mm: memcontrol: unshare v2-only charge API bits again

6b61138 ("memcg-v1: remove charge move code") removed the remaining
v1 callers.

Link: https://lkml.kernel.org/r/20250124043859.18808-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: hnaz

mm/memcontrol-v1.h

@@ -7,21 +7,6 @@
 
 /* Cgroup v1 and v2 common declarations */
 
-int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
-		     unsigned int nr_pages);
-
-static inline int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
-			     unsigned int nr_pages)
-{
-	if (mem_cgroup_is_root(memcg))
-		return 0;
-
-	return try_charge_memcg(memcg, gfp_mask, nr_pages);
-}
-
-void mem_cgroup_id_get_many(struct mem_cgroup *memcg, unsigned int n);
-void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n);
-
 /*
  * Iteration constructs for visiting all cgroups (under a tree).  If
  * loops are exited prematurely (break), mem_cgroup_iter_break() must

mm/memcontrol.c

@@ -2213,8 +2213,8 @@ void mem_cgroup_handle_over_high(gfp_t gfp_mask)
 	css_put(&memcg->css);
 }
 
-int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
-		     unsigned int nr_pages)
+static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
+			    unsigned int nr_pages)
 {
 	unsigned int batch = max(MEMCG_CHARGE_BATCH, nr_pages);
 	int nr_retries = MAX_RECLAIM_RETRIES;
@@ -2403,6 +2403,15 @@ int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
 	return 0;
 }
 
+static inline int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
+			     unsigned int nr_pages)
+{
+	if (mem_cgroup_is_root(memcg))
+		return 0;
+
+	return try_charge_memcg(memcg, gfp_mask, nr_pages);
+}
+
 static void commit_charge(struct folio *folio, struct mem_cgroup *memcg)
 {
 	VM_BUG_ON_FOLIO(folio_memcg_charged(folio), folio);
@@ -3389,13 +3398,13 @@ static void mem_cgroup_id_remove(struct mem_cgroup *memcg)
 	}
 }
 
-void __maybe_unused mem_cgroup_id_get_many(struct mem_cgroup *memcg,
+static void __maybe_unused mem_cgroup_id_get_many(struct mem_cgroup *memcg,
 					   unsigned int n)
 {
 	refcount_add(n, &memcg->id.ref);
 }
 
-void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n)
+static void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n)
 {
 	if (refcount_sub_and_test(n, &memcg->id.ref)) {
 		mem_cgroup_id_remove(memcg);