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net: Convert pernet_subsys, registered from inet_init()

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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 <ktkhai@virtuozzo.com>
Acked-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Kirill Tkhai
2018-02-13 12:29:52 +03:00
committed by David S. Miller
parent 232cf06c61
commit f84c6821aa
18 changed files with 23 additions and 0 deletions
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4
net/ipv4/route.c
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@@ -417,6 +417,7 @@ static void __net_exit ip_rt_do_proc_exit(struct net *net)
static struct pernet_operations ip_rt_proc_ops __net_initdata = {
.init = ip_rt_do_proc_init,
.exit = ip_rt_do_proc_exit,
.async = true,
};
static int __init ip_rt_proc_init(void)
@@ -2994,6 +2995,7 @@ static __net_exit void sysctl_route_net_exit(struct net *net)
static __net_initdata struct pernet_operations sysctl_route_ops = {
.init = sysctl_route_net_init,
.exit = sysctl_route_net_exit,
.async = true,
};
#endif
@@ -3007,6 +3009,7 @@ static __net_init int rt_genid_init(struct net *net)
static __net_initdata struct pernet_operations rt_genid_ops = {
.init = rt_genid_init,
.async = true,
};
static int __net_init ipv4_inetpeer_init(struct net *net)
@@ -3032,6 +3035,7 @@ static void __net_exit ipv4_inetpeer_exit(struct net *net)
static __net_initdata struct pernet_operations ipv4_inetpeer_ops = {
.init = ipv4_inetpeer_init,
.exit = ipv4_inetpeer_exit,
.async = true,
};
#ifdef CONFIG_IP_ROUTE_CLASSID