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From: Kuniyuki Iwashima To: "David S . Miller" , David Ahern , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , Kuniyuki Iwashima , Kuniyuki Iwashima , netdev@vger.kernel.org Content-Type: text/plain; charset="UTF-8" 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 --- include/linux/mroute_base.h | 8 ++++---- include/net/netns/ipv4.h | 2 +- include/net/netns/ipv6.h | 2 +- net/ipv4/ipmr.c | 4 ++-- net/ipv6/ip6mr.c | 4 ++-- 5 files changed, 10 insertions(+), 10 deletions(-) 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; diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 0dd683932d2b..bcb3f920e8c3 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -3224,7 +3224,7 @@ static const struct net_protocol pim_protocol = { static unsigned int ipmr_seq_read(const struct net *net) { - return READ_ONCE(net->ipv4.ipmr_seq) + ipmr_rules_seq_read(net); + return atomic_read(&net->ipv4.ipmr_seq) + ipmr_rules_seq_read(net); } static int ipmr_dump(struct net *net, struct notifier_block *nb, @@ -3245,7 +3245,7 @@ static int __net_init ipmr_notifier_init(struct net *net) { struct fib_notifier_ops *ops; - net->ipv4.ipmr_seq = 0; + atomic_set(&net->ipv4.ipmr_seq, 0); ops = fib_notifier_ops_register(&ipmr_notifier_ops_template, net); if (IS_ERR(ops)) diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index e047a4680ab0..85010ff21c98 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -1280,7 +1280,7 @@ static int ip6mr_device_event(struct notifier_block *this, static unsigned int ip6mr_seq_read(const struct net *net) { - return READ_ONCE(net->ipv6.ipmr_seq) + ip6mr_rules_seq_read(net); + return atomic_read(&net->ipv6.ipmr_seq) + ip6mr_rules_seq_read(net); } static int ip6mr_dump(struct net *net, struct notifier_block *nb, @@ -1305,7 +1305,7 @@ static int __net_init ip6mr_notifier_init(struct net *net) { struct fib_notifier_ops *ops; - net->ipv6.ipmr_seq = 0; + atomic_set(&net->ipv6.ipmr_seq, 0); ops = fib_notifier_ops_register(&ip6mr_notifier_ops_template, net); if (IS_ERR(ops)) -- 2.53.0.414.gf7e9f6c205-goog