From 65d43023171edc0d27208f6ac7a1a73732950cf7 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 26 Feb 2021 09:50:55 -0700 Subject: [PATCH] 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 --- fs/io-wq.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/io-wq.c b/fs/io-wq.c index 44e20248805a..965022fe9961 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -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; } -- 2.20.1