![Dan Carpenter](/assets/img/avatar_default.png)
We should only dereference the pointer if it's valid, not the other way round. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
273 lines
6.6 KiB
C
273 lines
6.6 KiB
C
#include <net/tcp.h>
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#include <net/tcp_memcontrol.h>
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#include <net/sock.h>
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#include <net/ip.h>
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#include <linux/nsproxy.h>
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#include <linux/memcontrol.h>
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#include <linux/module.h>
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static u64 tcp_cgroup_read(struct cgroup *cont, struct cftype *cft);
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static int tcp_cgroup_write(struct cgroup *cont, struct cftype *cft,
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const char *buffer);
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static int tcp_cgroup_reset(struct cgroup *cont, unsigned int event);
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static struct cftype tcp_files[] = {
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{
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.name = "kmem.tcp.limit_in_bytes",
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.write_string = tcp_cgroup_write,
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.read_u64 = tcp_cgroup_read,
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.private = RES_LIMIT,
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},
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{
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.name = "kmem.tcp.usage_in_bytes",
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.read_u64 = tcp_cgroup_read,
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.private = RES_USAGE,
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},
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{
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.name = "kmem.tcp.failcnt",
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.private = RES_FAILCNT,
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.trigger = tcp_cgroup_reset,
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.read_u64 = tcp_cgroup_read,
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},
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{
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.name = "kmem.tcp.max_usage_in_bytes",
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.private = RES_MAX_USAGE,
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.trigger = tcp_cgroup_reset,
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.read_u64 = tcp_cgroup_read,
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},
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};
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static inline struct tcp_memcontrol *tcp_from_cgproto(struct cg_proto *cg_proto)
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{
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return container_of(cg_proto, struct tcp_memcontrol, cg_proto);
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}
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static void memcg_tcp_enter_memory_pressure(struct sock *sk)
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{
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if (sk->sk_cgrp->memory_pressure)
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*sk->sk_cgrp->memory_pressure = 1;
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}
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EXPORT_SYMBOL(memcg_tcp_enter_memory_pressure);
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int tcp_init_cgroup(struct cgroup *cgrp, struct cgroup_subsys *ss)
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{
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/*
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* The root cgroup does not use res_counters, but rather,
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* rely on the data already collected by the network
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* subsystem
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*/
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struct res_counter *res_parent = NULL;
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struct cg_proto *cg_proto, *parent_cg;
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struct tcp_memcontrol *tcp;
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struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
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struct mem_cgroup *parent = parent_mem_cgroup(memcg);
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struct net *net = current->nsproxy->net_ns;
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cg_proto = tcp_prot.proto_cgroup(memcg);
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if (!cg_proto)
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goto create_files;
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tcp = tcp_from_cgproto(cg_proto);
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tcp->tcp_prot_mem[0] = net->ipv4.sysctl_tcp_mem[0];
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tcp->tcp_prot_mem[1] = net->ipv4.sysctl_tcp_mem[1];
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tcp->tcp_prot_mem[2] = net->ipv4.sysctl_tcp_mem[2];
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tcp->tcp_memory_pressure = 0;
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parent_cg = tcp_prot.proto_cgroup(parent);
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if (parent_cg)
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res_parent = parent_cg->memory_allocated;
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res_counter_init(&tcp->tcp_memory_allocated, res_parent);
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percpu_counter_init(&tcp->tcp_sockets_allocated, 0);
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cg_proto->enter_memory_pressure = memcg_tcp_enter_memory_pressure;
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cg_proto->memory_pressure = &tcp->tcp_memory_pressure;
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cg_proto->sysctl_mem = tcp->tcp_prot_mem;
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cg_proto->memory_allocated = &tcp->tcp_memory_allocated;
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cg_proto->sockets_allocated = &tcp->tcp_sockets_allocated;
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cg_proto->memcg = memcg;
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create_files:
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return cgroup_add_files(cgrp, ss, tcp_files,
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ARRAY_SIZE(tcp_files));
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}
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EXPORT_SYMBOL(tcp_init_cgroup);
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void tcp_destroy_cgroup(struct cgroup *cgrp, struct cgroup_subsys *ss)
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{
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struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
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struct cg_proto *cg_proto;
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struct tcp_memcontrol *tcp;
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u64 val;
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cg_proto = tcp_prot.proto_cgroup(memcg);
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if (!cg_proto)
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return;
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tcp = tcp_from_cgproto(cg_proto);
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percpu_counter_destroy(&tcp->tcp_sockets_allocated);
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val = res_counter_read_u64(&tcp->tcp_memory_allocated, RES_USAGE);
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if (val != RESOURCE_MAX)
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jump_label_dec(&memcg_socket_limit_enabled);
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}
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EXPORT_SYMBOL(tcp_destroy_cgroup);
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static int tcp_update_limit(struct mem_cgroup *memcg, u64 val)
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{
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struct net *net = current->nsproxy->net_ns;
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struct tcp_memcontrol *tcp;
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struct cg_proto *cg_proto;
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u64 old_lim;
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int i;
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int ret;
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cg_proto = tcp_prot.proto_cgroup(memcg);
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if (!cg_proto)
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return -EINVAL;
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if (val > RESOURCE_MAX)
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val = RESOURCE_MAX;
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tcp = tcp_from_cgproto(cg_proto);
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old_lim = res_counter_read_u64(&tcp->tcp_memory_allocated, RES_LIMIT);
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ret = res_counter_set_limit(&tcp->tcp_memory_allocated, val);
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if (ret)
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return ret;
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for (i = 0; i < 3; i++)
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tcp->tcp_prot_mem[i] = min_t(long, val >> PAGE_SHIFT,
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net->ipv4.sysctl_tcp_mem[i]);
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if (val == RESOURCE_MAX && old_lim != RESOURCE_MAX)
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jump_label_dec(&memcg_socket_limit_enabled);
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else if (old_lim == RESOURCE_MAX && val != RESOURCE_MAX)
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jump_label_inc(&memcg_socket_limit_enabled);
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return 0;
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}
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static int tcp_cgroup_write(struct cgroup *cont, struct cftype *cft,
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const char *buffer)
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{
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struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
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unsigned long long val;
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int ret = 0;
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switch (cft->private) {
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case RES_LIMIT:
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/* see memcontrol.c */
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ret = res_counter_memparse_write_strategy(buffer, &val);
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if (ret)
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break;
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ret = tcp_update_limit(memcg, val);
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break;
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default:
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ret = -EINVAL;
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break;
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}
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return ret;
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}
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static u64 tcp_read_stat(struct mem_cgroup *memcg, int type, u64 default_val)
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{
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struct tcp_memcontrol *tcp;
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struct cg_proto *cg_proto;
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cg_proto = tcp_prot.proto_cgroup(memcg);
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if (!cg_proto)
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return default_val;
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tcp = tcp_from_cgproto(cg_proto);
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return res_counter_read_u64(&tcp->tcp_memory_allocated, type);
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}
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static u64 tcp_read_usage(struct mem_cgroup *memcg)
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{
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struct tcp_memcontrol *tcp;
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struct cg_proto *cg_proto;
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cg_proto = tcp_prot.proto_cgroup(memcg);
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if (!cg_proto)
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return atomic_long_read(&tcp_memory_allocated) << PAGE_SHIFT;
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tcp = tcp_from_cgproto(cg_proto);
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return res_counter_read_u64(&tcp->tcp_memory_allocated, RES_USAGE);
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}
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static u64 tcp_cgroup_read(struct cgroup *cont, struct cftype *cft)
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{
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struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
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u64 val;
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switch (cft->private) {
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case RES_LIMIT:
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val = tcp_read_stat(memcg, RES_LIMIT, RESOURCE_MAX);
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break;
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case RES_USAGE:
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val = tcp_read_usage(memcg);
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break;
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case RES_FAILCNT:
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case RES_MAX_USAGE:
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val = tcp_read_stat(memcg, cft->private, 0);
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break;
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default:
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BUG();
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}
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return val;
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}
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static int tcp_cgroup_reset(struct cgroup *cont, unsigned int event)
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{
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struct mem_cgroup *memcg;
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struct tcp_memcontrol *tcp;
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struct cg_proto *cg_proto;
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memcg = mem_cgroup_from_cont(cont);
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cg_proto = tcp_prot.proto_cgroup(memcg);
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if (!cg_proto)
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return 0;
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tcp = tcp_from_cgproto(cg_proto);
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switch (event) {
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case RES_MAX_USAGE:
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res_counter_reset_max(&tcp->tcp_memory_allocated);
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break;
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case RES_FAILCNT:
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res_counter_reset_failcnt(&tcp->tcp_memory_allocated);
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break;
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}
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return 0;
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}
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unsigned long long tcp_max_memory(const struct mem_cgroup *memcg)
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{
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struct tcp_memcontrol *tcp;
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struct cg_proto *cg_proto;
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cg_proto = tcp_prot.proto_cgroup((struct mem_cgroup *)memcg);
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if (!cg_proto)
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return 0;
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tcp = tcp_from_cgproto(cg_proto);
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return res_counter_read_u64(&tcp->tcp_memory_allocated, RES_LIMIT);
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}
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void tcp_prot_mem(struct mem_cgroup *memcg, long val, int idx)
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{
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struct tcp_memcontrol *tcp;
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struct cg_proto *cg_proto;
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cg_proto = tcp_prot.proto_cgroup(memcg);
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if (!cg_proto)
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return;
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tcp = tcp_from_cgproto(cg_proto);
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tcp->tcp_prot_mem[idx] = val;
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}
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