io-wq: fix bug of creating io-wokers unconditionally
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@linux.alibaba.com>
Link: https://lore.kernel.org/r/20210808135434.68667-2-haoxu@linux.alibaba.com
[axboe: drop hunk that isn't strictly needed]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fs/io-wq.c b/fs/io-wq.c
index 12fc193..ac8604a 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -282,16 +282,24 @@ 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);
}