1 files changed, 55 insertions, 62 deletions

diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c
index 7ec14097fef1..cb97174e2366 100644
--- a/fs/btrfs/async-thread.c
+++ b/fs/btrfs/async-thread.c
@@ -64,6 +64,8 @@ struct btrfs_worker_thread {
         int idle;
 };
 
+static int __btrfs_start_workers(struct btrfs_workers *workers);
+
 /*
  * btrfs_start_workers uses kthread_run, which can block waiting for memory
  * for a very long time.  It will actually throttle on page writeback,
@@ -88,27 +90,10 @@ static void start_new_worker_func(struct btrfs_work *work)
 {
         struct worker_start *start;
         start = container_of(work, struct worker_start, work);
-        btrfs_start_workers(start->queue, 1);
+        __btrfs_start_workers(start->queue);
         kfree(start);
 }
 
-static int start_new_worker(struct btrfs_workers *queue)
-{
-        struct worker_start *start;
-        int ret;
-
-        start = kzalloc(sizeof(*start), GFP_NOFS);
-        if (!start)
-                return -ENOMEM;
-
-        start->work.func = start_new_worker_func;
-        start->queue = queue;
-        ret = btrfs_queue_worker(queue->atomic_worker_start, &start->work);
-        if (ret)
-                kfree(start);
-        return ret;
-}
-
 /*
  * helper function to move a thread onto the idle list after it
  * has finished some requests.
@@ -153,12 +138,20 @@ static void check_busy_worker(struct btrfs_worker_thread *worker)
 static void check_pending_worker_creates(struct btrfs_worker_thread *worker)
 {
         struct btrfs_workers *workers = worker->workers;
+        struct worker_start *start;
         unsigned long flags;
 
         rmb();
         if (!workers->atomic_start_pending)
                 return;
 
+        start = kzalloc(sizeof(*start), GFP_NOFS);
+        if (!start)
+                return;
+
+        start->work.func = start_new_worker_func;
+        start->queue = workers;
+
         spin_lock_irqsave(&workers->lock, flags);
         if (!workers->atomic_start_pending)
                 goto out;
@@ -170,10 +163,11 @@ static void check_pending_worker_creates(struct btrfs_worker_thread *worker)
 
         workers->num_workers_starting += 1;
         spin_unlock_irqrestore(&workers->lock, flags);
-        start_new_worker(workers);
+        btrfs_queue_worker(workers->atomic_worker_start, &start->work);
         return;
 
 out:
+        kfree(start);
         spin_unlock_irqrestore(&workers->lock, flags);
 }
 
@@ -331,7 +325,7 @@ again:
                         run_ordered_completions(worker->workers, work);
 
                         check_pending_worker_creates(worker);
-
+                        cond_resched();
                 }
 
                 spin_lock_irq(&worker->lock);
@@ -462,56 +456,55 @@ void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max,
  * starts new worker threads.  This does not enforce the max worker
  * count in case you need to temporarily go past it.
  */
-static int __btrfs_start_workers(struct btrfs_workers *workers,
-                                 int num_workers)
+static int __btrfs_start_workers(struct btrfs_workers *workers)
 {
         struct btrfs_worker_thread *worker;
         int ret = 0;
-        int i;
 
-        for (i = 0; i < num_workers; i++) {
-                worker = kzalloc(sizeof(*worker), GFP_NOFS);
-                if (!worker) {
-                        ret = -ENOMEM;
-                        goto fail;
-                }
+        worker = kzalloc(sizeof(*worker), GFP_NOFS);
+        if (!worker) {
+                ret = -ENOMEM;
+                goto fail;
+        }
 
-                INIT_LIST_HEAD(&worker->pending);
-                INIT_LIST_HEAD(&worker->prio_pending);
-                INIT_LIST_HEAD(&worker->worker_list);
-                spin_lock_init(&worker->lock);
-
-                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 + i);
-                if (IS_ERR(worker->task)) {
-                        ret = PTR_ERR(worker->task);
-                        kfree(worker);
-                        goto fail;
-                }
-                spin_lock_irq(&workers->lock);
-                list_add_tail(&worker->worker_list, &workers->idle_list);
-                worker->idle = 1;
-                workers->num_workers++;
-                workers->num_workers_starting--;
-                WARN_ON(workers->num_workers_starting < 0);
-                spin_unlock_irq(&workers->lock);
+        INIT_LIST_HEAD(&worker->pending);
+        INIT_LIST_HEAD(&worker->prio_pending);
+        INIT_LIST_HEAD(&worker->worker_list);
+        spin_lock_init(&worker->lock);
+
+        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);
+        if (IS_ERR(worker->task)) {
+                ret = PTR_ERR(worker->task);
+                kfree(worker);
+                goto fail;
         }
+        spin_lock_irq(&workers->lock);
+        list_add_tail(&worker->worker_list, &workers->idle_list);
+        worker->idle = 1;
+        workers->num_workers++;
+        workers->num_workers_starting--;
+        WARN_ON(workers->num_workers_starting < 0);
+        spin_unlock_irq(&workers->lock);
+
         return 0;
 fail:
-        btrfs_stop_workers(workers);
+        spin_lock_irq(&workers->lock);
+        workers->num_workers_starting--;
+        spin_unlock_irq(&workers->lock);
         return ret;
 }
 
-int btrfs_start_workers(struct btrfs_workers *workers, int num_workers)
+int btrfs_start_workers(struct btrfs_workers *workers)
 {
         spin_lock_irq(&workers->lock);
-        workers->num_workers_starting += num_workers;
+        workers->num_workers_starting++;
         spin_unlock_irq(&workers->lock);
-        return __btrfs_start_workers(workers, num_workers);
+        return __btrfs_start_workers(workers);
 }
 
 /*
@@ -568,6 +561,7 @@ static struct btrfs_worker_thread *find_worker(struct btrfs_workers *workers)
         struct btrfs_worker_thread *worker;
         unsigned long flags;
         struct list_head *fallback;
+        int ret;
 
 again:
         spin_lock_irqsave(&workers->lock, flags);
@@ -584,7 +578,9 @@ again:
                         workers->num_workers_starting++;
                         spin_unlock_irqrestore(&workers->lock, flags);
                         /* we're below the limit, start another worker */
-                        __btrfs_start_workers(workers, 1);
+                        ret = __btrfs_start_workers(workers);
+                        if (ret)
+                                goto fallback;
                         goto again;
                 }
         }
@@ -665,7 +661,7 @@ void btrfs_set_work_high_prio(struct btrfs_work *work)
 /*
  * places a struct btrfs_work into the pending queue of one of the kthreads
  */
-int btrfs_queue_worker(struct btrfs_workers *workers, struct btrfs_work *work)
+void btrfs_queue_worker(struct btrfs_workers *workers, struct btrfs_work *work)
 {
         struct btrfs_worker_thread *worker;
         unsigned long flags;
@@ -673,7 +669,7 @@ int btrfs_queue_worker(struct btrfs_workers *workers, struct btrfs_work *work)
 
         /* don't requeue something already on a list */
         if (test_and_set_bit(WORK_QUEUED_BIT, &work->flags))
-                goto out;
+                return;
 
         worker = find_worker(workers);
         if (workers->ordered) {
@@ -712,7 +708,4 @@ int btrfs_queue_worker(struct btrfs_workers *workers, struct btrfs_work *work)
         if (wake)
                 wake_up_process(worker->task);
         spin_unlock_irqrestore(&worker->lock, flags);
-
-out:
-        return 0;
 }