io-wq: warn on creating manager while exiting
Add a simple warning making sure that nobody tries to create a new
manager while we're under IO_WQ_BIT_EXIT. That can potentially happen
due to racy work submission after final put.
Signed-off-by: Pavel Begunkov <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
diff --git a/fs/io-wq.c b/fs/io-wq.c
index 1bfdb86..1ab9324 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -774,6 +774,8 @@ static int io_wq_fork_manager(struct io_wq *wq)
if (wq->manager)
return 0;
+ WARN_ON_ONCE(test_bit(IO_WQ_BIT_EXIT, &wq->state));
+
init_completion(&wq->worker_done);
atomic_set(&wq->worker_refs, 1);
tsk = create_io_thread(io_wq_manager, wq, NUMA_NO_NODE);
