diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 7bdc7eb808ea..709bad75c47b 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1473,7 +1473,17 @@ static int nbd_start_device(struct nbd_device *nbd) return -EINVAL; } - blk_mq_update_nr_hw_queues(&nbd->tag_set, config->num_connections); +retry: + mutex_unlock(&nbd->config_lock); + blk_mq_update_nr_hw_queues(&nbd->tag_set, num_connections); + mutex_lock(&nbd->config_lock); + + /* if another code path updated nr_hw_queues, retry until succeed */ + if (num_connections != config->num_connections) { + num_connections = config->num_connections; + goto retry; + } + nbd->pid = task_pid_nr(current); nbd_parse_flags(nbd);