[PATCH 5.15 448/917] io-wq: Remove duplicate code in io_workqueue_create()

Greg Kroah-Hartman
2021-11-15T23:40:00Z

From: Bixuan Cui <cuibixuan@huawei.com>

[ Upstream commit 71e1cef2d794338cc7b979d4c6144e1dc12718b5 ]

While task_work_add() in io_workqueue_create() is true,
then duplicate code is executed:

-> clear_bit_unlock(0, &worker->create_state);
-> io_worker_release(worker);
-> atomic_dec(&acct->nr_running);
-> io_worker_ref_put(wq);
-> return false;

-> clear_bit_unlock(0, &worker->create_state); // back to io_workqueue_create()
-> io_worker_release(worker);
-> kfree(worker);

The io_worker_release() and clear_bit_unlock() are executed twice.

Fixes: 3146cba99aa2 ("io-wq: make worker creation resilient against signals")
Signed-off-by: Bixuan Cui <cuibixuan@huawei.com>
Link: https://lore.kernel.org/r/20210911085847.34849-1-cuibixuan@huawei.com
Reviwed-by: Hao Xu <haoxu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/io-wq.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/fs/io-wq.c b/fs/io-wq.c
index 203c0e2a5dfae..5d189b24a8d4b 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -359,8 +359,10 @@ static bool io_queue_worker_create(struct io_worker *worker,

init_task_work(&worker->create_work, func);
worker->create_index = acct->index;
- if (!task_work_add(wq->task, &worker->create_work, TWA_SIGNAL))
+ if (!task_work_add(wq->task, &worker->create_work, TWA_SIGNAL)) {
+ clear_bit_unlock(0, &worker->create_state);
return true;
+ }
clear_bit_unlock(0, &worker->create_state);
fail_release:
io_worker_release(worker);
@@ -765,11 +767,8 @@ static void io_workqueue_create(struct work_struct *work)
struct io_worker *worker = container_of(work, struct io_worker, work);
struct io_wqe_acct *acct = io_wqe_get_acct(worker);

- if (!io_queue_worker_create(worker, acct, create_worker_cont)) {
- clear_bit_unlock(0, &worker->create_state);
- io_worker_release(worker);
+ if (!io_queue_worker_create(worker, acct, create_worker_cont))
kfree(worker);
- }
}

static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index)
--
2.33.0