+static void put_worker(struct btrfs_worker_thread *worker)
+{
+ if (atomic_dec_and_test(&worker->refs))
+ kfree(worker);
+}
+
+static int try_worker_shutdown(struct btrfs_worker_thread *worker)
+{
+ int freeit = 0;
+
+ spin_lock_irq(&worker->lock);
+ spin_lock(&worker->workers->lock);
+ if (worker->workers->num_workers > 1 &&
+ worker->idle &&
+ !worker->working &&
+ !list_empty(&worker->worker_list) &&
+ list_empty(&worker->prio_pending) &&
+ list_empty(&worker->pending) &&
+ atomic_read(&worker->num_pending) == 0) {
+ freeit = 1;
+ list_del_init(&worker->worker_list);
+ worker->workers->num_workers--;
+ }
+ spin_unlock(&worker->workers->lock);
+ spin_unlock_irq(&worker->lock);
+
+ if (freeit)
+ put_worker(worker);
+ return freeit;
+}
+
+static struct btrfs_work *get_next_work(struct btrfs_worker_thread *worker,
+ struct list_head *prio_head,
+ struct list_head *head)
+{
+ struct btrfs_work *work = NULL;
+ struct list_head *cur = NULL;
+
+ if(!list_empty(prio_head))
+ cur = prio_head->next;
+
+ smp_mb();
+ if (!list_empty(&worker->prio_pending))
+ goto refill;
+
+ if (!list_empty(head))
+ cur = head->next;
+
+ if (cur)
+ goto out;
+
+refill:
+ spin_lock_irq(&worker->lock);
+ list_splice_tail_init(&worker->prio_pending, prio_head);
+ list_splice_tail_init(&worker->pending, head);
+
+ if (!list_empty(prio_head))
+ cur = prio_head->next;
+ else if (!list_empty(head))
+ cur = head->next;
+ spin_unlock_irq(&worker->lock);
+
+ if (!cur)
+ goto out_fail;
+
+out:
+ work = list_entry(cur, struct btrfs_work, list);
+
+out_fail:
+ return work;
+}
+