On 1/17/25 02:25, Jakub Kicinski wrote:
On Thu, 16 Jan 2025 15:16:52 -0800 David Wei wrote:+static void __net_mp_close_rxq(struct net_device *dev, unsigned ifq_idx, + struct pp_memory_provider_params *old_p) +{ + struct netdev_rx_queue *rxq; + int ret; + + if (WARN_ON_ONCE(ifq_idx >= dev->real_num_rx_queues)) + return; + + rxq = __netif_get_rx_queue(dev, ifq_idx);I think there's a small race between io_uring closing and the netdev unregister. We can try to uninstall twice, let's put
They're gated by checking ifq->netdev in io_uring code, which is cleared by them under a spin. So either io_uring does __net_mp_close_rxq() and ->uninstall does nothing, or vise versa.
/* Callers holding a netdev ref may get here after we already * went thru shutdown via dev_memory_provider_uninstall(). */ if (dev->reg_state > NETREG_REGISTERED && !rxq->mp_params.mp_ops) return; here, and in dev_memory_provider_uninstall() clear the pointers?+ if (WARN_ON_ONCE(rxq->mp_params.mp_ops != old_p->mp_ops || + rxq->mp_params.mp_priv != old_p->mp_priv)) + return; + + rxq->mp_params.mp_ops = NULL; + rxq->mp_params.mp_priv = NULL; + ret = netdev_rx_queue_restart(dev, ifq_idx); + if (ret) + pr_devel("Could not restart queue %u after removing memory provider.\n", + ifq_idx); +}
-- Pavel Begunkov
