1 files changed, 19 insertions, 19 deletions

diff --git a/fs/io-wq.c b/fs/io-wq.c
index cf086b01c6c6..50dc93ffc153 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -130,6 +130,7 @@ struct io_cb_cancel_data {
 };
 
 static void create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index);
+static void io_wqe_dec_running(struct io_worker *worker);
 
 static bool io_worker_get(struct io_worker *worker)
 {
@@ -168,26 +169,21 @@ static void io_worker_exit(struct io_worker *worker)
 {
 	struct io_wqe *wqe = worker->wqe;
 	struct io_wqe_acct *acct = io_wqe_get_acct(worker);
-	unsigned flags;
 
 	if (refcount_dec_and_test(&worker->ref))
 		complete(&worker->ref_done);
 	wait_for_completion(&worker->ref_done);
 
-	preempt_disable();
-	current->flags &= ~PF_IO_WORKER;
-	flags = worker->flags;
-	worker->flags = 0;
-	if (flags & IO_WORKER_F_RUNNING)
-		atomic_dec(&acct->nr_running);
-	worker->flags = 0;
-	preempt_enable();
-
 	raw_spin_lock_irq(&wqe->lock);
-	if (flags & IO_WORKER_F_FREE)
+	if (worker->flags & IO_WORKER_F_FREE)
 		hlist_nulls_del_rcu(&worker->nulls_node);
 	list_del_rcu(&worker->all_list);
 	acct->nr_workers--;
+	preempt_disable();
+	io_wqe_dec_running(worker);
+	worker->flags = 0;
+	current->flags &= ~PF_IO_WORKER;
+	preempt_enable();
 	raw_spin_unlock_irq(&wqe->lock);
 
 	kfree_rcu(worker, rcu);
@@ -214,15 +210,19 @@ static bool io_wqe_activate_free_worker(struct io_wqe *wqe)
 	struct hlist_nulls_node *n;
 	struct io_worker *worker;
 
-	n = rcu_dereference(hlist_nulls_first_rcu(&wqe->free_list));
-	if (is_a_nulls(n))
-		return false;
-
-	worker = hlist_nulls_entry(n, struct io_worker, nulls_node);
-	if (io_worker_get(worker)) {
-		wake_up_process(worker->task);
+	/*
+	 * Iterate free_list and see if we can find an idle worker to
+	 * activate. If a given worker is on the free_list but in the process
+	 * of exiting, keep trying.
+	 */
+	hlist_nulls_for_each_entry_rcu(worker, n, &wqe->free_list, nulls_node) {
+		if (!io_worker_get(worker))
+			continue;
+		if (wake_up_process(worker->task)) {
+			io_worker_release(worker);
+			return true;
+		}
 		io_worker_release(worker);
-		return true;
 	}
 
 	return false;