From 310ae9eb2617c62deedef8f121d7ca1ae774fa76 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 24 Mar 2025 15:45:32 -0700 Subject: net: designate queue -> napi linking as "ops protected" netdev netlink is the only reader of netdev_{,rx_}queue->napi, and it already holds netdev->lock. Switch protection of the writes to netdev->lock to "ops protected". The expectation will be now that accessing queue->napi will require netdev->lock for "ops locked" drivers, and rtnl_lock for all other drivers. Current "ops locked" drivers don't require any changes. gve and netdevsim use _locked() helpers right next to netif_queue_set_napi() so they must be holding the instance lock. iavf doesn't call it. bnxt is a bit messy but all paths seem locked. Acked-by: Stanislav Fomichev Link: https://patch.msgid.link/20250324224537.248800-7-kuba@kernel.org Signed-off-by: Jakub Kicinski --- include/net/netdev_lock.h | 8 ++++++++ include/net/netdev_rx_queue.h | 2 +- 2 files changed, 9 insertions(+), 1 deletion(-) (limited to 'include/net') diff --git a/include/net/netdev_lock.h b/include/net/netdev_lock.h index efd302375ef2..1c0c9a94cc22 100644 --- a/include/net/netdev_lock.h +++ b/include/net/netdev_lock.h @@ -56,6 +56,14 @@ static inline void netdev_ops_assert_locked(const struct net_device *dev) ASSERT_RTNL(); } +static inline void +netdev_ops_assert_locked_or_invisible(const struct net_device *dev) +{ + if (dev->reg_state == NETREG_REGISTERED || + dev->reg_state == NETREG_UNREGISTERING) + netdev_ops_assert_locked(dev); +} + static inline int netdev_lock_cmp_fn(const struct lockdep_map *a, const struct lockdep_map *b) { diff --git a/include/net/netdev_rx_queue.h b/include/net/netdev_rx_queue.h index af40842f229d..b2238b551dce 100644 --- a/include/net/netdev_rx_queue.h +++ b/include/net/netdev_rx_queue.h @@ -24,7 +24,7 @@ struct netdev_rx_queue { struct xsk_buff_pool *pool; #endif /* NAPI instance for the queue - * Readers and writers must hold RTNL + * "ops protected", see comment about net_device::lock */ struct napi_struct *napi; struct pp_memory_provider_params mp_params; -- cgit v1.2.3