mm/mlock: Add mlock_vma_folio()

Convert mlock_page() into mlock_folio() and convert the callers.  Keep
mlock_vma_page() as a wrapper.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

mm/internal.h

@@ -416,8 +416,8 @@ extern int mlock_future_check(struct mm_struct *mm, unsigned long flags,
  * pte mappings of THPs, which cannot be consistently counted: a pte
  * mapping of the THP head cannot be distinguished by the page alone.
  */
-void mlock_page(struct page *page);
-static inline void mlock_vma_page(struct page *page,
+void mlock_folio(struct folio *folio);
+static inline void mlock_vma_folio(struct folio *folio,
 			struct vm_area_struct *vma, bool compound)
 {
 	/*
@@ -429,9 +429,16 @@ static inline void mlock_vma_page(struct page *page,
 	 *    still be set while VM_SPECIAL bits are added: so ignore it then.
 	 */
 	if (unlikely((vma->vm_flags & (VM_LOCKED|VM_SPECIAL)) == VM_LOCKED) &&
-	    (compound || !PageTransCompound(page)))
-		mlock_page(page);
+	    (compound || !folio_test_large(folio)))
+		mlock_folio(folio);
+}
+
+static inline void mlock_vma_page(struct page *page,
+			struct vm_area_struct *vma, bool compound)
+{
+	mlock_vma_folio(page_folio(page), vma, compound);
 }
+
 void munlock_page(struct page *page);
 static inline void munlock_vma_page(struct page *page,
 			struct vm_area_struct *vma, bool compound)

mm/mlock.c

@@ -218,23 +218,23 @@ bool need_mlock_page_drain(int cpu)
 }
 
 /**
- * mlock_page - mlock a page already on (or temporarily off) LRU
- * @page: page to be mlocked, either a normal page or a THP head.
+ * mlock_folio - mlock a folio already on (or temporarily off) LRU
+ * @folio: folio to be mlocked.
  */
-void mlock_page(struct page *page)
+void mlock_folio(struct folio *folio)
 {
 	struct pagevec *pvec = &get_cpu_var(mlock_pvec);
 
-	if (!TestSetPageMlocked(page)) {
-		int nr_pages = thp_nr_pages(page);
+	if (!folio_test_set_mlocked(folio)) {
+		int nr_pages = folio_nr_pages(folio);
 
-		mod_zone_page_state(page_zone(page), NR_MLOCK, nr_pages);
+		zone_stat_mod_folio(folio, NR_MLOCK, nr_pages);
 		__count_vm_events(UNEVICTABLE_PGMLOCKED, nr_pages);
 	}
 
-	get_page(page);
-	if (!pagevec_add(pvec, mlock_lru(page)) ||
-	    PageHead(page) || lru_cache_disabled())
+	folio_get(folio);
+	if (!pagevec_add(pvec, mlock_lru(&folio->page)) ||
+	    folio_test_large(folio) || lru_cache_disabled())
 		mlock_pagevec(pvec);
 	put_cpu_var(mlock_pvec);
 }
@@ -296,7 +296,7 @@ static int mlock_pte_range(pmd_t *pmd, unsigned long addr,
 			goto out;
 		page = pmd_page(*pmd);
 		if (vma->vm_flags & VM_LOCKED)
-			mlock_page(page);
+			mlock_folio(page_folio(page));
 		else
 			munlock_page(page);
 		goto out;
@@ -312,7 +312,7 @@ static int mlock_pte_range(pmd_t *pmd, unsigned long addr,
 		if (PageTransCompound(page))
 			continue;
 		if (vma->vm_flags & VM_LOCKED)
-			mlock_page(page);
+			mlock_folio(page_folio(page));
 		else
 			munlock_page(page);
 	}