Merge branch 'pernet_sysctls'

Eric W. Biederman says:

====================
ipv4: tcp_memcontrol and userns sysctls

While looking into allowing the ipv4 sysctls to be used in a network
namespace I stumbled upon the mess that is tcp_memcontrol.

I remove the dead code, broken code, and excessive abstraction in the
tcp_memcontrols then I clean up up and allow in the user namespace the
per net ipv4 sysctls.
====================

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

include/net/netns/ipv4.h

@@ -71,7 +71,6 @@ struct netns_ipv4 {
 	int sysctl_tcp_ecn;
 
 	kgid_t sysctl_ping_group_range[2];
-	long sysctl_tcp_mem[3];
 
 	atomic_t dev_addr_genid;
 

include/net/sock.h

@@ -1036,10 +1036,10 @@ enum cg_proto_flags {
 
 struct cg_proto {
 	void			(*enter_memory_pressure)(struct sock *sk);
-	struct res_counter	*memory_allocated;	/* Current allocated memory. */
-	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
-	int			*memory_pressure;
-	long			*sysctl_mem;
+	struct res_counter	memory_allocated;	/* Current allocated memory. */
+	struct percpu_counter	sockets_allocated;	/* Current number of sockets. */
+	int			memory_pressure;
+	long			sysctl_mem[3];
 	unsigned long		flags;
 	/*
 	 * memcg field is used to find which memcg we belong directly
@@ -1135,9 +1135,9 @@ static inline bool sk_under_memory_pressure(const struct sock *sk)
 		return false;
 
 	if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
-		return !!*sk->sk_cgrp->memory_pressure;
+		return !!sk->sk_cgrp->memory_pressure;
 
-	return !!*sk->sk_prot->memory_pressure;
+	return !!sk->sk_prot->memory_pressure;
 }
 
 static inline void sk_leave_memory_pressure(struct sock *sk)
@@ -1155,8 +1155,8 @@ static inline void sk_leave_memory_pressure(struct sock *sk)
 		struct proto *prot = sk->sk_prot;
 
 		for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
-			if (*cg_proto->memory_pressure)
-				*cg_proto->memory_pressure = 0;
+			if (cg_proto->memory_pressure)
+				cg_proto->memory_pressure = 0;
 	}
 
 }
@@ -1192,7 +1192,7 @@ static inline void memcg_memory_allocated_add(struct cg_proto *prot,
 	struct res_counter *fail;
 	int ret;
 
-	ret = res_counter_charge_nofail(prot->memory_allocated,
+	ret = res_counter_charge_nofail(&prot->memory_allocated,
 					amt << PAGE_SHIFT, &fail);
 	if (ret < 0)
 		*parent_status = OVER_LIMIT;
@@ -1201,13 +1201,13 @@ static inline void memcg_memory_allocated_add(struct cg_proto *prot,
 static inline void memcg_memory_allocated_sub(struct cg_proto *prot,
 					      unsigned long amt)
 {
-	res_counter_uncharge(prot->memory_allocated, amt << PAGE_SHIFT);
+	res_counter_uncharge(&prot->memory_allocated, amt << PAGE_SHIFT);
 }
 
 static inline u64 memcg_memory_allocated_read(struct cg_proto *prot)
 {
 	u64 ret;
-	ret = res_counter_read_u64(prot->memory_allocated, RES_USAGE);
+	ret = res_counter_read_u64(&prot->memory_allocated, RES_USAGE);
 	return ret >> PAGE_SHIFT;
 }
 
@@ -1255,7 +1255,7 @@ static inline void sk_sockets_allocated_dec(struct sock *sk)
 		struct cg_proto *cg_proto = sk->sk_cgrp;
 
 		for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
-			percpu_counter_dec(cg_proto->sockets_allocated);
+			percpu_counter_dec(&cg_proto->sockets_allocated);
 	}
 
 	percpu_counter_dec(prot->sockets_allocated);
@@ -1269,7 +1269,7 @@ static inline void sk_sockets_allocated_inc(struct sock *sk)
 		struct cg_proto *cg_proto = sk->sk_cgrp;
 
 		for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
-			percpu_counter_inc(cg_proto->sockets_allocated);
+			percpu_counter_inc(&cg_proto->sockets_allocated);
 	}
 
 	percpu_counter_inc(prot->sockets_allocated);
@@ -1281,7 +1281,7 @@ sk_sockets_allocated_read_positive(struct sock *sk)
 	struct proto *prot = sk->sk_prot;
 
 	if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
-		return percpu_counter_read_positive(sk->sk_cgrp->sockets_allocated);
+		return percpu_counter_read_positive(&sk->sk_cgrp->sockets_allocated);
 
 	return percpu_counter_read_positive(prot->sockets_allocated);
 }

include/net/tcp.h

@@ -259,6 +259,7 @@ extern int sysctl_tcp_max_orphans;
 extern int sysctl_tcp_fack;
 extern int sysctl_tcp_reordering;
 extern int sysctl_tcp_dsack;
+extern long sysctl_tcp_mem[3];
 extern int sysctl_tcp_wmem[3];
 extern int sysctl_tcp_rmem[3];
 extern int sysctl_tcp_app_win;
@@ -348,8 +349,6 @@ extern struct proto tcp_prot;
 #define TCP_ADD_STATS_USER(net, field, val) SNMP_ADD_STATS_USER((net)->mib.tcp_statistics, field, val)
 #define TCP_ADD_STATS(net, field, val)	SNMP_ADD_STATS((net)->mib.tcp_statistics, field, val)
 
-void tcp_init_mem(struct net *net);
-
 void tcp_tasklet_init(void);
 
 void tcp_v4_err(struct sk_buff *skb, u32);

include/net/tcp_memcontrol.h

@@ -1,19 +1,7 @@
 #ifndef _TCP_MEMCG_H
 #define _TCP_MEMCG_H
 
-struct tcp_memcontrol {
-	struct cg_proto cg_proto;
-	/* per-cgroup tcp memory pressure knobs */
-	struct res_counter tcp_memory_allocated;
-	struct percpu_counter tcp_sockets_allocated;
-	/* those two are read-mostly, leave them at the end */
-	long tcp_prot_mem[3];
-	int tcp_memory_pressure;
-};
-
 struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg);
 int tcp_init_cgroup(struct mem_cgroup *memcg, struct cgroup_subsys *ss);
 void tcp_destroy_cgroup(struct mem_cgroup *memcg);
-unsigned long long tcp_max_memory(const struct mem_cgroup *memcg);
-void tcp_prot_mem(struct mem_cgroup *memcg, long val, int idx);
 #endif /* _TCP_MEMCG_H */

mm/memcontrol.c

@@ -311,7 +311,7 @@ struct mem_cgroup {
 
 	atomic_t	dead_count;
 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
-	struct tcp_memcontrol tcp_mem;
+	struct cg_proto tcp_mem;
 #endif
 #if defined(CONFIG_MEMCG_KMEM)
 	/* analogous to slab_common's slab_caches list. per-memcg */
@@ -550,13 +550,13 @@ struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg)
 	if (!memcg || mem_cgroup_is_root(memcg))
 		return NULL;
 
-	return &memcg->tcp_mem.cg_proto;
+	return &memcg->tcp_mem;
 }
 EXPORT_SYMBOL(tcp_proto_cgroup);
 
 static void disarm_sock_keys(struct mem_cgroup *memcg)
 {
-	if (!memcg_proto_activated(&memcg->tcp_mem.cg_proto))
+	if (!memcg_proto_activated(&memcg->tcp_mem))
 		return;
 	static_key_slow_dec(&memcg_socket_limit_enabled);
 }

net/ipv4/af_inet.c

@@ -1697,8 +1697,6 @@ static int __init inet_init(void)
 	ip_static_sysctl_init();
 #endif
 
-	tcp_prot.sysctl_mem = init_net.ipv4.sysctl_tcp_mem;
-
 	/*
 	 *	Add all the base protocols.
 	 */

net/ipv4/sysctl_net_ipv4.c

@@ -200,49 +200,6 @@ static int proc_allowed_congestion_control(struct ctl_table *ctl,
 	return ret;
 }
 
-static int ipv4_tcp_mem(struct ctl_table *ctl, int write,
-			   void __user *buffer, size_t *lenp,
-			   loff_t *ppos)
-{
-	int ret;
-	unsigned long vec[3];
-	struct net *net = current->nsproxy->net_ns;
-#ifdef CONFIG_MEMCG_KMEM
-	struct mem_cgroup *memcg;
-#endif
-
-	struct ctl_table tmp = {
-		.data = &vec,
-		.maxlen = sizeof(vec),
-		.mode = ctl->mode,
-	};
-
-	if (!write) {
-		ctl->data = &net->ipv4.sysctl_tcp_mem;
-		return proc_doulongvec_minmax(ctl, write, buffer, lenp, ppos);
-	}
-
-	ret = proc_doulongvec_minmax(&tmp, write, buffer, lenp, ppos);
-	if (ret)
-		return ret;
-
-#ifdef CONFIG_MEMCG_KMEM
-	rcu_read_lock();
-	memcg = mem_cgroup_from_task(current);
-
-	tcp_prot_mem(memcg, vec[0], 0);
-	tcp_prot_mem(memcg, vec[1], 1);
-	tcp_prot_mem(memcg, vec[2], 2);
-	rcu_read_unlock();
-#endif
-
-	net->ipv4.sysctl_tcp_mem[0] = vec[0];
-	net->ipv4.sysctl_tcp_mem[1] = vec[1];
-	net->ipv4.sysctl_tcp_mem[2] = vec[2];
-
-	return 0;
-}
-
 static int proc_tcp_fastopen_key(struct ctl_table *ctl, int write,
 				 void __user *buffer, size_t *lenp,
 				 loff_t *ppos)
@@ -556,6 +513,13 @@ static struct ctl_table ipv4_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec
 	},
+	{
+		.procname	= "tcp_mem",
+		.maxlen		= sizeof(sysctl_tcp_mem),
+		.data		= &sysctl_tcp_mem,
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_minmax,
+	},
 	{
 		.procname	= "tcp_wmem",
 		.data		= &sysctl_tcp_wmem,
@@ -865,12 +829,6 @@ static struct ctl_table ipv4_net_table[] = {
 		.mode		= 0644,
 		.proc_handler	= ipv4_local_port_range,
 	},
-	{
-		.procname	= "tcp_mem",
-		.maxlen		= sizeof(init_net.ipv4.sysctl_tcp_mem),
-		.mode		= 0644,
-		.proc_handler	= ipv4_tcp_mem,
-	},
 	{ }
 };
 
@@ -880,32 +838,15 @@ static __net_init int ipv4_sysctl_init_net(struct net *net)
 
 	table = ipv4_net_table;
 	if (!net_eq(net, &init_net)) {
+		int i;
+
 		table = kmemdup(table, sizeof(ipv4_net_table), GFP_KERNEL);
 		if (table == NULL)
 			goto err_alloc;
 
-		table[0].data =
-			&net->ipv4.sysctl_icmp_echo_ignore_all;
-		table[1].data =
-			&net->ipv4.sysctl_icmp_echo_ignore_broadcasts;
-		table[2].data =
-			&net->ipv4.sysctl_icmp_ignore_bogus_error_responses;
-		table[3].data =
-			&net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr;
-		table[4].data =
-			&net->ipv4.sysctl_icmp_ratelimit;
-		table[5].data =
-			&net->ipv4.sysctl_icmp_ratemask;
-		table[6].data =
-			&net->ipv4.sysctl_ping_group_range;
-		table[7].data =
-			&net->ipv4.sysctl_tcp_ecn;
-		table[8].data =
-			&net->ipv4.sysctl_local_ports.range;
-
-		/* Don't export sysctls to unprivileged users */
-		if (net->user_ns != &init_user_ns)
-			table[0].procname = NULL;
+		/* Update the variables to point into the current struct net */
+		for (i = 0; i < ARRAY_SIZE(ipv4_net_table) - 1; i++)
+			table[i].data += (void *)net - (void *)&init_net;
 	}
 
 	/*
@@ -922,8 +863,6 @@ static __net_init int ipv4_sysctl_init_net(struct net *net)
 	net->ipv4.sysctl_local_ports.range[0] =  32768;
 	net->ipv4.sysctl_local_ports.range[1] =  61000;
 
-	tcp_init_mem(net);
-
 	net->ipv4.ipv4_hdr = register_net_sysctl(net, "net/ipv4", table);
 	if (net->ipv4.ipv4_hdr == NULL)
 		goto err_reg;

net/ipv4/tcp.c

@@ -288,9 +288,11 @@ int sysctl_tcp_min_tso_segs __read_mostly = 2;
 struct percpu_counter tcp_orphan_count;
 EXPORT_SYMBOL_GPL(tcp_orphan_count);
 
+long sysctl_tcp_mem[3] __read_mostly;
 int sysctl_tcp_wmem[3] __read_mostly;
 int sysctl_tcp_rmem[3] __read_mostly;
 
+EXPORT_SYMBOL(sysctl_tcp_mem);
 EXPORT_SYMBOL(sysctl_tcp_rmem);
 EXPORT_SYMBOL(sysctl_tcp_wmem);
 
@@ -3097,13 +3099,13 @@ static int __init set_thash_entries(char *str)
 }
 __setup("thash_entries=", set_thash_entries);
 
-void tcp_init_mem(struct net *net)
+static void tcp_init_mem(void)
 {
 	unsigned long limit = nr_free_buffer_pages() / 8;
 	limit = max(limit, 128UL);
-	net->ipv4.sysctl_tcp_mem[0] = limit / 4 * 3;
-	net->ipv4.sysctl_tcp_mem[1] = limit;
-	net->ipv4.sysctl_tcp_mem[2] = net->ipv4.sysctl_tcp_mem[0] * 2;
+	sysctl_tcp_mem[0] = limit / 4 * 3;
+	sysctl_tcp_mem[1] = limit;
+	sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;
 }
 
 void __init tcp_init(void)
@@ -3165,7 +3167,7 @@ void __init tcp_init(void)
 	sysctl_tcp_max_orphans = cnt / 2;
 	sysctl_max_syn_backlog = max(128, cnt / 256);
 
-	tcp_init_mem(&init_net);
+	tcp_init_mem();
 	/* Set per-socket limits to no more than 1/128 the pressure threshold */
 	limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
 	max_wshare = min(4UL*1024*1024, limit);

net/ipv4/tcp_ipv4.c

@@ -2749,6 +2749,7 @@ struct proto tcp_prot = {
 	.orphan_count		= &tcp_orphan_count,
 	.memory_allocated	= &tcp_memory_allocated,
 	.memory_pressure	= &tcp_memory_pressure,
+	.sysctl_mem		= sysctl_tcp_mem,
 	.sysctl_wmem		= sysctl_tcp_wmem,
 	.sysctl_rmem		= sysctl_tcp_rmem,
 	.max_header		= MAX_TCP_HEADER,