Fixed MTP to work with TWRP

net/ipv4/tcp_memcontrol.c

@@ -0,0 +1,228 @@
+#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, GFP_KERNEL);
+
+	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 ssize_t tcp_cgroup_reset(struct kernfs_open_file *of,
+				char *buf, size_t nbytes, loff_t off)
+{
+	struct mem_cgroup *memcg;
+	struct cg_proto *cg_proto;
+
+	memcg = mem_cgroup_from_css(of_css(of));
+	cg_proto = tcp_prot.proto_cgroup(memcg);
+	if (!cg_proto)
+		return nbytes;
+
+	switch (of_cft(of)->private) {
+	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 nbytes;
+}
+
+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,
+		.write = tcp_cgroup_reset,
+		.read_u64 = tcp_cgroup_read,
+	},
+	{
+		.name = "kmem.tcp.max_usage_in_bytes",
+		.private = RES_MAX_USAGE,
+		.write = tcp_cgroup_reset,
+		.read_u64 = tcp_cgroup_read,
+	},
+	{ }	/* terminate */
+};
+
+static int __init tcp_memcontrol_init(void)
+{
+	WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, tcp_files));
+	return 0;
+}
+__initcall(tcp_memcontrol_init);