net: drop tcp_memcontrol.c

tcp_memcontrol.c only contains legacy memory.tcp.kmem.* file definitions
and mem_cgroup->tcp_mem init/destroy stuff.  This doesn't belong to
network subsys.  Let's move it to memcontrol.c.  This also allows us to
reuse generic code for handling legacy memcg files.

Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: "David S. Miller" <davem@davemloft.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

7 files changed, 90 insertions, 222 deletions

diff --git a/include/net/tcp_memcontrol.h b/include/net/tcp_memcontrol.h
deleted file mode 100644
index 020c2dee65e8..000000000000
--- a/include/net/tcp_memcontrol.h
+++ /dev/null
@@ -1,10 +0,0 @@
-#ifndef _TCP_MEMCG_H
-#define _TCP_MEMCG_H
-
-struct cgroup_subsys;
-struct mem_cgroup;
-
-int tcp_init_cgroup(struct mem_cgroup *memcg);
-void tcp_destroy_cgroup(struct mem_cgroup *memcg);
-
-#endif /* _TCP_MEMCG_H */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 92e8ab67b6df..15896708429b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -66,7 +66,6 @@
 #include "internal.h"
 #include <net/sock.h>
 #include <net/ip.h>
-#include <net/tcp_memcontrol.h>
 #include "slab.h"
 
 #include <asm/uaccess.h>
@@ -242,6 +241,7 @@ enum res_type {
         _MEMSWAP,
         _OOM_TYPE,
         _KMEM,
+        _TCP,
 };
 
 #define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
@@ -2842,6 +2842,11 @@ static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css,
         case _KMEM:
                 counter = &memcg->kmem;
                 break;
+#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET)
+        case _TCP:
+                counter = &memcg->tcp_mem.memory_allocated;
+                break;
+#endif
         default:
                 BUG();
         }
@@ -3028,6 +3033,48 @@ static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
 #endif /* CONFIG_MEMCG_LEGACY_KMEM */
 
 
+#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET)
+static int memcg_update_tcp_limit(struct mem_cgroup *memcg, unsigned long limit)
+{
+        int ret;
+
+        mutex_lock(&memcg_limit_mutex);
+
+        ret = page_counter_limit(&memcg->tcp_mem.memory_allocated, limit);
+        if (ret)
+                goto out;
+
+        if (!memcg->tcp_mem.active) {
+                /*
+                 * The active flag 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.
+                 */
+                static_branch_inc(&memcg_sockets_enabled_key);
+                memcg->tcp_mem.active = true;
+        }
+out:
+        mutex_unlock(&memcg_limit_mutex);
+        return ret;
+}
+#else
+static int memcg_update_tcp_limit(struct mem_cgroup *memcg, unsigned long limit)
+{
+        return -EINVAL;
+}
+#endif /* CONFIG_MEMCG_LEGACY_KMEM && CONFIG_INET */
+
 /*
  * The user of this function is...
  * RES_LIMIT.
@@ -3060,6 +3107,9 @@ static ssize_t mem_cgroup_write(struct kernfs_open_file *of,
                 case _KMEM:
                         ret = memcg_update_kmem_limit(memcg, nr_pages);
                         break;
+                case _TCP:
+                        ret = memcg_update_tcp_limit(memcg, nr_pages);
+                        break;
                 }
                 break;
         case RES_SOFT_LIMIT:
@@ -3086,6 +3136,11 @@ static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf,
         case _KMEM:
                 counter = &memcg->kmem;
                 break;
+#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET)
+        case _TCP:
+                counter = &memcg->tcp_mem.memory_allocated;
+                break;
+#endif
         default:
                 BUG();
         }
@@ -4072,6 +4127,31 @@ static struct cftype mem_cgroup_legacy_files[] = {
                 .seq_show = memcg_slab_show,
         },
 #endif
+#ifdef CONFIG_INET
+        {
+                .name = "kmem.tcp.limit_in_bytes",
+                .private = MEMFILE_PRIVATE(_TCP, RES_LIMIT),
+                .write = mem_cgroup_write,
+                .read_u64 = mem_cgroup_read_u64,
+        },
+        {
+                .name = "kmem.tcp.usage_in_bytes",
+                .private = MEMFILE_PRIVATE(_TCP, RES_USAGE),
+                .read_u64 = mem_cgroup_read_u64,
+        },
+        {
+                .name = "kmem.tcp.failcnt",
+                .private = MEMFILE_PRIVATE(_TCP, RES_FAILCNT),
+                .write = mem_cgroup_reset,
+                .read_u64 = mem_cgroup_read_u64,
+        },
+        {
+                .name = "kmem.tcp.max_usage_in_bytes",
+                .private = MEMFILE_PRIVATE(_TCP, RES_MAX_USAGE),
+                .write = mem_cgroup_reset,
+                .read_u64 = mem_cgroup_read_u64,
+        },
+#endif
 #endif
         { },    /* terminate */
 };
@@ -4241,6 +4321,10 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
                 memcg->soft_limit = PAGE_COUNTER_MAX;
                 page_counter_init(&memcg->memsw, &parent->memsw);
                 page_counter_init(&memcg->kmem, &parent->kmem);
+#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET)
+                page_counter_init(&memcg->tcp_mem.memory_allocated,
+                                  &parent->tcp_mem.memory_allocated);
+#endif
 
                 /*
                  * No need to take a reference to the parent because cgroup
@@ -4252,6 +4336,9 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
                 memcg->soft_limit = PAGE_COUNTER_MAX;
                 page_counter_init(&memcg->memsw, NULL);
                 page_counter_init(&memcg->kmem, NULL);
+#if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET)
+                page_counter_init(&memcg->tcp_mem.memory_allocated, NULL);
+#endif
                 /*
                  * Deeper hierachy with use_hierarchy == false doesn't make
                  * much sense so let cgroup subsystem know about this
@@ -4267,12 +4354,6 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
                 return ret;
 
 #ifdef CONFIG_INET
-#ifdef CONFIG_MEMCG_LEGACY_KMEM
-        ret = tcp_init_cgroup(memcg);
-        if (ret)
-                return ret;
-#endif
-
         if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
                 static_branch_inc(&memcg_sockets_enabled_key);
 #endif
@@ -4330,7 +4411,8 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
         memcg_free_kmem(memcg);
 
 #if defined(CONFIG_MEMCG_LEGACY_KMEM) && defined(CONFIG_INET)
-        tcp_destroy_cgroup(memcg);
+        if (memcg->tcp_mem.active)
+                static_branch_dec(&memcg_sockets_enabled_key);
 #endif
 
         __mem_cgroup_free(memcg);
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index bee5055832a1..62c049b647e9 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -56,7 +56,6 @@ obj-$(CONFIG_TCP_CONG_SCALABLE) += tcp_scalable.o
 obj-$(CONFIG_TCP_CONG_LP) += tcp_lp.o
 obj-$(CONFIG_TCP_CONG_YEAH) += tcp_yeah.o
 obj-$(CONFIG_TCP_CONG_ILLINOIS) += tcp_illinois.o
-obj-$(CONFIG_MEMCG_LEGACY_KMEM) += tcp_memcontrol.o
 obj-$(CONFIG_NETLABEL) += cipso_ipv4.o
 
 obj-$(CONFIG_XFRM) += xfrm4_policy.o xfrm4_state.o xfrm4_input.o \
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 46ce410703b1..4d367b4139a3 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -24,7 +24,6 @@
 #include <net/cipso_ipv4.h>
 #include <net/inet_frag.h>
 #include <net/ping.h>
-#include <net/tcp_memcontrol.h>
 
 static int zero;
 static int one = 1;
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index c7d1fb50f381..5ced3e4013e3 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -73,7 +73,6 @@
 #include <net/timewait_sock.h>
 #include <net/xfrm.h>
 #include <net/secure_seq.h>
-#include <net/tcp_memcontrol.h>
 #include <net/busy_poll.h>
 
 #include <linux/inet.h>
diff --git a/net/ipv4/tcp_memcontrol.c b/net/ipv4/tcp_memcontrol.c
deleted file mode 100644
index 133eb5eac49f..000000000000
--- a/net/ipv4/tcp_memcontrol.c
+++ /dev/null
@@ -1,200 +0,0 @@
-#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 mem_cgroup *parent = parent_mem_cgroup(memcg);
-        struct page_counter *counter_parent = NULL;
-        /*
-         * The root cgroup does not use page_counters, but rather,
-         * rely on the data already collected by the network
-         * subsystem
-         */
-        if (memcg == root_mem_cgroup)
-                return 0;
-
-        memcg->tcp_mem.memory_pressure = 0;
-
-        if (parent)
-                counter_parent = &parent->tcp_mem.memory_allocated;
-
-        page_counter_init(&memcg->tcp_mem.memory_allocated, counter_parent);
-
-        return 0;
-}
-
-void tcp_destroy_cgroup(struct mem_cgroup *memcg)
-{
-        if (memcg == root_mem_cgroup)
-                return;
-
-        if (memcg->tcp_mem.active)
-                static_branch_dec(&memcg_sockets_enabled_key);
-}
-
-static int tcp_update_limit(struct mem_cgroup *memcg, unsigned long nr_pages)
-{
-        int ret;
-
-        if (memcg == root_mem_cgroup)
-                return -EINVAL;
-
-        ret = page_counter_limit(&memcg->tcp_mem.memory_allocated, nr_pages);
-        if (ret)
-                return ret;
-
-        if (!memcg->tcp_mem.active) {
-                /*
-                 * The active flag 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.
-                 */
-                static_branch_inc(&memcg_sockets_enabled_key);
-                memcg->tcp_mem.active = true;
-        }
-
-        return 0;
-}
-
-enum {
-        RES_USAGE,
-        RES_LIMIT,
-        RES_MAX_USAGE,
-        RES_FAILCNT,
-};
-
-static DEFINE_MUTEX(tcp_limit_mutex);
-
-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 nr_pages;
-        int ret = 0;
-
-        buf = strstrip(buf);
-
-        switch (of_cft(of)->private) {
-        case RES_LIMIT:
-                /* see memcontrol.c */
-                ret = page_counter_memparse(buf, "-1", &nr_pages);
-                if (ret)
-                        break;
-                mutex_lock(&tcp_limit_mutex);
-                ret = tcp_update_limit(memcg, nr_pages);
-                mutex_unlock(&tcp_limit_mutex);
-                break;
-        default:
-                ret = -EINVAL;
-                break;
-        }
-        return ret ?: nbytes;
-}
-
-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:
-                if (memcg == root_mem_cgroup)
-                        val = PAGE_COUNTER_MAX;
-                else
-                        val = memcg->tcp_mem.memory_allocated.limit;
-                val *= PAGE_SIZE;
-                break;
-        case RES_USAGE:
-                if (memcg == root_mem_cgroup)
-                        val = atomic_long_read(&tcp_memory_allocated);
-                else
-                        val = page_counter_read(&memcg->tcp_mem.memory_allocated);
-                val *= PAGE_SIZE;
-                break;
-        case RES_FAILCNT:
-                if (memcg == root_mem_cgroup)
-                        return 0;
-                val = memcg->tcp_mem.memory_allocated.failcnt;
-                break;
-        case RES_MAX_USAGE:
-                if (memcg == root_mem_cgroup)
-                        return 0;
-                val = memcg->tcp_mem.memory_allocated.watermark;
-                val *= PAGE_SIZE;
-                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;
-
-        memcg = mem_cgroup_from_css(of_css(of));
-        if (memcg == root_mem_cgroup)
-                return nbytes;
-
-        switch (of_cft(of)->private) {
-        case RES_MAX_USAGE:
-                page_counter_reset_watermark(&memcg->tcp_mem.memory_allocated);
-                break;
-        case RES_FAILCNT:
-                memcg->tcp_mem.memory_allocated.failcnt = 0;
-                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);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 4ad8edb46f7c..006396e31cb0 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -61,7 +61,6 @@
 #include <net/timewait_sock.h>
 #include <net/inet_common.h>
 #include <net/secure_seq.h>
-#include <net/tcp_memcontrol.h>
 #include <net/busy_poll.h>
 
 #include <linux/proc_fs.h>