memcg: convert mem_cgroup_swapin_charge_page() to mem_cgroup_swapin_charge_folio()

All callers now have a folio, so pass it in here and remove an unnecessary
call to page_folio().

Link: https://lkml.kernel.org/r/20220902194653.1739778-17-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/memcontrol.h

@@ -688,7 +688,7 @@ static inline int mem_cgroup_charge(struct folio *folio, struct mm_struct *mm,
 	return __mem_cgroup_charge(folio, mm, gfp);
 }
 
-int mem_cgroup_swapin_charge_page(struct page *page, struct mm_struct *mm,
+int mem_cgroup_swapin_charge_folio(struct folio *folio, struct mm_struct *mm,
 				  gfp_t gfp, swp_entry_t entry);
 void mem_cgroup_swapin_uncharge_swap(swp_entry_t entry);
 
@@ -1254,7 +1254,7 @@ static inline int mem_cgroup_charge(struct folio *folio,
 	return 0;
 }
 
-static inline int mem_cgroup_swapin_charge_page(struct page *page,
+static inline int mem_cgroup_swapin_charge_folio(struct folio *folio,
 			struct mm_struct *mm, gfp_t gfp, swp_entry_t entry)
 {
 	return 0;

mm/memcontrol.c

@@ -6844,21 +6844,20 @@ int __mem_cgroup_charge(struct folio *folio, struct mm_struct *mm, gfp_t gfp)
 }
 
 /**
- * mem_cgroup_swapin_charge_page - charge a newly allocated page for swapin
- * @page: page to charge
+ * mem_cgroup_swapin_charge_folio - Charge a newly allocated folio for swapin.
+ * @folio: folio to charge.
  * @mm: mm context of the victim
  * @gfp: reclaim mode
- * @entry: swap entry for which the page is allocated
+ * @entry: swap entry for which the folio is allocated
  *
- * This function charges a page allocated for swapin. Please call this before
- * adding the page to the swapcache.
+ * This function charges a folio allocated for swapin. Please call this before
+ * adding the folio to the swapcache.
  *
  * Returns 0 on success. Otherwise, an error code is returned.
  */
-int mem_cgroup_swapin_charge_page(struct page *page, struct mm_struct *mm,
+int mem_cgroup_swapin_charge_folio(struct folio *folio, struct mm_struct *mm,
 				  gfp_t gfp, swp_entry_t entry)
 {
-	struct folio *folio = page_folio(page);
 	struct mem_cgroup *memcg;
 	unsigned short id;
 	int ret;

mm/memory.c

@@ -3783,7 +3783,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
 				__folio_set_locked(folio);
 				__folio_set_swapbacked(folio);
 
-				if (mem_cgroup_swapin_charge_page(page,
+				if (mem_cgroup_swapin_charge_folio(folio,
 							vma->vm_mm, GFP_KERNEL,
 							entry)) {
 					ret = VM_FAULT_OOM;

mm/swap_state.c

@@ -480,7 +480,7 @@ struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
 	__folio_set_locked(folio);
 	__folio_set_swapbacked(folio);
 
-	if (mem_cgroup_swapin_charge_page(&folio->page, NULL, gfp_mask, entry))
+	if (mem_cgroup_swapin_charge_folio(folio, NULL, gfp_mask, entry))
 		goto fail_unlock;
 
 	/* May fail (-ENOMEM) if XArray node allocation failed. */