From 1c36d186a0c81f3b55b2722736163233b05f8756 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Sat, 28 Feb 2026 22:17:30 +0000 Subject: ipmr: Define net->ipv4.{ipmr_notifier_ops,ipmr_seq} under CONFIG_IP_MROUTE. net->ipv4.ipmr_notifier_ops and net->ipv4.ipmr_seq are used only in net/ipv4/ipmr.c. Let's move these definitions under CONFIG_IP_MROUTE. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260228221800.1082070-13-kuniyu@google.com Signed-off-by: Jakub Kicinski --- include/net/netns/ipv4.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h index 8e971c7bf164..380ff34c0233 100644 --- a/include/net/netns/ipv4.h +++ b/include/net/netns/ipv4.h @@ -279,6 +279,8 @@ struct netns_ipv4 { struct list_head mr_tables; struct fib_rules_ops *mr_rules_ops; #endif + struct fib_notifier_ops *ipmr_notifier_ops; + unsigned int ipmr_seq; /* protected by rtnl_mutex */ #endif #ifdef CONFIG_IP_ROUTE_MULTIPATH struct sysctl_fib_multipath_hash_seed sysctl_fib_multipath_hash_seed; @@ -290,9 +292,6 @@ struct netns_ipv4 { struct fib_notifier_ops *notifier_ops; unsigned int fib_seq; /* writes protected by rtnl_mutex */ - struct fib_notifier_ops *ipmr_notifier_ops; - unsigned int ipmr_seq; /* protected by rtnl_mutex */ - atomic_t rt_genid; siphash_key_t ip_id_key; struct hlist_head *inet_addr_lst; -- cgit v1.2.3 From 4480d5fa1f6ebe7dfc546e14371d63c8b915a82d Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Sat, 28 Feb 2026 22:17:31 +0000 Subject: ipmr/ip6mr: Convert net->ipv[46].ipmr_seq to atomic_t. We will no longer hold RTNL for ipmr_mfc_add() and ipmr_mfc_delete(). MFC entry can be loosely connected with VIF by its index for mrt->vif_table[] (stored in mfc_parent), but the two tables are not synchronised. i.e. Even if VIF 1 is removed, MFC for VIF 1 is not automatically removed. The only field that the MFC/VIF interfaces share is net->ipv[46].ipmr_seq, which is protected by RTNL. Adding a new mutex for both just to protect a single field is overkill. Let's convert the field to atomic_t. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260228221800.1082070-14-kuniyu@google.com Signed-off-by: Jakub Kicinski --- include/linux/mroute_base.h | 8 ++++---- include/net/netns/ipv4.h | 2 +- include/net/netns/ipv6.h | 2 +- 3 files changed, 6 insertions(+), 6 deletions(-) (limited to 'include') diff --git a/include/linux/mroute_base.h b/include/linux/mroute_base.h index 0075f6e5c3da..0baa6f994da9 100644 --- a/include/linux/mroute_base.h +++ b/include/linux/mroute_base.h @@ -76,7 +76,7 @@ static inline int mr_call_vif_notifiers(struct net *net, struct vif_device *vif, struct net_device *vif_dev, unsigned short vif_index, u32 tb_id, - unsigned int *ipmr_seq) + atomic_t *ipmr_seq) { struct vif_entry_notifier_info info = { .info = { @@ -89,7 +89,7 @@ static inline int mr_call_vif_notifiers(struct net *net, }; ASSERT_RTNL(); - (*ipmr_seq)++; + atomic_inc(ipmr_seq); return call_fib_notifiers(net, event_type, &info.info); } @@ -198,7 +198,7 @@ static inline int mr_call_mfc_notifiers(struct net *net, unsigned short family, enum fib_event_type event_type, struct mr_mfc *mfc, u32 tb_id, - unsigned int *ipmr_seq) + atomic_t *ipmr_seq) { struct mfc_entry_notifier_info info = { .info = { @@ -209,7 +209,7 @@ static inline int mr_call_mfc_notifiers(struct net *net, }; ASSERT_RTNL(); - (*ipmr_seq)++; + atomic_inc(ipmr_seq); return call_fib_notifiers(net, event_type, &info.info); } diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h index 380ff34c0233..94dca64fec41 100644 --- a/include/net/netns/ipv4.h +++ b/include/net/netns/ipv4.h @@ -280,7 +280,7 @@ struct netns_ipv4 { struct fib_rules_ops *mr_rules_ops; #endif struct fib_notifier_ops *ipmr_notifier_ops; - unsigned int ipmr_seq; /* protected by rtnl_mutex */ + atomic_t ipmr_seq; #endif #ifdef CONFIG_IP_ROUTE_MULTIPATH struct sysctl_fib_multipath_hash_seed sysctl_fib_multipath_hash_seed; diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h index 34bdb1308e8f..499e4288170f 100644 --- a/include/net/netns/ipv6.h +++ b/include/net/netns/ipv6.h @@ -118,7 +118,7 @@ struct netns_ipv6 { struct seg6_pernet_data *seg6_data; struct fib_notifier_ops *notifier_ops; struct fib_notifier_ops *ip6mr_notifier_ops; - unsigned int ipmr_seq; /* protected by rtnl_mutex */ + atomic_t ipmr_seq; struct { struct hlist_head head; spinlock_t lock; -- cgit v1.2.3 From 3c1e53e55418d4ca4040e281501643a96e227974 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Sat, 28 Feb 2026 22:17:32 +0000 Subject: ipmr: Add dedicated mutex for mrt->{mfc_hash,mfc_cache_list}. We will no longer hold RTNL for ipmr_rtm_route() to modify the MFC hash table. Only __dev_get_by_index() in rtm_to_ipmr_mfcc() is the RTNL dependant, otherwise, we just need protection for mrt->mfc_hash and mrt->mfc_cache_list. Let's add a new mutex for ipmr_mfc_add(), ipmr_mfc_delete(), and mroute_clean_tables() (setsockopt(MRT_FLUSH or MRT_DONE)). Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260228221800.1082070-15-kuniyu@google.com Signed-off-by: Jakub Kicinski --- include/net/netns/ipv4.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h index 94dca64fec41..4c249aeaf7f1 100644 --- a/include/net/netns/ipv4.h +++ b/include/net/netns/ipv4.h @@ -281,6 +281,7 @@ struct netns_ipv4 { #endif struct fib_notifier_ops *ipmr_notifier_ops; atomic_t ipmr_seq; + struct mutex mfc_mutex; #endif #ifdef CONFIG_IP_ROUTE_MULTIPATH struct sysctl_fib_multipath_hash_seed sysctl_fib_multipath_hash_seed; -- cgit v1.2.3 From bddafc06ca5ee1be4d10061f7954c6d6be5dc1d8 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Sat, 28 Feb 2026 22:17:33 +0000 Subject: ipmr: Don't hold RTNL for ipmr_rtm_route(). ipmr_mfc_add() and ipmr_mfc_delete() are already protected by a dedicated mutex. rtm_to_ipmr_mfcc() calls __ipmr_get_table(), __dev_get_by_index(), amd ipmr_find_vif(). Once __dev_get_by_index() is converted to dev_get_by_index_rcu(), we can move the other two functions under that same RCU section and drop RTNL for ipmr_rtm_route(). Let's do that conversion and drop ASSERT_RTNL() in mr_call_mfc_notifiers(). Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260228221800.1082070-16-kuniyu@google.com Signed-off-by: Jakub Kicinski --- include/linux/mroute_base.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include') diff --git a/include/linux/mroute_base.h b/include/linux/mroute_base.h index 0baa6f994da9..cf3374580f74 100644 --- a/include/linux/mroute_base.h +++ b/include/linux/mroute_base.h @@ -208,7 +208,6 @@ static inline int mr_call_mfc_notifiers(struct net *net, .tb_id = tb_id }; - ASSERT_RTNL(); atomic_inc(ipmr_seq); return call_fib_notifiers(net, event_type, &info.info); } -- cgit v1.2.3