From 3554b4345d855089ab7af5e3557f5dc3262d14c9 Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Thu, 16 Apr 2026 11:56:59 -0700 Subject: net: introduce ndo_set_rx_mode_async and netdev_rx_mode_work Add ndo_set_rx_mode_async callback that drivers can implement instead of the legacy ndo_set_rx_mode. The legacy callback runs under the netif_addr_lock spinlock with BHs disabled, preventing drivers from sleeping. The async variant runs from a work queue with rtnl_lock and netdev_lock_ops held, in fully sleepable context. When __dev_set_rx_mode() sees ndo_set_rx_mode_async, it schedules netdev_rx_mode_work instead of calling the driver inline. The work function takes two snapshots of each address list (uc/mc) under the addr_lock, then drops the lock and calls the driver with the work copies. After the driver returns, it reconciles the snapshots back to the real lists under the lock. Add netif_rx_mode_sync() to opportunistically execute the pending workqueue update inline, so that rx mode changes are committed before returning to userspace: - dev_change_flags (SIOCSIFFLAGS / RTM_NEWLINK) - dev_set_promiscuity - dev_set_allmulti - dev_ifsioc SIOCADDMULTI / SIOCDELMULTI - do_setlink (RTM_SETLINK) Note that some deep hierarchies still do skip the lower updates via: - dev_uc_sync - dev_mc_sync If we do end up hitting user-visible issues, we can add more calls to netif_rx_mode_sync in specific places. But hopefully we should not, the actual user-visible lists are still synced, it's that just HW state that might be lagging. Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20260416185712.2155425-3-sdf@fomichev.me Signed-off-by: Paolo Abeni --- include/linux/netdevice.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'include/linux/netdevice.h') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index a84c55488b8c..6ed97f4c3bc6 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1119,6 +1119,16 @@ struct netdev_net_notifier { * This function is called device changes address list filtering. * If driver handles unicast address filtering, it should set * IFF_UNICAST_FLT in its priv_flags. + * Cannot sleep, called with netif_addr_lock_bh held. + * Deprecated in favor of ndo_set_rx_mode_async. + * + * void (*ndo_set_rx_mode_async)(struct net_device *dev, + * struct netdev_hw_addr_list *uc, + * struct netdev_hw_addr_list *mc); + * Async version of ndo_set_rx_mode which runs in process context + * with rtnl_lock and netdev_lock_ops(dev) held. The uc/mc parameters + * are snapshots of the address lists - iterate with + * netdev_hw_addr_list_for_each(ha, uc). * * int (*ndo_set_mac_address)(struct net_device *dev, void *addr); * This function is called when the Media Access Control address @@ -1439,6 +1449,10 @@ struct net_device_ops { void (*ndo_change_rx_flags)(struct net_device *dev, int flags); void (*ndo_set_rx_mode)(struct net_device *dev); + void (*ndo_set_rx_mode_async)( + struct net_device *dev, + struct netdev_hw_addr_list *uc, + struct netdev_hw_addr_list *mc); int (*ndo_set_mac_address)(struct net_device *dev, void *addr); int (*ndo_validate_addr)(struct net_device *dev); @@ -1903,6 +1917,8 @@ enum netdev_reg_state { * has been enabled due to the need to listen to * additional unicast addresses in a device that * does not implement ndo_set_rx_mode() + * @rx_mode_node: List entry for rx_mode work processing + * @rx_mode_tracker: Refcount tracker for rx_mode work * @uc: unicast mac addresses * @mc: multicast mac addresses * @dev_addrs: list of device hw addresses @@ -2294,6 +2310,8 @@ struct net_device { unsigned int promiscuity; unsigned int allmulti; bool uc_promisc; + struct list_head rx_mode_node; + netdevice_tracker rx_mode_tracker; #ifdef CONFIG_LOCKDEP unsigned char nested_level; #endif -- cgit v1.2.3