io-wq: only remove worker from free_list, if it was there

If the worker isn't on the free_list, don't attempt to delete it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io-wq.c b/fs/io-wq.c
index acc67ed..3a506f1 100644 (file)
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -155,6 +155,7 @@ 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 we're not at zero, someone else is holding a brief reference
@@ -167,9 +168,11 @@ static void io_worker_exit(struct io_worker *worker)
 
        preempt_disable();
        current->flags &= ~PF_IO_WORKER;
-       if (worker->flags & IO_WORKER_F_RUNNING)
+       flags = worker->flags;
+       worker->flags = 0;
+       if (flags & IO_WORKER_F_RUNNING)
                atomic_dec(&acct->nr_running);
-       if (!(worker->flags & IO_WORKER_F_BOUND))
+       if (!(flags & IO_WORKER_F_BOUND))
                atomic_dec(&wqe->wq->user->processes);
        worker->flags = 0;
        preempt_enable();
@@ -180,7 +183,8 @@ static void io_worker_exit(struct io_worker *worker)
        }
 
        raw_spin_lock_irq(&wqe->lock);
-       hlist_nulls_del_rcu(&worker->nulls_node);
+       if (flags & IO_WORKER_F_FREE)
+               hlist_nulls_del_rcu(&worker->nulls_node);
        list_del_rcu(&worker->all_list);
        acct->nr_workers--;
        raw_spin_unlock_irq(&wqe->lock);