From f84c6821aa540342360067604ad156e3d53a67ed Mon Sep 17 00:00:00 2001 From: Kirill Tkhai Date: Tue, 13 Feb 2018 12:29:52 +0300 Subject: net: Convert pernet_subsys, registered from inet_init() arp_net_ops just addr/removes /proc entry. devinet_ops allocates and frees duplicate of init_net tables and (un)registers sysctl entries. fib_net_ops allocates and frees pernet tables, creates/destroys netlink socket and (un)initializes /proc entries. Foreign pernet_operations do not touch them. ip_rt_proc_ops only modifies pernet /proc entries. xfrm_net_ops creates/destroys /proc entries, allocates/frees pernet statistics, hashes and tables, and (un)initializes sysctl files. These are not touched by foreigh pernet_operations xfrm4_net_ops allocates/frees private pernet memory, and configures sysctls. sysctl_route_ops creates/destroys sysctls. rt_genid_ops only initializes fields of just allocated net. ipv4_inetpeer_ops allocated/frees net private memory. igmp_net_ops just creates/destroys /proc files and socket, noone else interested in. tcp_sk_ops seems to be safe, because tcp_sk_init() does not depend on any other pernet_operations modifications. Iteration over hash table in inet_twsk_purge() is made under RCU lock, and it's safe to iterate the table this way. Removing from the table happen from inet_twsk_deschedule_put(), but this function is safe without any extern locks, as it's synchronized inside itself. There are many examples, it's used in different context. So, it's safe to leave tcp_sk_exit_batch() unlocked. tcp_net_metrics_ops is synchronized on tcp_metrics_lock and safe. udplite4_net_ops only creates/destroys pernet /proc file. icmp_sk_ops creates percpu sockets, not touched by foreign pernet_operations. ipmr_net_ops creates/destroys pernet fib tables, (un)registers fib rules and /proc files. This seem to be safe to execute in parallel with foreign pernet_operations. af_inet_ops just sets up default parameters of newly created net. ipv4_mib_ops creates and destroys pernet percpu statistics. raw_net_ops, tcp4_net_ops, udp4_net_ops, ping_v4_net_ops and ip_proc_ops only create/destroy pernet /proc files. ip4_frags_ops creates and destroys sysctl file. So, it's safe to make the pernet_operations async. Signed-off-by: Kirill Tkhai Acked-by: Andrei Vagin Signed-off-by: David S. Miller --- net/ipv4/af_inet.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net/ipv4/af_inet.c') diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index f98e2f0db841..e8c7fad8c329 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1735,6 +1735,7 @@ static __net_exit void ipv4_mib_exit_net(struct net *net) static __net_initdata struct pernet_operations ipv4_mib_ops = { .init = ipv4_mib_init_net, .exit = ipv4_mib_exit_net, + .async = true, }; static int __init init_ipv4_mibs(void) @@ -1788,6 +1789,7 @@ static __net_exit void inet_exit_net(struct net *net) static __net_initdata struct pernet_operations af_inet_ops = { .init = inet_init_net, .exit = inet_exit_net, + .async = true, }; static int __init init_inet_pernet_ops(void) -- cgit v1.2.3