From: Hao Xu <haoxu@xxxxxxxxxxxxxxxxx> [ Upstream commit 49e7f0c789add1330b111af0b7caeb0e87df063e ] The former patch to add check between nr_workers and max_workers has a bug, which will cause unconditionally creating io-workers. That's because the result of the check doesn't affect the call of create_io_worker(), fix it by bringing in a boolean value for it. Fixes: 21698274da5b ("io-wq: fix lack of acct->nr_workers < acct->max_workers judgement") Signed-off-by: Hao Xu <haoxu@xxxxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210808135434.68667-2-haoxu@xxxxxxxxxxxxxxxxx [axboe: drop hunk that isn't strictly needed] Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- fs/io-wq.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/io-wq.c b/fs/io-wq.c index 77026d42cb79..2c8a9a394884 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -283,16 +283,24 @@ static void create_worker_cb(struct callback_head *cb) struct io_wq *wq; struct io_wqe *wqe; struct io_wqe_acct *acct; + bool do_create = false; cwd = container_of(cb, struct create_worker_data, work); wqe = cwd->wqe; wq = wqe->wq; acct = &wqe->acct[cwd->index]; raw_spin_lock_irq(&wqe->lock); - if (acct->nr_workers < acct->max_workers) + if (acct->nr_workers < acct->max_workers) { acct->nr_workers++; + do_create = true; + } raw_spin_unlock_irq(&wqe->lock); - create_io_worker(wq, cwd->wqe, cwd->index); + if (do_create) { + create_io_worker(wq, cwd->wqe, cwd->index); + } else { + atomic_dec(&acct->nr_running); + io_worker_ref_put(wq); + } kfree(cwd); } -- 2.30.2