Merge branch 'pernet-all-async'

Kirill Tkhai says:

====================
Make pernet_operations always read locked

All the pernet_operations are converted, and the last one
is in this patchset (nfsd_net_ops acked by J. Bruce Fields).
So, it's the time to kill pernet_operations::async field,
and make setup_net() and cleanup_net() always require
the rwsem only read locked.

All further pernet_operations have to be developed to fit
this rule. Some of previous patches added a comment to
struct pernet_operations about that.

Also, this patchset renames net_sem to pernet_ops_rwsem
to make the target area of the rwsem is more clear visible,
and adds more comments.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/infiniband/core/cma.c

@@ -4554,7 +4554,6 @@ static struct pernet_operations cma_pernet_operations = {
 	.exit = cma_exit_net,
 	.id = &cma_pernet_id,
 	.size = sizeof(struct cma_pernet),
-	.async = true,
 };
 
 static int __init cma_init(void)

drivers/net/bonding/bond_main.c

@@ -4791,7 +4791,6 @@ static struct pernet_operations bond_net_ops = {
 	.exit = bond_net_exit,
 	.id   = &bond_net_id,
 	.size = sizeof(struct bond_net),
-	.async = true,
 };
 
 static int __init bonding_init(void)

drivers/net/geneve.c

@@ -1694,7 +1694,6 @@ static struct pernet_operations geneve_net_ops = {
 	.exit_batch = geneve_exit_batch_net,
 	.id   = &geneve_net_id,
 	.size = sizeof(struct geneve_net),
-	.async = true,
 };
 
 static int __init geneve_init_module(void)

drivers/net/gtp.c

@@ -1325,7 +1325,6 @@ static struct pernet_operations gtp_net_ops = {
 	.exit	= gtp_net_exit,
 	.id	= &gtp_net_id,
 	.size	= sizeof(struct gtp_net),
-	.async	= true,
 };
 
 static int __init gtp_init(void)

drivers/net/ipvlan/ipvlan_main.c

@@ -1040,7 +1040,6 @@ static struct pernet_operations ipvlan_net_ops = {
 	.id = &ipvlan_netid,
 	.size = sizeof(struct ipvlan_netns),
 	.exit = ipvlan_ns_exit,
-	.async = true,
 };
 
 static int __init ipvlan_init_module(void)

drivers/net/loopback.c

@@ -230,5 +230,4 @@ out:
 /* Registered in net/core/dev.c */
 struct pernet_operations __net_initdata loopback_net_ops = {
 	.init = loopback_net_init,
-	.async = true,
 };

drivers/net/ppp/ppp_generic.c

@@ -970,7 +970,6 @@ static struct pernet_operations ppp_net_ops = {
 	.exit = ppp_exit_net,
 	.id   = &ppp_net_id,
 	.size = sizeof(struct ppp_net),
-	.async = true,
 };
 
 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set)

drivers/net/ppp/pppoe.c

@@ -1161,7 +1161,6 @@ static struct pernet_operations pppoe_net_ops = {
 	.exit = pppoe_exit_net,
 	.id   = &pppoe_net_id,
 	.size = sizeof(struct pppoe_net),
-	.async = true,
 };
 
 static int __init pppoe_init(void)

drivers/net/vrf.c

@@ -1435,7 +1435,6 @@ static struct pernet_operations vrf_net_ops __net_initdata = {
 	.init = vrf_netns_init,
 	.id   = &vrf_net_id,
 	.size = sizeof(bool),
-	.async = true,
 };
 
 static int __init vrf_init_module(void)

drivers/net/vxlan.c

@@ -3752,7 +3752,6 @@ static struct pernet_operations vxlan_net_ops = {
 	.exit_batch = vxlan_exit_batch_net,
 	.id   = &vxlan_net_id,
 	.size = sizeof(struct vxlan_net),
-	.async = true,
 };
 
 static int __init vxlan_init_module(void)

drivers/net/wireless/mac80211_hwsim.c

@@ -3542,7 +3542,6 @@ static struct pernet_operations hwsim_net_ops = {
 	.exit = hwsim_exit_net,
 	.id   = &hwsim_net_id,
 	.size = sizeof(struct hwsim_net),
-	.async = true,
 };
 
 static void hwsim_exit_netlink(void)

fs/lockd/svc.c

@@ -709,7 +709,6 @@ static struct pernet_operations lockd_net_ops = {
 	.exit = lockd_exit_net,
 	.id = &lockd_net_id,
 	.size = sizeof(struct lockd_net),
-	.async = true,
 };
 
 

fs/nfs/blocklayout/rpc_pipefs.c

@@ -261,7 +261,6 @@ static void nfs4blocklayout_net_exit(struct net *net)
 static struct pernet_operations nfs4blocklayout_net_ops = {
 	.init = nfs4blocklayout_net_init,
 	.exit = nfs4blocklayout_net_exit,
-	.async = true,
 };
 
 int __init bl_init_pipefs(void)

fs/nfs/dns_resolve.c

@@ -410,7 +410,6 @@ static void nfs4_dns_net_exit(struct net *net)
 static struct pernet_operations nfs4_dns_resolver_ops = {
 	.init = nfs4_dns_net_init,
 	.exit = nfs4_dns_net_exit,
-	.async = true,
 };
 
 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,

fs/nfs/inode.c

@@ -2122,7 +2122,6 @@ static struct pernet_operations nfs_net_ops = {
 	.exit = nfs_net_exit,
 	.id   = &nfs_net_id,
 	.size = sizeof(struct nfs_net),
-	.async = true,
 };
 
 /*

fs/nfs_common/grace.c

@@ -118,7 +118,6 @@ static struct pernet_operations grace_net_ops = {
 	.exit = grace_exit_net,
 	.id   = &grace_net_id,
 	.size = sizeof(struct list_head),
-	.async = true,
 };
 
 static int __init

fs/proc/proc_net.c

@@ -237,7 +237,6 @@ static __net_exit void proc_net_ns_exit(struct net *net)
 static struct pernet_operations __net_initdata proc_net_ns_ops = {
 	.init = proc_net_ns_init,
 	.exit = proc_net_ns_exit,
-	.async = true,
 };
 
 int __init proc_net_init(void)

include/linux/rtnetlink.h

@@ -36,7 +36,7 @@ extern int rtnl_is_locked(void);
 extern int rtnl_lock_killable(void);
 
 extern wait_queue_head_t netdev_unregistering_wq;
-extern struct rw_semaphore net_sem;
+extern struct rw_semaphore pernet_ops_rwsem;
 
 #ifdef CONFIG_PROVE_LOCKING
 extern bool lockdep_rtnl_is_held(void);

include/net/net_namespace.h

@@ -60,9 +60,10 @@ struct net {
 
 	struct list_head	list;		/* list of network namespaces */
 	struct list_head	exit_list;	/* To linked to call pernet exit
-						 * methods on dead net (net_sem
-						 * read locked), or to unregister
-						 * pernet ops (net_sem wr locked).
+						 * methods on dead net (
+						 * pernet_ops_rwsem read locked),
+						 * or to unregister pernet ops
+						 * (pernet_ops_rwsem write locked).
 						 */
 	struct llist_node	cleanup_list;	/* namespaces on death row */
 
@@ -95,8 +96,9 @@ struct net {
 	/* core fib_rules */
 	struct list_head	rules_ops;
 
-	struct list_head	fib_notifier_ops;  /* protected by net_sem */
-
+	struct list_head	fib_notifier_ops;  /* Populated by
+						    * register_pernet_subsys()
+						    */
 	struct net_device       *loopback_dev;          /* The loopback */
 	struct netns_core	core;
 	struct netns_mib	mib;
@@ -321,6 +323,10 @@ struct pernet_operations {
 	 * have to keep in mind all other pernet_operations and
 	 * to introduce a locking, if they share common resources.
 	 *
+	 * The only time they are called with exclusive lock is
+	 * from register_pernet_subsys(), unregister_pernet_subsys()
+	 * register_pernet_device() and unregister_pernet_device().
+	 *
 	 * Exit methods using blocking RCU primitives, such as
 	 * synchronize_rcu(), should be implemented via exit_batch.
 	 * Then, destruction of a group of net requires single
@@ -333,12 +339,6 @@ struct pernet_operations {
 	void (*exit_batch)(struct list_head *net_exit_list);
 	unsigned int *id;
 	size_t size;
-	/*
-	 * Indicates above methods are allowed to be executed in parallel
-	 * with methods of any other pernet_operations, i.e. they are not
-	 * need write locked net_sem.
-	 */
-	bool async;
 };
 
 /*

kernel/audit.c

@@ -1526,7 +1526,6 @@ static struct pernet_operations audit_net_ops __net_initdata = {
 	.exit = audit_net_exit,
 	.id = &audit_net_id,
 	.size = sizeof(struct audit_net),
-	.async = true,
 };
 
 /* Initialize audit support at boot time. */

lib/kobject_uevent.c

@@ -724,7 +724,6 @@ static void uevent_net_exit(struct net *net)
 static struct pernet_operations uevent_net_ops = {
 	.init	= uevent_net_init,
 	.exit	= uevent_net_exit,
-	.async  = true,
 };
 
 static int __init kobject_uevent_init(void)

net/8021q/vlan.c

@@ -729,7 +729,6 @@ static struct pernet_operations vlan_net_ops = {
 	.exit = vlan_exit_net,
 	.id   = &vlan_net_id,
 	.size = sizeof(struct vlan_net),
-	.async = true,
 };
 
 static int __init vlan_proto_init(void)

net/bridge/br.c

@@ -188,7 +188,6 @@ static void __net_exit br_net_exit(struct net *net)
 
 static struct pernet_operations br_net_ops = {
 	.exit	= br_net_exit,
-	.async	= true,
 };
 
 static const struct stp_proto br_stp_proto = {

net/bridge/br_netfilter_hooks.c

@@ -969,7 +969,6 @@ static struct pernet_operations brnf_net_ops __read_mostly = {
 	.exit = brnf_exit_net,
 	.id   = &brnf_net_id,
 	.size = sizeof(struct brnf_net),
-	.async = true,
 };
 
 static struct notifier_block brnf_notifier __read_mostly = {

net/bridge/netfilter/ebtable_broute.c

@@ -77,7 +77,6 @@ static void __net_exit broute_net_exit(struct net *net)
 static struct pernet_operations broute_net_ops = {
 	.init = broute_net_init,
 	.exit = broute_net_exit,
-	.async = true,
 };
 
 static int __init ebtable_broute_init(void)

net/bridge/netfilter/ebtable_filter.c

@@ -105,7 +105,6 @@ static void __net_exit frame_filter_net_exit(struct net *net)
 static struct pernet_operations frame_filter_net_ops = {
 	.init = frame_filter_net_init,
 	.exit = frame_filter_net_exit,
-	.async = true,
 };
 
 static int __init ebtable_filter_init(void)

net/bridge/netfilter/ebtable_nat.c

@@ -105,7 +105,6 @@ static void __net_exit frame_nat_net_exit(struct net *net)
 static struct pernet_operations frame_nat_net_ops = {
 	.init = frame_nat_net_init,
 	.exit = frame_nat_net_exit,
-	.async = true,
 };
 
 static int __init ebtable_nat_init(void)

net/bridge/netfilter/nf_log_bridge.c

@@ -48,7 +48,6 @@ static void __net_exit nf_log_bridge_net_exit(struct net *net)
 static struct pernet_operations nf_log_bridge_net_ops = {
 	.init = nf_log_bridge_net_init,
 	.exit = nf_log_bridge_net_exit,
-	.async = true,
 };
 
 static int __init nf_log_bridge_init(void)

net/caif/caif_dev.c

@@ -544,7 +544,6 @@ static struct pernet_operations caif_net_ops = {
 	.exit = caif_exit_net,
 	.id   = &caif_net_id,
 	.size = sizeof(struct caif_net),
-	.async = true,
 };
 
 /* Initialize Caif devices list */

net/can/af_can.c

@@ -954,7 +954,6 @@ static struct notifier_block can_netdev_notifier __read_mostly = {
 static struct pernet_operations can_pernet_ops __read_mostly = {
 	.init = can_pernet_init,
 	.exit = can_pernet_exit,
-	.async = true,
 };
 
 static __init int can_init(void)

net/can/bcm.c

@@ -1717,7 +1717,6 @@ static void canbcm_pernet_exit(struct net *net)
 static struct pernet_operations canbcm_pernet_ops __read_mostly = {
 	.init = canbcm_pernet_init,
 	.exit = canbcm_pernet_exit,
-	.async = true,
 };
 
 static int __init bcm_module_init(void)

net/can/gw.c

@@ -1010,7 +1010,6 @@ static void __net_exit cangw_pernet_exit(struct net *net)
 static struct pernet_operations cangw_pernet_ops = {
 	.init = cangw_pernet_init,
 	.exit = cangw_pernet_exit,
-	.async = true,
 };
 
 static __init int cgw_module_init(void)

net/core/dev.c

@@ -8883,7 +8883,6 @@ static void __net_exit netdev_exit(struct net *net)
 static struct pernet_operations __net_initdata netdev_net_ops = {
 	.init = netdev_init,
 	.exit = netdev_exit,
-	.async = true,
 };
 
 static void __net_exit default_device_exit(struct net *net)
@@ -8984,7 +8983,6 @@ static void __net_exit default_device_exit_batch(struct list_head *net_list)
 static struct pernet_operations __net_initdata default_device_ops = {
 	.exit = default_device_exit,
 	.exit_batch = default_device_exit_batch,
-	.async = true,
 };
 
 /*

net/core/fib_notifier.c

@@ -171,7 +171,6 @@ static void __net_exit fib_notifier_net_exit(struct net *net)
 static struct pernet_operations fib_notifier_net_ops = {
 	.init = fib_notifier_net_init,
 	.exit = fib_notifier_net_exit,
-	.async = true,
 };
 
 static int __init fib_notifier_init(void)

net/core/fib_rules.c

@@ -1130,7 +1130,6 @@ static void __net_exit fib_rules_net_exit(struct net *net)
 static struct pernet_operations fib_rules_net_ops = {
 	.init = fib_rules_net_init,
 	.exit = fib_rules_net_exit,
-	.async = true,
 };
 
 static int __init fib_rules_init(void)

net/core/net-procfs.c

@@ -349,7 +349,6 @@ static void __net_exit dev_proc_net_exit(struct net *net)
 static struct pernet_operations __net_initdata dev_proc_ops = {
 	.init = dev_proc_net_init,
 	.exit = dev_proc_net_exit,
-	.async = true,
 };
 
 static int dev_mc_seq_show(struct seq_file *seq, void *v)
@@ -406,7 +405,6 @@ static void __net_exit dev_mc_net_exit(struct net *net)
 static struct pernet_operations __net_initdata dev_mc_net_ops = {
 	.init = dev_mc_net_init,
 	.exit = dev_mc_net_exit,
-	.async = true,
 };
 
 int __init dev_proc_init(void)

net/core/net_namespace.c

@@ -40,12 +40,13 @@ struct net init_net = {
 EXPORT_SYMBOL(init_net);
 
 static bool init_net_initialized;
-static unsigned nr_sync_pernet_ops;
 /*
- * net_sem: protects: pernet_list, net_generic_ids, nr_sync_pernet_ops,
+ * pernet_ops_rwsem: protects: pernet_list, net_generic_ids,
  * init_net_initialized and first_device pointer.
+ * This is internal net namespace object. Please, don't use it
+ * outside.
  */
-DECLARE_RWSEM(net_sem);
+DECLARE_RWSEM(pernet_ops_rwsem);
 
 #define MIN_PERNET_OPS_ID	\
 	((sizeof(struct net_generic) + sizeof(void *) - 1) / sizeof(void *))
@@ -73,7 +74,7 @@ static int net_assign_generic(struct net *net, unsigned int id, void *data)
 	BUG_ON(id < MIN_PERNET_OPS_ID);
 
 	old_ng = rcu_dereference_protected(net->gen,
-					   lockdep_is_held(&net_sem));
+					   lockdep_is_held(&pernet_ops_rwsem));
 	if (old_ng->s.len > id) {
 		old_ng->ptr[id] = data;
 		return 0;
@@ -290,7 +291,7 @@ struct net *get_net_ns_by_id(struct net *net, int id)
  */
 static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
 {
-	/* Must be called with net_sem held */
+	/* Must be called with pernet_ops_rwsem held */
 	const struct pernet_operations *ops, *saved_ops;
 	int error = 0;
 	LIST_HEAD(net_exit_list);
@@ -339,7 +340,6 @@ static int __net_init net_defaults_init_net(struct net *net)
 
 static struct pernet_operations net_defaults_ops = {
 	.init = net_defaults_init_net,
-	.async = true,
 };
 
 static __init int net_defaults_init(void)
@@ -406,7 +406,6 @@ struct net *copy_net_ns(unsigned long flags,
 {
 	struct ucounts *ucounts;
 	struct net *net;
-	unsigned write;
 	int rv;
 
 	if (!(flags & CLONE_NEWNET))
@@ -424,25 +423,14 @@ struct net *copy_net_ns(unsigned long flags,
 	refcount_set(&net->passive, 1);
 	net->ucounts = ucounts;
 	get_user_ns(user_ns);
-again:
-	write = READ_ONCE(nr_sync_pernet_ops);
-	if (write)
-		rv = down_write_killable(&net_sem);
-	else
-		rv = down_read_killable(&net_sem);
+
+	rv = down_read_killable(&pernet_ops_rwsem);
 	if (rv < 0)
 		goto put_userns;
 
-	if (!write && unlikely(READ_ONCE(nr_sync_pernet_ops))) {
-		up_read(&net_sem);
-		goto again;
-	}
 	rv = setup_net(net, user_ns);
 
-	if (write)
-		up_write(&net_sem);
-	else
-		up_read(&net_sem);
+	up_read(&pernet_ops_rwsem);
 
 	if (rv < 0) {
 put_userns:
@@ -490,21 +478,11 @@ static void cleanup_net(struct work_struct *work)
 	struct net *net, *tmp, *last;
 	struct llist_node *net_kill_list;
 	LIST_HEAD(net_exit_list);
-	unsigned write;
 
 	/* Atomically snapshot the list of namespaces to cleanup */
 	net_kill_list = llist_del_all(&cleanup_list);
-again:
-	write = READ_ONCE(nr_sync_pernet_ops);
-	if (write)
-		down_write(&net_sem);
-	else
-		down_read(&net_sem);
 
-	if (!write && unlikely(READ_ONCE(nr_sync_pernet_ops))) {
-		up_read(&net_sem);
-		goto again;
-	}
+	down_read(&pernet_ops_rwsem);
 
 	/* Don't let anyone else find us. */
 	rtnl_lock();
@@ -543,10 +521,7 @@ again:
 	list_for_each_entry_reverse(ops, &pernet_list, list)
 		ops_free_list(ops, &net_exit_list);
 
-	if (write)
-		up_write(&net_sem);
-	else
-		up_read(&net_sem);
+	up_read(&pernet_ops_rwsem);
 
 	/* Ensure there are no outstanding rcu callbacks using this
 	 * network namespace.
@@ -573,8 +548,8 @@ again:
  */
 void net_ns_barrier(void)
 {
-	down_write(&net_sem);
-	up_write(&net_sem);
+	down_write(&pernet_ops_rwsem);
+	up_write(&pernet_ops_rwsem);
 }
 EXPORT_SYMBOL(net_ns_barrier);
 
@@ -654,7 +629,6 @@ static __net_exit void net_ns_net_exit(struct net *net)
 static struct pernet_operations __net_initdata net_ns_ops = {
 	.init = net_ns_net_init,
 	.exit = net_ns_net_exit,
-	.async = true,
 };
 
 static const struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
@@ -897,12 +871,12 @@ static int __init net_ns_init(void)
 
 	rcu_assign_pointer(init_net.gen, ng);
 
-	down_write(&net_sem);
+	down_write(&pernet_ops_rwsem);
 	if (setup_net(&init_net, &init_user_ns))
 		panic("Could not setup the initial network namespace");
 
 	init_net_initialized = true;
-	up_write(&net_sem);
+	up_write(&pernet_ops_rwsem);
 
 	register_pernet_subsys(&net_ns_ops);
 
@@ -1006,9 +980,6 @@ again:
 		rcu_barrier();
 		if (ops->id)
 			ida_remove(&net_generic_ids, *ops->id);
-	} else if (!ops->async) {
-		pr_info_once("Pernet operations %ps are sync.\n", ops);
-		nr_sync_pernet_ops++;
 	}
 
 	return error;
@@ -1016,8 +987,6 @@ again:
 
 static void unregister_pernet_operations(struct pernet_operations *ops)
 {
-	if (!ops->async)
-		BUG_ON(nr_sync_pernet_ops-- == 0);
 	__unregister_pernet_operations(ops);
 	rcu_barrier();
 	if (ops->id)
@@ -1046,9 +1015,9 @@ static void unregister_pernet_operations(struct pernet_operations *ops)
 int register_pernet_subsys(struct pernet_operations *ops)
 {
 	int error;
-	down_write(&net_sem);
+	down_write(&pernet_ops_rwsem);
 	error =  register_pernet_operations(first_device, ops);
-	up_write(&net_sem);
+	up_write(&pernet_ops_rwsem);
 	return error;
 }
 EXPORT_SYMBOL_GPL(register_pernet_subsys);
@@ -1064,9 +1033,9 @@ EXPORT_SYMBOL_GPL(register_pernet_subsys);
  */
 void unregister_pernet_subsys(struct pernet_operations *ops)
 {
-	down_write(&net_sem);
+	down_write(&pernet_ops_rwsem);
 	unregister_pernet_operations(ops);
-	up_write(&net_sem);
+	up_write(&pernet_ops_rwsem);
 }
 EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
 
@@ -1092,11 +1061,11 @@ EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
 int register_pernet_device(struct pernet_operations *ops)
 {
 	int error;
-	down_write(&net_sem);
+	down_write(&pernet_ops_rwsem);
 	error = register_pernet_operations(&pernet_list, ops);
 	if (!error && (first_device == &pernet_list))
 		first_device = &ops->list;
-	up_write(&net_sem);
+	up_write(&pernet_ops_rwsem);
 	return error;
 }
 EXPORT_SYMBOL_GPL(register_pernet_device);
@@ -1112,11 +1081,11 @@ EXPORT_SYMBOL_GPL(register_pernet_device);
  */
 void unregister_pernet_device(struct pernet_operations *ops)
 {
-	down_write(&net_sem);
+	down_write(&pernet_ops_rwsem);
 	if (&ops->list == first_device)
 		first_device = first_device->next;
 	unregister_pernet_operations(ops);
-	up_write(&net_sem);
+	up_write(&pernet_ops_rwsem);
 }
 EXPORT_SYMBOL_GPL(unregister_pernet_device);
 

net/core/pktgen.c

@@ -3852,7 +3852,6 @@ static struct pernet_operations pg_net_ops = {
 	.exit = pg_net_exit,
 	.id   = &pg_net_id,
 	.size = sizeof(struct pktgen_net),
-	.async = true,
 };
 
 static int __init pg_init(void)

net/core/rtnetlink.c

@@ -459,12 +459,12 @@ static void rtnl_lock_unregistering_all(void)
  */
 void rtnl_link_unregister(struct rtnl_link_ops *ops)
 {
-	/* Close the race with cleanup_net() */
-	down_write(&net_sem);
+	/* Close the race with setup_net() and cleanup_net() */
+	down_write(&pernet_ops_rwsem);
 	rtnl_lock_unregistering_all();
 	__rtnl_link_unregister(ops);
 	rtnl_unlock();
-	up_write(&net_sem);
+	up_write(&pernet_ops_rwsem);
 }
 EXPORT_SYMBOL_GPL(rtnl_link_unregister);
 
@@ -4730,7 +4730,6 @@ static void __net_exit rtnetlink_net_exit(struct net *net)
 static struct pernet_operations rtnetlink_net_ops = {
 	.init = rtnetlink_net_init,
 	.exit = rtnetlink_net_exit,
-	.async = true,
 };
 
 void __init rtnetlink_init(void)

net/core/sock.c

@@ -3175,7 +3175,6 @@ static void __net_exit sock_inuse_exit_net(struct net *net)
 static struct pernet_operations net_inuse_ops = {
 	.init = sock_inuse_init_net,
 	.exit = sock_inuse_exit_net,
-	.async = true,
 };
 
 static __init int net_inuse_init(void)
@@ -3470,7 +3469,6 @@ static __net_exit void proto_exit_net(struct net *net)
 static __net_initdata struct pernet_operations proto_net_ops = {
 	.init = proto_init_net,
 	.exit = proto_exit_net,
-	.async = true,
 };
 
 static int __init proto_init(void)

net/core/sock_diag.c

@@ -324,7 +324,6 @@ static void __net_exit diag_net_exit(struct net *net)
 static struct pernet_operations diag_net_ops = {
 	.init = diag_net_init,
 	.exit = diag_net_exit,
-	.async = true,
 };
 
 static int __init sock_diag_init(void)

net/core/sysctl_net_core.c

@@ -584,7 +584,6 @@ static __net_exit void sysctl_core_net_exit(struct net *net)
 static __net_initdata struct pernet_operations sysctl_core_ops = {
 	.init = sysctl_core_net_init,
 	.exit = sysctl_core_net_exit,
-	.async = true,
 };
 
 static __init int sysctl_core_init(void)

net/dccp/ipv4.c

@@ -1031,7 +1031,6 @@ static struct pernet_operations dccp_v4_ops = {
 	.init	= dccp_v4_init_net,
 	.exit	= dccp_v4_exit_net,
 	.exit_batch = dccp_v4_exit_batch,
-	.async	= true,
 };
 
 static int __init dccp_v4_init(void)

net/dccp/ipv6.c

@@ -1116,7 +1116,6 @@ static struct pernet_operations dccp_v6_ops = {
 	.init   = dccp_v6_init_net,
 	.exit   = dccp_v6_exit_net,
 	.exit_batch = dccp_v6_exit_batch,
-	.async	= true,
 };
 
 static int __init dccp_v6_init(void)

net/ieee802154/6lowpan/reassembly.c

@@ -603,7 +603,6 @@ static void __net_exit lowpan_frags_exit_net(struct net *net)
 static struct pernet_operations lowpan_frags_ops = {
 	.init = lowpan_frags_init_net,
 	.exit = lowpan_frags_exit_net,
-	.async = true,
 };
 
 int __init lowpan_net_frag_init(void)

net/ieee802154/core.c

@@ -345,7 +345,6 @@ static void __net_exit cfg802154_pernet_exit(struct net *net)
 
 static struct pernet_operations cfg802154_pernet_ops = {
 	.exit = cfg802154_pernet_exit,
-	.async = true,
 };
 
 static int __init wpan_phy_class_init(void)

net/ipv4/af_inet.c

@@ -1735,7 +1735,6 @@ 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)
@@ -1789,7 +1788,6 @@ 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)

net/ipv4/arp.c

@@ -1447,7 +1447,6 @@ static void __net_exit arp_net_exit(struct net *net)
 static struct pernet_operations arp_net_ops = {
 	.init = arp_net_init,
 	.exit = arp_net_exit,
-	.async = true,
 };
 
 static int __init arp_proc_init(void)

net/ipv4/devinet.c

@@ -2469,7 +2469,6 @@ static __net_exit void devinet_exit_net(struct net *net)
 static __net_initdata struct pernet_operations devinet_ops = {
 	.init = devinet_init_net,
 	.exit = devinet_exit_net,
-	.async = true,
 };
 
 static struct rtnl_af_ops inet_af_ops __read_mostly = {

net/ipv4/fib_frontend.c

@@ -1362,7 +1362,6 @@ static void __net_exit fib_net_exit(struct net *net)
 static struct pernet_operations fib_net_ops = {
 	.init = fib_net_init,
 	.exit = fib_net_exit,
-	.async = true,
 };
 
 void __init ip_fib_init(void)

net/ipv4/fou.c

@@ -1081,7 +1081,6 @@ static struct pernet_operations fou_net_ops = {
 	.exit = fou_exit_net,
 	.id   = &fou_net_id,
 	.size = sizeof(struct fou_net),
-	.async = true,
 };
 
 static int __init fou_init(void)

net/ipv4/icmp.c

@@ -1257,7 +1257,6 @@ fail:
 static struct pernet_operations __net_initdata icmp_sk_ops = {
        .init = icmp_sk_init,
        .exit = icmp_sk_exit,
-       .async = true,
 };
 
 int __init icmp_init(void)

net/ipv4/igmp.c

@@ -3028,7 +3028,6 @@ static void __net_exit igmp_net_exit(struct net *net)
 static struct pernet_operations igmp_net_ops = {
 	.init = igmp_net_init,
 	.exit = igmp_net_exit,
-	.async = true,
 };
 #endif
 

net/ipv4/ip_fragment.c

@@ -885,7 +885,6 @@ static void __net_exit ipv4_frags_exit_net(struct net *net)
 static struct pernet_operations ip4_frags_ops = {
 	.init = ipv4_frags_init_net,
 	.exit = ipv4_frags_exit_net,
-	.async = true,
 };
 
 void __init ipfrag_init(void)

net/ipv4/ip_gre.c

@@ -1044,7 +1044,6 @@ static struct pernet_operations ipgre_net_ops = {
 	.exit_batch = ipgre_exit_batch_net,
 	.id   = &ipgre_net_id,
 	.size = sizeof(struct ip_tunnel_net),
-	.async = true,
 };
 
 static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
@@ -1628,7 +1627,6 @@ static struct pernet_operations ipgre_tap_net_ops = {
 	.exit_batch = ipgre_tap_exit_batch_net,
 	.id   = &gre_tap_net_id,
 	.size = sizeof(struct ip_tunnel_net),
-	.async = true,
 };
 
 static int __net_init erspan_init_net(struct net *net)
@@ -1647,7 +1645,6 @@ static struct pernet_operations erspan_net_ops = {
 	.exit_batch = erspan_exit_batch_net,
 	.id   = &erspan_net_id,
 	.size = sizeof(struct ip_tunnel_net),
-	.async = true,
 };
 
 static int __init ipgre_init(void)

net/ipv4/ip_vti.c

@@ -454,7 +454,6 @@ static struct pernet_operations vti_net_ops = {
 	.exit_batch = vti_exit_batch_net,
 	.id   = &vti_net_id,
 	.size = sizeof(struct ip_tunnel_net),
-	.async = true,
 };
 
 static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],

net/ipv4/ipip.c

@@ -669,7 +669,6 @@ static struct pernet_operations ipip_net_ops = {
 	.exit_batch = ipip_exit_batch_net,
 	.id   = &ipip_net_id,
 	.size = sizeof(struct ip_tunnel_net),
-	.async = true,
 };
 
 static int __init ipip_init(void)

net/ipv4/ipmr.c

@@ -3009,7 +3009,6 @@ static void __net_exit ipmr_net_exit(struct net *net)
 static struct pernet_operations ipmr_net_ops = {
 	.init = ipmr_net_init,
 	.exit = ipmr_net_exit,
-	.async = true,
 };
 
 int __init ip_mr_init(void)

net/ipv4/netfilter/arp_tables.c

@@ -1635,7 +1635,6 @@ static void __net_exit arp_tables_net_exit(struct net *net)
 static struct pernet_operations arp_tables_net_ops = {
 	.init = arp_tables_net_init,
 	.exit = arp_tables_net_exit,
-	.async = true,
 };
 
 static int __init arp_tables_init(void)

net/ipv4/netfilter/arptable_filter.c

@@ -65,7 +65,6 @@ static void __net_exit arptable_filter_net_exit(struct net *net)
 
 static struct pernet_operations arptable_filter_net_ops = {
 	.exit = arptable_filter_net_exit,
-	.async = true,
 };
 
 static int __init arptable_filter_init(void)

net/ipv4/netfilter/ip_tables.c

@@ -1916,7 +1916,6 @@ static void __net_exit ip_tables_net_exit(struct net *net)
 static struct pernet_operations ip_tables_net_ops = {
 	.init = ip_tables_net_init,
 	.exit = ip_tables_net_exit,
-	.async = true,
 };
 
 static int __init ip_tables_init(void)

net/ipv4/netfilter/ipt_CLUSTERIP.c

@@ -845,7 +845,6 @@ static struct pernet_operations clusterip_net_ops = {
 	.exit = clusterip_net_exit,
 	.id   = &clusterip_net_id,
 	.size = sizeof(struct clusterip_net),
-	.async = true,
 };
 
 static int __init clusterip_tg_init(void)

net/ipv4/netfilter/iptable_filter.c

@@ -87,7 +87,6 @@ static void __net_exit iptable_filter_net_exit(struct net *net)
 static struct pernet_operations iptable_filter_net_ops = {
 	.init = iptable_filter_net_init,
 	.exit = iptable_filter_net_exit,
-	.async = true,
 };
 
 static int __init iptable_filter_init(void)

net/ipv4/netfilter/iptable_mangle.c

@@ -113,7 +113,6 @@ static void __net_exit iptable_mangle_net_exit(struct net *net)
 
 static struct pernet_operations iptable_mangle_net_ops = {
 	.exit = iptable_mangle_net_exit,
-	.async = true,
 };
 
 static int __init iptable_mangle_init(void)

net/ipv4/netfilter/iptable_nat.c

@@ -129,7 +129,6 @@ static void __net_exit iptable_nat_net_exit(struct net *net)
 
 static struct pernet_operations iptable_nat_net_ops = {
 	.exit	= iptable_nat_net_exit,
-	.async	= true,
 };
 
 static int __init iptable_nat_init(void)

net/ipv4/netfilter/iptable_raw.c

@@ -76,7 +76,6 @@ static void __net_exit iptable_raw_net_exit(struct net *net)
 
 static struct pernet_operations iptable_raw_net_ops = {
 	.exit = iptable_raw_net_exit,
-	.async = true,
 };
 
 static int __init iptable_raw_init(void)

net/ipv4/netfilter/iptable_security.c

@@ -76,7 +76,6 @@ static void __net_exit iptable_security_net_exit(struct net *net)
 
 static struct pernet_operations iptable_security_net_ops = {
 	.exit = iptable_security_net_exit,
-	.async = true,
 };
 
 static int __init iptable_security_init(void)

net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c

@@ -399,7 +399,6 @@ static struct pernet_operations ipv4_net_ops = {
 	.exit = ipv4_net_exit,
 	.id = &conntrack4_net_id,
 	.size = sizeof(struct conntrack4_net),
-	.async = true,
 };
 
 static int __init nf_conntrack_l3proto_ipv4_init(void)

net/ipv4/netfilter/nf_defrag_ipv4.c

@@ -118,7 +118,6 @@ static void __net_exit defrag4_net_exit(struct net *net)
 
 static struct pernet_operations defrag4_net_ops = {
 	.exit = defrag4_net_exit,
-	.async = true,
 };
 
 static int __init nf_defrag_init(void)

net/ipv4/netfilter/nf_log_arp.c

@@ -122,7 +122,6 @@ static void __net_exit nf_log_arp_net_exit(struct net *net)
 static struct pernet_operations nf_log_arp_net_ops = {
 	.init = nf_log_arp_net_init,
 	.exit = nf_log_arp_net_exit,
-	.async = true,
 };
 
 static int __init nf_log_arp_init(void)

net/ipv4/netfilter/nf_log_ipv4.c

@@ -358,7 +358,6 @@ static void __net_exit nf_log_ipv4_net_exit(struct net *net)
 static struct pernet_operations nf_log_ipv4_net_ops = {
 	.init = nf_log_ipv4_net_init,
 	.exit = nf_log_ipv4_net_exit,
-	.async = true,
 };
 
 static int __init nf_log_ipv4_init(void)

net/ipv4/ping.c

@@ -1204,7 +1204,6 @@ static void __net_exit ping_v4_proc_exit_net(struct net *net)
 static struct pernet_operations ping_v4_net_ops = {
 	.init = ping_v4_proc_init_net,
 	.exit = ping_v4_proc_exit_net,
-	.async = true,
 };
 
 int __init ping_proc_init(void)

net/ipv4/proc.c

@@ -549,7 +549,6 @@ static __net_exit void ip_proc_exit_net(struct net *net)
 static __net_initdata struct pernet_operations ip_proc_ops = {
 	.init = ip_proc_init_net,
 	.exit = ip_proc_exit_net,
-	.async = true,
 };
 
 int __init ip_misc_proc_init(void)

net/ipv4/raw.c

@@ -1154,7 +1154,6 @@ static __net_exit void raw_exit_net(struct net *net)
 static __net_initdata struct pernet_operations raw_net_ops = {
 	.init = raw_init_net,
 	.exit = raw_exit_net,
-	.async = true,
 };
 
 int __init raw_proc_init(void)

net/ipv4/route.c

@@ -418,7 +418,6 @@ 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)
@@ -3017,7 +3016,6 @@ 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
 
@@ -3031,7 +3029,6 @@ 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)
@@ -3057,7 +3054,6 @@ 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

net/ipv4/sysctl_net_ipv4.c

@@ -1219,7 +1219,6 @@ static __net_exit void ipv4_sysctl_exit_net(struct net *net)
 static __net_initdata struct pernet_operations ipv4_sysctl_ops = {
 	.init = ipv4_sysctl_init_net,
 	.exit = ipv4_sysctl_exit_net,
-	.async = true,
 };
 
 static __init int sysctl_ipv4_init(void)

net/ipv4/tcp_ipv4.c

@@ -2391,7 +2391,6 @@ static void __net_exit tcp4_proc_exit_net(struct net *net)
 static struct pernet_operations tcp4_net_ops = {
 	.init = tcp4_proc_init_net,
 	.exit = tcp4_proc_exit_net,
-	.async = true,
 };
 
 int __init tcp4_proc_init(void)
@@ -2578,7 +2577,6 @@ static struct pernet_operations __net_initdata tcp_sk_ops = {
        .init	   = tcp_sk_init,
        .exit	   = tcp_sk_exit,
        .exit_batch = tcp_sk_exit_batch,
-       .async	   = true,
 };
 
 void __init tcp_v4_init(void)

net/ipv4/tcp_metrics.c

@@ -1024,7 +1024,6 @@ static void __net_exit tcp_net_metrics_exit_batch(struct list_head *net_exit_lis
 static __net_initdata struct pernet_operations tcp_net_metrics_ops = {
 	.init		=	tcp_net_metrics_init,
 	.exit_batch	=	tcp_net_metrics_exit_batch,
-	.async		=	true,
 };
 
 void __init tcp_metrics_init(void)

net/ipv4/udp.c

@@ -2756,7 +2756,6 @@ static void __net_exit udp4_proc_exit_net(struct net *net)
 static struct pernet_operations udp4_net_ops = {
 	.init = udp4_proc_init_net,
 	.exit = udp4_proc_exit_net,
-	.async = true,
 };
 
 int __init udp4_proc_init(void)
@@ -2843,7 +2842,6 @@ static int __net_init udp_sysctl_init(struct net *net)
 
 static struct pernet_operations __net_initdata udp_sysctl_ops = {
 	.init	= udp_sysctl_init,
-	.async	= true,
 };
 
 void __init udp_init(void)

net/ipv4/udplite.c

@@ -104,7 +104,6 @@ static void __net_exit udplite4_proc_exit_net(struct net *net)
 static struct pernet_operations udplite4_net_ops = {
 	.init = udplite4_proc_init_net,
 	.exit = udplite4_proc_exit_net,
-	.async = true,
 };
 
 static __init int udplite4_proc_init(void)

net/ipv4/xfrm4_policy.c

@@ -367,7 +367,6 @@ static void __net_exit xfrm4_net_exit(struct net *net)
 static struct pernet_operations __net_initdata xfrm4_net_ops = {
 	.init	= xfrm4_net_init,
 	.exit	= xfrm4_net_exit,
-	.async	= true,
 };
 
 static void __init xfrm4_policy_init(void)

net/ipv6/addrconf.c

@@ -4282,7 +4282,6 @@ static void __net_exit if6_proc_net_exit(struct net *net)
 static struct pernet_operations if6_proc_net_ops = {
 	.init = if6_proc_net_init,
 	.exit = if6_proc_net_exit,
-	.async = true,
 };
 
 int __init if6_proc_init(void)
@@ -6592,7 +6591,6 @@ static void __net_exit addrconf_exit_net(struct net *net)
 static struct pernet_operations addrconf_ops = {
 	.init = addrconf_init_net,
 	.exit = addrconf_exit_net,
-	.async = true,
 };
 
 static struct rtnl_af_ops inet6_ops __read_mostly = {

net/ipv6/addrlabel.c

@@ -344,7 +344,6 @@ static void __net_exit ip6addrlbl_net_exit(struct net *net)
 static struct pernet_operations ipv6_addr_label_ops = {
 	.init = ip6addrlbl_net_init,
 	.exit = ip6addrlbl_net_exit,
-	.async = true,
 };
 
 int __init ipv6_addr_label_init(void)

net/ipv6/af_inet6.c

@@ -857,7 +857,6 @@ static void __net_exit inet6_net_exit(struct net *net)
 static struct pernet_operations inet6_net_ops = {
 	.init = inet6_net_init,
 	.exit = inet6_net_exit,
-	.async = true,
 };
 
 static const struct ipv6_stub ipv6_stub_impl = {

net/ipv6/fib6_rules.c

@@ -397,7 +397,6 @@ static void __net_exit fib6_rules_net_exit(struct net *net)
 static struct pernet_operations fib6_rules_net_ops = {
 	.init = fib6_rules_net_init,
 	.exit = fib6_rules_net_exit,
-	.async = true,
 };
 
 int __init fib6_rules_init(void)

net/ipv6/icmp.c

@@ -998,7 +998,6 @@ static void __net_exit icmpv6_sk_exit(struct net *net)
 static struct pernet_operations icmpv6_sk_ops = {
 	.init = icmpv6_sk_init,
 	.exit = icmpv6_sk_exit,
-	.async = true,
 };
 
 int __init icmpv6_init(void)

net/ipv6/ila/ila_xlat.c

@@ -613,7 +613,6 @@ static struct pernet_operations ila_net_ops = {
 	.exit = ila_exit_net,
 	.id   = &ila_net_id,
 	.size = sizeof(struct ila_net),
-	.async = true,
 };
 
 static int ila_xlat_addr(struct sk_buff *skb, bool sir2ila)

net/ipv6/ip6_fib.c

@@ -2161,7 +2161,6 @@ static void fib6_net_exit(struct net *net)
 static struct pernet_operations fib6_net_ops = {
 	.init = fib6_net_init,
 	.exit = fib6_net_exit,
-	.async = true,
 };
 
 int __init fib6_init(void)

net/ipv6/ip6_flowlabel.c

@@ -873,7 +873,6 @@ static void __net_exit ip6_flowlabel_net_exit(struct net *net)
 static struct pernet_operations ip6_flowlabel_net_ops = {
 	.init = ip6_flowlabel_proc_init,
 	.exit = ip6_flowlabel_net_exit,
-	.async = true,
 };
 
 int ip6_flowlabel_init(void)

net/ipv6/ip6_gre.c

@@ -1528,7 +1528,6 @@ static struct pernet_operations ip6gre_net_ops = {
 	.exit_batch = ip6gre_exit_batch_net,
 	.id   = &ip6gre_net_id,
 	.size = sizeof(struct ip6gre_net),
-	.async = true,
 };
 
 static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],

net/ipv6/ip6_tunnel.c

@@ -2260,7 +2260,6 @@ static struct pernet_operations ip6_tnl_net_ops = {
 	.exit_batch = ip6_tnl_exit_batch_net,
 	.id   = &ip6_tnl_net_id,
 	.size = sizeof(struct ip6_tnl_net),
-	.async = true,
 };
 
 /**

net/ipv6/ip6_vti.c

@@ -1148,7 +1148,6 @@ static struct pernet_operations vti6_net_ops = {
 	.exit_batch = vti6_exit_batch_net,
 	.id   = &vti6_net_id,
 	.size = sizeof(struct vti6_net),
-	.async = true,
 };
 
 static struct xfrm6_protocol vti_esp6_protocol __read_mostly = {

net/ipv6/ip6mr.c

@@ -1348,7 +1348,6 @@ static void __net_exit ip6mr_net_exit(struct net *net)
 static struct pernet_operations ip6mr_net_ops = {
 	.init = ip6mr_net_init,
 	.exit = ip6mr_net_exit,
-	.async = true,
 };
 
 int __init ip6_mr_init(void)

net/ipv6/mcast.c

@@ -2997,7 +2997,6 @@ static void __net_exit igmp6_net_exit(struct net *net)
 static struct pernet_operations igmp6_net_ops = {
 	.init = igmp6_net_init,
 	.exit = igmp6_net_exit,
-	.async = true,
 };
 
 int __init igmp6_init(void)

net/ipv6/ndisc.c

@@ -1883,7 +1883,6 @@ static void __net_exit ndisc_net_exit(struct net *net)
 static struct pernet_operations ndisc_net_ops = {
 	.init = ndisc_net_init,
 	.exit = ndisc_net_exit,
-	.async = true,
 };
 
 int __init ndisc_init(void)

net/ipv6/netfilter/ip6_tables.c

@@ -1928,7 +1928,6 @@ static void __net_exit ip6_tables_net_exit(struct net *net)
 static struct pernet_operations ip6_tables_net_ops = {
 	.init = ip6_tables_net_init,
 	.exit = ip6_tables_net_exit,
-	.async = true,
 };
 
 static int __init ip6_tables_init(void)

net/ipv6/netfilter/ip6table_filter.c

@@ -87,7 +87,6 @@ static void __net_exit ip6table_filter_net_exit(struct net *net)
 static struct pernet_operations ip6table_filter_net_ops = {
 	.init = ip6table_filter_net_init,
 	.exit = ip6table_filter_net_exit,
-	.async = true,
 };
 
 static int __init ip6table_filter_init(void)

net/ipv6/netfilter/ip6table_mangle.c

@@ -107,7 +107,6 @@ static void __net_exit ip6table_mangle_net_exit(struct net *net)
 
 static struct pernet_operations ip6table_mangle_net_ops = {
 	.exit = ip6table_mangle_net_exit,
-	.async = true,
 };
 
 static int __init ip6table_mangle_init(void)

net/ipv6/netfilter/ip6table_nat.c

@@ -131,7 +131,6 @@ static void __net_exit ip6table_nat_net_exit(struct net *net)
 
 static struct pernet_operations ip6table_nat_net_ops = {
 	.exit	= ip6table_nat_net_exit,
-	.async	= true,
 };
 
 static int __init ip6table_nat_init(void)

net/ipv6/netfilter/ip6table_raw.c

@@ -75,7 +75,6 @@ static void __net_exit ip6table_raw_net_exit(struct net *net)
 
 static struct pernet_operations ip6table_raw_net_ops = {
 	.exit = ip6table_raw_net_exit,
-	.async = true,
 };
 
 static int __init ip6table_raw_init(void)