From: Stanislav Fomichev Date: Mon, 8 Jun 2026 15:40:13 +0000 (-0700) Subject: net: add retry mechanism to ndo_set_rx_mode_async X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d90b85c23b3d64cc58a2bc59ceda6f6aa4df9ea3;p=thirdparty%2Flinux.git net: add retry mechanism to ndo_set_rx_mode_async When ndo_set_rx_mode_async returns an error, schedule a retry with exponential backoff (1s, 2s, 4s, 8s -- 15s total). Give up after the 4th retry and log an error via netdev_err(). This moves retry logic from individual drivers into the core stack. Timer callback does not hold a ref on dev. Safe because the timer can only be armed when dev is IFF_UP, and __dev_close_many runs timer_delete_sync before clearing IFF_UP. Unregister always closes IFF_UP devices first, so by the time dev can be freed the timer is dead and cannot be re-armed. Reviewed-by: Jakub Kicinski Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20260608154014.227538-3-sdf@fomichev.me Signed-off-by: Jakub Kicinski --- diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 51ec2df02094..7f4f0837c09f 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1933,6 +1933,8 @@ enum netdev_reg_state { * @rx_mode_node: List entry for rx_mode work processing * @rx_mode_tracker: Refcount tracker for rx_mode work * @rx_mode_addr_cache: Recycled snapshot entries for rx_mode work + * @rx_mode_retry_timer: Timer that re-queues rx_mode work after failure + * @rx_mode_retry_count: Number of consecutive retries already scheduled * @uc: unicast mac addresses * @mc: multicast mac addresses * @dev_addrs: list of device hw addresses @@ -2326,6 +2328,8 @@ struct net_device { struct list_head rx_mode_node; netdevice_tracker rx_mode_tracker; struct netdev_hw_addr_list rx_mode_addr_cache; + struct timer_list rx_mode_retry_timer; + unsigned int rx_mode_retry_count; #ifdef CONFIG_LOCKDEP unsigned char nested_level; #endif @@ -5152,6 +5156,7 @@ static inline void __dev_mc_unsync(struct net_device *dev, /* Functions used for secondary unicast and multicast support */ void dev_set_rx_mode(struct net_device *dev); +void netif_rx_mode_schedule_retry(struct net_device *dev); int netif_set_promiscuity(struct net_device *dev, int inc); int dev_set_promiscuity(struct net_device *dev, int inc); int netif_set_allmulti(struct net_device *dev, int inc, bool notify); diff --git a/net/core/dev.c b/net/core/dev.c index 1ecd5691992e..202e35acb15b 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1775,6 +1775,7 @@ static void __dev_close_many(struct list_head *head) if (ops->ndo_stop) ops->ndo_stop(dev); + netif_rx_mode_cancel_retry(dev); netif_set_up(dev, false); netpoll_poll_enable(dev); } @@ -12094,8 +12095,7 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name, #endif mutex_init(&dev->lock); - INIT_LIST_HEAD(&dev->rx_mode_node); - __hw_addr_init(&dev->rx_mode_addr_cache); + netif_rx_mode_init(dev); dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM; setup(dev); diff --git a/net/core/dev.h b/net/core/dev.h index 9e9431440869..4121c50e7c88 100644 --- a/net/core/dev.h +++ b/net/core/dev.h @@ -166,8 +166,10 @@ int dev_change_carrier(struct net_device *dev, bool new_carrier); void __dev_set_rx_mode(struct net_device *dev); int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify); +void netif_rx_mode_init(struct net_device *dev); bool netif_rx_mode_clean(struct net_device *dev); void netif_rx_mode_sync(struct net_device *dev); +void netif_rx_mode_cancel_retry(struct net_device *dev); void __dev_notify_flags(struct net_device *dev, unsigned int old_flags, unsigned int gchanges, u32 portid, diff --git a/net/core/dev_addr_lists.c b/net/core/dev_addr_lists.c index 6b493af8dc8b..e17f64a65e17 100644 --- a/net/core/dev_addr_lists.c +++ b/net/core/dev_addr_lists.c @@ -1252,6 +1252,35 @@ static int netif_uc_promisc_update(struct net_device *dev) return 0; } +/* Total retry budget (4): 1+2+4+8 = 15 seconds */ +#define NETIF_RX_MODE_RETRY_MAX 4 + +void netif_rx_mode_schedule_retry(struct net_device *dev) +{ + unsigned long delay; + + netdev_assert_locked_ops_compat(dev); + + if (dev->rx_mode_retry_count >= NETIF_RX_MODE_RETRY_MAX) { + netdev_err(dev, "rx_mode retry limit reached, giving up\n"); + return; + } + + delay = HZ << dev->rx_mode_retry_count; + if (mod_timer(&dev->rx_mode_retry_timer, jiffies + delay)) + return; + if (!dev->rx_mode_retry_count) + netdev_info(dev, "rx_mode install failed, retrying with backoff\n"); + dev->rx_mode_retry_count++; +} +EXPORT_SYMBOL_GPL(netif_rx_mode_schedule_retry); + +void netif_rx_mode_cancel_retry(struct net_device *dev) +{ + timer_delete_sync(&dev->rx_mode_retry_timer); + dev->rx_mode_retry_count = 0; +} + static void netif_rx_mode_run(struct net_device *dev) { struct netdev_hw_addr_list uc_snap, mc_snap, uc_ref, mc_ref; @@ -1275,8 +1304,8 @@ static void netif_rx_mode_run(struct net_device *dev) err = netif_addr_lists_snapshot(dev, &uc_snap, &mc_snap, &uc_ref, &mc_ref); if (err) { - netdev_WARN(dev, "failed to sync uc/mc addresses\n"); netif_addr_unlock_bh(dev); + netif_rx_mode_schedule_retry(dev); return; } @@ -1292,12 +1321,17 @@ static void netif_rx_mode_run(struct net_device *dev) __dev_set_promiscuity(dev, promisc_inc, false); if (ops->ndo_set_rx_mode_async) { - ops->ndo_set_rx_mode_async(dev, &uc_snap, &mc_snap); + err = ops->ndo_set_rx_mode_async(dev, &uc_snap, &mc_snap); netif_addr_lock_bh(dev); netif_addr_lists_reconcile(dev, &uc_snap, &mc_snap, &uc_ref, &mc_ref); netif_addr_unlock_bh(dev); + + if (err) + netif_rx_mode_schedule_retry(dev); + else + dev->rx_mode_retry_count = 0; } else if (ops->ndo_set_rx_mode) { netif_addr_lock_bh(dev); ops->ndo_set_rx_mode(dev); @@ -1350,6 +1384,21 @@ static void netif_rx_mode_queue(struct net_device *dev) schedule_work(&rx_mode_work); } +static void netif_rx_mode_retry(struct timer_list *t) +{ + struct net_device *dev = + timer_container_of(dev, t, rx_mode_retry_timer); + + netif_rx_mode_queue(dev); +} + +void netif_rx_mode_init(struct net_device *dev) +{ + INIT_LIST_HEAD(&dev->rx_mode_node); + __hw_addr_init(&dev->rx_mode_addr_cache); + timer_setup(&dev->rx_mode_retry_timer, netif_rx_mode_retry, 0); +} + /** * __dev_set_rx_mode() - upload unicast and multicast address lists to device * and configure RX filtering.