From: Shin Hong Date: Thu, 11 Jun 2009 00:11:29 +0000 (-0400) Subject: Btrfs: init worker struct fields before kthread-run X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=fd0fb038d5a308c7faddd1701be5e70aaffec98b;p=linux-beck.git Btrfs: init worker struct fields before kthread-run This patch fixes a bug which may result race condition between btrfs_start_workers() and worker_loop(). btrfs_start_workers() executed in a parent thread writes on workers->worker and worker_loop() in a child thread reads workers->worker. However, there is no synchronization enforcing the order of two operations. This patch makes btrfs_start_workers() fill workers->worker before it starts a child thread with worker_loop() Signed-off-by: Chris Mason --- diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c index 502c3d61de62..7f88628a1a72 100644 --- a/fs/btrfs/async-thread.c +++ b/fs/btrfs/async-thread.c @@ -294,10 +294,10 @@ int btrfs_start_workers(struct btrfs_workers *workers, int num_workers) INIT_LIST_HEAD(&worker->worker_list); spin_lock_init(&worker->lock); atomic_set(&worker->num_pending, 0); + worker->workers = workers; worker->task = kthread_run(worker_loop, worker, "btrfs-%s-%d", workers->name, workers->num_workers + i); - worker->workers = workers; if (IS_ERR(worker->task)) { kfree(worker); ret = PTR_ERR(worker->task);