From 7c550daffe22a97282effa75fe7c1f6b83563ecb Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Thu, 3 Oct 2019 11:49:27 +0200 Subject: net: fib_notifier: make FIB notifier per-netns Currently all users of FIB notifier only cares about events in init_net. Later in this patchset, users get interested in other namespaces too. However, for every registered block user is interested only about one namespace. Make the FIB notifier registration per-netns and avoid unnecessary calls of notifier block for other namespaces. Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- net/core/fib_notifier.c | 87 ++++++++++++++++++++++--------------------------- 1 file changed, 39 insertions(+), 48 deletions(-) (limited to 'net/core/fib_notifier.c') diff --git a/net/core/fib_notifier.c b/net/core/fib_notifier.c index 470a606d5e8d..fbd029425638 100644 --- a/net/core/fib_notifier.c +++ b/net/core/fib_notifier.c @@ -12,17 +12,15 @@ static unsigned int fib_notifier_net_id; struct fib_notifier_net { struct list_head fib_notifier_ops; + struct atomic_notifier_head fib_chain; }; -static ATOMIC_NOTIFIER_HEAD(fib_chain); - -int call_fib_notifier(struct notifier_block *nb, struct net *net, +int call_fib_notifier(struct notifier_block *nb, enum fib_event_type event_type, struct fib_notifier_info *info) { int err; - info->net = net; err = nb->notifier_call(nb, event_type, info); return notifier_to_errno(err); } @@ -31,35 +29,29 @@ EXPORT_SYMBOL(call_fib_notifier); int call_fib_notifiers(struct net *net, enum fib_event_type event_type, struct fib_notifier_info *info) { + struct fib_notifier_net *fn_net = net_generic(net, fib_notifier_net_id); int err; - info->net = net; - err = atomic_notifier_call_chain(&fib_chain, event_type, info); + err = atomic_notifier_call_chain(&fn_net->fib_chain, event_type, info); return notifier_to_errno(err); } EXPORT_SYMBOL(call_fib_notifiers); -static unsigned int fib_seq_sum(void) +static unsigned int fib_seq_sum(struct net *net) { - struct fib_notifier_net *fn_net; + struct fib_notifier_net *fn_net = net_generic(net, fib_notifier_net_id); struct fib_notifier_ops *ops; unsigned int fib_seq = 0; - struct net *net; rtnl_lock(); - down_read(&net_rwsem); - for_each_net(net) { - fn_net = net_generic(net, fib_notifier_net_id); - rcu_read_lock(); - list_for_each_entry_rcu(ops, &fn_net->fib_notifier_ops, list) { - if (!try_module_get(ops->owner)) - continue; - fib_seq += ops->fib_seq_read(net); - module_put(ops->owner); - } - rcu_read_unlock(); + rcu_read_lock(); + list_for_each_entry_rcu(ops, &fn_net->fib_notifier_ops, list) { + if (!try_module_get(ops->owner)) + continue; + fib_seq += ops->fib_seq_read(net); + module_put(ops->owner); } - up_read(&net_rwsem); + rcu_read_unlock(); rtnl_unlock(); return fib_seq; @@ -69,68 +61,66 @@ static int fib_net_dump(struct net *net, struct notifier_block *nb) { struct fib_notifier_net *fn_net = net_generic(net, fib_notifier_net_id); struct fib_notifier_ops *ops; + int err = 0; + rcu_read_lock(); list_for_each_entry_rcu(ops, &fn_net->fib_notifier_ops, list) { - int err; - if (!try_module_get(ops->owner)) continue; err = ops->fib_dump(net, nb); module_put(ops->owner); if (err) - return err; + goto unlock; } - return 0; +unlock: + rcu_read_unlock(); + + return err; } -static bool fib_dump_is_consistent(struct notifier_block *nb, +static bool fib_dump_is_consistent(struct net *net, struct notifier_block *nb, void (*cb)(struct notifier_block *nb), unsigned int fib_seq) { - atomic_notifier_chain_register(&fib_chain, nb); - if (fib_seq == fib_seq_sum()) + struct fib_notifier_net *fn_net = net_generic(net, fib_notifier_net_id); + + atomic_notifier_chain_register(&fn_net->fib_chain, nb); + if (fib_seq == fib_seq_sum(net)) return true; - atomic_notifier_chain_unregister(&fib_chain, nb); + atomic_notifier_chain_unregister(&fn_net->fib_chain, nb); if (cb) cb(nb); return false; } #define FIB_DUMP_MAX_RETRIES 5 -int register_fib_notifier(struct notifier_block *nb, +int register_fib_notifier(struct net *net, struct notifier_block *nb, void (*cb)(struct notifier_block *nb)) { int retries = 0; int err; do { - unsigned int fib_seq = fib_seq_sum(); - struct net *net; - - rcu_read_lock(); - for_each_net_rcu(net) { - err = fib_net_dump(net, nb); - if (err) - goto err_fib_net_dump; - } - rcu_read_unlock(); - - if (fib_dump_is_consistent(nb, cb, fib_seq)) + unsigned int fib_seq = fib_seq_sum(net); + + err = fib_net_dump(net, nb); + if (err) + return err; + + if (fib_dump_is_consistent(net, nb, cb, fib_seq)) return 0; } while (++retries < FIB_DUMP_MAX_RETRIES); return -EBUSY; - -err_fib_net_dump: - rcu_read_unlock(); - return err; } EXPORT_SYMBOL(register_fib_notifier); -int unregister_fib_notifier(struct notifier_block *nb) +int unregister_fib_notifier(struct net *net, struct notifier_block *nb) { - return atomic_notifier_chain_unregister(&fib_chain, nb); + struct fib_notifier_net *fn_net = net_generic(net, fib_notifier_net_id); + + return atomic_notifier_chain_unregister(&fn_net->fib_chain, nb); } EXPORT_SYMBOL(unregister_fib_notifier); @@ -181,6 +171,7 @@ static int __net_init fib_notifier_net_init(struct net *net) struct fib_notifier_net *fn_net = net_generic(net, fib_notifier_net_id); INIT_LIST_HEAD(&fn_net->fib_notifier_ops); + ATOMIC_INIT_NOTIFIER_HEAD(&fn_net->fib_chain); return 0; } -- cgit v1.2.3