From 4ec9031cbeb73a66979560bbb6d355329be762de Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Tue, 8 Apr 2025 12:59:50 -0700 Subject: netdev: add "ops compat locking" helpers Add helpers to "lock a netdev in a backward-compatible way", which for ops-locked netdevs will mean take the instance lock. For drivers which haven't opted into the ops locking we'll take rtnl_lock. The scoped foreach is dropping and re-taking the lock for each device, even if prev and next are both under rtnl_lock. I hope that's fine since we expect that netdev nl to be mostly supported by modern drivers, and modern drivers should also opt into the instance locking. Note that these helpers are mostly needed for queue related state, because drivers modify queue config in their ops in a non-atomic way. Or differently put, queue changes don't have a clear-cut API like NAPI configuration. Any state that can should just use the instance lock directly, not the "compat" hacks. Reviewed-by: Joe Damato Acked-by: Stanislav Fomichev Link: https://patch.msgid.link/20250408195956.412733-4-kuba@kernel.org Signed-off-by: Jakub Kicinski --- include/net/netdev_lock.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'include') diff --git a/include/net/netdev_lock.h b/include/net/netdev_lock.h index c316b551df8d..5706835a660c 100644 --- a/include/net/netdev_lock.h +++ b/include/net/netdev_lock.h @@ -64,6 +64,22 @@ netdev_ops_assert_locked_or_invisible(const struct net_device *dev) netdev_ops_assert_locked(dev); } +static inline void netdev_lock_ops_compat(struct net_device *dev) +{ + if (netdev_need_ops_lock(dev)) + netdev_lock(dev); + else + rtnl_lock(); +} + +static inline void netdev_unlock_ops_compat(struct net_device *dev) +{ + if (netdev_need_ops_lock(dev)) + netdev_unlock(dev); + else + rtnl_unlock(); +} + static inline int netdev_lock_cmp_fn(const struct lockdep_map *a, const struct lockdep_map *b) { -- cgit v1.2.3