user/sven/linux.git/include/linux/rtnetlink.h, branch v6.13.4

rtnetlink: Define rtnl_net_trylock().

2024-10-29T10:54:57Z

We will need the per-netns version of rtnl_trylock(). rtnl_net_trylock() calls __rtnl_net_lock() only when rtnl_trylock() successfully holds RTNL. When RTNL is removed, we will use mutex_trylock() for per-netns RTNL. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Signed-off-by: Paolo Abeni

rtnetlink: Make per-netns RTNL dereference helpers to macro.

2024-10-29T10:54:57Z

When CONFIG_DEBUG_NET_SMALL_RTNL is off, rtnl_net_dereference() is the static inline wrapper of rtnl_dereference() returning a plain (void *) pointer to make sure net is always evaluated as requested in [0]. But, it makes sparse complain [1] when the pointer has __rcu annotation: net/ipv4/devinet.c:674:47: sparse: warning: incorrect type in argument 2 (different address spaces) net/ipv4/devinet.c:674:47: sparse: expected void *p net/ipv4/devinet.c:674:47: sparse: got struct in_ifaddr [noderef] __rcu * Also, if we evaluate net as (void *) in a macro, then the compiler in turn fails to build due to -Werror=unused-value. #define rtnl_net_dereference(net, p) \ ({ \ (void *)net; \ rtnl_dereference(p); \ }) net/ipv4/devinet.c: In function ‘inet_rtm_deladdr’: ./include/linux/rtnetlink.h:154:17: error: statement with no effect [-Werror=unused-value] 154 | (void *)net; \ net/ipv4/devinet.c:674:21: note: in expansion of macro ‘rtnl_net_dereference’ 674 | (ifa = rtnl_net_dereference(net, *ifap)) != NULL; | ^~~~~~~~~~~~~~~~~~~~ Let's go back to the original simplest macro. Note that checkpatch complains about this approach, but it's one-shot and less noisy than the other two. WARNING: Argument 'net' is not used in function-like macro #76: FILE: include/linux/rtnetlink.h:142: +#define rtnl_net_dereference(net, p) \ + rtnl_dereference(p) Fixes: 844e5e7e656d ("rtnetlink: Add assertion helpers for per-netns RTNL.") Link: https://lore.kernel.org/netdev/20241004132145.7fd208e9@kernel.org/ [0] Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202410200325.SaEJmyZS-lkp@intel.com/ [1] Signed-off-by: Kuniyuki Iwashima Reviewed-by: Simon Horman Signed-off-by: Paolo Abeni

rtnetlink: Add assertion helpers for per-netns RTNL.

2024-10-08T13:16:59Z

Once an RTNL scope is converted with rtnl_net_lock(), we will replace RTNL helper functions inside the scope with the following per-netns alternatives: ASSERT_RTNL() -> ASSERT_RTNL_NET(net) rcu_dereference_rtnl(p) -> rcu_dereference_rtnl_net(net, p) Note that the per-netns helpers are equivalent to the conventional helpers unless CONFIG_DEBUG_NET_SMALL_RTNL is enabled. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Signed-off-by: Paolo Abeni

rtnetlink: Add per-netns RTNL.

2024-10-08T13:16:59Z

The goal is to break RTNL down into per-netns mutex. This patch adds per-netns mutex and its helper functions, rtnl_net_lock() and rtnl_net_unlock(). rtnl_net_lock() acquires the global RTNL and per-netns RTNL mutex, and rtnl_net_unlock() releases them. We will replace 800+ rtnl_lock() with rtnl_net_lock() and finally removes rtnl_lock() in rtnl_net_lock(). When we need to nest per-netns RTNL mutex, we will use __rtnl_net_lock(), and its locking order is defined by rtnl_net_lock_cmp_fn() as follows: 1. init_net is first 2. netns address ascending order Note that the conversion will be done under CONFIG_DEBUG_NET_SMALL_RTNL with LOCKDEP so that we can carefully add the extra mutex without slowing down RTNL operations during conversion. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Signed-off-by: Paolo Abeni

Revert "rtnetlink: add guard for RTNL"

2024-10-08T13:16:59Z

This reverts commit 464eb03c4a7cfb32cb3324249193cf6bb5b35152. Once we have a per-netns RTNL, we won't use guard(rtnl). Also, there's no users for now. $ grep -rnI "guard(rtnl" || true $ Suggested-by: Eric Dumazet Link: https://lore.kernel.org/netdev/CANn89i+KoYzUH+VPLdGmLABYf5y4TW0hrM4UAeQQJ9AREty0iw@mail.gmail.com/ Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Signed-off-by: Paolo Abeni

rtnetlink: add guard for RTNL

2024-04-03T08:59:38Z

The new guard/scoped_gard can be useful for the RTNL as well, so add a guard definition for it. It gets used like { guard(rtnl)(); // RTNL held until end of block } or scoped_guard(rtnl) { // RTNL held in this block } as with any other guard/scoped_guard. Signed-off-by: Johannes Berg Reviewed-by: Simon Horman Signed-off-by: David S. Miller

net: add netdev_set_operstate() helper

2024-02-14T11:20:13Z

dev_base_lock is going away, add netdev_set_operstate() helper so that hsr does not have to know core internals. Remove dev_base_lock acquisition from rfc2863_policy() v3: use an "unsigned int" for dev->operstate, so that try_cmpxchg() can work on all arches. ( https://lore.kernel.org/oe-kbuild-all/202402081918.OLyGaea3-lkp@intel.com/ ) Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: make dev_unreg_count global

2024-02-04T16:08:21Z

We can use a global dev_unreg_count counter instead of a per netns one. As a bonus we can factorize the changes done on it for bulk device removals. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: rtnl: introduce rcu_replace_pointer_rtnl

2023-12-18T02:05:45Z

Introduce the rcu_replace_pointer_rtnl helper to lockdep check rtnl lock rcu replacements, alongside the already existing helpers. This is a quality of life helper so instead of using: rcu_replace_pointer(rp, p, lockdep_rtnl_is_held()) .. or the open coded.. rtnl_dereference() / rcu_assign_pointer() .. or the lazy check version .. rcu_replace_pointer(rp, p, 1) Use: rcu_replace_pointer_rtnl(rp, p) Signed-off-by: Jamal Hadi Salim Signed-off-by: Victor Nogueira Signed-off-by: Pedro Tammela Reviewed-by: Ido Schimmel Reviewed-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

rtnl: add helper to send if skb is not null

2023-12-12T02:52:57Z

This is a convenience helper for routines handling conditional rtnl events, that is code that might send a notification depending on rtnl_has_listeners/rtnl_notify_needed. Instead of: if (skb) rtnetlink_send(...) Use: rtnetlink_maybe_send(...) Reviewed-by: Jiri Pirko Reviewed-by: Simon Horman Signed-off-by: Pedro Tammela Link: https://lore.kernel.org/r/20231208192847.714940-4-pctammela@mojatatu.com Signed-off-by: Jakub Kicinski