[PATCH v1 net-next 1/2] ipv4: fib: Define fib_table_hash_lock under CONFIG_IP_MULTIPLE_TABLES.
From: Kuniyuki Iwashima <kuniyu@google.com>
Date: 2026-07-02 04:44:40
Subsystem:
documentation, networking [general], networking [ipv4/ipv6], the rest · Maintainers:
Jonathan Corbet, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
When CONFIG_IP_MULTIPLE_TABLES is disabled, fib_new_table() is fib_get_table(), and no new table is created. Let's move net->ipv4.fib_table_hash_lock under CONFIG_IP_MULTIPLE_TABLES. While at it, netns_ipv4_sysctl.rst is updated. Suggested-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> --- Documentation/networking/net_cachelines/netns_ipv4_sysctl.rst | 1 + include/net/netns/ipv4.h | 2 +- net/ipv4/fib_frontend.c | 3 +++ 3 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/Documentation/networking/net_cachelines/netns_ipv4_sysctl.rst b/Documentation/networking/net_cachelines/netns_ipv4_sysctl.rst
index 6dbd97d435e9..3dc03bff739e 100644
--- a/Documentation/networking/net_cachelines/netns_ipv4_sysctl.rst
+++ b/Documentation/networking/net_cachelines/netns_ipv4_sysctl.rst@@ -22,6 +22,7 @@ struct_mutex ra_mutex struct_fib_rules_ops* rules_ops struct_fib_table fib_main struct_fib_table fib_default +spinlock_t fib_table_hash_lock unsigned_int fib_rules_require_fldissect bool fib_has_custom_rules bool fib_has_custom_local_routes
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 59506320558a..cb7f8bf15671 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h@@ -118,6 +118,7 @@ struct netns_ipv4 { struct fib_rules_ops *rules_ops; struct fib_table __rcu *fib_main; struct fib_table __rcu *fib_default; + spinlock_t fib_table_hash_lock; unsigned int fib_rules_require_fldissect; bool fib_has_custom_rules; #endif
@@ -127,7 +128,6 @@ struct netns_ipv4 { atomic_t fib_num_tclassid_users; #endif struct hlist_head *fib_table_hash; - spinlock_t fib_table_hash_lock; struct sock *fibnl; struct hlist_head *fib_info_hash; unsigned int fib_info_hash_bits;
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 54eb72695093..6f5d0d25b110 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c@@ -1584,7 +1584,10 @@ static int __net_init ip_fib_net_init(struct net *net) net->ipv4.sysctl_fib_multipath_hash_fields = FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK; #endif + +#ifdef CONFIG_IP_MULTIPLE_TABLES spin_lock_init(&net->ipv4.fib_table_hash_lock); +#endif /* Avoid false sharing : Use at least a full cache line */ size = max_t(size_t, size, L1_CACHE_BYTES);
--
2.55.0.rc0.799.gd6f94ed593-goog