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#include <net/tcp.h>
#include <net/tcp_memcontrol.h>
#include <net/sock.h>
#include <net/ip.h>
#include <linux/nsproxy.h>
#include <linux/memcontrol.h>
#include <linux/module.h>
int tcp_init_cgroup(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
{
/*
* The root cgroup does not use res_counters, but rather,
* rely on the data already collected by the network
* subsystem
*/
struct res_counter *res_parent = NULL;
struct cg_proto *cg_proto, *parent_cg;
struct mem_cgroup *parent = parent_mem_cgroup(memcg);
cg_proto = tcp_prot.proto_cgroup(memcg);
if (!cg_proto)
return 0;
cg_proto->sysctl_mem[0] = sysctl_tcp_mem[0];
cg_proto->sysctl_mem[1] = sysctl_tcp_mem[1];
cg_proto->sysctl_mem[2] = sysctl_tcp_mem[2];
cg_proto->memory_pressure = 0;
cg_proto->memcg = memcg;
parent_cg = tcp_prot.proto_cgroup(parent);
if (parent_cg)
res_parent = &parent_cg->memory_allocated;
res_counter_init(&cg_proto->memory_allocated, res_parent);
percpu_counter_init(&cg_proto->sockets_allocated, 0);
return 0;
}
EXPORT_SYMBOL(tcp_init_cgroup);
void tcp_destroy_cgroup(struct mem_cgroup *memcg)
{
struct cg_proto *cg_proto;
cg_proto = tcp_prot.proto_cgroup(memcg);
if (!cg_proto)
return;
percpu_counter_destroy(&cg_proto->sockets_allocated);
}
EXPORT_SYMBOL(tcp_destroy_cgroup);
static int tcp_update_limit(struct mem_cgroup *memcg, u64 val)
{
struct cg_proto *cg_proto;
int i;
int ret;
cg_proto = tcp_prot.proto_cgroup(memcg);
if (!cg_proto)
return -EINVAL;
if (val > RES_COUNTER_MAX)
val = RES_COUNTER_MAX;
ret = res_counter_set_limit(&cg_proto->memory_allocated, val);
if (ret)
return ret;
for (i = 0; i < 3; i++)
cg_proto->sysctl_mem[i] = min_t(long, val >> PAGE_SHIFT,
sysctl_tcp_mem[i]);
if (val == RES_COUNTER_MAX)
clear_bit(MEMCG_SOCK_ACTIVE, &cg_proto->flags);
else if (val != RES_COUNTER_MAX) {
/*
* The active bit needs to be written after the static_key
* update. This is what guarantees that the socket activation
* function is the last one to run. See sock_update_memcg() for
* details, and note that we don't mark any socket as belonging
* to this memcg until that flag is up.
*
* We need to do this, because static_keys will span multiple
* sites, but we can't control their order. If we mark a socket
* as accounted, but the accounting functions are not patched in
* yet, we'll lose accounting.
*
* We never race with the readers in sock_update_memcg(),
* because when this value change, the code to process it is not
* patched in yet.
*
* The activated bit is used to guarantee that no two writers
* will do the update in the same memcg. Without that, we can't
* properly shutdown the static key.
*/
if (!test_and_set_bit(MEMCG_SOCK_ACTIVATED, &cg_proto->flags))
static_key_slow_inc(&memcg_socket_limit_enabled);
set_bit(MEMCG_SOCK_ACTIVE, &cg_proto->flags);
}
return 0;
}
static ssize_t tcp_cgroup_write(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off)
{
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
unsigned long long val;
int ret = 0;
buf = strstrip(buf);
switch (of_cft(of)->private) {
case RES_LIMIT:
/* see memcontrol.c */
ret = res_counter_memparse_write_strategy(buf, &val);
if (ret)
break;
ret = tcp_update_limit(memcg, val);
break;
default:
ret = -EINVAL;
break;
}
return ret ?: nbytes;
}
static u64 tcp_read_stat(struct mem_cgroup *memcg, int type, u64 default_val)
{
struct cg_proto *cg_proto;
cg_proto = tcp_prot.proto_cgroup(memcg);
if (!cg_proto)
return default_val;
return res_counter_read_u64(&cg_proto->memory_allocated, type);
}
static u64 tcp_read_usage(struct mem_cgroup *memcg)
{
struct cg_proto *cg_proto;
cg_proto = tcp_prot.proto_cgroup(memcg);
if (!cg_proto)
return atomic_long_read(&tcp_memory_allocated) << PAGE_SHIFT;
return res_counter_read_u64(&cg_proto->memory_allocated, RES_USAGE);
}
static u64 tcp_cgroup_read(struct cgroup_subsys_state *css, struct cftype *cft)
{
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
u64 val;
switch (cft->private) {
case RES_LIMIT:
val = tcp_read_stat(memcg, RES_LIMIT, RES_COUNTER_MAX);
break;
case RES_USAGE:
val = tcp_read_usage(memcg);
break;
case RES_FAILCNT:
case RES_MAX_USAGE:
val = tcp_read_stat(memcg, cft->private, 0);
break;
default:
BUG();
}
return val;
}
static int tcp_cgroup_reset(struct cgroup_subsys_state *css, unsigned int event)
{
struct mem_cgroup *memcg;
struct cg_proto *cg_proto;
memcg = mem_cgroup_from_css(css);
cg_proto = tcp_prot.proto_cgroup(memcg);
if (!cg_proto)
return 0;
switch (event) {
case RES_MAX_USAGE:
res_counter_reset_max(&cg_proto->memory_allocated);
break;
case RES_FAILCNT:
res_counter_reset_failcnt(&cg_proto->memory_allocated);
break;
}
return 0;
}
static struct cftype tcp_files[] = {
{
.name = "kmem.tcp.limit_in_bytes",
.write = tcp_cgroup_write,
.read_u64 = tcp_cgroup_read,
.private = RES_LIMIT,
},
{
.name = "kmem.tcp.usage_in_bytes",
.read_u64 = tcp_cgroup_read,
.private = RES_USAGE,
},
{
.name = "kmem.tcp.failcnt",
.private = RES_FAILCNT,
.trigger = tcp_cgroup_reset,
.read_u64 = tcp_cgroup_read,
},
{
.name = "kmem.tcp.max_usage_in_bytes",
.private = RES_MAX_USAGE,
.trigger = tcp_cgroup_reset,
.read_u64 = tcp_cgroup_read,
},
{ } /* terminate */
};
static int __init tcp_memcontrol_init(void)
{
WARN_ON(cgroup_add_cftypes(&memory_cgrp_subsys, tcp_files));
return 0;
}
__initcall(tcp_memcontrol_init);
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