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tcp_memcontrol: Remove setting cgroup settings via sysctl 

The code is broken and does not constrain sysctl_tcp_mem as
tcp_update_limit does.  With the result that it allows the cgroup tcp
memory limits to be bypassed.

The semantics are broken as the settings are not per netns and are in a
per netns table, and instead looks at current.

Since the code is broken in both design and implementation and does not
implement the functionality for which it was written remove it.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric W. Biederman 2013-10-19 16:24:52 -07:00 committed by David S. Miller
parent cd91cce620
commit f594d63199
3 changed files with 2 additions and 52 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
include/net/tcp_memcontrol.h
View File

@ -14,5 +14,4 @@ struct tcp_memcontrol {
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);
void tcp_prot_mem(struct mem_cgroup *memcg, long val, int idx);
#endif /* _TCP_MEMCG_H */

39
net/ipv4/sysctl_net_ipv4.c
View File

@ -204,43 +204,8 @@ 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;
ctl->data = &current->nsproxy->net_ns->ipv4.sysctl_tcp_mem;
return proc_doulongvec_minmax(ctl, write, buffer, lenp, ppos);
}
static int proc_tcp_fastopen_key(struct ctl_table *ctl, int write,

14
net/ipv4/tcp_memcontrol.c
View File

@ -226,20 +226,6 @@ static int tcp_cgroup_reset(struct cgroup_subsys_state *css, unsigned int event)
return 0;
}
void tcp_prot_mem(struct mem_cgroup *memcg, long val, int idx)
{
struct tcp_memcontrol *tcp;
struct cg_proto *cg_proto;
cg_proto = tcp_prot.proto_cgroup(memcg);
if (!cg_proto)
return;
tcp = tcp_from_cgproto(cg_proto);
tcp->tcp_prot_mem[idx] = val;
}
static struct cftype tcp_files[] = {
{
.name = "kmem.tcp.limit_in_bytes",