[PATCH 5.13 072/175] io-wq: fix lack of acct->nr_workers < acct->max_workers judgement

From: Greg Kroah-Hartman
Date: Tue Aug 10 2021 - 13:59:48 EST


From: Hao Xu <haoxu@xxxxxxxxxxxxxxxxx>

[ Upstream commit 21698274da5b6fc724b005bc7ec3e6b9fbcfaa06 ]

There should be this judgement before we create an io-worker

Fixes: 685fe7feedb9 ("io-wq: eliminate the need for a manager thread")
Signed-off-by: Hao Xu <haoxu@xxxxxxxxxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/io-wq.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/io-wq.c b/fs/io-wq.c
index e00ac0969470..400fba839734 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -281,9 +281,17 @@ static void create_worker_cb(struct callback_head *cb)
{
struct create_worker_data *cwd;
struct io_wq *wq;
+ struct io_wqe *wqe;
+ struct io_wqe_acct *acct;

cwd = container_of(cb, struct create_worker_data, work);
- wq = cwd->wqe->wq;
+ wqe = cwd->wqe;
+ wq = wqe->wq;
+ acct = &wqe->acct[cwd->index];
+ raw_spin_lock_irq(&wqe->lock);
+ if (acct->nr_workers < acct->max_workers)
+ acct->nr_workers++;
+ raw_spin_unlock_irq(&wqe->lock);
create_io_worker(wq, cwd->wqe, cwd->index);
kfree(cwd);
}
--
2.30.2