io-wq: wait for worker startup when forking a new one

We need to have our worker count updated before continuing, to avoid
cases where we repeatedly think we need a new worker, but a fork is
already in progress.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2021-02-26 09:50:55 -07:00
parent fe07bfda2f
commit 65d4302317

View File

@ -56,6 +56,7 @@ struct io_worker {
const struct cred *saved_creds;
struct completion ref_done;
struct completion started;
struct rcu_head rcu;
};
@ -267,6 +268,7 @@ static void io_worker_start(struct io_worker *worker)
{
worker->flags |= (IO_WORKER_F_UP | IO_WORKER_F_RUNNING);
io_wqe_inc_running(worker);
complete(&worker->started);
}
/*
@ -644,6 +646,7 @@ static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index)
worker->wqe = wqe;
spin_lock_init(&worker->lock);
init_completion(&worker->ref_done);
init_completion(&worker->started);
refcount_inc(&wq->refs);
@ -656,6 +659,7 @@ static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index)
kfree(worker);
return false;
}
wait_for_completion(&worker->started);
return true;
}