Commit fd0fb038 authored by Shin Hong's avatar Shin Hong Committed by Chris Mason
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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: default avatarChris Mason <>
parent 4eedeb75
...@@ -294,10 +294,10 @@ int btrfs_start_workers(struct btrfs_workers *workers, int num_workers) ...@@ -294,10 +294,10 @@ int btrfs_start_workers(struct btrfs_workers *workers, int num_workers)
INIT_LIST_HEAD(&worker->worker_list); INIT_LIST_HEAD(&worker->worker_list);
spin_lock_init(&worker->lock); spin_lock_init(&worker->lock);
atomic_set(&worker->num_pending, 0); atomic_set(&worker->num_pending, 0);
worker->workers = workers;
worker->task = kthread_run(worker_loop, worker, worker->task = kthread_run(worker_loop, worker,
"btrfs-%s-%d", workers->name, "btrfs-%s-%d", workers->name,
workers->num_workers + i); workers->num_workers + i);
worker->workers = workers;
if (IS_ERR(worker->task)) { if (IS_ERR(worker->task)) {
kfree(worker); kfree(worker);
ret = PTR_ERR(worker->task); ret = PTR_ERR(worker->task);
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