net: Clean up __sk_mem_raise_allocated().

In __sk_mem_raise_allocated(), charged is initialised as true due
to the weird condition removed in the previous patch.

It makes the variable unreliable by itself, so we have to check
another variable, memcg, in advance.

Also, we will factorise the common check below for memcg later.

    if (mem_cgroup_sockets_enabled && sk->sk_memcg)

As a prep, let's initialise charged as false and memcg as NULL.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Link: https://patch.msgid.link/20250815201712.1745332-6-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/core/sock.c b/net/core/sock.c
index 380bc1aa69829b99185a6183f1117df53b78b13a..000940ecf360e09f5eda09231bab8b94d7f3189f 100644 (file)
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -3263,15 +3263,16 @@ EXPORT_SYMBOL(sk_wait_data);
  */
 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
 {
-       struct mem_cgroup *memcg = mem_cgroup_sockets_enabled ? sk->sk_memcg : NULL;
        struct proto *prot = sk->sk_prot;
-       bool charged = true;
+       struct mem_cgroup *memcg = NULL;
+       bool charged = false;
        long allocated;
 
        sk_memory_allocated_add(sk, amt);
        allocated = sk_memory_allocated(sk);
 
-       if (memcg) {
+       if (mem_cgroup_sockets_enabled && sk->sk_memcg) {
+               memcg = sk->sk_memcg;
                charged = mem_cgroup_charge_skmem(memcg, amt, gfp_memcg_charge());
                if (!charged)
                        goto suppress_allocation;
@@ -3358,7 +3359,7 @@ suppress_allocation:
 
        sk_memory_allocated_sub(sk, amt);
 
-       if (memcg && charged)
+       if (charged)
                mem_cgroup_uncharge_skmem(memcg, amt);
 
        return 0;