q, "noop", false);
-               }
+               printk(KERN_ERR
+                       "Default I/O scheduler not found. Using noop.\n");
+               e = elevator_get(q, "noop", false);
        }
 
-       if (e->uses_mq)
-               err = blk_mq_init_sched(q, e);
-       else
-               err = e->ops.sq.elevator_init_fn(q, e);
+       err = e->ops.sq.elevator_init_fn(q, e);
        if (err)
                elevator_put(e);
+out_unlock:
+       mutex_unlock(&q->sysfs_lock);
        return err;
 }
-EXPORT_SYMBOL(elevator_init);
 
 void elevator_exit(struct request_queue *q, struct elevator_queue *e)
 {
@@ -281,7 +251,6 @@ void elevator_exit(struct request_queue *q, struct elevator_queue *e)
 
        kobject_put(&e->kobj);
 }
-EXPORT_SYMBOL(elevator_exit);
 
 static inline void __elv_rqhash_del(struct request *rq)
 {
@@ -1004,6 +973,40 @@ out:
        return ret;
 }
 
+/*
+ * For blk-mq devices, we default to using mq-deadline, if available, for single
+ * queue devices.  If deadline isn't available OR we have multiple queues,
+ * default to "none".
+ */
+int elevator_init_mq(struct request_queue *q)
+{
+       struct elevator_type *e;
+       int err = 0;
+
+       if (q->nr_hw_queues != 1)
+               return 0;
+
+       /*
+        * q->sysfs_lock must be held to provide mutual exclusion between
+        * elevator_switch() and here.
+        */
+       mutex_lock(&q->sysfs_lock);
+       if (unlikely(q->elevator))
+               goto out_unlock;
+
+       e = elevator_get(q, "mq-deadline", false);
+       if (!e)
+               goto out_unlock;
+
+       err = blk_mq_init_sched(q, e);
+       if (err)
+               elevator_put(e);
+out_unlock:
+       mutex_unlock(&q->sysfs_lock);
+       return err;
+}
+
+
 /*
  * switch to new_e io scheduler. be careful not to introduce deadlocks -
  * we don't free the old io scheduler, before we have allocated what we