1 files changed, 19 insertions, 6 deletions

diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c
index 58b7d14b08ee..08cc08f037a6 100644
--- a/fs/btrfs/async-thread.c
+++ b/fs/btrfs/async-thread.c
@@ -107,7 +107,8 @@ static void check_idle_worker(struct btrfs_worker_thread *worker)
                 worker->idle = 1;
 
                 /* the list may be empty if the worker is just starting */
-                if (!list_empty(&worker->worker_list)) {
+                if (!list_empty(&worker->worker_list) &&
+                    !worker->workers->stopping) {
                         list_move(&worker->worker_list,
                                  &worker->workers->idle_list);
                 }
@@ -127,7 +128,8 @@ static void check_busy_worker(struct btrfs_worker_thread *worker)
                 spin_lock_irqsave(&worker->workers->lock, flags);
                 worker->idle = 0;
 
-                if (!list_empty(&worker->worker_list)) {
+                if (!list_empty(&worker->worker_list) &&
+                    !worker->workers->stopping) {
                         list_move_tail(&worker->worker_list,
                                       &worker->workers->worker_list);
                 }
@@ -412,6 +414,7 @@ void btrfs_stop_workers(struct btrfs_workers *workers)
         int can_stop;
 
         spin_lock_irq(&workers->lock);
+        workers->stopping = 1;
         list_splice_init(&workers->idle_list, &workers->worker_list);
         while (!list_empty(&workers->worker_list)) {
                 cur = workers->worker_list.next;
@@ -455,6 +458,7 @@ void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max,
         workers->ordered = 0;
         workers->atomic_start_pending = 0;
         workers->atomic_worker_start = async_helper;
+        workers->stopping = 0;
 }
 
 /*
@@ -480,15 +484,19 @@ static int __btrfs_start_workers(struct btrfs_workers *workers)
         atomic_set(&worker->num_pending, 0);
         atomic_set(&worker->refs, 1);
         worker->workers = workers;
-        worker->task = kthread_run(worker_loop, worker,
-                                   "btrfs-%s-%d", workers->name,
-                                   workers->num_workers + 1);
+        worker->task = kthread_create(worker_loop, worker,
+                                      "btrfs-%s-%d", workers->name,
+                                      workers->num_workers + 1);
         if (IS_ERR(worker->task)) {
                 ret = PTR_ERR(worker->task);
-                kfree(worker);
                 goto fail;
         }
+
         spin_lock_irq(&workers->lock);
+        if (workers->stopping) {
+                spin_unlock_irq(&workers->lock);
+                goto fail_kthread;
+        }
         list_add_tail(&worker->worker_list, &workers->idle_list);
         worker->idle = 1;
         workers->num_workers++;
@@ -496,8 +504,13 @@ static int __btrfs_start_workers(struct btrfs_workers *workers)
         WARN_ON(workers->num_workers_starting < 0);
         spin_unlock_irq(&workers->lock);
 
+        wake_up_process(worker->task);
         return 0;
+
+fail_kthread:
+        kthread_stop(worker->task);
 fail:
+        kfree(worker);
         spin_lock_irq(&workers->lock);
         workers->num_workers_starting--;
         spin_unlock_irq(&workers->lock);