cgroup: pass struct mem_cgroup instead of struct cgroup to socket memcg

The only reason cgroup was used, was to be consistent with the populate()
interface. Now that we're getting rid of it, not only we no longer need
it, but we also *can't* call it this way.

Since we will no longer rely on populate(), this will be called from
create(). During create, the association between struct mem_cgroup
and struct cgroup does not yet exist, since cgroup internals hasn't
yet initialized its bookkeeping. This means we would not be able
to draw the memcg pointer from the cgroup pointer in these
functions, which is highly undesirable.

Signed-off-by: Glauber Costa <[email protected]>
Acked-by: Kamezawa Hiroyuki <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
CC: Li Zefan <[email protected]>
CC: Johannes Weiner <[email protected]>
CC: Michal Hocko <[email protected]>

diff --git a/include/net/sock.h b/include/net/sock.h
index a6ba1f8871fda3077183717a1e099cd5161b555c..b3ebe6b3e7dbd1ddc19ed5133ea8353ede3b2367 100644 (file)
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -70,16 +70,16 @@
 struct cgroup;
 struct cgroup_subsys;
 #ifdef CONFIG_NET
-int mem_cgroup_sockets_init(struct cgroup *cgrp, struct cgroup_subsys *ss);
-void mem_cgroup_sockets_destroy(struct cgroup *cgrp);
+int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss);
+void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg);
 #else
 static inline
-int mem_cgroup_sockets_init(struct cgroup *cgrp, struct cgroup_subsys *ss)
+int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
 {
        return 0;
 }
 static inline
-void mem_cgroup_sockets_destroy(struct cgroup *cgrp)
+void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg)
 {
 }
 #endif
@@ -900,9 +900,9 @@ struct proto {
         * This function has to setup any files the protocol want to
         * appear in the kmem cgroup filesystem.
         */
-       int                     (*init_cgroup)(struct cgroup *cgrp,
+       int                     (*init_cgroup)(struct mem_cgroup *memcg,
                                               struct cgroup_subsys *ss);
-       void                    (*destroy_cgroup)(struct cgroup *cgrp);
+       void                    (*destroy_cgroup)(struct mem_cgroup *memcg);
        struct cg_proto         *(*proto_cgroup)(struct mem_cgroup *memcg);
 #endif
 };

diff --git a/include/net/tcp_memcontrol.h b/include/net/tcp_memcontrol.h
index 48410ff25c9ee7414613479f76202c0f803ed391..7df18bc43a97fccef8478436f8f43f3a5553b997 100644 (file)
--- a/include/net/tcp_memcontrol.h
+++ b/include/net/tcp_memcontrol.h
@@ -12,8 +12,8 @@ struct tcp_memcontrol {
 };
 
 struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg);
-int tcp_init_cgroup(struct cgroup *cgrp, struct cgroup_subsys *ss);
-void tcp_destroy_cgroup(struct cgroup *cgrp);
+int tcp_init_cgroup(struct mem_cgroup *memcg, struct cgroup_subsys *ss);
+void tcp_destroy_cgroup(struct mem_cgroup *memcg);
 unsigned long long tcp_max_memory(const struct mem_cgroup *memcg);
 void tcp_prot_mem(struct mem_cgroup *memcg, long val, int idx);
 #endif /* _TCP_MEMCG_H */

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index d28359cd6b5554e3b4c3172b618a798688708283..785c32367075eca603687a0e04ee76ecade3f81e 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4640,29 +4640,22 @@ static int mem_control_numa_stat_open(struct inode *unused, struct file *file)
 #endif /* CONFIG_NUMA */
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
-static int register_kmem_files(struct cgroup *cont, struct cgroup_subsys *ss)
+static int register_kmem_files(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
 {
-       /*
-        * Part of this would be better living in a separate allocation
-        * function, leaving us with just the cgroup tree population work.
-        * We, however, depend on state such as network's proto_list that
-        * is only initialized after cgroup creation. I found the less
-        * cumbersome way to deal with it to defer it all to populate time
-        */
-       return mem_cgroup_sockets_init(cont, ss);
+       return mem_cgroup_sockets_init(memcg, ss);
 };
 
-static void kmem_cgroup_destroy(struct cgroup *cont)
+static void kmem_cgroup_destroy(struct mem_cgroup *memcg)
 {
-       mem_cgroup_sockets_destroy(cont);
+       mem_cgroup_sockets_destroy(memcg);
 }
 #else
-static int register_kmem_files(struct cgroup *cont, struct cgroup_subsys *ss)
+static int register_kmem_files(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
 {
        return 0;
 }
 
-static void kmem_cgroup_destroy(struct cgroup *cont)
+static void kmem_cgroup_destroy(struct mem_cgroup *memcg)
 {
 }
 #endif
@@ -5034,7 +5027,7 @@ static void mem_cgroup_destroy(struct cgroup *cont)
 {
        struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
 
-       kmem_cgroup_destroy(cont);
+       kmem_cgroup_destroy(memcg);
 
        mem_cgroup_put(memcg);
 }
@@ -5042,7 +5035,8 @@ static void mem_cgroup_destroy(struct cgroup *cont)
 static int mem_cgroup_populate(struct cgroup_subsys *ss,
                                struct cgroup *cont)
 {
-       return register_kmem_files(cont, ss);
+       struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
+       return register_kmem_files(memcg, ss);
 }
 
 #ifdef CONFIG_MMU

diff --git a/net/core/sock.c b/net/core/sock.c
index b2e14c07d9205467f0a8d83af3fe6108d277a15f..878f7447cf61b5adb267bbeb3c96d23b4357a828 100644 (file)
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -140,7 +140,7 @@ static DEFINE_MUTEX(proto_list_mutex);
 static LIST_HEAD(proto_list);
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
-int mem_cgroup_sockets_init(struct cgroup *cgrp, struct cgroup_subsys *ss)
+int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
 {
        struct proto *proto;
        int ret = 0;
@@ -148,7 +148,7 @@ int mem_cgroup_sockets_init(struct cgroup *cgrp, struct cgroup_subsys *ss)
        mutex_lock(&proto_list_mutex);
        list_for_each_entry(proto, &proto_list, node) {
                if (proto->init_cgroup) {
-                       ret = proto->init_cgroup(cgrp, ss);
+                       ret = proto->init_cgroup(memcg, ss);
                        if (ret)
                                goto out;
                }
@@ -159,19 +159,19 @@ int mem_cgroup_sockets_init(struct cgroup *cgrp, struct cgroup_subsys *ss)
 out:
        list_for_each_entry_continue_reverse(proto, &proto_list, node)
                if (proto->destroy_cgroup)
-                       proto->destroy_cgroup(cgrp);
+                       proto->destroy_cgroup(memcg);
        mutex_unlock(&proto_list_mutex);
        return ret;
 }
 
-void mem_cgroup_sockets_destroy(struct cgroup *cgrp)
+void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg)
 {
        struct proto *proto;
 
        mutex_lock(&proto_list_mutex);
        list_for_each_entry_reverse(proto, &proto_list, node)
                if (proto->destroy_cgroup)
-                       proto->destroy_cgroup(cgrp);
+                       proto->destroy_cgroup(memcg);
        mutex_unlock(&proto_list_mutex);
 }
 #endif

diff --git a/net/ipv4/tcp_memcontrol.c b/net/ipv4/tcp_memcontrol.c
index 8f1753defa5ca6ab6409bb992e09910d6845536b..151703791bb0d43818700349fb0a585736c7dc19 100644 (file)
--- a/net/ipv4/tcp_memcontrol.c
+++ b/net/ipv4/tcp_memcontrol.c
@@ -18,7 +18,7 @@ static void memcg_tcp_enter_memory_pressure(struct sock *sk)
 }
 EXPORT_SYMBOL(memcg_tcp_enter_memory_pressure);
 
-int tcp_init_cgroup(struct cgroup *cgrp, struct cgroup_subsys *ss)
+int tcp_init_cgroup(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
 {
        /*
         * The root cgroup does not use res_counters, but rather,
@@ -28,7 +28,6 @@ int tcp_init_cgroup(struct cgroup *cgrp, struct cgroup_subsys *ss)
        struct res_counter *res_parent = NULL;
        struct cg_proto *cg_proto, *parent_cg;
        struct tcp_memcontrol *tcp;
-       struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
        struct mem_cgroup *parent = parent_mem_cgroup(memcg);
        struct net *net = current->nsproxy->net_ns;
 
@@ -61,9 +60,8 @@ int tcp_init_cgroup(struct cgroup *cgrp, struct cgroup_subsys *ss)
 }
 EXPORT_SYMBOL(tcp_init_cgroup);
 
-void tcp_destroy_cgroup(struct cgroup *cgrp)
+void tcp_destroy_cgroup(struct mem_cgroup *memcg)
 {
-       struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
        struct cg_proto *cg_proto;
        struct tcp_memcontrol *tcp;
        u64 val;