mm/hugetlb: convert alloc_surplus_huge_page() to folios

Change alloc_surplus_huge_page() to alloc_surplus_hugetlb_folio() and
update its callers.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Sidhartha Kumar <[e-mail]>
Reviewed-by: Mike Kravetz <[e-mail]>
Cc: John Hubbard <[e-mail]>
Cc: Matthew Wilcox <[e-mail]>
Cc: Muchun Song <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

mm/hugetlb.c

···
 /*
  * Allocates a fresh surplus page from the page allocator.
  */
-static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask,
-						int nid, nodemask_t *nmask)
+static struct folio *alloc_surplus_hugetlb_folio(struct hstate *h,
+				gfp_t gfp_mask,	int nid, nodemask_t *nmask)
 {
 	struct folio *folio = NULL;
 
···
 out_unlock:
 	spin_unlock_irq(&hugetlb_lock);
 
-	return &folio->page;
+	return folio;
 }
 
 static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask,
···
 struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h,
 		struct vm_area_struct *vma, unsigned long addr)
 {
-	struct page *page = NULL;
+	struct folio *folio = NULL;
 	struct mempolicy *mpol;
 	gfp_t gfp_mask = htlb_alloc_mask(h);
 	int nid;
···
 		gfp_t gfp = gfp_mask | __GFP_NOWARN;
 
 		gfp &=  ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL);
-		page = alloc_surplus_huge_page(h, gfp, nid, nodemask);
+		folio = alloc_surplus_hugetlb_folio(h, gfp, nid, nodemask);
 
 		/* Fallback to all nodes if page==NULL */
 		nodemask = NULL;
 	}
 
-	if (!page)
-		page = alloc_surplus_huge_page(h, gfp_mask, nid, nodemask);
+	if (!folio)
+		folio = alloc_surplus_hugetlb_folio(h, gfp_mask, nid, nodemask);
 	mpol_cond_put(mpol);
-	return page;
+	return &folio->page;
 }
 
 /* page migration callback function */
···
 	__must_hold(&hugetlb_lock)
 {
 	LIST_HEAD(surplus_list);
+	struct folio *folio;
 	struct page *page, *tmp;
 	int ret;
 	long i;
···
 retry:
 	spin_unlock_irq(&hugetlb_lock);
 	for (i = 0; i < needed; i++) {
-		page = alloc_surplus_huge_page(h, htlb_alloc_mask(h),
+		folio = alloc_surplus_hugetlb_folio(h, htlb_alloc_mask(h),
 				NUMA_NO_NODE, NULL);
-		if (!page) {
+		if (!folio) {
 			alloc_ok = false;
 			break;
 		}
-		list_add(&page->lru, &surplus_list);
+		list_add(&folio->lru, &surplus_list);
 		cond_resched();
 	}
 	allocated += i;
···
 	 * First take pages out of surplus state.  Then make up the
 	 * remaining difference by allocating fresh huge pages.
 	 *
-	 * We might race with alloc_surplus_huge_page() here and be unable
+	 * We might race with alloc_surplus_hugetlb_folio() here and be unable
 	 * to convert a surplus huge page to a normal huge page. That is
 	 * not critical, though, it just means the overall size of the
 	 * pool might be one hugepage larger than it needs to be, but
···
 	 * By placing pages into the surplus state independent of the
 	 * overcommit value, we are allowing the surplus pool size to
 	 * exceed overcommit. There are few sane options here. Since
-	 * alloc_surplus_huge_page() is checking the global counter,
+	 * alloc_surplus_hugetlb_folio() is checking the global counter,
 	 * though, we'll note that we're not allowed to exceed surplus
 	 * and won't grow the pool anywhere else. Not until one of the
 	 * sysctls are changed, or the surplus pages go out of use.