Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull btrfs fixes from Chris Mason:
 "This is a small collection of fixes, including a regression fix from
  Liu Bo that solves rare crashes with compression on.

  I've merged my for-linus up to 3.12-rc3 because the top commit is only
  meant for 3.12.  The rest of the fixes are also available in my master
  branch on top of my last 3.11 based pull"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: Fix crash due to not allocating integrity data for a bioset
  Btrfs: fix a use-after-free bug in btrfs_dev_replace_finishing
  Btrfs: eliminate races in worker stopping code
  Btrfs: fix crash of compressed writes
  Btrfs: fix transid verify errors when recovering log tree

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);