1 files changed, 44 insertions, 22 deletions

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 1e38e99998c7..b6eda2ab205d 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -466,34 +466,34 @@ static inline struct mem_cgroup *folio_memcg_rcu(struct folio *folio)
 }
 
 /*
- * page_memcg_check - get the memory cgroup associated with a page
- * @page: a pointer to the page struct
+ * folio_memcg_check - Get the memory cgroup associated with a folio.
+ * @folio: Pointer to the folio.
  *
- * Returns a pointer to the memory cgroup associated with the page,
- * or NULL. This function unlike page_memcg() can take any page
- * as an argument. It has to be used in cases when it's not known if a page
+ * Returns a pointer to the memory cgroup associated with the folio,
+ * or NULL. This function unlike folio_memcg() can take any folio
+ * as an argument. It has to be used in cases when it's not known if a folio
  * has an associated memory cgroup pointer or an object cgroups vector or
  * an object cgroup.
  *
- * For a non-kmem page any of the following ensures page and memcg binding
+ * For a non-kmem folio any of the following ensures folio and memcg binding
  * stability:
  *
- * - the page lock
+ * - the folio lock
  * - LRU isolation
- * - lock_page_memcg()
+ * - lock_folio_memcg()
  * - exclusive reference
  * - mem_cgroup_trylock_pages()
  *
- * For a kmem page a caller should hold an rcu read lock to protect memcg
- * associated with a kmem page from being released.
+ * For a kmem folio a caller should hold an rcu read lock to protect memcg
+ * associated with a kmem folio from being released.
  */
-static inline struct mem_cgroup *page_memcg_check(struct page *page)
+static inline struct mem_cgroup *folio_memcg_check(struct folio *folio)
 {
 	/*
-	 * Because page->memcg_data might be changed asynchronously
-	 * for slab pages, READ_ONCE() should be used here.
+	 * Because folio->memcg_data might be changed asynchronously
+	 * for slabs, READ_ONCE() should be used here.
 	 */
-	unsigned long memcg_data = READ_ONCE(page->memcg_data);
+	unsigned long memcg_data = READ_ONCE(folio->memcg_data);
 
 	if (memcg_data & MEMCG_DATA_OBJCGS)
 		return NULL;
@@ -508,6 +508,13 @@ static inline struct mem_cgroup *page_memcg_check(struct page *page)
 	return (struct mem_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
 }
 
+static inline struct mem_cgroup *page_memcg_check(struct page *page)
+{
+	if (PageTail(page))
+		return NULL;
+	return folio_memcg_check((struct folio *)page);
+}
+
 static inline struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *objcg)
 {
 	struct mem_cgroup *memcg;
@@ -794,6 +801,11 @@ static inline void obj_cgroup_put(struct obj_cgroup *objcg)
 	percpu_ref_put(&objcg->refcnt);
 }
 
+static inline bool mem_cgroup_tryget(struct mem_cgroup *memcg)
+{
+	return !memcg || css_tryget(&memcg->css);
+}
+
 static inline void mem_cgroup_put(struct mem_cgroup *memcg)
 {
 	if (memcg)
@@ -878,7 +890,7 @@ static inline bool mm_match_cgroup(struct mm_struct *mm,
 	return match;
 }
 
-struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page);
+struct cgroup_subsys_state *mem_cgroup_css_from_folio(struct folio *folio);
 ino_t page_cgroup_ino(struct page *page);
 
 static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
@@ -1165,6 +1177,11 @@ static inline struct mem_cgroup *folio_memcg_rcu(struct folio *folio)
 	return NULL;
 }
 
+static inline struct mem_cgroup *folio_memcg_check(struct folio *folio)
+{
+	return NULL;
+}
+
 static inline struct mem_cgroup *page_memcg_check(struct page *page)
 {
 	return NULL;
@@ -1301,6 +1318,11 @@ static inline void obj_cgroup_put(struct obj_cgroup *objcg)
 {
 }
 
+static inline bool mem_cgroup_tryget(struct mem_cgroup *memcg)
+{
+	return true;
+}
+
 static inline void mem_cgroup_put(struct mem_cgroup *memcg)
 {
 }
@@ -1760,24 +1782,24 @@ static inline bool memcg_bpf_enabled(void)
 	return static_branch_likely(&memcg_bpf_enabled_key);
 }
 
-extern struct static_key_false memcg_kmem_enabled_key;
+extern struct static_key_false memcg_kmem_online_key;
 
-static inline bool memcg_kmem_enabled(void)
+static inline bool memcg_kmem_online(void)
 {
-	return static_branch_likely(&memcg_kmem_enabled_key);
+	return static_branch_likely(&memcg_kmem_online_key);
 }
 
 static inline int memcg_kmem_charge_page(struct page *page, gfp_t gfp,
 					 int order)
 {
-	if (memcg_kmem_enabled())
+	if (memcg_kmem_online())
 		return __memcg_kmem_charge_page(page, gfp, order);
 	return 0;
 }
 
 static inline void memcg_kmem_uncharge_page(struct page *page, int order)
 {
-	if (memcg_kmem_enabled())
+	if (memcg_kmem_online())
 		__memcg_kmem_uncharge_page(page, order);
 }
 
@@ -1798,7 +1820,7 @@ static inline void count_objcg_event(struct obj_cgroup *objcg,
 {
 	struct mem_cgroup *memcg;
 
-	if (!memcg_kmem_enabled())
+	if (!memcg_kmem_online())
 		return;
 
 	rcu_read_lock();
@@ -1843,7 +1865,7 @@ static inline bool memcg_bpf_enabled(void)
 	return false;
 }
 
-static inline bool memcg_kmem_enabled(void)
+static inline bool memcg_kmem_online(void)
 {
 	return false;
 }