From: Beld Zhang beldzhang@gmail.com
[ Upstream commit 71c9ce27bb57c59d8d7f5298e730c8096eef3d1f ]
In io-wq.c:io_wq_max_workers(), new_count[] was changed right after each node's value was set. This caused the following node getting the setting of the previous one.
Returned values are copied from node 0.
Fixes: 2e480058ddc2 ("io-wq: provide a way to limit max number of workers") Signed-off-by: Beld Zhang beldzhang@gmail.com [axboe: minor fixups] Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- fs/io-wq.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/fs/io-wq.c b/fs/io-wq.c index 5d189b24a8d4b..8c61315657546 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -1318,7 +1318,9 @@ int io_wq_cpu_affinity(struct io_wq *wq, cpumask_var_t mask) */ int io_wq_max_workers(struct io_wq *wq, int *new_count) { - int i, node, prev = 0; + int prev[IO_WQ_ACCT_NR]; + bool first_node = true; + int i, node;
BUILD_BUG_ON((int) IO_WQ_ACCT_BOUND != (int) IO_WQ_BOUND); BUILD_BUG_ON((int) IO_WQ_ACCT_UNBOUND != (int) IO_WQ_UNBOUND); @@ -1329,6 +1331,9 @@ int io_wq_max_workers(struct io_wq *wq, int *new_count) new_count[i] = task_rlimit(current, RLIMIT_NPROC); }
+ for (i = 0; i < IO_WQ_ACCT_NR; i++) + prev[i] = 0; + rcu_read_lock(); for_each_node(node) { struct io_wqe *wqe = wq->wqes[node]; @@ -1337,14 +1342,19 @@ int io_wq_max_workers(struct io_wq *wq, int *new_count) raw_spin_lock(&wqe->lock); for (i = 0; i < IO_WQ_ACCT_NR; i++) { acct = &wqe->acct[i]; - prev = max_t(int, acct->max_workers, prev); + if (first_node) + prev[i] = max_t(int, acct->max_workers, prev[i]); if (new_count[i]) acct->max_workers = new_count[i]; - new_count[i] = prev; } raw_spin_unlock(&wqe->lock); + first_node = false; } rcu_read_unlock(); + + for (i = 0; i < IO_WQ_ACCT_NR; i++) + new_count[i] = prev[i]; + return 0; }